Two cDNAs coding for putative phosphoinositide-specific phospholipase C (PI
-PLC, EC 3.1.4.3) from cowpea leaves (Vigna unguiculata L. Walp) were clone
d and characterized. These cDNAs designated VuPLC1 and VuPLC2 belong to the
delta-type PI-PLCs and revealed deduced amino acid homology of 66 %. North
ern blot analysis of mRNA from leaves of two V. unguiculata cultivars diffe
ring in their sensitivity to drought (drought-sensitive, 1183, and drought-
tolerant, EPACE-1) showed that VuPLC1 transcript level decreased under prog
ressive water stress in the two cultivars, whereas VuPLC2 gene expression i
s stimulated up to -1.5 MPa only in the tolerant cultivar. These results su
ggest different physiological roles for the two genes and demonstrate diffe
rential behaviour of one PI-PLC gene expression in two cultivars belonging
to the same species. (C) 2001 Editions scientifiques et medicales Elsevier
SAS.