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We recently reported that H 2S could significantly promote the germination of wheat grains subjected to aluminum (Al(3+)) stress.1 In these experiments seeds were pretreated with the H 2S donor NaHS for 12 h prior to Al(3+) stress. During this pre-incubation period we observed that H2S increased the activity of grain amylase in the absence of Al(3+). Using embryoless half grains of wheat we now show that H2S preferentially affects the activity of endosperm β-amylase and that α-amylase synthesis and activity is unaffected by this treatment.

Abstract: We report the effects of hydrogen sulfide (H2S) on flower senescence in various species of cut flowers. H2S was found to delay flower opening and senescence in cut flowers and branches from Erigeron annuus (L.), Euonymus maackii Rupr., Hibiscus syriacus L., Liriope spicata (Thump.), Loropetalum chinense (R. Br.), Punica granatum L., Rosa chinensis Jacq., and Salix matsudana Koidz. Cut explants of these plants were cultured in solution containing different concentrations of the H2S donor, NaHS. H2S donor treatment prolonged the vase time of cut flowers and prevented senescence in a dose-dependent manner. We measured the levels of malondialdehyde (MDA) as an indicator of oxidative damage to cells and showed that it was inversely related to endogenous H2S concentration in explants. Flowers that had senesced showed higher levels of MDA and lower amounts of H2S. Furthermore, NaHS treatment increased the activities of catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and guaiacol peroxidase (POD), and sustained much lower levels of H2O2 and O2 − in cut flowers of E. annuus and explant leaves of S. matsudana. The present study implies that H2S is involved in improving longevity of cut flowers and functions in activity of antioxidant enzymes in plants. [Copyright &y& Elsevier]