Involvement of CDSP 32, a drought-induced thioredoxin, in the response to oxidative stress in potato plants

In animal cells, yeast and bacteria, thioredoxins are known to participate in the response to oxidative stress. We recently identified a novel type of plant thioredoxin named CDSP 32 for chloroplastic drought-induced stress p rotein of 32 kDa, In the present work, we measured comparable increases in the glutathione oxidation ratio and in the level of chlorophyll thermolumin escence, a specific marker for thylakoid lipid peroxidation in Solanum tube rosum plants subjected to drought or oxidative treatments (photooxidative s tress, gamma irradiation and methyl viologen spraying). Further, substantia l accumulations of CDSP 32 mRNA and protein were revealed upon oxidative tr eatments. These data show for the first time in plants the induction of a t hioredoxin by oxidative stress. We conclude that CDSP 32 may preserve chlor oplastic structures against oxidative injury upon drought. (C) 2000 Federat ion of European Biochemical Societies.