Selenium Inhibits Root Elongation by Repressing the Generation of Endogenous Hydrogen Sulfide in Brassica rapa

摘要: Selenium (Se) has been becoming an emerging pollutant causing severe phytotoxicity, which the biochemical mechanism is rarely known. Although hydrogen sulfide (H2S) suggested as important exogenous regulator modulating plant physiological adaptions in response to heavy metal stress, whether and how endogenous H2S regulates Se-induce phytotoxicity remains unclear. In this work, a self-developed specific fluorescent probe (WSP-1) was applied track situ roots of Brassica rapa under Se(IV) stress. Se(IV)-induced root growth stunt closely correlated with inhibition generation tips. stress dampened expression most LCD DCD homologues B. rapa. By using various probes for bio-imaging tips situ, we found that increase by application donor NaHS could significantly alleviate reactive oxygen species (ROS) over-accumulation, oxidative impairment, cell death tips, further resulted recovery However, dampening block alleviated effect on phytotoxicity. Finally, enhancement glutathione (GSH) Se(IV)-treated roots, may share similar molecular dominant role removing ROS activating GSH biosynthesis mammals. Altogether, these data provide first direct evidences confirming pivotal roots.