Hydrogen sulfide and rhizobia synergistically regulate nitrogen (N) assimilation and remobilization during N deficiency‐induced senescence in soybean

Hydrogen sulfide (H 2 S) is emerging as an important signalling molecule that regulates plant growth and abiotic stress responses. However, the roles of H 2 S in symbiotic nitrogen (N) assimilation and remobilization have not been characterized. Therefore, we examined how H 2 S influences the soybean ( Glycine max )/rhizobia interaction in terms of symbiotic N fixation and mobilization during N deficiency‐induced senescence. H 2 S enhanced biomass accumulation and delayed leaf senescence through effects on nodule numbers, leaf chlorophyll contents, leaf N resorption efficiency, and the N contents in different tissues. Moreover, grain numbers and yield were regulated by H 2 S and rhizobia, together with N accumulation in the organs, and N use efficiency. The synergistic effects of H 2 S and rhizobia were also demonstrated by effects on the enzyme activities, protein abundances, and gene expressions associated with N metabolism, and senescence‐associated genes ( SAG s) expression in soybeans grown under conditions of N deficiency. Taken together, these results show that H 2 S and rhizobia accelerate N assimilation and remobilization by regulation of the expression of SAG s during N deficiency‐induced senescence. Thus, H 2 S enhances the vegetative and reproductive growth of soybean, presumably through interactions with rhizobia under conditions of N deficiency.