Interactions between hydrogen sulfide and rhizobia modulate the
physiology and metabolism during water deficiency-induced oxidative
defense in soybean
Abstract
Hydrogen sulphide (H2S), as a new gas signal molecule, participates in
the regulation of a variety of abiotic stresses in plants. However, it
was unclear how H2S and rhizobia can together to affect the adaptation
of soybean to water deficiency. Here, the adaptation mechanism of H2S
and rhizobia in soybean to water deficiency was studied. Our results
showed that H2S and rhizobia jointly enhanced leaf chlorophyll content,
the relative water content (RWC) and caused an increase biomass in
soybean under water deficiency. Besides, under water deficiency, H2S
enhanced biomass by affecting nodule numbers and nitrogenase activity
during the growth of soybean. The expression of soybean nodulation
marker genes including early nodulin 40 (GmENOD40), ERF required for
nodulation (GmERN), and nodulation inception genes were up-regulated by
H2S and rhizobia in nodules. Moreover, the combined effect of H2S and
rhizobia were proved to affect the enzyme activities and gene expression
level of antioxidant, as well as osmotic protective substance under
water deficiency. In addition, the metabolomics results provided that
the changes of lipids and lipid-like molecules were remarkably promoted
by the combined effect of H2S and rhizobia. Thus, H2S and rhizobia
synergistically subsided the oxidative damage by increasing the
accumulation of metabolites and strengthening the antioxidant capacity
under water deficiency.