Regulation of the rab17 Gene in Aba-Deficient and Aba-Insensitive viviparous Mutants of Maize

Abstract

Previous studies on the regulation of gene expression during embryogenesis in Zea mays L. have shown that a group of stagespecific mRNAs and proteins which accumulate in late embryogenesis are induced precociously in immature embryos when abscisic acid (ABA) is supplied in the culture medium (Sanchez- Martinez et al. 1986, Goday et al 1988). Abscisic acid (ABA) is supposed to mediate a large number of physiological and developmental processes in plants such as embryo maturation, seed dormancy and the response of plants to osmotic stress (for a review see Zeevaart and Creelman 1988). The response of the plant cells to ABA include modulation of specific mRNAs and proteins in embryo and vegetative tissues (Quatrano et al. 1986, Gomez et al 1988, Mundy et al. 1988). Although the molecular basis of the effect of ABA on gene expression has been the subject of numerous studies, to date little progress has been made in the elucidation of the intermediates in the ABA signal transduction pathway.