Effect of H2S and rhizobia on the number of
soybean nodules, endogenous H2S content and nitrogenase
activity under water deficiency condition
Soybean nodules numbers were prominently enhanced by Q8 and Q8+NaHS
treatments under MW condition compared with NW and SW conditions,
whereas no significant difference was observed between Q8 and Q8+NaHS
treatments under MW and SW condition (Fig. 2A, B). Interestingly, the
increase in the nodules number did not lead to enhance the root nodule
biomass. On the contrary, under MW condition plant treated with Q8
exhibited a 49.9% loss of nodules biomass compared with the NW
condition, and the MW condition plant treated with Q8+NaHS exhibited a
44.2% loss of nodules biomass compared with the NW condition (Fig. 2C).
In addition, the endogenous H2S content of the nodule
was reduced by Q8 and NaHS+Q8 treatments with the decrease of water
content. Under SW condition, the endogenous H2S content
of the nodule was observably higher by Q8+NaHS treatment than Q8
treatment, but it was no apparent difference between the NW and MW
conditions (Fig. 2D). Additionally, the nitrogenase activities were
reduced by Q8 and Q8+NaHS treatments with the decrease of water content,
similar to the changes of nodule endogenous H2S (Fig.
2E), but there was a slight enhancement of the nitrogenase activity by
Q8+NaHS treatment under the three water conditions compared with Q8
treatment.