BAK1 plays contrasting roles in regulating abscisic acid-induced stomatal closure and abscisic acid-inhibited primary root growth in Arabidopsis
BAK1 plays contrasting roles in regulating abscisic acid-induced stomatal closure and abscisic acid-inhibited primary root growth in Arabidopsis
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BAK1 在调节拟南芥脱落酸诱导的气孔关闭和脱落酸抑制初生根生长方面发挥着截然不同的作用
DOI：
10.1111/jipb.13257
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发表时间：
2022-05-31
影响因子：
11.4
通讯作者：
Gong, Zhizhong
中科院分区：
文献类型：
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作者：
Deng, Jinping;Kong, Lingyao;Gong, Zhizhong
平衡植物生长和胁迫反应的机制知之甚少，但它们似乎涉及蛋白激酶介导的脱落酸（阿坝）信号传导。在这里，为了探索这些机制，我们研究了拟南芥蛋白激酶突变体阿坝处理的反应。我们发现，突变体的油菜甾醇不敏感1相关受体激酶1（BAK 1）是超敏感的阿坝对种子萌发和初生根生长的影响。阿坝对bak 1突变体的气孔开放激酶1（OST 1）的激活作用强于野生型。BAK 1在显性失活突变体abi 1 -1或pyr 1 pyl 4 pyl 5 pyl 8四重突变体中不被阿坝处理激活，但在abi 1 -2 abi 2 -2 hab 1 -1功能丧失三重突变体中比野生型被ABA处理更高度激活。BAK 1磷酸化OST 1 T146并抑制其活性。遗传分析表明，BAK 1的行为或阿坝信号通路的核心组件，包括PYLs，PP 2Cs，和SnRK 2的上游，在种子萌发和初生根生长。虽然上游油菜素类固醇（BR）信号组分BAK 1和BR不敏感1（BRI 1）正调控ABA诱导的气孔关闭，影响BR信号下游组分的突变，包括油菜素类固醇信号激酶（BSKs）和油菜素类固醇不敏感2（BIN 2），不影响ABA介导的气孔运动。因此，我们的研究揭示了BAK 1在种子萌发和初生根生长过程中负调节阿坝信号，但正调节ABA诱导的气孔关闭，从而优化植物生长在干旱胁迫下的重要作用。
The mechanisms that balance plant growth and stress responses are poorly understood, but they appear to involve abscisic acid (ABA) signaling mediated by protein kinases. Here, to explore these mechanisms, we examined the responses of Arabidopsis thaliana protein kinase mutants to ABA treatment. We found that mutants of BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) were hypersensitive to the effects of ABA on both seed germination and primary root growth. The kinase OPEN STOMATA 1 (OST1) was more highly activated by ABA in bak1 mutant than the wild type. BAK1 was not activated by ABA treatment in the dominant negative mutant abi1-1 or the pyr1 pyl4 pyl5 pyl8 quadruple mutant, but it was more highly activated by this treatment in the abi1-2 abi2-2 hab1-1 loss-of-function triple mutant than the wild type. BAK1 phosphorylates OST1 T146 and inhibits its activity. Genetic analyses suggested that BAK1 acts at or upstream of core components in the ABA signaling pathway, including PYLs, PP2Cs, and SnRK2s, during seed germination and primary root growth. Although the upstream brassinosteroid (BR) signaling components BAK1 and BR INSENSITIVE 1 (BRI1) positively regulate ABA-induced stomatal closure, mutations affecting downstream components of BR signaling, including BRASSINOSTEROID-SIGNALING KINASEs (BSKs) and BRASSINOSTEROID-INSENSITIVE 2 (BIN2), did not affect ABA-mediated stomatal movement. Thus, our study uncovered an important role of BAK1 in negatively regulating ABA signaling during seed germination and primary root growth, but positively modulating ABA-induced stomatal closure, thus optimizing the plant growth under drought stress.