Hydrogen peroxide is involved in hydrogen sulfide-induced carbon assimilation and photoprotection in cucumber seedlings
Hydrogen peroxide is involved in hydrogen sulfide-induced carbon assimilation and photoprotection in cucumber seedlings
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DOI：
10.1016/j.envexpbot.2020.104052
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发表时间：
2020-07-01
影响因子：
5.7
通讯作者：
Ai, Xizhen
中科院分区：
文献类型：
--
作者：
Liu, Fengjiao;Fu, Xin;Ai, Xizhen
硫化氢 (H2S) 和过氧化氢 (H2O2) 是参与各种生理过程和非生物胁迫的两种重要的气体信号分子。然而，H2S和H2O2如何协同调节光合作用却鲜有研究。本研究旨在揭示植物光合作用反应中 H2S 和 H2O2 相互作用的机制。以黄瓜（Cucumis sativus L.，'金优35'）幼苗为材料，在26℃/18℃、光子通量密度（PFD）为600μmol m(-2).s(-1)的气候室中生长。水合硫氢化钠（NaHS，H2S供体）、H2O2及其清除剂或抑制剂在二叶苗期叶面喷施。结果表明，NaHS和H2O2均增加了CO2同化，这主要归因于光合酶活性和基因表达的增加。 NaHS 和 H2O2 还通过在冷胁迫下激活 D1 蛋白修复途径，诱导黄瓜幼苗光系统 II (PSII) 和光系统 I (PSI) 的光保护。有趣的是，1.0 mM NaHS 显着增强了呼吸爆发氧化酶同源物 (RBOH) 的相对基因表达，进而增加了黄瓜幼苗内源 H2O2 的积累。然而，H2O2对L-/D-半胱氨酸脱硫酶(L-/D-CD)基因表达和内源H2S水平影响不大。二亚苯基碘鎓（DPI，一种 H2O2 生成抑制剂）或二甲基硫脲（DMTU，一种 H2O2 清除剂）可抑制 H2S 诱导的光合作用对冷胁迫的适应性反应。这些数据表明，NaHS通过改善光合碳同化、碳代谢以及对黄瓜幼苗PSII和PSI的光保护来减轻冷胁迫对光合作用的负面影响。 H2O2 可能作为 H2S 诱导的寒冷胁迫下黄瓜幼苗光合机构保护的下游信号。
Hydrogen sulfide (H2S) and Hydrogen peroxide (H2O2) are two crucial gaseous signaling molecules that participate in various physiological processes and abiotic stresses. However, how the synergy of H2S and H2O2 regulates photosynthesis have rarely been studied. This study aimed to reveal the mechanism underlying the interaction between H2S and H2O2 in plants response to photosynthesis. Cucumber (Cucumis sativus L., 'Jinyou 35') seedlings were used as the material and grown in a climate chamber at 26 degrees C/18 degrees C with a 600 mu mol m(-2).s(-1) photon flux density (PFD). Sodium hydrosulfide hydrate (NaHS, an H2S donor), H2O2, and their scavengers or inhibitors were applied as foliar sprayed at the two-leaf seedling stage. The result showed that both NaHS and H2O2 increased the CO2 assimilation, which mainly attributed to an increase in the activity and gene expression of photosynthetic enzymes. NaHS and H2O2 also induced photoprotection for both photosystem II (PSII) and photosystem I (PSI) in cucumber seedlings, by activating the D1 protein repair pathway under chilling stress. Interestingly, 1.0 mM NaHS significantly enhanced the relative gene expression of respiratory burst oxidase homolog (RBOH), which in turn elevated endogenous H2O2 accumulation in cucumber seedlings. However, H2O2 had little effect on gene expression of L-/D-cysteine desulfhydrase (L-/D-CD) and endogenous H2S level. The H2S-induced adaptive response of photosynthesis to chilling stress was suppressed by diphenyleneiodonium (DPI, a H2O2 generation inhibitor) or dimethylthiourea (DMTU, a H2O2 scavenger). These data suggest that NaHS alleviates the negative effects of chilling stress on photosynthesis by improving photosynthetic carbon assimilation, carbon metabolism, and photoprotection for both PSII and PSI in cucumber seedlings. H2O2 may act as a downstream signal in H2S-induced protection of the photosynthetic apparatus in cucumber seedlings under chilling stress.