Biotic and abiotic stress can induce cystatin expression in chestnut

A cysteine proteinase inhibitor (cystatin) from chestnut (Castanca sativa) seeds, designated CsC, has been previously characterized. Its antifungal, a caricide and inhibitory activities have allowed to involve CsC in defence m echanisms. The CsC transcription levels decreased during seed maturation an d increased throughout germination, an opposite behavior to that shown by m ost phytocystatins. So inhibition of endogenous proteinase activity by puri fied CsC was found during the seed maturation or germination processes. CsC message accumulation was induced in chestnut leaves after fungal infection , as well as by wounding and jasmonic acid treatment, Induction in roots wa s also observed by the last tno treatments. Furthermore, CsC transcript lev els strongly raised, both in roots and leaves, when chestnut plantlets were subjected to cold- and saline-shocks, and also in roots by heat stress. Al l together, these data suggest that chestnut cystatin is not only involved in defence responses to pests and pathogen invasion, but also in those rela ted to abiotic stress. (C) 2000 Federation of European Biochemical Societie s.