Nitric oxide (NO) and hydrogen sulfide (H2S) Play Different Roles in Plant Response to Selenium (Se) Stress—the New Mechanisms of Se-induced Phytotoxicity Revealed by Chen’s Lab in IFQS
Selenium (Se) is an essential and beneficial micronutrient for crops, but Se is suggested as an emerging pollutant in agricultural environment because of the increasing anthropogenic release of Se. Until now, the detailed mechanism of Se-induced phytotoxicity is largely unknown. The research group of Jian Chen has just found that two important gasotransmitters (NO and H2S) in plants played vital roles in regulating the adaption of Brassica rapa under Se stress.
Se(IV) induces faster accumulation of NO than ROS in the roots of B. rapa. Both NO and ROS accumulation are positively correlated with Se(IV)-induced growth retardation. The expression analysis combined with pharmacological experiments suggest that NO mediates Se(IV)-induced oxidative injury by differentially regulating a set of Rbohs (respiratory burst oxidative homologues) in a genome wide. This study uncovered a new toxic role of NO, which is pretty different from the previous reports that NO always play the protective role in plants under environmental stresses. The results has been published online in PLoS ONE on Oct. 21, 2014, which can be accessed at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0110901.
Additionally, they also find that Se(IV)-induced root growth stunt is closely correlated with the inhibition of endogenous H2S generation in root tips. The genomic screening reveals the extensive down-regulation of LCDs and DCDs induced by Se(IV) stress. Enhancing endogenous H2S can remarkably rescue Se(IV)-induced phytotoxicty by stimulating the biosynthesis of glutathione (GSH) in root cells, which share the similar mechanism of H2S signaling in mammalian cells. This study provides the direct evidence for the protective role of H2S against Se(IV) stress. These results has been published online in PLoS ONE on Oct. 21, 2014, which can be accessed at