Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants
Bacterial fruit blotch (BFB), caused by <i>Acidovorax citrulli</i>, seriously affects watermelon and other cucurbit crops, resulting in significant economic losses. However, the pathogenicity mechanism of <i>A. citrulli</i> is not well understood. Plant pathogenic bacteria of...
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MDPI AG
2020-08-01
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| Series: | International Journal of Molecular Sciences |
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| author | Xiaoxiao Zhang Mei Zhao Jie Jiang Linlin Yang Yuwen Yang Shanshan Yang Ron Walcott Dewen Qiu Tingchang Zhao |
| author_facet | Xiaoxiao Zhang Mei Zhao Jie Jiang Linlin Yang Yuwen Yang Shanshan Yang Ron Walcott Dewen Qiu Tingchang Zhao |
| author_sort | Xiaoxiao Zhang |
| collection | DOAJ |
| description | Bacterial fruit blotch (BFB), caused by <i>Acidovorax citrulli</i>, seriously affects watermelon and other cucurbit crops, resulting in significant economic losses. However, the pathogenicity mechanism of <i>A. citrulli</i> is not well understood. Plant pathogenic bacteria often suppress the plant immune response by secreting effector proteins. Thus, identifying <i>A. citrulli</i> effector proteins and determining their functions may improve our understanding of the underlying pathogenetic mechanisms. In this study, a novel effector, AopN, which is localized on the cell membrane of <i>Nicotiana benthamiana,</i> was identified. The functional analysis revealed that AopN significantly inhibited the flg22-induced reactive oxygen species burst. AopN induced a programmed cell death (PCD) response. Unlike its homologous protein, the ability of AopN to induce PCD was dependent on two motifs of unknown functions (including DUP4129 and Cpta_toxin), but was not dependent on LXXLL domain. More importantly, the virulence of the <i>aopN</i> mutant of <i>A. citrulli</i> in <i>N. benthamiana</i> significantly decreased, indicating that it was a core effector. Further analysis revealed that AopN interacted with watermelon ClHIPP and ClLTP, which responds to <i>A. citrulli</i> strain Aac5 infection at the transcription level. Collectively, these findings indicate that AopN suppresses plant immunity and activates the effector-triggered immunity pathway. |
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| language | English |
| last_indexed | 2024-03-10T16:58:58Z |
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| spelling | doaj.art-71654e47c24a45f4a95292407fbb23d52023-11-20T11:01:44ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672020-08-012117605010.3390/ijms21176050Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in PlantsXiaoxiao Zhang0Mei Zhao1Jie Jiang2Linlin Yang3Yuwen Yang4Shanshan Yang5Ron Walcott6Dewen Qiu7Tingchang Zhao8State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaDepartment of Plant Pathology, University of Georgia, Athens, GA 30602, USAState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaInstitute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, ChinaDepartment of Plant Pathology, University of Georgia, Athens, GA 30602, USAState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaState Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, ChinaBacterial fruit blotch (BFB), caused by <i>Acidovorax citrulli</i>, seriously affects watermelon and other cucurbit crops, resulting in significant economic losses. However, the pathogenicity mechanism of <i>A. citrulli</i> is not well understood. Plant pathogenic bacteria often suppress the plant immune response by secreting effector proteins. Thus, identifying <i>A. citrulli</i> effector proteins and determining their functions may improve our understanding of the underlying pathogenetic mechanisms. In this study, a novel effector, AopN, which is localized on the cell membrane of <i>Nicotiana benthamiana,</i> was identified. The functional analysis revealed that AopN significantly inhibited the flg22-induced reactive oxygen species burst. AopN induced a programmed cell death (PCD) response. Unlike its homologous protein, the ability of AopN to induce PCD was dependent on two motifs of unknown functions (including DUP4129 and Cpta_toxin), but was not dependent on LXXLL domain. More importantly, the virulence of the <i>aopN</i> mutant of <i>A. citrulli</i> in <i>N. benthamiana</i> significantly decreased, indicating that it was a core effector. Further analysis revealed that AopN interacted with watermelon ClHIPP and ClLTP, which responds to <i>A. citrulli</i> strain Aac5 infection at the transcription level. Collectively, these findings indicate that AopN suppresses plant immunity and activates the effector-triggered immunity pathway.https://www.mdpi.com/1422-0067/21/17/6050AopNprogrammed cell death<i>Acidovorax citrulli</i>plant pathogeneffector-triggered immunity |
| spellingShingle | Xiaoxiao Zhang Mei Zhao Jie Jiang Linlin Yang Yuwen Yang Shanshan Yang Ron Walcott Dewen Qiu Tingchang Zhao Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants International Journal of Molecular Sciences AopN programmed cell death <i>Acidovorax citrulli</i> plant pathogen effector-triggered immunity |
| title | Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants |
| title_full | Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants |
| title_fullStr | Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants |
| title_full_unstemmed | Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants |
| title_short | Identification and Functional Analysis of AopN, an <i>Acidovorax Citrulli</i> Effector that Induces Programmed Cell Death in Plants |
| title_sort | identification and functional analysis of aopn an i acidovorax citrulli i effector that induces programmed cell death in plants |
| topic | AopN programmed cell death <i>Acidovorax citrulli</i> plant pathogen effector-triggered immunity |
| url | https://www.mdpi.com/1422-0067/21/17/6050 |
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