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硫化氢(hydrogen sulfide,H_2S)是一种新型气体信号分子,钙离子(calcium,Ca~(2+))为重要的第二信使,两者在调控植物生长发育及多种逆境胁迫中分别起着重要作用。然而,H_2S和Ca~(2+)信号在调控植物耐冷性中的作用关系并不十分清楚。本研究针对以上问题以‘津优35号’黄瓜为试材进行研究,结果表明,低温胁迫可诱导H_2S信号的产生,且这种信号可被外源Ca~(2+)增强;低温胁迫可诱导Ca~(2+)信号转导相关基因CaM、CIPK5的mRNA表达,且外源H_2S能够上调低温下CaM、CIPK5的表达量;进一步研究发现,外源H_2S和Ca~(2+)可显著增强植株的抗氧化能力,减少活性氧积累,从而降低低温胁迫对黄瓜幼苗的损伤,且加入Ca~(2+)螯合剂乙二醇二乙醚二胺四乙酸(ethylene glycol tetraacetic acid,EGTA)或钙调素拮抗剂氯丙嗪(chlorpromazine,CPZ)后,H_2S对黄瓜幼苗抗氧化能力的促进效应明显减弱,同样的,H_2S清除剂次牛磺酸(hypotaurine,HT)也会降低Ca~(2+)的作用。以上结果表明H_2S与Ca~(2+)信号间存在着复杂的联系,而且他们可以通过相互作用调控黄瓜幼苗的抗氧化系统,从而增强植株耐冷性。
Hydrogen sulfide (H 2 S) is a new type of gas signaling molecule, and calcium (Ca 2+) is an important second messenger. Both of them play important roles in the regulation of plant growth and development and under various stress conditions An important role. However, the role of H 2 S and Ca 2+ signals in the regulation of cold tolerance in plants is not well understood. In this study, ’Jinyou 35’ cucumber was used to study the above problems. The results showed that low temperature stress induced the production of H2S signal, and this signal could be enhanced by exogenous Ca2 +. Low temperature stress could Induced the mRNA expression of Ca 2+ and CIPK5 in Ca 2+ -induced signal transduction, and exogenous H 2 S up-regulated the expression of CaM and CIPK5 at low temperature. Further study showed that exogenous H 2 S and Ca 2+ could be significantly increased Enhances the antioxidant capacity of plants and reduces the accumulation of reactive oxygen species, thereby reducing the damage of cucumber seedlings under low temperature stress, and adding Ca 2+ chelating agent ethylene glycol tetraacetic acid (EGTA) or The effect of H 2 S on the antioxidant capacity of cucumber seedlings was significantly weakened by chlorpromazine (CPZ), and H 2 S scavenger hypotaurine (HT) also decreased the content of Ca 2 +) Role. The above results indicate that there is a complex relationship between H2S and Ca2 + signals, and they can regulate the antioxidant system of cucumber seedlings through interaction, thereby enhancing the plant chilling tolerance.