Hydrogen peroxide mediates spermidine-induced autophagy to alleviate salt stress in cucumber
Hydrogen peroxide mediates spermidine-induced autophagy to alleviate salt stress in cucumber
复制标题
过氧化氢介导亚精胺诱导的自噬减轻黄瓜盐胁迫
DOI：
10.1080/15548627.2020.1847797
复制
发表时间：
2020-11-29
期刊：
影响因子：
13.3
通讯作者：
Guo, Shirong
中科院分区：
文献类型：
--
作者：
Zhang, Yuemei;Wang, Yu;Guo, Shirong
自噬是一种进化上保守的细胞降解过程，在植物发育和应激反应中发挥着关键作用。尽管有大量关于自噬在应对环境压力中的重要作用的信息，但人们对自噬的调节知之甚少。在本研究中，我们证明亚精胺（Spd）是一种多胺，在盐胁迫下通过激活黄瓜自噬相关基因的表达和自噬体的形成来参与耐盐性的调节。此外，NADPH 氧化酶衍生的质外体 H2O2 介导的 Spd 诱导的耐盐性和自噬。外源Spd显着提高对盐胁迫的耐受性并抑制不溶性蛋白的积累和泛素化。叶面喷施Spd可促进ATG基因的转录水平和自噬体的形成。此外，Spd 还诱导 RBOH（呼吸爆发氧化酶同源物）的表达以及叶和根中 H2O2 的积累。然而，用二甲基硫脲（DMTU，一种 H2O2 清除剂）或二亚苯基碘鎓氯化物（DPI，一种 NADPH 氧化酶抑制剂）进行预处理都会减少 Spd 诱导的质外体 H2O2 的积累。重要的是，当植物用 DMTU 或 DPI 预处理时，Spd 诱导的耐盐性和自噬会受到损害。此外，ATG4 和 ATG7 的沉默降低了 Spd 诱导的耐盐性和自噬体形成。综上所述，这些结果表明，RBOH 依赖性 H2O2 介导了 Spd 诱导的黄瓜自噬和耐盐性。
Autophagy, an evolutionally conserved cellular degradation process, plays critical roles in plant development and stress response. Despite the wealth of information on the vital role of autophagy in responses to environmental stresses, little is known about the regulation of autophagy. In this study, we demonstrated that spermidine (Spd), a kind of polyamine, was involved in the regulation of salt tolerance through activating the expression of ATG (autophagy-related) genes and the formation of autophagosomes in cucumber under salt stress. Furthermore, NADPH oxidase-derived apoplastic H2O2-mediated Spd-induced salt tolerance and autophagy. Exogenous Spd significantly increased the tolerance to salt stress and inhibited the accumulation and ubiquitination of insoluble proteins. Foliar application of Spd promoted the transcript levels of ATG genes and autophagosomes formation. Besides, Spd induced the expression of RBOH (respiratory burst oxidase homolog), and the accumulation of H2O2 both in leaves and roots. However, either pretreatment with dimethylthiourea (DMTU, an H2O2 scavenger) or diphenyleneiodonium chloride (DPI, an inhibitor of NADPH oxidase) reduced Spd-induced accumulation of apoplastic H2O2. Importantly, Spd-induced salt tolerance and autophagy were compromised when plants were pretreated with DMTU or DPI. Furthermore, the silencing of ATG4 and ATG7 reduced Spd-induced salt tolerance and autophagosomes formation. Taken together, these results revealed that RBOH-dependent H2O2 mediated the Spd-induced autophagy and salt tolerance in cucumber.