MITOGEN-ACTIVATED PROTEIN KINASE3 enhances disease resistance of edr1 mutants by phosphorylating MAPKKK5
MITOGEN-ACTIVATED PROTEIN KINASE3 enhances disease resistance of edr1 mutants by phosphorylating MAPKKK5
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DOI：
10.1093/plphys/kiad472
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发表时间：
2023-09-09
期刊：
影响因子：
7.4
通讯作者：
Tang，Dingzhong
中科院分区：
文献类型：
--
作者：
Wang，Wei;Chen，Shuling;Tang，Dingzhong
丝裂原激活蛋白激酶 (MAPK/MPK) 级联是调节植物免疫的关键信号模块。ENHANCED DISEASE RESISTANCE1 (EDR1) 编码一种 Raf 样 MAPK 激酶激酶 (MAPKKK)，可负调节拟南芥 (Arabidopsis thaliana) 的植物防御。 edr1 的增强抵抗力需要 MAPK KINASE4 (MKK4)、MKK5 和 MPK3。尽管 theedr1 突变体表现出更高的 MPK3/6 激活，但植物增加 MAPK 级联激活的机制仍然难以捉摸。我们之前的研究表明，在edr1突变体中，MAPKKK5的Ser-90残基被磷酸化。在这项研究中，我们证明了 edr1 增强的抗病性需要 MAPKKK5。磷酸化死亡的MAPKKK5S90部分损害了edr1的抗性，磷酸模拟物MAPKKK5S90Dinmapkkk5-2的表达导致对白粉病Golovinomyces cichoracearumstrain UCSC1和细菌病原体Pseudomonas syringaepv.tomato(Pto)菌株DC3000的抗性增强。因此，MAPKKK5 中的 Ser-90 磷酸化似乎在抗病性中发挥着至关重要的作用。然而，MAPKKK5 触发的细胞死亡并未被 EDR1 抑制。此外，激活的MPK3磷酸化MAPKKK5的N末端，而Ser-90是磷酸化位点之一。 Ser-90 磷酸化增加了 MAPKKK5 的稳定性，EDR1 可能通过抑制 MPK3 介导的 MAPKKK5 反馈调节来负向调节 MAPK 级联激活。综上所述，这些结果表明 MPK3 磷酸化 MAPKKK5 以增强 MAPK 级联激活和 inedr1 突变体的抗病性。
Mitogen-activated protein kinase (MAPK/MPK) cascades are key signaling modules that regulate plant immunity.ENHANCED DISEASE RESISTANCE1(EDR1) encodes a Raf-like MAPK kinase kinase (MAPKKK) that negatively regulates plant defense in Arabidopsis (Arabidopsis thaliana). The enhanced resistance ofedr1requires MAPK KINASE4 (MKK4), MKK5, and MPK3. Although theedr1mutant displays higher MPK3/6 activation, the mechanism by which plants increase MAPK cascade activation remains elusive. Our previous study showed that MAPKKK5 is phosphorylated at the Ser-90 residue inedr1mutants. In this study, we demonstrated that the enhanced disease resistance ofedr1required MAPKKK5. Phospho-dead MAPKKK5S90Apartially impaired the resistance ofedr1, and the expression of phospho-mimetic MAPKKK5S90Dinmapkkk5-2resulted in enhanced resistance to the powdery mildewGolovinomyces cichoracearumstrain UCSC1 and the bacterial pathogenPseudomonas syringaepv.tomato(Pto) strain DC3000. Thus, Ser-90 phosphorylation in MAPKKK5 appears to play a crucial role in disease resistance. However, MAPKKK5-triggered cell death was not suppressed by EDR1. Furthermore, activated MPK3 phosphorylated the N terminus of MAPKKK5, and Ser-90 was one of the phosphorylated sites. Ser-90 phosphorylation increased MAPKKK5 stability, and EDR1 might negatively regulate MAPK cascade activation by suppressing the MPK3-mediated feedback regulation of MAPKKK5. Taken together, these results indicate that MPK3 phosphorylates MAPKKK5 to enhance MAPK cascade activation and disease resistance inedr1mutants.