Effects of sodium hydrosulfide and rhizobia on the growth rate, nutrient stoichiometry, and nutrient resorption of soybean (Glycine max L.)

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.