Hydrogen Sulfide Signal Enhances Drought Resistance by Regulating RuBisCo in Arabidopsis thaliana

Hydrogen sulfide (H2S), as a gasotransmitter, was reported to be involved in the induced stomatal closure and enhanced photosynthesis, which were contradictory physiological processes in plants. In order to explore the potential mechanism underlying this process, the model plant Arabidopsis thaliana wild type (WT) and mutant defective in the gene encoding H2S-producing enzyme (lcd/des1) were used as experimental materials to study the effect of H2S signal on non-stomatal factors under drought stress. The results showed that in the presence of exogenous physiological concentrations of H2S, stomatal conductance (Gs) decreased, intercellular carbon dioxide concentration (Ci) decreased significantly, while net photosynthetic rate (Pn) increased significantly in lcd/ des1 mutant. Under drought stress, compared with WT, Gs in lcd/des1 increased and Pn decreased significantly. In particular, after the treatment of exogenous H2S under drought conditions, the expression levels of RuBisCo (the key enzyme in the calvin cycle of photosynthesis) coding genes in lcd/des1 were up-regulated and the activity of RuBisCo was significantly improved. In summary, H2S can increase Pn by regulating the transcriptional expression of RuBisCo, which is one of the non-stomatal factors, and increasing its carboxylation activity, so that the plants under drought stress maintain high-efficiency photosynthesis during the stomatal closure.

CSTR: 32200.14.cjcb.2019.10.0009