Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress

摘要: Nitric oxide (NO) and 5-aminolevulinic acid (ALA) are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, role NO in ALA-induced antioxidant defense leaves two sources Elymus nutans Griseb. (Damxung, DX Zhengdao, ZD) was investigated. Chilling stress enhanced electrolyte leakage, accumulation malondialdehyde (MDA), hydrogen peroxide (H2O2) superoxide radical E. nutans, which were substantially alleviated exogenous ALA application. Pretreatment with scavenger PTIO or NOS inhibitor L-NNA alone combination induced enhancements leakage MDA, H2O2 ZD exposed chilling stress, indicating that inhibition biosynthesis reduced resistance ALA-enhanced resistance. Further analyses showed activated plasma membrane (PM) H+-ATPase decreased ROS stress. A pronounced increase nitric synthase (NOS) activity release treatment found chilling-resistant while only a little observed chilling-sensitive ZD. Furthermore, blocked protective effect ALA, endogenous did not induce production. These results suggested might be downstream signal mediating nutans.