Endogenous hydrogen sulfide enhances salt tolerance by coupling the reestablishment of redox homeostasis and preventing salt-induced K+ loss in seedlings of Medicago sativa
Endogenous hydrogen sulfide enhances salt tolerance by coupling the reestablishment of redox homeostasis and preventing salt-induced K+ loss in seedlings of Medicago sativa
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DOI：
10.1016/j.plantsci.2014.06.006
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发表时间：
2014-08-01
期刊：
影响因子：
5.2
通讯作者：
Xie, Yanjie
中科院分区：
文献类型：
--
作者：
Lai, Diwen;Mao, Yu;Xie, Yanjie
尽管外用硫化氢（H2S）赋予植物对各种环境信号的耐受性，但l -半胱氨酸脱硫酶（L-DES）相关的内源性H2S产生参与盐胁迫信号传导的生理意义尚不清楚。为了解决这一空白，研究了植物中H2S稳态的变化与苜蓿耐盐性的关系。随着NaCl浓度的增加（从50 ~ 300 mM）， L-DES总活性逐渐升高，内源H2S产量增加。H2S供体氢硫化钠（NaHS; 100 μ M）可减轻nacl引发的毒性症状（175 mM），包括幼苗生长抑制和脂质过氧化，而L-DES抑制剂或H2S清除剂则会加重毒性症状。低剂量或高剂量的NaHS反应较弱或阴性。进一步的研究结果表明，内源性l- des相关的H2S可以调节多种抗氧化防御酶的基因/活性，并调节抗氧化化合物的含量，从而抵消nacl诱导的脂质过氧化。H2S通过阻止nacl引发的K+外排来维持K+/Na+稳态，这可能是SKOR表达受损的结果。综上所述，我们的研究结果表明，内源H2S稳态通过耦合重新建立氧化还原平衡和抑制K+外排来增强苜蓿幼苗的耐盐性。2014爱思唯尔爱尔兰有限公司版权所有。
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 mu M), 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. (C) 2014 Elsevier Ireland Ltd. All rights reserved.