Characterization of a stress-induced, developmentally regulated gene family from soybean.

We describe a family of stress-induced, developmentally regulated soybean genes for which cDNAs have been obtained from two different cultivars (Glycine max cv. Mandarin and Glycine max cv. Williams). The mRNAs corresponding to these cDNAs, called SAM22 and H4, respectively, accumulate predominantly in the roots of soybean seedlings but are present at high levels in the roots and leaves of mature plants. SAM22 accumulation is especially dramatic in senescent leaves. In addition, SAM22 accumulation can be induced on young leaves by wounding or by transpiration-mediated uptake of salicylic acid, methyl viologen, fungal elicitor, hydrogen peroxide or sodium phosphate (pH 6.9). Taken together, these data indicate that the genes corresponding to SAM22 and H4 are induced by various stresses and developmental cues. Southern blot analysis indicates that multiple copies of sequences related to SAM22 exist in the soybean genome. We also show that the nucleotide sequences of the cDNAs corresponding to SAM22 and H4 are 86% identical at the nucleotide level to each other and 70% identical at the amino acid level to the 'disease resistance response proteins' of Pisum sativum.