Abstract
Cuticle and cuticular waxes form the first level of barrier between the land plants and their external environment. This hydrophobic layer protects the plant tissues from excessive non-stomatal water loss, controls exchange of gases and solutes, conferring tolerance to enormous abiotic and biotic challenges. The cuticular waxes synthesized in epidermal cells is a complex mixture of very long-chain fatty acids, their esters, and derivatives. Its biosynthesis, transport, and deposition involve multiple genes and are tightly coordinated by complex molecular networks, which in turn is regulated in response to various environmental factors. Past few decades of research evidences from model as well as from non-model systems greatly expanded our understanding and knowledge of the genes involved in cuticular wax biosynthesis and its regulation in plants. This chapter briefly summarizes on the significance of cuticular waxes, its biosynthesis, transport, and deposition. Further, focus has been given toward the transcription factors identified in wax biosynthesis, its positive and negative regulators, and the targeted manipulation of cuticular wax biosynthesis in Arabidopsis and different crop plants resulted in tolerance toward adverse conditions.
Access provided by Autonomous University of Puebla. Download chapter PDF
Similar content being viewed by others
Keywords
7.1 Introduction
Plant cuticle forms the first layer of resistance between all land plants and their surroundings. It performs multiple functions of which the most important is to restrict the non-stomatal water loss (Kerstiens 1996; Goodwin and Jenks 2005; Mamrutha et al. 2010; McFarlane et al. 2014). The cuticle mainly consists of cutin, lipid, intra-, and epi-cuticular waxes accumulated on the plant surface. The C16 and C18 oxygenated aliphatic monomers derived from fatty acids (FAs) and glycerol form the insoluble polymer cutin that can resist mechanical damage and act as structural support for cuticular waxes (Kolattukudy 1980; Pollard et al. 2008). The cuticular waxes are subdivided into intra- and epi-cuticular. These are generally complex mixtures of very long-chain (VLC) saturated FA derivatives (Borisjuk et al. 2014). The intra-cuticular waxes are mixture of amorphous lipids implanted in the cutin that links the cuticle with the cell wall matrix, and epi-cuticular waxes are the surface lipids forming various crystal like or smooth film structures (Jetter and Schaffer 2001; Kunst and Samuels 2003). Waxes are chemically complex mixtures of lipids consisting of very long-chain fatty acids (VLCFA), hydrocarbons, alkanes, alkenes, ketones, aldehydes, esters, primary alcohols, secondary alcohols, triterpenes, flavonoids, and sterols (Rashotte et al. 1997; Nawrath et al. 2013; Lee and Suh 2015a; Xue et al. 2017). The wax concentration and chemical composition highly vary among plant species, tissues, and developmental stages and contribute to wax crystal morphology, structure, and surface hydrophobicity (Mamrutha et al. 2010, 2017).
Cuticular waxes can play various roles in plant protection against stresses such as cold, salinity, drought, high temperature, ultraviolet (UV) radiations, and mechanical damage (Jenks et al. 1994; Long et al. 2003; Mamrutha et al. 2010; Sajeevan et al. 2017b), bacterial and fungal pathogens, and insects (Eigenbrode and Espelie 1995; Eigenbrode and Jetter 2002; Ziv et al. 2018; Zhang et al. 2019a, b, c; Wang et al. 2019; Kong et al. 2020). In addition to its protective roles, the cuticle is also involved in regulating the plant developmental processes (Ingram and Nawrath 2017). Both biotic and abiotic stresses can act as environmental clues and alter the concentration and composition of waxes. The Arabidopsis thaliana (At) plants under drought/dehydration stress showed altered cuticular wax biosynthesis and increased epi-cuticular wax deposition (Kosma et al. 2009; Yang et al. 2011). Similarly, drought stress-induced epi-cuticular wax deposition was reported in plants such as cotton, rose, peanut, and tree tobacco (Bondada et al. 1996; Jenks et al. 2001; Samdur et al. 2003; Cameron et al. 2006). A high correlation between improved drought tolerance and higher cuticular waxes was reported in oats (Bengtson et al. 1978), sorghum (Jordan et al. 1984), rice (Islam et al. 2009), alfalfa, and crested wheat grass (Jefferson et al. 1989). In biotic stress, cuticular waxes act as the plant’s first physical barrier restricting pathogen entry. On the other hand, pathogens can exploit the cuticular waxes to initiate their pre-penetration and infection processes in regulating the plant–pathogen interactions (Skamnioti and Gurr 2007; Ju et al. 2017; Cui et al. 2019). With its diverse role in multiple abiotic and biotic stresses, cuticular waxes have gained increasing attention and considered to be an indispensable trait for crop improvement.
7.2 Cuticular Wax Biosynthesis in Plants
Through various forward and reverse genetics approaches in model plants like A. thaliana and tomato and crop plants such as rice and barley, a number of genes engaged in cuticular wax biosynthesis, transport, and deposition was identified and characterized. From the current knowledge, cuticular wax biosynthesis can be divided into three steps—a de novo synthesis of the C16 or C18 FAs followed by the extension to form VLCFAs. In the third step, the synthesis of various derivatives of VLCFAs such as aldehydes, alcohols, alkanes, ketones, esters, etc. via either the alcohol- or alkane-forming pathways. These VLCFA derivatives are further transported across plasma membrane and deposited as intra- and epi-cuticular waxes.
In short, the cuticular wax biosynthesis begins in endoplasmic reticulum (ER) by the addition of two carbons donated by malonyl CoA for the extension of C16 and C18 fatty acid (FA) precursors formed in plastid. This extension process is a sequential cycle that is facilitated by fatty acid elongase (FAE) complex results in the formation of VLCFAs consists of 20–36 carbons. The FA extension carries through a series of four consecutive reactions of condensation (β-ketoacyl-CoA synthase, KCS), reduction (β-ketoacyl-CoA reductase, KCR), dehydration (β-hydroxyacyl-CoA dehydratase, HCD), and a second reduction (enoyl-CoA reductase, ECR), for each of two carbon atom extension, that are collectively called elongase (Ohlrogge et al. 1978). Mutation in one of the four extension enzymes (elongase) will result in pleiotropic effects and severe reduction in overall cuticular waxes, indicating the importance of FA extension is an important rate limiting step in cuticular wax synthesis (Beaudoin et al. 2009; Seo and Park 2011). These VLCFAs are further modified/processed to form a variety of cuticular wax components through two distinct pathways—decarbonylation pathway (alkane forming) and acyl reduction pathway (alcohol forming) (Li et al. 2008; Rowland et al. 2006; Rowland and Domergue 2012). In Arabidopsis, decarbonylation pathway is predominantly responsible for the production of major derivatives of cuticular waxes with chain length between 21 and 35C atoms such as aldehydes, alkanes, ketones, and secondary alcohols. On the other hand, acyl reduction pathway leads to the production of primary alcohols and wax esters (Bernard and Joubes 2013; Lee and Suh 2015a). A simplified schematic representation of plant cuticular wax biosynthesis pathways in ER is shown in Fig. 7.1.
7.3 Transporters of Cuticle Precursors
The cutin and wax precursors synthesized in ER are transported across the plasma membrane, cell wall, and the emerging cuticular membrane. To date, most of the steps involved in wax biosynthesis are well understood, but the mechanism of transport is poorly known. A close group of half transporters ABCG, an ATP binding cassette, are shown to be involved in the transport of both wax and cutin derivatives across the plasma membrane (Do et al. 2018). The Arabidopsis genome consists of four ABCG transporters—ABCG11, ABCG12, ABCG13, and an uncharacterized ABCG15 (Pighin et al. 2004; Bird et al. 2007; Panikashvili et al. 2011). The ABCG11 is a homodimer likely to export cutin precursors (Bird et al. 2007; Elejalde-Palmett et al. 2021) and ABCG11 and ABCG12/CER5 need to form heterodimer for wax secretion (Bird et al. 2007; McFarlane et al. 2010). The ABCG13, third half transporter, was reported to be involved in the cutin deposition in Arabidopsis flowers (Panikashvili et al. 2011).
A full transporter ABCG32 identified from A. thaliana, Hordeum spontaneum, and Oryza sativa is involved in cutin deposition (Bessire et al. 2011; Chen et al. 2011). More recently, another ABC transporter from rice (OsABCG9), an ortholog of AtABCG11, has been reported that specifically transport wax but not cutin (Nguyen et al. 2018). Despite having well-documented evidences to show the involvement of different ABC transporters in trafficking cuticular lipids, there is lack of evidences to demonstrate the substrate specificity in vitro. Till date, all the ABC transporters identified from different systems are members of the ABCG subfamily that are involved in the transport of lipids and hydrophobic compounds (Moitra et al. 2011). Studies have shown that ABC transporter mutants resulted in lipid embodiments intracellularly. This further supports the direct involvement of ABC transporters in cuticular lipid transport (Pighin et al. 2004; Bird et al. 2007; Bessire et al. 2011).
Glycosyl phosphatidyl inositol (GPI)-anchored lipid transfer proteins (LTPs), LTPG1 and LTPG2, are plasma membrane bound that are involved in the transport of wax derivatives (Debono et al. 2009; Lee et al. 2009a; Kim et al. 2012). These LTPs are a unique class of soluble proteins that can bind to a variety of lipid substrates (Yeats and Rose 2008). It is proposed that the apoplastic LTPs are involved in the trafficking of wax derivatives, although genetic or biochemical evidences are clearly lacking (Yeats and Rose 2008). Recently, Arabidopsis mutant analysis demonstrated the involvement of gnom like1-1 (GNL1) and echidna (ECH)-dependent endo-membrane vesicle transport of waxes to plasma membrane-localized ATP-binding cassette transporters (McFarlane et al. 2014).
7.4 Transcriptional Regulation in Biosynthesis of Cuticular Waxes
Efforts to elucidate the biosynthesis of cuticular wax pathway and its players were mainly identified through mutants and concentrated with the model plant, Arabidopsis. A large number of genes involved in the biosynthesis of cuticular waxes has been identified, isolated, and characterized (Jetter et al. 2006; Jetter and Kunst 2008; Samuels et al. 2008). In Arabidopsis, more than 190 genes have been identified to be involved in the biosynthesis of cuticular waxes, its transport, or deposition (Li-Beisson et al. 2013). Among these, CER1, CER2, CER6/CUT1, KCS1, IDDLEHEAD (FDH), and WAX2 from Arabidopsis, GL1 and GL8 from maize encode wax synthesis and transport related enzymes (Aarts et al. 1995; Hansen et al. 1997; Todd et al. 1999; Fiebig et al. 2000; Chen et al. 2003; Zhang et al. 2005). A summary of genes identified from the model plant Arabidopsis that are involved in cuticular wax biosynthesis, transport, or deposition is detailed in Table 7.1.
The key regulators involved in the biosynthesis of waxes and cuticular components deposition are transcription factors (TFs). Different families of TFs belong to ethylene-responsive factors (ERFs), myeloblastosis family (MYB), and homeodomain-leucine zipper class IV (HD-Zip IV) factors identified as regulators of wax biosynthesis, of which ERFs gained more importance (Aharoni et al. 2004; Seo et al. 2011). Overexpression of these TFs lead to changes in wax biosynthesis, its accumulation, and changes in the chemical composition (Broun et al. 2004). It has also been demonstrated that overexpression of these TFs often resulted in increased stress tolerance (Broun et al. 2004; Javelle et al. 2010; Seo and Park 2011). However, despite their obvious positive effects on plant protection, it was also demonstrated that the ectopic expression could negatively affect plant growth, yield, and decreased stress tolerance (Aharoni et al. 2004; Zhang et al. 2005). A summary of TFs identified that play a role in the biosynthesis of cuticular waxes, targeted genes, and cuticular composition affected identified through overexpression or down-regulation is detailed in Table 7.2.
7.4.1 APETALA2/Ethylene Responsive Factor
The APETALA2/Ethylene Responsive Factor (AP2/ERF) superfamily is known to be one of the largest plant-specific families of TF involved in diverse plant physiological processes (Licausi et al. 2013). These TFs can regulate the gene expression transcriptionally and posttranslationally at different stages of plant growth and development, hormone signaling, and in response to various abiotic and biotic stresses (Elliott et al. 1996; Xu et al. 2011; Licausi et al. 2013). The AP2/ERF proteins were first identified from Arabidopsis, typically consists of a highly conserved AP2 domain of 40–70 amino acids in length (Jofuku et al. 1994). Based on the number of AP2 and other DNA binding domains, they are categorized into four different subfamilies—AP2, ERF, DREB (Dehydration Responsive Element Binding), and RAV (related to ABI3/VP1) (Mizoi et al. 2012). Members of AP2 subfamily consist of two AP2/ERF domains (Sakuma et al. 2002). The ERFs and DREB subfamilies contain single AP2 domain that usually binds to an ethylene responsive (AGCCGCC) cis-element designated as GCC-box (Ecker 1995; Eini et al. 2013). However, the RAV subfamily proteins are characterized by the presence of two different DNA binding domains, AP2/ERF and B3 (Kagaya et al. 1999).
The first TF identified and reported to be involved in cuticular wax biosynthesis was WAX INDUCER1/SHINE1 (WIN1/SHN1) from Arabidopsis simultaneously by two independent research groups designated as WAX INDUCER1 (WIN1) and SHINE1 (SHN1) (Aharoni et al. 2004; Broun et al. 2004). WIN1/SHN1 belonging to the subfamily of AP2/ERF TFs is a member of a clade of three close homolog proteins (SHN2 and SHN3) in Arabidopsis genome belonging to group V or B6 (Sakuma et al. 2002; Nakano et al. 2006). All three SHN clade genes exist with a single intron in nature, and no splice variants are reported. The AtWIN1/SHN1 share 55% and 71% protein sequence homology with AtSHN2 and AtSHN3, respectively (Aharoni et al. 2004). All three SHN proteins contain three conserved domains/motifs, AP2 domain at N-terminal, a middle, and C-terminal conserved motifs (Nakano et al. 2006).
The overexpression of WIN1/SHN1 showed increased accumulation of cutin/leaf epi-cuticular waxes and resulted in improved dehydration tolerance of transgenic Arabidopsis and downregulation leads to decreased cutin content in the outer parts of the plant (Aharoni et al. 2004; Broun et al. 2004; Kannangara et al. 2007). The WIN1/SHN1 overexpression also reflected in altering the structure of leaf epidermis and stomatal index, trichrome number, and branching (Aharoni et al. 2004). Therefore, it is possible that WIN1/SHN1 and other AP2 domain superfamily members not only involved in cuticle formation but also function in other metabolic pathways. Shi et al. (2011) showed that WIN1/SHN1 TF plays an important role in the metabolism of cell wall. The constitutive overexpression of WIN1/SHN1 TF leads to an upregulation of three downstream genes (CER1, CER2, and KCS1) that were initially identified and known to be involved in the biosynthesis of epidermal waxes (Broun et al. 2004). Transgenic Arabidopsis plants expressing WIN1/SHN1 resulted in altering the expression of 12 genes, of which 11 were upregulated and one with an unknown function strongly downregulated (Kannangara et al. 2007). Even though WIN1/SHN1 overexpression altered cuticular wax load and resulted in improved stress tolerance, evidences for the direct activation of downstream genes by WIN1/SHN1 are still lacking. In the last few years, WIN/SHN-related members were identified and characterized from different crops like soybean, cotton, barley, wheat, etc. Overexpression resulted in altered cuticle properties and imparts tolerance to multiple abiotic stresses (Xu et al. 2016; Bi et al. 2018; Djemal et al. 2018; Djemal and Khoudi 2015, 2021).
7.4.2 Homologous of WIN/SHN
In rice, four homologous of Arabidopsis WIN/SHN were identified and designated as Wax Synthesis Regulatory genes 1–4 (OsWR1–4) (Wang et al. 2012). Sequence homology studies showed the OsWR1 protein sequence is closely related to AtWIN1/SHN1 protein. Transgenic rice plants overexpressing OsWR1 resulted in decreased cuticle permeability, in contrast to the results exhibited in AtWIN1/SHN1 overexpression studies by Aharoni et al. (2004), but an enhancement in drought tolerance has been reported in both the cases. The decreased cuticle permeability of OsWR1 overexpression was due to alterations in long-chain FAs and alkanes. In addition, it was demonstrated that OsWR1 could interact with wax-related genes, OsLACS2 and OsFAE1-L, by direct binding to GCC and DRE elements present in the promoter region. The OsWR1 overexpression in rice resulted in more than two-fold upregulation of 12 wax biosynthesis-related genes and four cutin biosynthesis genes. The overexpression also showed an increased expression of non-cuticle biosynthesis genes involved in membrane stabilization and reactive oxygen species (ROS) scavenging such as late embryogenesis abundant protein (LEA3), ascorbate peroxidase (APX1), superoxide dismutase (SOD), and catalase (Cat A and Cat B) that could independently contribute to improved drought tolerance. On the other hand, silencing of OsWR1 by RNAi resulted in significant downregulation of many of those genes (Table 7.2) and partial silencing resulted in decreased transcript levels of Cat A and Cat B (Wang et al. 2012).
7.4.3 Negative Regulators of WIN/SHN
Two negative regulators, NUCLEAR FACTOR X LIKE2 (NFXL2) and SPINDLY (SPY) of WIN/SHN genes, were reported. The Arabidopsis NFXL2 mutant analysis showed difference in the composition of cutin, reduced stomatal aperture, and an increase in drought tolerance by regulating the expression of all three SHN genes (Lisso et al. 2012). Further analysis revealed that NFXL2 gene could act as a negative regulator for WIN1/SHN1 and several others by directly interacting with the gene promoter region. Thus, NFXL2 protein modulated the cuticle components biosynthesis through a direct repression of WIN1/SHN gene (Lisso et al. 2012).
7.4.4 WAX PRODUCTION1 (WXP1)
WXP1, an AP2 domain containing TF from Medicago truncatula (Mt), is evidently distinct from other AP2/ERF TF family genes. The MtWXP1 identified to be a homolog to ERFs has 53% amino acid sequence identity with RAP2.4. The WXP1 transcript was highly upregulated by abscisic acid (ABA) treatment in both shoot and root of seedlings, and upregulation was observed only in shoot under cold and drought stress. Under cold stress conditions, the upregulation was very rapid and could be detected within 30 minutes (Zhang et al. 2005). The constitutive overexpression of WXP1 in alfalfa resulted an increase in total leaf wax load to nearly 40% and enhanced drought stress tolerance (Zhang et al. 2005). The gas chromatography-mass spectrometry (GCMS) analysis of transgenic plants leaves showed a significant difference in multiple wax derivatives such as higher content of C30 alcohol moieties (25–35%) and elevated levels of other wax components (Table 7.2). The increase in wax content resulted in reduced water loss by decreasing water permeability, lower chlorophyll leaching, and showed better tolerance to drought stress. The WXP1 overexpression resulted in the upregulation of three FAE-like and two LACERATA (LCR, encoding cytochrome P450 monooxygenases) wax biosynthesis pathway genes (Zhang et al. 2005).
The constitutive overexpression of MtWXP1 and its paralog WXP2 significantly enhanced the deposition of cuticular waxes due to the accumulation of specific wax components and their chain length distributions on leaves of Arabidopsis (Zhang et al. 2007). The WXP1 and WXP2 transgenic lines showed higher levels of n-alkanes. The primary alcohol levels were increased in WXP1 plants but showed an opposite trend in WXP2 as compared to their wild type plants (Table 7.2). The WXP1 plants did not show any changes in the cuticle permeability while WXP2 resulted in decreased levels. Surprisingly, detached leaves of WXP1 and WXP2 transgenic plants retained better water content and showed significantly enhanced survival under drought stress conditions. Under the low-temperature stress, WXP1 transgenic plants showed an improved tolerance while WXP2 was susceptible as compared to control plants. The Arabidopsis plants constitutively expressing WXP1 did not exhibit any negative effects on plant growth and development; however, slower plant growth was observed in WXP2 overexpression (Zhang et al. 2007).
7.4.5 WRINKLED and CBF TFs
The WRINKLED1 (WRI1) gene contain two AP2 domain was identified from Arabidopsis through the mutant analysis. The mature seeds of wri1 mutants showed a wrinkled appearance and decreased content of water-insoluble oils (Cernac and Benning 2004). The overexpression of WRI1 resulted in 10–20% increased seed oil content without reducing the seed number (Cernac and Benning 2004). The WRI3 and WRI4 homologs of WRI1 were identified to be involved in gene expression of the synthesis of acyl chain and glycerol backbones that are main precursors of different lipid biosynthetic pathways (To et al. 2012). On the other hand, significant downregulation of most glycolytic and late FA biosynthetic genes were observed in wri triple mutants. The C-repeat binding factor genes (CBF1a and 1b) associated with drought and cold tolerance were found to be involved in the regulation of deposition of cuticular waxes in Eucalyptus gunii, an Australian drought- and cold-tolerant tree species (Navarro et al. 2011). The eucalyptus transgenic plants exhibited a high accumulation of anthocyanins, decrease in the stomatal density, reduced growth, better water retention capacity with reduced leaf area, and increase in leaf thickness and leaf cell size as compared to the control plants. Also, transgenic plant leaves showed a higher density of oil glands, and amount of cuticular waxes were significantly higher (Navarro et al. 2011). Overexpression of CBF4 TF gene in grape vine resulted in enhanced freezing tolerance and decreased electrolyte leakage due to freezing. The mRNA expression profiling of transgenic line showed the expression of CBF4 targets the lipid metabolism, epi-cuticular wax formation, and cell wall structure-related genes (Tillett et al. 2012). So far, these are the only reports showing the involvement of CBF genes on cuticle wax deposition (Table 7.2).
7.4.6 Myeloblastosis Family (MYB)
To date, many MYB TFs have been shown to be involved in the complex network that control cuticle biosynthesis, cell-wall modification, and cuticle deposition in the model plant Arabidopsis. A R2R3-type MYB TF in Arabidopsis, MYB41 is reported to be involved in the cuticle biosynthesis and wax transport regulation (Cominelli et al. 2008). AtMYB41 interacts with mitogen-activated protein kinase 6 (MPK6), a member of protein kinases family interacts with a number of signaling pathways involved in plant development and responses to stress (Hoang et al. 2012). It was demonstrated that AtMYB41 can physically interact with MPK6 and get phosphorylated at residue Ser251, which can enhance MYB41 DNA binding capacity to the LTP gene promoter. This was further proved by wild type AtMYB41 gene overexpression that showed improved tolerance to high salinity while overexpression of a mutated MYB41 (Serine 251 to alanine) resulted in decreased tolerance to salt stress (Hoang et al. 2012).
A R2R3-type MYB protein, MYB96, identified as a stress-responsive TF modulates the responses of drought stress by combining the auxin and ABA signals (Seo et al. 2009). The Arabidopsis mutant plants overexpressing MYB96 suppressed the lateral root growth but were resistant to drought stress, while the knockout mutants were highly sensitive to drought stress (Seo et al. 2009). The microarray results showed upregulation of a large group of genes encoding the wax biosynthetic enzymes by MYB96, specifically those of VLCFA condensing enzymes (Seo et al. 2011; Table 7.2). Most of the target genes of MYB96 were also upregulated under drought stress and ABA due to the presence of MYB-responsive cis-element “TAACTA/G” in their promoter. The transgenic AtMYB96 plants showed increased epi-cuticular wax crystal deposition in leaves but reduced in stem and showed a slight change in the color of leaves. Also, these plants were significantly shorter with no characteristic “shiny” phenotype; however, no changes in epidermal development was observed (Seo et al. 2011). The myb96 loss of function mutant was susceptible to drought stress due to the alteration in cuticular wax biosynthesis (Guo et al. 2013). A closely related MYB94 TF gene can effectively replace MYB96 in cuticular wax biosynthesis (Lee et al. 2016). The MYB94 and MYB96 TFs are closely related and can additively function in the biosynthesis of waxes under drought stress and well-watered conditions via an ABA-dependent pathway (Lee et al. 2016).
The role of AtMYB96 in frost tolerance and response to biotic stresses were also reported (Guo et al. 2013; Seo and Park 2011). The LTP3 gene overexpression resulted in increased freezing tolerance without showing an effect on CBF expression or their target cold regulated (COR) genes. The MYB96 directly binds to the LTP3 gene promoter results in positive regulation of LTP3 expression results in enhanced freezing tolerance, consistent with MYB96 overexpressing transgenic plants (Guo et al. 2013). An inhibitor of the rust germ tube differentation1 (irg1) mutant showed complete loss of epi-cuticular wax crystals in the abaxial surface and consequent reduction in the surface hydrophobicity that conferred non-host resistance to biotrophic fungal pathogens. The abaxial leaf surface wax composition analysis of irg1 mutant showed 90% reduction in primary alcohols (C30) and alkanes (C29 and C31) were increased compared to control (Table 7.2). It is proposed that IRG1 may be a direct or indirect regulator of MtMYB96 transcription; however, there is no evidence to claim that IRG1 could regulate the cuticular wax biosynthesis-related genes directly or is performed only through MYB96.
MIXTA, an MYB-related TF, has been identified with the role in cuticular wax biosynthesis and epidermal cell shape formation. The Arabidopsis and Torenia fournieri MYB106 and MYB16, MIXTA-like TF genes can regulate the development of cuticle that coordinate with TF WIN1/SHN1 (Oshima et al. 2013; Table 7.2). The downregulation of MYB106 and MYB16 TF genes resulted in cuticle deficiencies of flowering organs, organ adhesion, and decreased epi-cuticular wax crystals. Microarray results showed MYB106 and WIN1/SHN1 TFs regulate similar set of genes (Oshima et al. 2013; Table 7.2). Among these, the genes involved in the accumulation of waxes such as FDH, KCS1, and CER2 and cutin biosynthesis genes such as LACERATA and LONG-CHAIN ACYL COA SYNTHETASE2 were identified. The overexpression of MYB16 in Arabidopsis resulted in the accumulation of waxy substances on leaves, and both MYB106 and MYB16 downregulation by RNAi leads to reduced expression of cuticular wax biosynthesis genes LACERATA and ECERIFERUM1 with severe permeable cuticle phenotype (Oshima and Mitsuda 2013; Oshima et al. 2013).
7.4.7 Homeodomain-Leucine Zipper Class IV Factors
The homeodomain leucine zipper IV (HD-Zip IV) TFs are predominantly expressed in epidermal cells with epidermis-related functions have been identified from number of plant systems (Javelle et al. 2011; Chew et al. 2013). Maize (Zea Mays) Outer Cell Layer 1 (ZmOCL1) gene is a member of HD-ZIP IV comes under the subclass of HD-ZIP homeodomain proteins, was detected in protoderm, floral organs, and developing leaves (Ingram et al. 1999, 2000). The transgenic maize plants overexpressing ZmOCL1 gene had less effect on phenotype as compared to its control, but the transcriptome analysis revealed expression of many genes involved in the metabolism of lipids and its transport (Javelle et al. 2010). Some of the genes identified are carboxylesterase, type 2 LTP, phosphatidylinositol transport protein, three ABC transporters, and FA reductase (Table 7.2). The FA reductases responsible for the long-chain primary alcohol synthesis from FA precursors were closely related to CER4 protein in Arabidopsis (Rowland et al. 2006). The transgenic plants of ZmOCL1 did not show significant changes in the wax layer structure or size as compared to the wild-type plants. However, wax chemical component analysis showed a significant increase in C32 alcohol content and decrease in C32 aldehydes in the young leaves of ZmOCL1 transgenic. Few of the independent transgenic lines showed significant two- to threefold increase in C44 to C48 wax esters as compared to the control (Javelle et al. 2010).
7.4.8 Curly Flag Leaf1, a Negative Regulator of HD-Zip IV
The Curly Flag Leaf1 (CFL1) gene, a WW domain encoding protein, was reported as a negative regulator of cuticle development (Wu et al. 2011). The overexpression of OsCFL1 and AtCFL1 in transgenic Arabidopsis plants resulted in an organ fusion phenotype with decreased levels of epi-cuticular waxes and defective cuticles. Yeast two hybrid assay provided evidences for direct interaction of AtCFL1 with HDG1, a HD-Zip IV protein (Wu et al. 2011). The HDG1 gene suppression resulted in a defective cuticle phenotype in transgenic Arabidopsis, similar to that of the CFL1 overexpressing plants. The AtCFL1 overexpression and HDG1 downregulation in transgenic Arabidopsis resulted in the downregulation of FIDDLEHEAD (FDH) and BODYGUARD (BDG), two cuticle biosynthesis-associated genes. The BDG encodes a member of the α/β-hydrolase fold protein superfamily and FDH is also known as KCS10 (Kurdyukov et al. 2006; Wellesen et al. 2001; Yephremov et al. 1999). It was demonstrated that HDG1 could function as a positive regulator by directly binding to the L1 boxes in the promoters of BDG and FDH genes. The HDG1 function is negatively regulated by CFL1, thereby affecting the cuticle development (Wu et al. 2011; Table 7.2).
7.5 Cuticular Wax, a Multifunctional Trait
Plant cuticle and cuticular waxes play multifunctional role in crop protection and survival against various abiotic and biotic stresses like transpiration water loss, drought, high light intensity, salinity, invading pathogens, and insect herbivores (Lewandowska et al. 2020). It is well documented and demonstrated that drought stress induces wax production (Aharoni et al. 2004; Zhang et al. 2005; Cameron et al. 2006). Significant correlations were observed between the content of waxes, yield, water use efficiency (WUE), and drought tolerance in crops like rice, wheat, barley, and sorghum (Jordan et al. 1984; Richards et al. 1986; Febrero et al. 1998; Zhu and Xiong 2013). These evidences point toward the fact that as the wax content decreases, the crop plants will become more sensitive in general to desiccation and drought stress compared to more waxy ones (Guo et al. 2016). The role of cuticular waxes in imparting salinity stress tolerance is through controlling the residual transpiration, which is negatively correlated with wax content (Hasanuzzaman et al. 2017). Higher leaf surface wax containing genotypes generally have a cooler canopy temperature that helps to resist high temperature or heat stress (Awika et al. 2017). Similarly, higher cuticular waxes can protect from high light conditions such as excessive ultraviolet (UV) radiations, indicating these stresses can affect and alter the plant cuticular waxes (Fukuda et al. 2008; Xue et al. 2017; Lewandowska et al. 2020).
Infection with plant pathogens can also result in increased epi-cuticular wax load and change the cuticular properties. Infections with fungal pathogens Colletotrichum gloeosporioides and C. acutatum in tomato and citrus plants resulted in increased cuticular wax biosynthesis, deposition, and changes the cuticular structure (Alkan and Fortes 2015; Marques et al. 2016). The increase in epi-cuticular wax load and changes in chemical composition may not always necessarily result in plant resistance against biotic stresses. The epi-cuticular waxes can play divergent roles in different plants and for different pathogens. This was demonstrated through the functional studies of the Arabidopsis DEWAX gene, a negative regulator of wax biosynthesis. The Arabidopsis dewax mutant lines showed an increased epi-cuticular wax were susceptible to Botrytis cinerea and resistant to Pseudomonas syringae, fungal and bacterial pathogens, respectively (Ju et al. 2017). Overexpression of DEWAX in Arabidopsis and Camelina showed inverse defense regulation to Botrytis and Pseudomonas (Ju et al. 2017).
7.6 Attempts to Manipulate Cuticular Trait
Attempts have been made to improve crop plants by targeting the wax biosynthesis pathway and altering the cuticular properties by conventional and modern breeding as well as through transgenic approaches. The prerequisite for crop improvement through breeding or transgenic approaches is to have the prior knowledge about the genomic region/s and gene/s contributing for wax traits. This has been achieved to an extent through the loss- and gain-of-function mutants in either model or crop species. Over the domestication process of major crops like wheat, rice, corn, barley, soybean, and tomato, focus was on yield traits and the yield targeted breeding over generations resulted in reduced genetic diversity for other biotic and abiotic stressors in commercial varieties. A good source to regain the lost genetic diversity is to incorporate the wild relatives and landraces of crops plants in the breeding program. Multiple quantitative trait loci (QTL) regions involved in the biosynthesis of epi-cuticular waxes and its transport have been reported from multiple crops like rice, sorghum, cabbage, and pearl millet and can be used for marker-assisted breeding (MAS) programs (Srinivasan et al. 2008; Burow et al. 2009; Liu et al. 2018).
Considerable amount of work has been carried out in Arabidopsis to identify and characterize the functional and regulatory genes involved in cuticular wax biosynthesis (Aharoni et al. 2004; Kannangara et al. 2007; Seo et al. 2009; Shi et al. 2011; Yang et al. 2020). Many of these genes or its homologs identified from crop plants have been used for targeted engineering of wax biosynthetic pathway in crop plants that resulted in altered cuticle properties and showed multiple stress tolerance (Zhang et al. 2005, 2019a, b, c; Adato et al. 2009; Shi et al. 2013; Kumar et al. 2016; Sajeevan et al. 2017a; Liu et al. 2019; More et al. 2019; Wang et al. 2020). It has also been shown that ectopic expression of Arabidopsis or its homologs overexpression in biofuel crop, Camelina sativa and tree species like Morus and Malus resulted in altered total wax load, composition, structure, and contributed to drought tolerance (Lee et al. 2014; Sajeevan et al. 2017a; Zhang et al. 2019b, c). Alterations in the wax biosynthesis pathway is hampered due to the lack of clear knowledge in cuticular wax load, its chemical composition, and structural characteristics required to improve specific crops, and also to what extent these factors needs to be species- or tissue-specific.
7.7 Conclusion
Cuticle is a natural film covering the outer parts of the plant that consists of lipid polyesters covered and embedded with waxes that protect the tissues from multiple abiotic and biotic stresses. During the land plants evolution from aquatic to a more desiccating terrestrial environment, plants evolve to synthesize cuticular waxes as a fundamental morphological and physiological adaptation. There is a high level of compositional and structural differences exist in cuticular waxes among different crop plants and organs. These cuticular waxes are largely produced by two complex pathways controlled by the expression of different genes/enzymes in turn influenced by multiple environmental stresses. Although past decade advancement in genome sequencing technologies and through various forward and reverse genetics approaches allowed us to elucidate and understand the complex gene regulatory network involved in biosynthesis, transport, and deposition of cuticular waxes in model as well as different crop plants, to an extent. We still have long way to go towards fully understanding the regulatory mechanisms controlling the cuticular wax biosynthesis, compositional and structural differences, transport, and deposition in response to various stressors. In addition, a limited understanding of the role of plant cuticle components as signaling molecules that promote resistance or susceptibility to biotic stresses needs to be further investigated. Unraveling these mechanisms would aid in targeted manipulation of the trait using modern biotechnological applications for the development of crop cultivars with improved health thereby promoting sustainable agriculture.
References
Aarts MGM, Keijzer CJ, Stiekema WJ, Pereira A (1995) Molecular characterization of the CER1 gene of Arabidopsis involved in epicuticular wax biosynthesis and pollen fertility. Plant Cell 7:2115–2127
Adato A, Mandel T, Mintz-Oron S, Venger I, Levy D, Yativ M, Domínguez E, Wang Z, De Vos RC, Jetter R, Schreiber L, Heredia A, Rogachev I, Aharoni A (2009) Fruit–surface flavonoid accumulation in tomato is controlled by a SlMYB12–regulated transcriptional network. PLoS Genet 5:e1000777
Aharoni A, Dixit S, Jetter R, Thoenes E, van Arkel G, Pereira A (2004) The SHINE clade of AP2 domain transcription factors activates wax biosynthesis alters cuticle properties and confers drought tolerance when overexpressed in Arabidopsis. Plant Cell 16:2463–2480
Al-Abdallat AM, Al-Debei HS, Ayad JY, Hasan S (2014) Over-expression of SlSHN1 gene improves drought tolerance by increasing cuticular wax accumulation in tomato. Int J Mol Sci 15:19499–19515
Alkan N, Fortes AM (2015) Insights into molecular and metabolic events associated with fruit response to postharvest fungal pathogens. Front Plant Sci 6:889
Awika HO, Hays DB, Mullet JE, Rooney WL, Weers BD (2017) QTL mapping and loci dissection for leaf epicuticular wax load and canopy temperature depression and their association with QTL for staygreen in Sorghum bicolor under stress. Euphytica 213:207
Bach L, Michaelson LV, Haslam R, Bellec Y, Gissot L, Marion J, Costa MD, Boutin JP, Miquel M, Tellier F, Domergue F, Markham JE, Beaudoin F, Napier JA, Faure JD (2008) The very- long-chain hydroxy fatty acyl-CoA dehydratase PASTICCINO2 is essential and limiting for plant development. Proc Natl Acad Sci U S A 105:14727–14731
Beaudoin F, Wu X, Li F, Haslam RP, Markham JE, Zheng H, Napier JA, Kunst L (2009) Functional characterization of the Arabidopsis β-Ketoacyl-Coenzyme A reductase candidates of the fatty acid elongase. Plant Physiol 150:1174–1191
Bengtson C, Larsson S, Liljenberg C (1978) Effects of water stress on cuticular transpiration rate and amount and composition of epicuticular wax in seedlings of six oat varieties. Physiol Plant 44:319–324
Bernard A, Joubes J (2013) Arabidopsis cuticular waxes: advances in synthesis export and regulation. Prog Lipid Res 52:110–129
Bernard A, Domergue F, Pascal S, Jetter R, Renne C, Faure JD, Haslam RP, Napier JA, Lessire R, Joubès J (2012) Reconstitution of plant alkane biosynthesis in yeast demonstrates that Arabidopsis ECERIFERUM1 and ECERIFERUM3 are core components of a very- long- chain alkane synthesis complex. Plant Cell 24:3106–3118
Bessire M, Borel S, Fabre G, Carraça L, Efremova N, Yephremov A, Cao Y, Jetter R, Jacquat AC, Métraux JP, Nawrath C (2011) A member of the Pleiotropic Drug Resistance family of ATP binding cassette transporters is required for the formation of a functional cuticle in Arabidopsis. Plant Cell 23:1958–1970
Bi H, Shi J, Kovalchuk N, Luang S, Bazanova N, Chirkova L, Zhang D, Stepanenko A, Tricker P, Langridge P, Hrmova M, Lopato S, Borisjuk N (2018) Overexpression of the TaSHN1 transcription factor in bread wheat leads to leaf surface modifications, improved drought tolerance, and no yield penalty under controlled growth conditions. Plant Cell Environ 41:2549–2566
Bird D, Beisson F, Brigham A, Shin J, Greer S, Jetter R, Kunst L, Wu X, Yephremov A, Samuels L (2007) Characterization of Arabidopsis ABCG11/WBC11 an ATP binding cassette (ABC) transporter that is required for cuticular lipid secretion. Plant J 52:485–498
Bonaventure G, Salas JJ, Pollard MR, Ohlrogge JB (2003) Disruption of the FATB gene in Arabidopsis demonstrates an essential role of saturated fatty acids in plant growth. Plant Cell 15:1020–1033
Bondada B, Oosterhuis DM, Murphy JB, Kim KS (1996) Effect of water stress on the epicuticular wax composition and ultrastructure of cotton (Gossypium hirsutum L.) leaf bract and boll. Environ Exp Bot 36:61–67
Borisjuk N, Hrmova M, Lopato S (2014) Transcriptional regulation of cuticle biosynthesis. Biotechnol Adv 2(2):526–540
Bourdenx B, Bernard A, Domergue F, Pascal S, Léger A, Roby D, Pervent M, Vile D, Haslam RP, Napier JA, Lessire R, Joubès J (2011) Overexpression of Arabidopsis ECERIFERUM1 promotes wax very-long-chain alkane biosynthesis and influences plant response to biotic and abiotic stresses. Plant Physiol 156:29–45
Broun P, Poindexter P, Osborne E, Jiang CZ, Riechmann JL (2004) WIN1 a transcriptional activator of epidermal wax accumulation in Arabidopsis. Proc Natl Acad Sci U S A 101:4706–4711
Burow GB, Franks CD, Acosta-Martinez V, Xin Z (2009) Molecular mapping and characterization of BLMC, a locus for profuse wax (bloom) and enhanced cuticular features of sorghum (Sorghum bicolor (L.) Moench.). Theor Appl Genet 118:423–431
Cameron KD, Teece MA, Smart LB (2006) Increased accumulation of cuticular wax and expression of lipid transfer protein in response to periodic drying events in leaves of tree tobacco. Plant Physiol 140:176–183
Cernac A, Benning C (2004) WRINKLED1 encodes an AP2/EREB domain protein involved in the control of storage compound biosynthesis in Arabidopsis. Plant J 40:575–585
Chen X, Goodwin SM, Boroff VL, Liu X, Jenks MA (2003) Cloning and characterization of the WAX2 gene of Arabidopsis involved in cuticle membrane and wax production. Plant Cell 15:1170–1185
Chen X, Goodwin SM, Liu X, Chen X, Bressan RA, Jenks MA (2005) Mutation of the RESURRECTION1 locus of Arabidopsis reveals an association of cuticular wax with embryo development. Plant Physiol 139:909–919
Chen G, Komatsuda T, Ma JF, Nawrath C, Pourkheirandish M, Tagiri A, Hu YG, Sameri M, Li X, Zhao X, Liu Y, Li C, Ma X, Wang A, Nair S, Wang N, Miyao A, Sakuma S, Yamaji N, Zheng X, Nevo E (2011) An ATP– binding cassette subfamily G full transporter is essential for the retention of leaf water in both wild barley and rice. Proc Natl Acad Sci U S A 108:12354–12359
Chew W, Hrmova M, Lopato S (2013) Role of Homeodomain Leucine Zipper (HD–Zip) IV transcription factors in plant development and plant protection from deleterious environmental factors. Int J Mol Sci 14:8122–8147
Cominelli E, Sala T, Calvi D, Gusmaroli G, Tonelli C (2008) Overexpression of the Arabidopsis AtMYB41 gene alters cell expansion and leaf surface permeability. Plant J 53:53–64
Cui F, Wu W, Wang K, Zhang Y, Hu Z, Brosché M, Liu S, Overmyer K (2019) Cell death regulation but not abscisic acid signaling is required for enhanced immunity to Botrytis in Arabidopsis cuticle-permeable mutants. J Exp Bot 70:5971–5984
Debono A, Yeats TH, Rose JKC, Bird D, Jetter R, Kunst L, Samuels L (2009) Arabidopsis LTPG is a glycosylphosphatidyl inositol–anchored lipid transfer protein required for export of lipids to the plant s urface. Plant Cell 21:1230–1238
Djemal R, Khoudi H (2015) Isolation and molecular characterization of a novel WIN1/SHN1 ethylene-responsive transcription factor TdSHN1 from durum wheat (Triticum turgidum. L. subsp. durum). Protoplasma 252:1461–1473
Djemal R, Khoudi H (2021) The barley SHN1-type transcription factor HvSHN1 imparts heat, drought and salt tolerances in transgenic tobacco. Plant Physiol Biochem 16:44–53
Djemal R, Mila I, Bouzayen M, Pirrello J, Khoudi H (2018) Molecular cloning and characterization of a novel WIN1/SHN1 ethylene-responsive transcription HvSHN1 in barley (Hordeum vulgare L.). J Plant Physiol 228:39–46
Do THT, Martinoia E, Lee Y (2018) Functions of ABC transporters in plant growth and development. Curr Opin Plant Biol 41:32–48
Ecker JR (1995) The ethylene signal transduction pathway in plants. Science 268:667–675
Eigenbrode SD, Espelie KE (1995) Effects of plant epicuticular lipids on insect herbivores. Annu Rev Entomol 40:171–194
Eigenbrode SD, Jetter R (2002) Attachment to plant surface waxes by an insect predator. Integr Comp Biol 42:1091–1099
Eini O, Yang N, Pyvovarenko T, Pillman K, Bazanova N, Tikhomirov N, Eliby S, Shirley N, Sivasankar S, Tingey S, Langridge P, Hrmova M, Lopato S (2013) Complex regulation by Apetala2 domain-containing transcription factors revealed through analysis of the stress-responsive TdCor410b promoter from durum wheat. PLoS One 8:e58713
Elejalde-Palmett C, Martinez San Segundo I, Garroum I, Charrier L, De Bellis D, Mucciolo A, Guerault A, Liu J, Zeisler-Diehl V, Aharoni A, Schreiber L, Bakan B, Clausen MH, Geisler M, Nawrath C (2021) ABCG transporters export cutin precursors for the formation of the plant cuticle. Curr Biol 31:2111–2123
Elliott RC, Betzner AS, Huttner E, Oakes MP, Tucker WQ, Gerentes D, Perez P, Smyth DR (1996) AINTEGUMENTA an APETALA2-like gene of Arabidopsis with pleiotropic roles in ovule development and floral organ growth. Plant Cell 8:155–168
Febrero A, Fernández S, Molina-Cano JL, Araus JL (1998) Yield, carbon isotope discrimination, canopy reflectance and cuticular conductance of barley isolines of differing glaucousness. J Exp Bot 49:1575–1581
Fiebig A, Mayfield JA, Miley NL, Chau S, Fischer RL, Preuss D (2000) Alterations in CER6 a gene identical to CUT1 differentially affect long-chain lipid content on the surface of pollen and stems. Plant Cell 12:2001–2008
Franke R, Höfer R, Briesen I, Emsermann M, Efremova N, Yephremov A, Schreiber L (2009) The DAISY gene from Arabidopsis encodes a fatty acid elongase condensing enzyme involved in the biosynthesis of aliphatic suberin in roots and the chalaza-micropyle region of seeds. Plant J 57:80–95
Fukuda S, Satoh A, Kasahara H, Matsuyama H, Takeuchi Y (2008) Effects of ultraviolet-B irradiation on the cuticular wax of cucumber (Cucumis sativus) cotyledons. J Plant Res 121:179–189
Gilding EK, Marks MD (2010) Analysis of purified glabra 3-shapeshifter trichomes reveals a role for NOECK in regulating early trichome morphogenic events. Plant J 64:304–317
Goodwin SM, Jenks MA (2005) Plant cuticle function as a barrier to water loss. In: Jenks MA, Hasegawa PM (eds) Plant abiotic stress. Blackwell Publishing, Inc
Greer S, Wen M, Bird D, Wu X, Samuels L, Kunst L, Jetter R (2007) The Cytochrome P450 Enzyme CYP96A15 is the midchain alkane hydroxylase responsible for formation of secondary alcohols and ketones in stem cuticular wax of Arabidopsis. Plant Physiol 145:653–667
Guo L, Yang H, Zhang X, Yang S (2013) Lipid transfer protein 3 as a target of MYB96 mediates freezing and drought stress in Arabidopsis. J Exp Bot 64:1755–1767
Guo J, Xu W, Yu X, Shen H, Li H, Cheng D, Liu A, Liu J, Liu C, Zhao S, Song J (2016) Cuticular wax accumulation is associated with drought tolerance in wheat near-isogenic lines. Front Plant Sci 7:1809
Hansen JD, Pyee J, Xia Y, Wen TJ, Robertson DS, Kolattukudy PE, Nikolau BJ, Schnable PS (1997) The glossy1 locus of maize and an epidermis-specific cDNA from Kleinia odora define a class of receptor- like proteins required for the normal accumulation of cuticular waxes. Plant Physiol 113:1091–1100
Hasanuzzaman M, Davies NW, Shabala L, Zhou M, Brodribb TJ, Shabala S (2017) Residual transpiration as a component of salinity stress tolerance mechanism: a case study for barley. BMC Plant Biol 17:107
Haslam TM, Mañas-Fernández A, Zhao L, Kunst L (2012) Arabidopsis ECERIFERUM2 is a component of the fatty acid elongation machinery required for fatty acid extension to exceptional lengths. Plant Physiol 160:1164–1174
Haslam TM, Haslam R, Thoraval D, Pascal S, Delude C, Domergue F, Fernández AM, Beaudoin F, Napier JA, Kunst L, Joubès J (2015) ECERIFERUM2-LIKE proteins have unique biochemical and physiological functions in very-long-chain fatty acid elongation. Plant Physiol 167(3):682–692
Hoang MH, Nguyen XC, Lee K, Kwon YS, Pham HT, Park HC, Yun DJ, Lim CO, Chung WS (2012) Phosphorylation by AtMPK6 is required for the biological function of AtMYB41 in Arabidopsis. Biochem Biophys Res Commun 422:181–186
Hooker TS, Millar AA, Kunst L (2002) Significance of the expression of the CER6 condensing enzyme for cuticular wax production in Arabidopsis. Plant Physiol 129:1568–1580
Ingram G, Nawrath C (2017) The roles of the cuticle in plant development: organ adhesions and beyond. J Exp Bot 68:5307–5321
Ingram GC, Magnard JL, Vergne P, Dumas C, Rogowsky PM (1999) ZmOCL1 an HDGL2 family homeobox gene is expressed in the outer cell layer throughout maize development. Plant Mol Biol 40:343–354
Ingram GC, Boisnard-Lorig C, Dumas C, Rogowsky PM (2000) Expression patterns of genes encoding HD–zip IV homeo domain proteins define specific domains in maize embryos and meristems. Plant J 22:401–414
Islam MA, Du H, Ning J, Ye H, Xiong L (2009) Characterization of Glossy1-homologous genes in rice involved in leaf wax accumulation and drought resistance. Plant Mol Biol 70:443–456
Javelle M, Vernoud V, Depège-Fargeix N, Arnould C, Oursel D, Domergue F, Sarda X, Rogowsky PM (2010) Overexpression of the epidermis-specific homeodomain-leucine zipper IV transcription factor outer cell layer1 in maize identifies target genes involved in lipid metabolism and cuticle biosynthesis. Plant Physiol 154:273–286
Javelle M, Klein-Cosson C, Vernoud V, Boltz V, Maher C, Timmermans M, Depège-Fargeix N, Rogowsky PM (2011) Genome-wide characterization of the HD–ZIP IV transcription factor family in maize: preferential expression in the epidermis. Plant Physiol 157:790–803
Jefferson P, Johnson D, Rumbaugh M, Asay K (1989) Water stress and genotypic effects on epicuticular wax production of alfalfa and crested wheatgrass in relation to yield and excised leaf water loss rate. Can J Plant Sci 69:481–490
Jenks MA, Joly RJ, Peters PJ, Rich PJ, Axtell JD, Ashworth EN (1994) Chemically induced cuticle mutation affecting epidermal conductance to water vapor and disease susceptibility in Sorghum bicolor (L.) Moench. Plant Physiol 105:1239–1245
Jenks MA, Andersen L, Teusink RS, Williams MH (2001) Leaf cuticular waxes of potted rose cultivars as affected by plant development drought and paclobutrazol treatments. Physiol Plant 112:62–70
Jessen D, Olbrich A, Knüfer J, Krüger A, Hoppert M, Polle A, Fulda M (2011) Combined activity of LACS1 and LACS4 is required for proper pollen coat formation in Arabidopsis. Plant J 68:715–726
Jetter R, Kunst L (2008) Plant surface lipid biosynthetic pathways and their utility for metabolic engineering of waxes and hydrocarbon biofuels. Plant J 54:670–683
Jetter R, Schaffer S (2001) Chemical composition of the Prunus laurocerasus leaf surface: dynamic changes of the epicuticular wax film during leaf development. Plant Physiol 126:1725–1734
Jetter R, Kunst L, Samuels AL (2006) Composition of plant cuticular waxes. In: Riederer M, Müller C (eds) Annual plant reviews 23: biology of the plant cuticle. Blackwell Publishing, Oxford, pp 145–181
Jofuku KD, den Boer BG, Van Montagu M, Okamuro JK (1994) Control of Arabidopsis flower and seed development by the homeotic gene APETALA2. Plant Cell 6:1211–1225
Jordan W, Shouse PJ, Blum A, Miller FR, Monk RL (1984) Environmental physiology of sorghum, II, epicuticular wax load and cuticular transpiration. Crop Sci 24:1168–1173
Ju S, Go YS, Choi HJ, Park JM, Suh MC (2017) DEWAX transcription factor is involved in resistance to Botrytis cinerea in Arabidopsis thaliana and Camelina sativa. Front Plant Sci 8:1210
Kagaya Y, Ohmiya K, Hattori T (1999) RAV1, a novel DNA-binding protein, binds to bipartite recognition sequence through two distinct DNA-binding domains uniquely found in higher plants. Nucleic Acids Res 27(2):470–478
Kannangara R, Branigan C, Liu Y, Penfield T, Rao V, Mouille G, Hofte H, Pauly M, Riechmann JL, Broun P (2007) The transcription factor WIN1/SHN1 regulates cutin biosynthesis in Arabidopsis thaliana. Plant Cell 19(4):1278–1294
Kerstiens G (ed) (1996) Plant cuticles: an integrated functional approach. BIOS Scientific Publishers Limited, Oxford
Kim H, Lee SB, Kim HJ, Min MK, Hwang I, Suh MC (2012) Characterization of glycosylphosphatidyl inositol- anchored lipid transfer protein 2 (LTPG2) and overlapping function between LTPG/LTPG1 and LTPG2 in cuticular wax export or accumulation in Arabidopsis thaliana. Plant Cell Physiol 53:1391–1403
Kim J, Jung JH, Lee SB, Go YS, Kim HJ, Cahoon R, Markham JE, Cahoon EB, Suh MC (2013) Arabidopsis 3- Ketoacyl-Coenzyme A Synthase9 is involved in the synthesis of tetracosanoic acids as precursors of cuticular waxes, suberins, sphingolipids, and phospholipids. Plant Physiol 162:567–580
Kim H, Go YS, Suh MC (2018) DEWAX2 transcription factor negatively regulates cuticular wax biosynthesis in Arabidopsis leaves. Plant Cell Physiol 59(5):966–977
Kolattukudy P (1980) Cutin suberin and waxes. In: Stumpf PK (ed) The biochemistry of plants a comprehensive treatise, vol 4. Academic Press, New York, pp 571–641
Kong L, Zhi P, Liu J, Li H, Zhang X, Xu J, Zhou J, Wang X, Chang C (2020) Epigenetic activation of enoyl-CoA reductase by an acetyltransferase complex triggers wheat wax biosynthesis. Plant Physiol 183:1250–1267
Kosma DK, Bourdenx B, Bernard A, Parsons EP, Lü S, Joubès J, Jenks MA (2009) The impact of water deficiency on leaf cuticle lipids of Arabidopsis. Plant Physiol 151:1918–1929
Kumar A, Yogendra KN, Karre S, Kushalappa AC, Dion Y, Choo TM (2016) WAX INDUCER1 (HvWIN1) transcription factor regulates free fatty acid biosynthetic genes to reinforce cuticle to resist fusarium head blight in barley spikelets. J Exp Bot 67(14):4127–4139
Kunst L, Samuels AL (2003) Biosynthesis and secretion of plant cuticular wax. Prog Lipid Res 42:51–80
Kurdyukov S, Faust A, Nawrath C, Bär S, Voisin D, Efremova N, Franke R, Schreiber L, Saedler H, Métraux JP, Yephremov A (2006) The epidermis-specific extracellular BODYGUARD controls cuticle development and morphogenesis in Arabidopsis. Plant Cell 18:321–339
Lee SB, Suh MC (2015a) Advances in the understanding of cuticular waxes in Arabidopsis thaliana and crop species. Plant Cell Rep 34:557–572
Lee SB, Suh MC (2015b) Cuticular wax biosynthesis is up-regulated by the MYB94 transcription factor in Arabidopsis. Plant Cell Physiol 56(1):48–60
Lee SB, Go YS, Bae HJ, Park JH, Cho SH, Cho HJ, Lee DS, Park OK, Hwang I, Suh MC (2009a) Disruption of glycosylphosphatidyl inositol-anchored lipid transfer protein gene altered cuticular lipid composition increased plastoglobules and enhanced susceptibility to infection by the fungal pathogen Alternaria brassicicola. Plant Physiol 150:42–54
Lee SB, Jung SJ, Go YS, Kim HU, Kim JK, Cho HJ, Park OK, Suh MC (2009b) Two Arabidopsis 3- ketoacyl CoA synthase genes, KCS20 and KCS2/DAISY, are functionally redundant in cuticular wax and root suberin biosynthesis, but differentially controlled by osmotic stress. Plant J 60:462–475
Lee SB, Kim H, Kim RJ, Suh MC (2014) Overexpression of Arabidopsis MYB96 confers drought resistance in Camelina sativa via cuticular wax accumulation. Plant Cell Rep 33:1535–1546
Lee SB, Kim HU, Suh MC (2016) MYB94 and MYB96 additively active cuticular wax biosynthesis in Arabidopsis. Plant Cell Physiol 57:2300–2311
Lewandowska M, Keyl A, Feussner I (2020) Wax biosynthesis in response to danger: its regulation upon abiotic and biotic stress. New Phytol 227:698–713
Li F, Wu X, Lam P, Bird D, Zheng H, Samuels L, Jetter R, Kunst L (2008) Identification of the wax ester synthase/acyl-coenzyme a: diacylglycerol acyltransferase WSD1 required for stem wax ester biosynthesis in Arabidopsis. Plant Physiol 148:97–107
Li-Beisson Y, Shorrosh B, Beisson F, Andersson MX, Arondel V, Bates PD, Baud S, Bird D, Debono A, Durrett TP, Franke RB, Graham IA, Katayama K, Kelly AA, Larson T, Markham JE, Miquel M, Molina I, Nishida I, Rowland O, Samuels L, Schmid KM, Wada H, Welti R, Xu C, Zallot R, Ohlrogge J (2013) Acyl- lipid metabolism. Arabidopsis Book 8:e0161
Licausi F, Ohme-Takagi M, Perata P (2013) APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription factors: mediators of stress responses and developmental programs. New Phytol 199:639–649
Lisso J, Schroder F, Schippers JH, Mussig C (2012) NFXL2 modifies cuticle properties in Arabidopsis. Plant Signal Behav 7:551–555
Liu D, Dong X, Liu Z, Tang J, Zhuang M, Zhang Y, Lv H, Liu Y, Li Z, Fang Z, Yang L (2018) Fine mapping and candidate gene identification for wax biosynthesis locus, BoWax1 in Brassica oleracea L. var. capitata. Front. Plant Sci 9:309
Liu N, Chen J, Wang T, Li Q, Cui P, Jia C, Hong Y (2019) Overexpression of WAX INDUCER1/SHINE1 gene enhances wax accumulation under osmotic stress and oil synthesis in Brassica napus. Int J Mol Sci 20(18):4435
Long LM, Patel HP, Cory WC, Stapleton AE (2003) The maize epicuticular wax layer provides UV protection. Fun Plant Biol 30:75–81
Lü S, Song T, Kosma DK, Parsons EP, Rowland O, Jenks MA (2009) Arabidopsis CER8 encodes LONG–CHAIN ACYLCOA SYNTHETASE 1 (LACS1) that has overlapping functions with LACS2 in plant wax and cutin synthesis. Plant J 59:553–564
Lü S, Zhao H, Parsons EP, Xu C, Kosma DK, Xu X, Chao D, Lohrey G, Bangarusamy DK, Wang G, Bressan RA, Jenks MA (2011) The glossyhead1 allele of ACC1 reveals a principal role f or multidomain Acetyl- Coenzyme A Carboxylase in the biosynthesis of cuticular waxes by Arabidopsis. Plant Physiol 157:1079–1092
Luo B, Xue XY, Hu WL, Wang LJ, Chen XY (2007) An ABC transporter gene of Arabidopsis thaliana, AtWBC11, is involved in cuticle development and prevention of organ fusion. Plant Cell Physiol 48:1790–1802
Mamrutha HM, Mogili T, Lakshmi JK, Rama N, Kosma D, Udaya Kumar M, Jenks MA, Karaba NN (2010) Leaf cuticular wax amount and crystal morphology regulate post-harvest water loss in mulberry (Morus species). Plant Physiol Biochem 48:690–696
Mamrutha HM, Nataraja KN, Rama N, Kosma DK, Mogili T, Jhansi-Lakshmi K, Udaya Kumar M, Jenks MA (2017) Leaf surface wax composition of genetically diverse mulberry (Morus sp.) genotypes and its close association with expression of genes involved in wax metabolism. Curr Sci 112:759–766
Marques WL, Salazar MM, Camargo ELO, Lepikson-Neto J, Tiburcio RA, Costa do Nascimento L, Pereira GAG (2013) Identification of four Eucalyptus genes potentially involved in cell wall biosynthesis and evolutionarily related to SHINE transcription factors. Plant Growth Regul 69:203–208
Marques JPR, Amorim L, Spósito MB, Appezzato-da-Glória B (2016) Ultrastructural changes in the epidermis of petals of the sweet orange infected by Colletotrichum acutatum. Protoplasma 253:1233–1242
Masaki T, Mitsui N, Tsukagoshi H, Nishii T, Morikami A, Nakamura K (2005) ACTIVATOR of Spomin::LUC1/WRINKLED1 of Arabidopsis thaliana transactivates sugar-inducible promoters. Plant Cell Physiol 46:547–556
McFarlane HE, Shin JJ, Bird DA, Samuels AL (2010) Arabidopsis ABCG transporters which are required for export of diverse cuticular lipids dimerize in different combinations. Plant Cell 22:3066–3075
McFarlane HE, Watanabe Y, Yang W, Huang Y, Ohlrogge J, Samuels AL (2014) Golgi- and trans- Golgi network-mediated vesicle trafficking is required for wax secretion from epidermal cells. Plant Physiol 164(3):1250–1260
Mintz-Oron S, Mandel T, Rogachev I, Feldberg L, Lotan O, Yativ M, Wang Z, Jetter R, Venger I, Adato Aharoni A (2008) Gene expression and metabolism in tomato fruit surface tissues. Plant Physiol 147:823–851
Mizoi J, Shinozaki K, Yamaguchi-Shinozaki K (2012) AP2/ERF family transcription factors in plant abiotic stress responses. Biochim Biophys Acta 1819:86–96
Moitra K, Silverton L, Limpert K, Im K, Dean M (2011) Moving out: from sterol transport to drug resistance, the ABCG subfamily of efflux pumps. Drug Metabol Drug Interact 26:105–111
More P, Agarwal P, Joshi PS, Agarwal PK (2019) The JcWRKY tobacco transgenics showed improved photosynthetic efficiency and wax accumulation during salinity. Sci Rep 9:19617
Nadakuduti SS, Pollard M, Kosma DK, Allen JC, Ohlrogge JB, Barry CS (2012) Pleiotropic phenotypes of the sticky peel mutant provide new insight into the role of CUTIN DEFICIENT2 in epidermal cell function in tomato. Plant Physiol 159:945–960
Nakano T, Suzuki K, Fujimura T, Shinshi H (2006) Genome-wide analysis of the ERF gene family in Arabidopsis and rice. Plant Physiol 140:411–432
Navarro M, Ayax C, Martinez Y, Laur J, El Kayal W, Marque C, Teulières C (2011) Two EguCBF1 genes overexpressed in eucalyptus display a different impact on stress tolerance and plant development. Plant Biotechnol J 9:50–63
Nawrath C, Schreiber L, Franke RB, Geldner N, Reina-Pinto JJ, Kunst L (2013) Apoplastic diffusion barriers in Arabidopsis. Arabidopsis Book 11:e0167
Nguyen VNT, Lee SB, Suh MC, An G, Jung KH (2018) OsABCG9 is an important ABC transporter of cuticular wax deposition in rice. Front Plant Sci 9:960
Ohlrogge JB, Pollard MR, Stumpf PK (1978) Studies on biosynthesis of waxes by developing jojoba seed tissues. Lipids 13:203–210
Oshima Y, Mitsuda N (2013) The MIXTA-like transcription factor MYB16 is a major regulator of cuticle formation in vegetative organs. Plant Signal Behav 9:e26826
Oshima Y, Shikata M, Koyama T, Ohtsubo N, Mitsuda N, Ohme-Takagi M (2013) MIXTA-like transcription factors and WAX INDUCER1/SHINE1 coordinately regulate cuticle development in Arabidopsis and Torenia fournieri. Plant Cell 25:1609–1624
Panikashvili D, Shi JX, Schreiber L, Aharoni A (2011) The Arabidopsis ABCG13 transporter is required for flower cuticle secretion and patterning of the petal epidermis. New Phytol 190:113–124
Park CS, Go YS, Suh MC (2016) Cuticular wax biosynthesis is positively regulated by WRINKLED4, an AP2/ERF-type transcription factor, in Arabidopsis stems. Plant J 88(2):257–270
Pascal S, Bernard A, Sorel M, Pervent M, Vile D, Haslam RP, Napier JA, Lessire R, Domergue F, Joubès J (2013) The Arabidopsis cer26 mutant, like the cer2 mutant, is specifically affected in the very long-chain fatty acid elongation process. Plant J 73:733–746
Pighin JA, Zheng H, Balakshin LJ, Goodman IP, Western TL, Jetter R, Kunst L, Samuels AL (2004) Plant cuticular lipid export requires an ABC transporter. Science 306:702–704
Pollard M, Beisson F, Li Y, Ohlrogge JB (2008) Building lipid barriers: biosynthesis of cutin and suberin. Trends Plant Sci 13:236–246
Rashotte AM, Jenks MA, Nguyen TD, Feldmann KA (1997) Epicuticular wax variation in ecotypes of Arabidopsis thaliana. Phytochemistry 45(2):251–255
Richards RA, Rawson HM, Johnson DA (1986) Glaucousness in wheat: its development and effect on water use efficiency, gas exchange and photosynthetic tissue temperatures. Funct Plant Biol 13:465–473
Rowland O, Domergue F (2012) Plant fatty acyl reductases: enzymes generating fatty alcohols for protective layers with potential for industrial applications. Plant Sci 193–194:28–38
Rowland O, Zheng H, Hepworth SR, Lam P, Jetter R, Kunst L (2006) CER4 encodes an alcohol- forming fatty acyl-coenzyme a reductase involved in cuticular wax production in Arabidopsis. Plant Physiol 142:866–877
Rowland O, Lee R, Franke R, Schreiber L, Kunst L (2007) The CER3 wax biosynthetic gene from Arabidopsis thaliana is allelic to WAX2/YRE/FLP1. FEBS Lett 581:3538–3544
Sajeevan RS, Nataraja KN, Shivashankara KS, Pallavi N, Gurumurthy DS, Shivanna MB (2017a) Expression of Arabidopsis SHN1 in Indian mulberry (Morus indica L.) increases leaf surface wax content and reduces post-harvest water loss. Front Plant Sci 8:418
Sajeevan RS, Parvathi MS, Nataraja KN (2017b) Leaf wax trait in crops for drought and biotic stress tolerance: regulators of epicuticular wax synthesis and role of small RNAs. Indian J Plant Physiol 22:434–447
Sakuma Y, Liu Q, Dubouzet JG, Abe H, Shinozaki K, Yamaguchi-Shinozaki K (2002) DNA- binding specificity of the ERF/AP2 domain of Arabidopsis DREBs transcription factors involved in dehydration- and cold-inducible gene expression. Biochem Biophys Res Commun 290:998–1009
Sakuradani E, Zhao L, Haslam TM, Kunst L (2013) The CER22 gene required for the synthesis of cuticular wax alkanes in Arabidopsis thaliana is allelic to CER1. Planta 237:731–738
Samdur M, Manivel P, Jain VB, Chikani BM, Gor HK, Desai S, Misra JB (2003) Genotypic differences and water–deficit induced enhancement in epicuticular wax load in peanut. Crop Sci 43:1294–1299
Samuels L, DeBono A, Lam P, Wen M, Jetter R, Kunst L (2008) Use of Arabidopsis eceriferum mutants to explore plant cuticle biosynthesis. J Vis Exp 31:709
Seo PJ, Park CM (2011) Cuticular wax biosynthesis as a way of inducing drought resistance. Plant Signal Behav 6:1043–1045
Seo PJ, Xiang F, Qiao M, Park JY, Lee YN, Kim SG, Kim SG, Lee YH, Park WJ, Park CM (2009) The MYB96 transcription factor mediates abscisic acid signaling during drought stress response in Arabidopsis. Plant Physiol 151:275–289
Seo PJ, Lee SB, Suh MC, Park MJ, Go YS, Park CM (2011) The MYB96 transcription factor regulates cuticular wax biosynthesis under drought conditions in Arabidopsis. Plant Cell 23:1138–1152
Shi JX, Malitsky S, De Oliveira S, Branigan C, Franke RB, Schreiber L, Aharoni A (2011) SHINE transcription factors act redundantly to pattern the archetypal surface of Arabidopsis flower organs. PLoS Genet 7:e1001388
Shi JX, Adato A, Alkan N, He Y, Lashbrooke J, Matas AJ, Meir S, Malitsky S, Isaacson T, Prusky D, Leshkowitz D, Schreiber L, Granell AR, Widemann E, Grausem B, Pinot F, Rose JKC, Rogachev I, Rothan C, Aharoni A (2013) The tomato SlSHINE3 transcription factor regulates fruit cuticle formation and epidermal patterning. New Phytol 197:468–480
Skamnioti P, Gurr SJ (2007) Magnaporthe grisea cutinase2 mediates aspersorium differentiation and host penetration and is required for full virulence. Plant Cell 19:2674–2689
Srinivasan S, Gomez SM, Kumar SS, Ganesh SK, Biji KR, Senthil A, Ranganathan C (2008) QTLs linked to leaf epicuticular wax, physio-morphological and plant production traits under drought stress in rice (Oryza sativa L.). Plant Growth Regul 56:245–256
Taketa S, Amano S, Tsujino Y, Sato T, Saisho D, Kakeda K, Nomura M, Suzuki T, Matsumoto T, Sato K, Kanamori H, Kawasaki S, Takeda K (2008) Barley grain with adhering hulls is controlled by an ERF family transcription factor gene regulating a lipid biosynthesis pathway. Proc Natl Acad Sci U S A 105:4062–4067
Tillett RL, Wheatley MD, Tattersall EA, Schlauch KA, Cramer GR, Cushman JC (2012) The Vitis vinifera C-repeat binding protein 4 (VvCBF4) transcriptional factor enhances freezing tolerance in wine grape. Plant Biotechnol J 10(1):105–124
To A, Joubès J, Barthole G, Lécureuil A, Scagnelli A, Jasinski S, Lepiniec L, Baud S (2012) WRINKLED transcription factors orchestrate tissue-specific regulation of fatty acid biosynthesis in Arabidopsis. Plant Cell 24:5007–5023
Todd J, Post BD, Jaworski JG (1999) KCS1 encodes a fatty acid elongase 3-ketoacyl-CoA synthase affecting wax biosynthesis in Arabidopsis thaliana. Plant J 17:119–130
Wang Y, Wan L, Zhang L, Zhang Z, Zhang H, Quan R, Zhou S, Huang R (2012) An ethylene response factor OsWR1 responsive to drought stress transcriptionally activates wax synthesis related genes and increases wax production in rice. Plant Mol Biol 78:275–288
Wang X, Zhi P, Fan Q, Zhang M, Chang C (2019) Wheat CHD3 protein TaCHR729 regulates the cuticular wax biosynthesis required for stimulating germination of Blumeria graminis f. sp. tritici. J Exp Bot 70:701–713
Wang L, Xue W, Li X, Li J, Wu J, Xie L, Kawabata S, Li Y, Zhang Y (2020) EgMIXTA1, a MYB- type transcription factor, promotes cuticular wax formation in Eustoma grandiflorum leaves. Front Plant Sci 11:524947
Wellesen K, Durst F, Pinot F, Benveniste I, Nettesheim K, Wisman E, Steiner-Lange S, Saedler H, Yephremov A (2001) Functional analysis of the LACERATA gene of Arabidopsis provides evidence for different roles of fatty acid omega-hydroxylation in development. Proc Natl Acad Sci U S A 98:9694–9699
Weng H, Molina I, Shockey J, Browse J (2010) Organ fusion and defective cuticle function in a lacs1 lacs2 double mutant of Arabidopsis. Planta 231:1089–1100
Wu R, Li S, He S, Wassmann F, Yu C, Qin G, Schreiber L, Qu LJ, Gu H (2011) CFL1 a WW domain protein regulates cuticle development by modulating the function of HDG1 a class IV homeodomain transcription factor in rice and Arabidopsis. Plant Cell 23:3392–3411
Xu Z-S, Chen M, Li L-C, Ma YZ (2011) Functions and application of the AP2/ERF transcription factor family in crop improvement. J Integr Plant Biol 53(7):570–585
Xu Y, Wu H, Zhao M, Wu W, Xu Y, Gu D (2016) Overexpression of the transcription factors GmSHN1 and GmSHN9 differentially regulates wax and cutin biosynthesis, alters cuticle properties, and changes leaf phenotypes in Arabidopsis. Int J Mol Sci 17:587
Xue D, Zhang X, Lu X, Chen G, Chen Z-H (2017) Molecular and evolutionary mechanisms of cuticular wax for plant drought tolerance. Front Plant Sci 8:621
Yang J, Zhao X, Liang L, Xia Z, Lei L, Niu X, Zou C, Zhang KQ (2011) Overexpression of a cuticle-degrading protease Ver112 increases the nematicidal activity of Paecilomyces lilacinus. Appl Microbiol Biotechnol 89:1895–1903
Yang X, Zhao H, Kosma DK, Tomasi P, Dyer JM, Li R, Liu X, Wang Z, Parsons EP, Jenks MA, Lü S (2017) The acyl desaturase CER17 is involved in producing wax unsaturated primary alcohols and cutin monomers. Plant Physiol 173:1109–1124
Yang SU, Kim H, Kim RJ, Kim J, Suh MC (2020) AP2/DREB transcription factor RAP2.4 activates cuticular wax biosynthesis in Arabidopsis leaves under drought. Front. Plant Sci 11:895
Yeats TH, Rose JKC (2008) The biochemistry and biology of extracellular plant lipid-transfer proteins (LTPs). Protein Sci 17:191–198
Yephremov A, Wisman E, Huijser P, Huijser C, Wellesen K, Saedler H (1999) Characterization of the FIDDLE HEAD gene of Arabidopsis reveals a link between adhesion response and cell differentiation in the epidermis. Plant Cell 11:2187–2201
Zhang JY, Broeckling CD, Blancaflor EB, Sledge MK, Sumner LW, Wang ZY (2005) Overexpression of WXP1 a putative Medicago truncatula AP2 domain-containing transcription factor gene increases cuticular wax accumulation and enhances drought tolerance in transgenic alfalfa (Medicago sativa). Plant J 42:689–707
Zhang JY, Broeckling CD, Sumner LW, Wang ZY (2007) Heterologous expression of two Medicago truncatula putative ERF transcription factor genes WXP1 and WXP2 in Arabidopsis led to increased leaf wax accumulation and improved drought tolerance but differential response in freezing tolerance. Plant Mol Biol 64:265–278
Zhang J, Yang J, Yang Y, Luo J, Zheng X, Wen C, Xu Y (2019a) Transcription factor CsWIN1 regulates pericarp wax biosynthesis in cucumber grafted on pumpkin. Front Plant Sci 10:1564
Zhang YL, Zhang CL, Wang GL, Wang YX, Qi CH, You CX, Li YY, Hao YJ (2019b) Apple AP2/EREBP transcription factor MdSHINE2 confers drought resistance by regulating wax biosynthesis. Planta 249(5):1627–1643
Zhang YL, Zhang CL, Wang GL, Wang YX, Qi CH, Zhao Q, You CX, Li YY, Hao YJ (2019c) The R2R3 MYB transcription factor MdMYB30 modulates plant resistance against pathogens by regulating cuticular wax biosynthesis. BMC Plant Biol 19:362
Zheng H, Rowland O, Kunst L (2005) Disruptions of the Arabidopsis Enoyl–CoA reductase gene reveal an essential role for very–long–chain fatty acid synthesis in cell expansion during plant morphogenesis. Plant Cell 17:1467–1481
Zhu X, Xiong L (2013) Putative megaenzyme DWA1 plays essential roles in drought resistance by regulating stress-induced wax deposition in rice. Proc Natl Acad Sci U S A 110:17790–17795
Zhu L, Guo J, Zhu J, Zhou C (2014) Enhanced expression of EsWAX1 improves drought tolerance with increased accumulation of cuticular wax and ascorbic acid in transgenic Arabidopsis. Plant Physiol Biochem 75:24–35
Ziv C, Zhao Z, Gao YG, Xia Y (2018) Multifunctional roles of plant cuticle during plant-pathogen interactions. Front Plant Sci 9:1088
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2023 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
About this chapter
Cite this chapter
Sajeevan, R.S. (2023). Cuticular Waxes and Its Application in Crop Improvement. In: Harohalli Masthigowda, M., Gopalareddy, K., Khobra, R., Singh, G., Pratap Singh, G. (eds) Translating Physiological Tools to Augment Crop Breeding. Springer, Singapore. https://doi.org/10.1007/978-981-19-7498-4_7
Download citation
DOI: https://doi.org/10.1007/978-981-19-7498-4_7
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-19-7497-7
Online ISBN: 978-981-19-7498-4
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)