Hydrogen sulfide partly mediates abscisic acid-induced heat tolerance in tobacco (Nicotiana tabacum L.) suspension cultured cells

摘要

Abscisic acid (ABA), a plant hormone, plays crucial roles in plant growth, development and response to environmental stress. Recently, hydrogen sulfide (H2S) also has emerged similar functions, but interaction between ABA and H2S in the acquisition of heat tolerance is not clear. In this study, pretreatment of tobacco suspension cultured cells with ABA improved the survival percentage and regrowth ability, alleviated a decrease in cell vitality, increase in malondialdehyde content and electrolyte leakage of cells under heat stress, suggesting that ABA pretreatment could improve the heat tolerance of tobacco cells. In addition, treatment with ABA induced the accumulation of endogenous H2S in both tobacco cells and culture medium, increased the activity of l-cysteine desulfhydrase, a key enzyme in H2S biosynthesis. Also, ABA-induced heat tolerance was enhanced by addition of NaHS, a H2S donor, but weakened by dl-propargylglycine (specific inhibitor of H2S biosynthesis) and hypotaurine (H2S scavenger) respectively. These results suggest that ABA pretreatment could improve the heat tolerance of tobacco suspension cultured cells, and H2S, at least partly, mediated the acquisition of heat tolerance induced by ABA.