Putrescine metabolism modulates the biphasic effects of brassinosteroids on canola and Arabidopsis salt tolerance
Putrescine metabolism modulates the biphasic effects of brassinosteroids on canola and Arabidopsis salt tolerance
复制标题
腐胺代谢调节油菜素类固醇对双低油菜籽和拟南芥耐盐性的双相作用
DOI：
10.1111/pce.13757
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发表时间：
2020-06-01
影响因子：
7.3
通讯作者：
Zheng, Qingsong
中科院分区：
文献类型：
--
作者：
Liu, Jinlong;Yang, Rongchen;Zheng, Qingsong
已知类维生素C（BR）可提高植物的耐盐性，但并非在所有情况下。一定浓度的24-表油菜素内酯（EBL）可以提高油菜对高盐胁迫的耐性，但在低盐胁迫下，相同浓度的EBL对油菜的耐性不利。我们将这种现象定义为激素应激水平依赖性双相（SLDB）效应。EBL提高油菜耐盐性的SLDB效应与H2 O2积累密切相关，H2 O2积累受多胺代谢，特别是腐胺（Put）氧化的调节。低盐胁迫下EBL对油菜的抑制作用可以通过抑制Put生物合成或二胺氧化酶活性来减轻，从而减少H2 O2的产生。BRI 1和BAK 1的bri 1 -9、bak 1、bes 1-D和bzr 1 -1D突变体及过表达系的遗传和表型结果表明，BR信号的适当增强有利于植物抵抗盐胁迫，而过度增强与缺乏一样有害。这些结果突出了BR信号和Put代谢之间的串扰参与H2 O2积累，这是BR在植物耐盐性中的双重作用的基础。
Brassinosteroids (BRs) are known to improve salt tolerance of plants, but not in all situations. Here, we show that a certain concentration of 24-epibrassinolide (EBL), an active BR, can promote the tolerance of canola under high-salt stress, but the same concentration is disadvantageous under low-salt stress. We define this phenomenon as hormonal stress-level-dependent biphasic (SLDB) effects. The SLDB effects of EBL on salt tolerance in canola are closely related to H2O2 accumulation, which is regulated by polyamine metabolism, especially putrescine (Put) oxidation. The inhibition of EBL on canola under low-salt stress can be ameliorated by repressing Put biosynthesis or diamine oxidase activity to reduce H2O2 production. Genetic and phenotypic results of bri1-9, bak1, bes1-D, and bzr1-1D mutants and overexpression lines of BRI1 and BAK1 in Arabidopsis indicate that a proper enhancement of BR signaling benefits plants in countering salt stress, whereas excessive enhancement is just as harmful as a deficiency. These results highlight the involvement of crosstalk between BR signaling and Put metabolism in H2O2 accumulation, which underlies the dual role of BR in plant salt tolerance.