bHLH13 Regulates Jasmonate-Mediated Defense Responses and Growth
bHLH13 Regulates Jasmonate-Mediated Defense Responses and Growth
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bHLH13 调节茉莉酸介导的防御反应和生长
DOI：
10.1177/1176934318790265
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发表时间：
2018-07-23
影响因子：
2.6
通讯作者：
Song, Susheng
中科院分区：
文献类型：
--
作者：
Huang, Huang;Gao, Hua;Song, Susheng
茉莉酸（JAs）调节植物生长和防御反应。在感知生物活性JA时，JA受体CORONATINE INSENSITIVE 1（COI 1）招募JA ZIM结构域（JAZ）蛋白进行降解，并释放JAZ靶向转录因子以调节JA反应。亚群IIId bHLH转录因子，包括bHLH 17、bHLH 13、bHLH 3和bHLH 14，与JAZ相互作用并抑制JA反应。在这项研究中，我们表明，IIId bHLH因子通过C-末端在酵母中形成二聚体。bHLH 13的N端是其转录抑制功能所必需的。bHLH 13过表达抑制拟南芥对灰葡萄孢的抗性和对甜菜夜蛾的防御。COI 1突变破坏了四重突变体bhlh 3 bhlh 13 bhlh 14 bhlh 17在各种JA反应中的过度敏感性，包括花青素积累、根生长抑制以及对B cinerea和甜菜夜蛾的防御。TTG 1/bHLH/MYB复合物的破坏阻断了bhlh 3 bhlh 13 bhlh 14 bhlh 17的花青素苷积累，而MYC 2的废除减弱了bhlh 3 bhlh 13 bhlh 14 bhlh 17的JA抑制性根生长。这些结果从遗传学上证明，IIId bHLH因子在COI 1下游发挥作用，通过拮抗不同的转录激活因子来抑制独特的JA反应。
Jasmonates (JAs) regulate plant growth and defense responses. On perception of bioactive JAs, the JA receptor CORONATINE INSENSITIVE1 (COI1) recruits JA ZIM-domain (JAZ) proteins for degradation, and JAZ-targeted transcription factors are released to regulate JA responses. The subgroup IIId bHLH transcriptional factors, including bHLH17, bHLH13, bHLH3, and bHLH14, interact with JAZs and repress JA responses. In this study, we show that IIId bHLH factors form dimers via the C-terminus in yeast. N-terminus of bHLH13 is essential for its transcriptional repression function. bHLH13 overexpression inhibits Arabidopsis resistance to the necrotrophic fungi Botrytis cinerea and defense against the insect Spodoptera exigua. COI1 mutation disrupts the oversensitivity of the quadruple mutant bhlh3 bhlh13 bhlh14 bhlh17 in various JA responses, including anthocyanin accumulation, root growth inhibition, and defense against B cinerea and S exigua. Disruption of the TTG1/bHLH/MYB complex blocks anthocyanin accumulation of bhlh3 bhlh13 bhlh14 bhlh17, whereas abolishment of MYC2 attenuates JA-inhibitory root growth of bhlh3 bhlh13 bhlh14 bhlh17. These results genetically demonstrate that IIId bHLH factors function downstream of COI1 to inhibit distinctive JA responses via antagonizing different transcriptional activators.