Joydeep Chakraborty, Guy Sobol, Fan Xia, Ning Zhang, Gregory B Martin, Guido Sessa
求助PDF
{"title":"PP2C Phosphatase Pic6 Suppresses MAPK Activation and Disease Resistance in Tomato.","authors":"Joydeep Chakraborty, Guy Sobol, Fan Xia, Ning Zhang, Gregory B Martin, Guido Sessa","doi":"10.1094/MPMI-10-24-0124-SC","DOIUrl":null,"url":null,"abstract":"<p><p>Type 2C protein phosphatases (PP2Cs) are essential for regulating plant immune responses to pathogens. Our study focuses on the tomato PP2C-immunity associated candidate 6 (Pic6), elucidating its role in negatively regulating pattern-triggered immunity (PTI) signaling pathways in tomato. Using reverse-transcription quantitative polymerase chain reaction (RT-qPCR), we observed that treatment with microbe-associated molecular patterns (MAMPs)-flg22 and flgII-28-significantly increased <i>Pic6</i> mRNA levels in wild-type (RG-PtoR) tomato plants. Pic6 features a conserved N-terminal kinase-interacting motif (KIM) and a C-terminal PP2C domain. We produced variants of Pic6 with mutations in these regions, demonstrating their involvements in negatively regulating tomato immunity. <i>Agrobacterium</i>-mediated transient overexpression of Pic6 resulted in enhanced growth of the bacterial pathogen <i>Pseudomonas syringae</i> pathovar <i>tomato</i> (<i>Pst</i>) strain DC3000Δ<i>hopQ1-1</i> compared with a yellow fluorescent protein (YFP) control. Additionally, Pic6 overexpression inhibited mitogen-activated protein kinase (MAPK) activation in response to flg22 and flgII-28 treatments. Importantly, Pic6 exhibited phosphatase activity and interacted with tomato Mkk1/Mkk2 proteins and dephosphorylated them in a KIM-dependent manner. Furthermore, we generated RG-pic6 loss-of-function mutants by CRISPR/Cas9, revealing that the absence of Pic6 heightened MAPK activity and increased resistance to <i>Xanthomonas euvesicatoria</i> strain 85-10 (<i>Xe</i> 85-10) when compared with the wild-type (RG-PtoR) plants. Transcript analyses showed that after flg22/flgII-28 treatment, PTI-reporter genes <i>NAC</i> and <i>Osmotin</i> were significantly upregulated in RG-pic6 mutants in comparison to the wild-type (RG-PtoR) plants. Overall, our findings indicate that Pic6 acts as a negative regulator of MAPK signaling and plays a pivotal role in modulating tomato immunity against bacterial pathogens. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.</p>","PeriodicalId":19009,"journal":{"name":"Molecular Plant-microbe Interactions","volume":" ","pages":"43-49"},"PeriodicalIF":3.2000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Plant-microbe Interactions","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1094/MPMI-10-24-0124-SC","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/2/22 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
引用
批量引用
Abstract
Type 2C protein phosphatases (PP2Cs) are essential for regulating plant immune responses to pathogens. Our study focuses on the tomato PP2C-immunity associated candidate 6 (Pic6), elucidating its role in negatively regulating pattern-triggered immunity (PTI) signaling pathways in tomato. Using reverse-transcription quantitative polymerase chain reaction (RT-qPCR), we observed that treatment with microbe-associated molecular patterns (MAMPs)-flg22 and flgII-28-significantly increased Pic6 mRNA levels in wild-type (RG-PtoR) tomato plants. Pic6 features a conserved N-terminal kinase-interacting motif (KIM) and a C-terminal PP2C domain. We produced variants of Pic6 with mutations in these regions, demonstrating their involvements in negatively regulating tomato immunity. Agrobacterium -mediated transient overexpression of Pic6 resulted in enhanced growth of the bacterial pathogen Pseudomonas syringae pathovar tomato (Pst ) strain DC3000ΔhopQ1-1 compared with a yellow fluorescent protein (YFP) control. Additionally, Pic6 overexpression inhibited mitogen-activated protein kinase (MAPK) activation in response to flg22 and flgII-28 treatments. Importantly, Pic6 exhibited phosphatase activity and interacted with tomato Mkk1/Mkk2 proteins and dephosphorylated them in a KIM-dependent manner. Furthermore, we generated RG-pic6 loss-of-function mutants by CRISPR/Cas9, revealing that the absence of Pic6 heightened MAPK activity and increased resistance to Xanthomonas euvesicatoria strain 85-10 (Xe 85-10) when compared with the wild-type (RG-PtoR) plants. Transcript analyses showed that after flg22/flgII-28 treatment, PTI-reporter genes NAC and Osmotin were significantly upregulated in RG-pic6 mutants in comparison to the wild-type (RG-PtoR) plants. Overall, our findings indicate that Pic6 acts as a negative regulator of MAPK signaling and plays a pivotal role in modulating tomato immunity against bacterial pathogens. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
PP2C 磷酸酶 Pic6 可抑制 MAPK 激活和番茄的抗病性。
2C 型蛋白磷酸酶(PP2Cs)对于调节植物对病原体的免疫反应至关重要。我们的研究侧重于番茄 PP2C 免疫相关候选 6(Pic6),阐明其在负向调节番茄模式触发免疫(PTI)信号通路中的作用。利用反转录定量聚合酶链式反应(RT-qPCR),我们观察到用微生物相关分子模式(MAMPs)--flg22 和 flgII-28 处理野生型(RG-PtoR)番茄植株后,Pic6 mRNA 水平显著增加。Pic6 具有一个保守的 N 端激酶相互作用基序(KIM)和一个 C 端 PP2C 结构域。我们制备了这些区域发生突变的 Pic6 变体,证明它们参与了番茄免疫的负向调控。与 YFP 对照相比,农杆菌介导的 Pic6 瞬时过表达导致细菌病原体 Pseudomonas syringae pv. tomato(Pst)菌株 DC3000ΔhopQ1-1 的生长增强。此外,Pic6 的过表达抑制了丝裂原活化蛋白激酶(MAPK)对 flg22 和 flgII-28 处理的激活。重要的是,Pic6 具有磷酸酶活性,能与番茄 Mkk1/Mkk2 蛋白相互作用,并以 KIM 依赖性方式使其去磷酸化。此外,我们还通过 CRISPR/Cas9 生成了 RG-pic6 功能缺失突变体,结果表明,与野生型(RG-PtoR)植株相比,Pic6 的缺失提高了 MAPK 活性,增强了对黄单胞菌菌株 85-10 (Xe 85-10)的抗性。转录本分析表明,与野生型(RG-PtoR)植物相比,经 flg22/flgII-28 处理后,RG-pic6 突变体中的 PTI 报告基因 NAC 和 osmotin 明显上调。总之,我们的研究结果表明,Pic6 是 MAPK 信号转导的负调控因子,在调节番茄对细菌病原体的免疫力方面起着关键作用。
本文章由计算机程序翻译,如有差异,请以英文原文为准。