Nucleotide sequence of a cDNA from Atriplex canescens (Pursh.) Nutt. A homolog of a jasmonate-induced protein from barley.

The alteration in gene expression that occurs in plants subjected to water shortage has been documented extensively (Skriver and Mundy, 19901, and gene cloning and sequencing has shed some light on the molecular processes that may protect cells from the harmful effects of osmotic stress (Bray, 1991, 1993). Since plant hormones such as ABA and jasmonate are in some cases capable of causing expression of water stress-related genes under non-stress conditions, these hormones have been implicated as mediators of environmental cues (Bray, 1991; Sembdner and Parthier, 1993; Reinbothe et al., 1994). Promoter analysis has succeeded in identifying motifs important for gene induction (Mundy et al., 1990; Michel et al., 1993; Yamaguchi-Shinozaki and Shinozaki, 1994), and the activities of some of the cognate DNA-binding proteins have been shown to be modulated by hormones (Mundy et al., 1990; Nelson et al., 1994). Most work to date, however, has been carried out with glycophytes whose growth range, with respect to water potential, is limited. A study of halophytic plants subject to perennial drought and extremes of climate may provide important insight into plant growth under stress. Such plants have been suggested as sources of unique genes or novel genetic mechanisms that might be applied in the genetic engineering of crop plants. As the incidence of drought increases and the areas of land designated as arid or semi-arid expand, a study of halophytic plants becomes increasingly pertinent. We have isolated a number cDNA clones of water deficitinducible genes from the hardy desert shrub Atviplex canescens (Saltbush). A cDNA library was constructed from RNA isolated from a plant growing under water deficit (-0.9 MPa). The library was differentially screened and apparent inducible clones were isolated (Adair et al., 1992) (Table I). The putative polypeptide encoded by one of these clones, pS10-2, shows strong homology to a major jas-