Keywords

19.1 Introduction

Plant nutrition deficiency is an important limiting aspect for plant growth and productivity after drought and salinity (Rajemahadik et al. 2018). The plant requires nutrients for their growth and development and absorbs most mineral nutrients present in the soil through their roots. However, to compensate the deficiency of nutrients, fertilizers are applied to the soil for healthy development of plants (Baloch et al. 2008; Bernal et al. 2007). Plants require seventeen elements for their growth and development out of which 14 are essential nutrients required. Among these essential nutrients, six are macronutrients that required in large amounts viz. calcium (Ca), potassium (K), magnesium (Mg), nitrogen (N), phosphorus (P), and sulfur (S) (Maathuis 2009). The micronutrients viz. chloride (Cl), copper (Cu), manganese (Mn), iron (Fe), zinc (Zn), cobalt (Co), molybdenum (Mo), and nickel (Ni) are required in a small amount (Marschner 2012; Zeng 2014). The nutrition deficiency found in commercially available economic crops influence human health, especially the people that belong to the rural areas, but the sustainable approach of nanotechnology diminishing these challenges.

During past few decades, biotechnological approach used for bioremediation or phytoremediation to restore agro-chemically damaged soils (Ghormade et al. 2011) to raise the use of nutrient efficiency in crops and to inhibit mineral losses. Several research studies revealed that plants grow by adapting a specific mechanism to uptake their required level and acclimate variation of nutrient availability (Ohkama-Ohtsu and Wasaki 2010; Schachtman and Shin 2007). Several strategies have attempted to provide protection and nutrition to the plants. The plant growth was hampered by two causes, the lack of micronutrients or either the pore size of roots is so small that it is unable to uptake and translocate the nutrients inside the plant. Therefore, it is essential to get better nutrient uptake competency strategies to enhance the quality and production of the crop (Elemike et al. 2019). The required necessities of nutrients in plants are provided by the fertilizers, with the certainty that minerals could be absorbed from the soil. The widespread contributions of biotechnology from conventional breeding to improve crop nutrient efficiency have been made through the molecular technique approach, but these achievements are limited (Ashraf et al. 2011). The transporters and enzymes efficiently involve in nutrient absorption and are necessary for acquiring elevated nutrient uptake, and it directly affect the status of crop yield. In an instance, the accumulation of nitrogen in shoot and grains of wheat plants increased by the over-expression of the glutamine synthetase gene (GS1) (Hu et al. 2018), while in maize plants the number of kernels enhanced by the over-expression of GS13 (Martin et al. 2006). The transgenic rice plants required a high amount of nitrogen for growth, OsAMT1 efficiently working as ammonium transporter function in elevating the nutrient uptake efficiency under optimal as well as suboptimal nitrogen conditions (Ranathunge et al. 2014). However, these approaches are inadequate and it is necessary to resolve the limited approach of biotechnology by involving the application of nanotechnology towards agriculture (Ghormade et al. 2011). The main purpose of the application of nanomaterial in agriculture is to overcome nutrient stress, pest control, reduce the effect of hazardous chemicals and crop protection as shown in Fig. 19.1 (Thakur et al. 2018).

Fig. 19.1
figure 1

Schematic representation of application of nanobiotechnology in agriculture for better crop productivity (Fig constructed by Saima Amjad)

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The ongoing application of nanobiotechnology provides an opportunity to overcome the mineral nutrient stress in plants. The engineered nanoparticles hold an immense promise in the growing use of nanofertilizers, which utilize competence along with growing agriculture production.

19.2 Sustainable Approach of Nanobiotechnology in Agriculture

Nanotechnology is the upcoming innovatory technology after biotechnology revolution. It has an extensive application in various disciplines such as electronics, optics, pharmaceuticals, agriculture, and the environment. In the last few decades, it is growing with time and become a significant application in agriculture (Chhipa 2017). Nanotechnology can be used to design, develop and synthesize minerals in nanoform and this application gives considerable assurance for agricultural crop productivity (Baruah and Dutta 2009; Kuzma 2007; Navrotsky 2000). It is the procedure to design, develop and synthesize nanomaterials to represents an area holding considerable assurance for agricultural field in the form of nanofertilizers (Baruah and Dutta 2009; Kuzma 2007; Navrotsky 2000). Nanotechnologies using next generation of pesticides and fertilizers in agriculture by using functionalize nanomaterial and nanoparticle. It also minimizes the loss of pesticides and fertilizers by controlled and targeted delivery through nanocarriers (Ghormade et al. 2011; Joseph and Morrison 2006; Khot et al. 2012; Nair et al. 2010; Robinson and Morrison 2009; Scott and Chen 2013). The plant protection material (nanopesticides) and nutrients (nanofertilizers) have advanced properties because of their unique physical, chemical and rapidly dispersible properties of nanoparticles, which also enhanced the uptake of nutrition in the plant (Ghormade et al. 2011). There are several wide varieties of materials used to synthesize nanoparticles are magnetic materials, metal oxides, semiconductors, quantum dots, lipids, ceramics, polymers (synthetic or natural), emulsions and dendrimers (Puoci et al. 2008). However, the limitation of conventional fertilizers is that it does not contain all the required nutrients for plant augmentation and development. Therefore, it becomes an interesting venture for nanofertilizers that can address nutrient deficiency and environmental issues related with fertilizers (Dimkpa and Bindraban 2017). Sustainable and productive crop management can also be achieved by using an important tool of foliar fertilization in nanotechnology. The present knowledge of the factors, which influence the efficacy of foliar applications, may be determined by the art of nanotechnology (Eichert et al. 2008; Mortvedt 1992; Millán et al. 2008; Pandey et al. 2010; Roco 2011).

Leaching and loss of harmful substances have also reduced by using the encapsulated nanominerals, it plays a vital role in environmental protection (Zheng et al. 2005). The other accomplishment of nanobiotechnology is to develop nano-carriers for smart delivery systems and nanosensors, which are broadly used to assess environmental pollution in soil and water system of the agricultural field. Several sensors already developed on the concept of nano-detection to detect the traces of heavy metals such as electrochemical sensors, optical sensors, biosensors and so on (Handforda et al. 2015; Ion et al. 2010; Parisi et al. 2014). Nanobiotechnology is also being explored to improve crop productivity in plant reproduction through hereditary transfection (Prasad et al. 2014; Torney et al. 2007). It offers a new set of devices to develop a genetically based tool using nanocapsules, nanofibers and nanoparticles (Gutiérrez et al. 2011 and Nair et al. 2010). A Chitosan nanoparticle has versatile properties and emerged as a valuable carrier for genetic transfer of material; it can be modified by PEGylated to control the transfer of genetic material (Kashyap et al. 2015).

19.3 Strategies to Improve Plant Nutrient Uptake by Nanobiotechnology

The nanobiotechnology plays a noteworthy role in the plant production through the controlled release of mineral nutrients (Gruère 2012; Mukhopadhyay 2014). Nanoparticles or nanominerals size lies between 1−100 nm and different from their corresponding parental materials, which produce both useful and harmful biological effects in a living cell (Nel et al. 2006). Fertilizer nanoparticles are also known as magic bullets which enhance crop productivity to deal with global food problems (Bhatt et al. 2020). Several research studies reported the toxicological interaction of engineered nanoparticles on plants even though these studies implicated the exposure of nanoparticles in a certain specific situation with a short period of time at high doses. On the contrary, very few studies paying attention on the favorable impact of nanoparticles on plant development and productivity. Furthermore, a mineral nanoparticle integrated into conventional fertilizers and pesticides to increase the production, also reduces the chance of diseases and improves nutritional augmentation (Elmer and White 2018; Prasad et al. 2017). The potential benefits of nanotechnology can understand by application of some mineral nanoparticles on plants and analyze the mechanism of transport and nutrient uptake. The mechanism of some nanoparticles in nutrient stress has given in Table 19.1 to understand the function of mineral nanoparticles in plants.

Table 19.1 Nanomineral nutrients and their application on different type of crops and their effect on plant growth and physiology
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19.3.1 Calcium Nanoparticles

The calcium in the nanoforms was more effective compared to the chelated form; it improves plant growth and production (Liu et al. 2005). Effect of calcium carbonate nanoparticles have studied on Arachis hypogeae, L. it showed that the nano form of calcium enhanced branch number and increased 15% weight (fresh and dry) of plants (Liu et al. 2004; Tantawy et al. 2014). Liu et al. (2005) have reported a study that showed improvement in the physiological process for instance chlorophyll content of tomato plant increased by the effect of nano calcium. Biomimetic calcium phosphate nanoparticles with the composition of potassium (K) and nitrogen (N, as nitrate and urea) was used as a multinutrient nanofertilizear (nano U-NPK) for the cultivation of Triticum durum Desf. The result showed the application of the slow-release nano U-NPK were a promising strategy towards increasing the competency of the fertilization, and yields of grains were obtained, and the additional advantage of using a much lower N amount (a decline of 40 wt%) (Ramírez-Rodrígu et al. 2020). Zea mays L. crop has been treated with calcium phosphate nanoparticles (CaPNPs) along with Piriformospora indica and Glomus mosseaec which promote plant growth efficiency, root enhancement, and improved vitality properties (Rane et al. 2015).

19.3.2 Cerium Oxide Nanoparticles

Zhao et al. (2014) conducted a study on cucumber (Cucumis sativus L.) plants grown in soil treated with Cerium Oxide (CeO2) nanoparticles. The results indicated that CeO2NPs influenced the fruit flavor decreased the antioxidant capacity and increased starch and globulin content. It considerably enhanced the uptake of Mg2+ ion, which is a vital constituent of the chlorophyll molecule. It also decreased the uptake of molybdenum (Mo) concentration and altered the non-reducing sugars, phenolic content and changed the protein fractionation.

19.3.3 Copper Nanoparticles

Copper (Cu) metal is an important micronutrient required for plants enzymatic activity, which functions as a regulatory co-factor or catalyst for a large number of enzymes or acts as a functional structural. Adhikari et al. (2016) investigated the effect of copper oxide (CuO) nanoparticles (< 50 nm) on the development, bioaccumulation and enzymatic action of maize (Zea mays L.) plant. The experimental studies showed the easy assimilation of CuO nanoparticles through plant cells and increase the growth of maize by regulating the different enzyme activities. The glucose-6-phosphate dehydrogenase enzymatic activity was extremely influenced by copper oxide (CuO) nanoparticles and affected the pentose phosphate pathway in maize plants. Hafeez et al. (2015) have studied the effect of the concentration-dependent copper nanoparticles (CuNPs) on Millat-2011 (Triticum aestivum L.) crop which significantly enhanced growth and yield of the plant, chlorophyll content, leaf area, fresh and dry weight, and root dry weight. Similarly, the exposure of biogenic CuNPs (20 ppm) on pigeon pea (Cajanus cajan L.) plant was evaluated which enhances growth such as height, root length, fresh, and dry weights and seedlings of the plant (Shende et al. 2017).

19.3.4 Hydroxyapatite Nanoparticles

Urea based nitrogen fertilizers viz. Urea-coated zeolite chips and hydroxyapatite has been used in nanoparticle form as a source of nitrogen (N) to study the controlled release of N for a long duration of time (Kottegoda et al. 2011; Millán et al. 2008). Similarly, hydroxyapatite (Ca5(PO4)3OH) nanoparticles have a significant impact on seed yield of Glycine max (L.) Merr., 20% and 33% increment in seed yield as compared with conventional phosphorus treated plant (Liu and Lal 2014).

19.3.5 Iron Oxide Nanoparticles

Delfani et al. (2014) analyzed the iron nanoparticles (FeNPs) effect on blacked eyed pea plants which not only improved the pods number per plant but also enhanced the weight of seeds and improved the chlorophyll biosynthesis. FeNPs enhanced the seed protein content by 2% compared to Fe. In another study comparative effect of iron oxide nanoparticles (Fe2O3NPs) and a chelated-Fe fertilizer (ethylenediaminetetraaceticacid-Fe; EDTA-Fe) were studied on the development and growth of Arachis hypogaea L. plant. The obtained results showed Fe2O3NPs enhanced root length, biomass, and Soil Plant Analysis Development (SPAD) chlorophyll meter values of peanut (Arachis hypogaea L.) plants. It also regulated phytohormone contents and antioxidant enzyme activity which promote plant growth (Rui et al. 2016). Also, in Glycine max (L.) Merr. plant chlorophyll content was enhanced by superparamagnetic iron oxide nanoparticles (SPIONs) without any phytotoxicity. Additionally, the physicochemical characteristics of SPIONs had an essential role in sub-apical leaves of soybean for an increment of chlorophyll content (Ghafariyan et al. 2013). Kokina et al. (2020) studied the exposure of different sizes of iron oxide nanoparticles (FeONPs) on yellow medick (Medicago falcata L.) plants. The observed results indicated a significant increase in chlorophyll α fluorescence, plant root length, induced genotoxicity, and reduced genome stability compared to the control plant. Moreover, enhanced miR159c expression indicated enhanced plant resistance against fungal pathogens.

19.3.6 Manganese Nanoparticles

Manganese (Mn) micronutrient is primarily essential for the photosynthesis process in plants. Pradhan et al. (2013) observed the effect of manganese nanoparticles (MnNPs) on leguminous plant Vigna radiate (L.) R. Wilczek at a specific concentration as compared to conventionally available manganese salt, MnSO4 under laboratory conditions. The higher concentration of MnNP had not induced phytotoxicity to the plant and the size of MnNP possibly helped plants to uptake these nanoparticles more easily and translocated itself in the leaves using xylem. The MnNPs treated chloroplasts increased the function of CP43 protein in the reaction center of photosystem II (PS II) and had shown higher photophosphorylation, where oxygen was generated by water molecule splitting and also enhanced the electron transport chain.

Manganese hollow core shell nanoparticles have used for the controlled and targeted release of zinc (Zn) to the plant (Oryza sativa L.) soil. The result indicated that the nano-sized manganese hollow core shell enhances and improve Zn uptake by rice plant and reduce the loss of nutrients (Yuvaraj and Subramanian 2015).

19.3.7 Magnesium Nanoparticles

Magnesium nanoparticles (MgNPs) used as an alternate of Mg in the Vigna unguiculata (L.) Walp. plant, which enhanced the seed weight and yield (Delfani et al. 2014). Further, a study was conducted by Rathore and Tarafdar (2015), on the controlled delivery of magnesium nanoparticles (MgNPs) to wheat plants. The foliar application of MgNPs on plant increased the light absorption on the leaf surface and it also improved different enzyme activities which resulted in the enhanced mobilization of nutrients (Fe, Cu, Zn, P, and Mg) uptake. It also significantly improved the wheat plant root length and biomass. Magnesium oxide nanoparticles (MgONPs) (15 nm) enhanced seed germination and growth rate mechanism in Arachis hypogaea L. at 0.5 mg/L concentrations by penetrating seeds coat and internally support water retention in seeds which increased biomass production for the plant (Jhansi et al. 2017).

19.3.8 Molybdenum Nanoparticles

The colloidal solution of molybdenum nanoparticles (MoNPs) enhances plant resistance and also increased crops productivity due to the active uptake of nanoparticle into the plant cells. The experimental studies showed when the Cicer arietinum L. seeds were treated with MoNPs (colloidal solution) it enhanced the formation of nodule per plant by four fold as compared to control (Taran et al. 2014). Thomas et al. have also studied (2017), the effect of MoNPs (2–7 nm) on Cicer arietinum L. plant at 4 ppm concentration. The results showed a significant improvement in the root area, diameter, length, perimeter, and tips number. It also enhanced microbial activities and useful enzymes along with increased biomass and grain yield.

19.3.9 Silicon Nanoparticles

Silicon nanoparticles (SiNPs) application has used for Basil plant to reduce the pollution caused by salinity (Ocimum basilicum L.). SiNPs significantly increased the chlorophyll and reduced proline content in basil (Kalteh et al. 2018). Tripathi et al. 2015 studied the shielding effect of SiNP for Pisum sativum L. against chromium Cr(VI) phytotoxicity. The results showed that SiNPs reduced the accumulation of Cr in roots and shoots and enhances the intake of mineral nutrients which possess antioxidant activity and also reduces the ROS level. According to the study of Ali et al. (2019) SiNPs have the ability to restrain the accumulation of cadmium (Cd) concentrations in Triticum aestivum L. grain and other parts of the plant. Moreover, SiNPs improved the development, photosynthesis and also reduced the oxidative stress of wheat grain and in future, it can also be used as a fertilizer for controlling metal accumulation in crop plants.

19.3.10 Titanium Dioxide Nanoparticles

The comparative study of nano-TiO2 and TiO2 was investigated on the enlargement and germination of naturally-aged spinach seed (Spinacia oleracea L.) (Zheng et al. 2005). The experimental studies indicated that at a certain concentration nano-TiO2 treated spinach seed enhances the germination of the aged seeds. The 30 days nano-TiO2 effect on spinach plants showed a 73% increase in dry weight, improves the chlorophyll formation up to 45% and enhances the photosynthetic rate three times as compared to the control during the germination stage. This effect of the development rate of spinach seeds was inversely proportional to the size of TiO2 signifying, smaller the nanoparticle different the germination growth. Furthermore, the researcher defines the possibility of entry of nano-TiO2 into cells those have increased oxidation–reduction reactions via the superoxide ion radical during germination in the dark and resulted in the quenching of free radicals during the germination of seeds,which also increased the photosynthetic rate. Effect of TiO2NP on coriander plant (Coriandrum sativum L.) at concentration dependent manner improved the nutritional quality, enhanced root and shoot fresh biomass (Hu et al. 2020).

19.3.11 Zinc Nanoparticles

Zinc oxide nanoparticles (ZnONPs) have been used in industry for the last many years. Zn is the most important vital micronutrient that is mandatory to enhance the crop productivity. Prasad et al. (2012) investigated the effect of Zn micronutrient into peanut seeds through ZnONPs (25 nm mean particle size). It improves the uptake of Zn through leaf and kernel and a high content of Zn was found in the seed and increase chlorophyll amount in leaf. These nanoparticles proved helpful in enhancing stem and root growth (Prasad et al. 2012). Lin and Xing (2007), reported ZnONPs significantly adhered to the root surface and enter inside the plant cell through penetration and found in the apoplast and protoplast of the root endodermis and stele. Rawashdeh et al. (2020) studied effect of two different concentrations of ZnONPs (25 ppm or 50 ppm) on Lettuce seeds (Lactuca sativa L.). The obtained results showed enhanced seed germination, and biomass of seeds due to stimulated catalase enzyme activity.

19.4 Conclusion and Prospects

The sustainable agriculture, nutrient safety, and food accessibility are included the key sustainable development objectives to cope the crop nutrient deficiency. Hence, it is necessary to exploit the benefits of nanotechnology in reaching the feat by enhancing plant nutrient accessibility and reducing their losses on agricultural field. Nanobiotechnology application plays a notable role in agriculture to manage nutrient deficiency stress for crop management which is necessary for sustainable agriculture. It could be significantly enhanced nutritional health and sanitation of crops simultaneously, improved food security and sustainability in the coming times. Nanobiotechnology has a multidirectional approach therefore, it is necessary to exploit the benefits of its application in reaching the feat by enhancing plant nutrient accessibility and reducing their losses on the agricultural field. Previous studies indicated that the mineral nanoparticles are beneficial for plant growth efficiency, root enhancement, chlorophyll content, uptake of mineral, regulation of phytohormone contents and antioxidant enzyme activity, enhanced gene expression, and seed development. Additionally, it is also beneficial for inhibition of accumulation of heavy metals concentration inside the plants. Although the obtained results are limited to the experimental level, therefore it is necessary to introduce the application of nanofertilizer in the nursery stage to proceed towards a large-scale agriculture field. More scientific research studies required to analyze the environmental risks of nanoparticles to encourage the safe development of nanofertilizer. Hence, nanotechnology is a promising sector to provide commercialized nanofertilizers for better crop productivity and soon that will be available in the market.