Molecular cloning of glutathione reductase cDNAs and analysis of GR gene expression in cowpea and common bean leaves during recovery from moderate drought stress.
Two cDNAs of the enzyme glutathione reductase (GR; EC 1.6.4.2) encoding a dual-targeted isoform (dtGR) and a cytosolic isoform (cGR), were cloned from leaves of common bean (Phaseolus vulgaris L.). Moderate drought stress (Psi w=-1.5MPa) followed by re-watering was applied to common bean cultivars, one tolerant to drought (IPA), the other susceptible (Carioca) and to cowpea (Vigna unguiculata L. Walp) cultivars, one tolerant to drought (EPACE-1), and the other susceptible (1183). mRNA levels were much higher for PvcGR than for PvdtGR in all cases. Moderate drought stress induced an up-regulation of the expression of PvcGR in the susceptible cultivars. On the contrary, PvdtGR expression decreased. In the tolerant cowpea EPACE-1, GR gene expression remained stable under drought. During recovery from drought, an up-regulation of the two GR isoforms occurred, with a peak at 6-10h after re-hydration. This suggests that moderate drought stress may lead to a hardening process and acclimation tolerance. The role of GR isoforms in plant tolerance and capacity to recover from drought stress is discussed.
Torres-Franklin
Maria Lucia
ML
Laboratoire d'Ecophysiologie Moléculaire, UMR-IRD 137 BioSol, Université Paris 12, 61 Avenue du Général de Gaulle, 94010 Créteil Cedex, France.
Contour-Ansel
Dominique
D
Zuily-Fodil
Yasmine
Y
Pham-Thi
Anh-Thu
AT
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004190:Disasters; D007887:Fabaceae / Q000201:enzymology / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005980:Glutathione Reductase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000201:enzymology / Q000235:genetics; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D010940:Plant Proteins; D005980:Glutathione Reductase