CHARACTERIZATION OF 2 CDNAS FOR NOVEL DROUGHT-INDUCIBLE GENES IN THE HIGHLY DROUGHT-TOLERANT COWPEA

Ten cDNAs for drought-inducible genes were isolated using differential screening of a cDNA library prepared from 10-hr dehydrated cowpea pla nts, Vigna unguiculata (S. luchi, K. Yamaguchi-Shinozaki, T. Urao, T. Terao, K. Shinozaki; Plant Cell Physiology, 1996 in press). Two of the cDNA clones, designated CPRD12 and CPRD46, were sequenced and charact erized. The CPRD12 and CPRD46 cDNAs encode putative proteins related t o nonmetallo-short-chain alcohol dehydrogenase (CPRD12) and chloroplas tic lipoxygenase (CPRD46). Northern blot analysis revealed that these genes are induced by high-salinity stress and exogenous abscisic acid, but not by cold stress. The CPRD46 gene is also responsive to heat st ress and methyl jasmonate and salicylic acid. Genomic Southern blot an alysis suggested that CPRD12 constitutes a small gene family, but that CPRD46 is a single copy gene. We discuss the possible functions of th ese two CPRD gene products under drought stress.