title: Endogenous hydrogen sulfide enhances salt tolerance by coupling the reestablishment of redox homeostasis and preventing salt-induced K⁺ loss in seedlings of Medicago sativa.
abstract: Despite the external application of hydrogen sulfide (H2S) conferring plant tolerance against various environmental cues, the physiological significance of l-cysteine desulfhydrase (L-DES)-associated endogenous H2S production involved in salt-stress signaling was poorly understood. To address this gap, the participation of in planta changes of H2S homeostasis involved in alfalfa salt tolerance was investigated. The increasing concentration of NaCl (from 50 to 300 mM) progressively caused the induction of total l-DES activity and the increase of endogenous H2S production. NaCl-triggered toxicity symptoms (175 mM), including seedling growth inhibition and lipid peroxidation, were alleviated by sodium hydrosulfide (NaHS; 100 μM), a H2S donor, whereas aggravated by an inhibitor of l-DES or a H2S scavenger. A weaker or negative response was observed in lower or higher dose of NaHS. Further results showed that endogenous l-DES-related H2S modulated several genes/activities of antioxidant defence enzymes, and also regulated the contents of antioxidant compounds, thus counterbalancing the NaCl-induced lipid peroxidation. Moreover, H2S maintained K(+)/Na(+) homeostasis by preventing the NaCl-triggered K(+) efflux, which might be result form the impairment of SKOR expression. Together, our findings indicated that endogenous H2S homeostasis enhance salt tolerance by coupling the reestablishment of redox balance and restraining K(+) efflux in alfalfa seedlings.
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Diwen
authors.initials: D
authors.lastname: Lai
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Mao
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China.
authors.forename: Mingzhu
authors.initials: M
authors.lastname: Wu
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Ziyi
authors.initials: Z
authors.lastname: He
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Weiti
authors.initials: W
authors.lastname: Cui
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: yjxie@njau.edu.cn.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Xie
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D003542:Cystathionine gamma-Lyase / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D006706:Homeostasis; D006862:Hydrogen Sulfide / Q000378:metabolism*; D015227:Lipid Peroxidation; D000455:Medicago sativa / Q000254:growth & development / Q000378:metabolism*; D010084:Oxidation-Reduction; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism; D055049:Salt Tolerance; D036226:Seedlings / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000009:adverse effects* / Q000378:metabolism; D013312:Stress, Physiological; D013440:Sulfides / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D015221:Potassium Channels; D013440:Sulfides; D012965:Sodium Chloride; D012964:Sodium; D003542:Cystathionine gamma-Lyase; C025451:sodium bisulfide; D011188:Potassium; D006862:Hydrogen Sulfide
keywords: Hydrogen sulfide; Medicago sativa; Oxidative damage; Potassium efflux; Redox homeostasis; Salt tolerance