Hydrogen sulphide (H 2 S), a new gas signal molecule, participates in the regulation of various abiotic stresses in plants. However, how the tandem working of H 2 S and rhizobia affects the adaptation of soybean to water deficiency is still unclear. In this study, we investigated the adaptation mechanism of H 2 S and rhizobia in soybean to water deficiency. Our results revealed that H 2 S and rhizobia jointly enhanced the leaf

Background and aims NaHS, a donor of hydrogen sulfide (H2S), which is emerging as a potential signaling molecule, may regulate various physiological processes in plants. However, how soybean (Glycine max L.) responds to NaHS and rhizobia (Sinorhizobium fredii) inoculation remains unclear. Methods We explored the effects of NaHS and rhizobia on the growth rate, nodules, nitrogenase activities (NA), chlorophyll content, soluble protein content, photosynthesis (Pn), chlorophyll fluorescent parameters, endogenous H2S accumulation, l/d‐cysteine desulfhydrase (GmLCD and GmDCD) gene expression, nitrogen (N), phosphorus (P), potassium (K) contents, and nutrient resorption. Results The results showed that rhizobia significantly increased the shoot, root, total dry weight, and growth rate, and NaHS promoted nodule numbers and NA in soybean. Moreover, chlorophyll content, soluble protein content, Pn, endogenous H2S accumulation, and GmLCD and GmDCD gene expression levels were promoted by NaHS and rhizobia. In addition, during all growth stages of soybean, the levels of N, P, and K and the N:P ratio in different tissues were affected by NaHS and rhizobia. Additionally, NaHS and rhizobia also significantly enhanced N resorption efficiency (NRE) and K resorption efficiency (KRE), but decreased P resorption efficiency (PRE). Conclusion Therefore, NaHS and rhizobia regulated the growth rate, nutrient stoichiometry, and nutrient resorption efficiency of soybean. These findings provide information that will be useful for predicting how NaHS and rhizobia lead to variations in nutrient uptake and nutrient conservation strategies.

AimHydrogen sulphide (H 2 S), as a signaling molecule, modulate the process of plant growth and development. H 2 S is involved in the establishment of legume and rhizobia symbiosis relationship, but little is known about the role of H 2 S during nodule senescence. MethodWe study the function of H 2 S during nodule senescence in Glycine max-Sinorhizobium fredii symbiotic system. Physiological and biochemical method were conducted to modulate the nitrogen xation, nodule structure, symbiotic and senescence related protein and gene expression. ResultsOur results indicated that exogenous H 2 S decreased the senesced nodules number, increased nitrogenease (Nase) activity, and promoted the accumulation of NO 3 --N, NH 4 + -N, and total N, which caused the accumulation of biomass in the late steps of symbiosis. H 2 S alleviated nodule senescence by maintaining nodule normal nitrogen xation structure. Meanwhile, the expression abundances of NifH and NodGS proteins were enhanced by H 2 S during nodule senescence. Moreover, H 2 S simulated the expression of symbiosis and nitrogen metabolism related genes in nodules. Finally, senescence related genes expression abundances were regulated by H 2 S during nodule senescence. ConclusionThese ndings suggested that H 2 S prolonged the lifespan of N 2 xation by delaying nodule senescence and, which will be important to the increase of soybean yield and agricultural sustainability development.

Aim Hydrogen sulphide (H2S), as a signaling molecule, modulate the process of plant growth and development. H2S is involved in the establishment of legume and rhizobia symbiosis relationship, but little is known about the role of H2S during nodule senescence. Method We study the function of H2S during nodule senescence in Glycine max-Sinorhizobium fredii symbiotic system. Physiological and biochemical method were conducted to modulate the nitrogen fixation, nodule structure, symbiotic and senescence related protein and gene expression. Results Our results indicated that exogenous H2S decreased the senesced nodules number, increased nitrogenease (Nase) activity, and promoted the accumulation of NO3--N, NH4+-N, and total N, which caused the accumulation of biomass in the late steps of symbiosis. H2S alleviated nodule senescence by maintaining nodule normal nitrogen fixation structure. Meanwhile, the expression abundances of NifH and NodGS proteins were enhanced by H2S during nodule senescence. Moreover, H2S simulated the expression of symbiosis and nitrogen metabolism related genes in nodules. Finally, senescence related genes expression abundances were regulated by H2S during nodule senescence. ConclusionThese findings suggested that H2S prolonged the lifespan of N2 fixation by delaying nodule senescence and, which will be important to the increase of soybean yield and agricultural sustainability development.