外源微生物缓解甘薯锑胁迫的效果研究OA

Antimony(Sb)is a metalloid with high mobility and biological toxicity,and its accumulation in farmland soils of mining areas poses a serious threat to crop growth.In this study,a pot experiment was conducted with the sweet potato variety'Yanshu 2'to investigate the effects of Sb at different concentrations on the photosynthetic physiology and antioxidant characteristics of sweet potato plants.Furthermore,the alleviating effects of Bacillus subtilis and soil microbial communities from tin-mining areas in Lengshuijiang City on Sb stress were explored.The results showed that with the increase in Sb concentration,the chlorophyll content decreased.The net photosynthetic rate,transpiration rate,and stomatal conductance first increased and then decreased,while the intercellular CO2 concentration showed the opposite trend,first decreasing and then increasing.These findings indicated that high Sb stress disrupted the stability of the photosynthetic system and inhibited photosynthesis.The activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)generally exhibited a trend of first increasing and then decreasing with the increase in Sd concentration,whereas the malondialdehyde(MDA)content increased under moderate to high Sb stress,which suggested that Sb stress induced oxidative damage.Exogenous microorganisms significantly improved photosynthetic performance and enhanced antioxidant defense under low to moderate Sb stress.Among them,B.subtilis showed a more pronounced in improving photosynthetic capacity and reducing membrane lipid peroxidation,while the soil microbial community performed wew ehhancing in maintaining antioxidant enzyme activities.However,under high Sb stress,the alleviating effects of both B.subtilis and the soil microbial community on Sb stress in sweet potato plants were limited.