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Dong Y, Jing M, Shen D, Wang C, Zhang M, Liang D, Nyawira KT, Xia Q, Zuo K, Wu S, Wu Y, Dou D, Xia A. The mirid bug Apolygus lucorum deploys a glutathione peroxidase as a candidate effector to enhance plant susceptibility. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2701-2712. [PMID: 31950164 PMCID: PMC7210764 DOI: 10.1093/jxb/eraa015] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/15/2020] [Indexed: 05/04/2023]
Abstract
The mirid bug Apolygus lucorum has become a major agricultural pest since the large-scale cultivation of Bt-cotton. It was assumed that A. lucorum, similarly to other phloem sap insects, could secrete saliva that contains effector proteins into plant interfaces to perturb host cellular processes during feeding. However, the secreted effectors of A. lucorum are still uncharacterized and unstudied. In this study, 1878 putative secreted proteins were identified from the transcriptome of A. lucorum, which either had homology with published aphid effectors or shared common features with plant pathogens and insect effectors. One hundred and seventy-two candidate effectors were used for cell death-inducing/suppressing assays, and a putative salivary gland effector, Apolygus lucorum cell death inhibitor 6 (Al6), was characterized. The mRNAs of Al6 were enriched at feeding stages (nymph and adult) and, in particular, in salivary glands. Moreover, we revealed that the secreted Al6 encoded an active glutathione peroxidase that reduced reactive oxygen species (ROS) accumulation induced by INF1 or Flg22. Expression of the Al6 gene in planta altered insect feeding behavior and promoted plant pathogen infections. Inhibition of cell death and enhanced plant susceptibility to insect and pathogens are dependent on glutathione peroxidase activity of Al6. Thus, this study shows that a candidate salivary gland effector, Al6, functions as a glutathione peroxidase and suppresses ROS induced by pathogen-associated molecular pattern to inhibit pattern-triggered immunity (PTI)-induced cell death. The identification and molecular mechanism analysis of the Al6 candidate effector in A. lucorum will provide new insight into the molecular mechanisms of insect-plant interactions.
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Affiliation(s)
| | | | - Danyu Shen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Chenyang Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Meiqian Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Dong Liang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Karani T Nyawira
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qingyue Xia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Kairan Zuo
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Shuwen Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yidong Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Daolong Dou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Ai Xia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Huerta-Ocampo JA, García-Muñoz MS, Velarde-Salcedo AJ, Hernández-Domínguez EE, González-Escobar JL, Barrera-Pacheco A, Grajales-Lagunes A, Barba de la Rosa AP. The proteome map of the escamolera ant (Liometopum apiculatum Mayr) larvae reveals immunogenic proteins and several hexamerin proteoforms. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2018; 28:107-121. [PMID: 30149319 DOI: 10.1016/j.cbd.2018.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/20/2018] [Accepted: 07/20/2018] [Indexed: 10/28/2022]
Abstract
The larvae of escamolera ant (Liometopum apiculatum Mayr) have been considered a delicacy since Pre-Hispanic times. The increased demand for this stew has led to massive collection of ant nests. Yet biological aspects of L. apiculatum larvae remain unknown, and mapping the proteome of this species is important for understanding its biological characteristics. Two-dimensional gel electrophoresis (2-DE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used to characterize the larvae proteome profile. From 380 protein spots analyzed, 174 were identified by LC-MS/MS and homology search against the Hymenoptera subset of the NCBInr protein database using the Mascot search engine. Peptide de novo sequencing and homology-based alignment allowed the identification of 36 additional protein spots. Identified proteins were classified by cellular location, molecular function, and biological process according to the Gene Ontology annotation. Immunity- and defense-related proteins were identified including PPIases, FK506, PEBP, and chitinases. Several hexamerin proteoforms were identified and the cDNA of the most abundant protein detected in the 2-DE map was isolated and characterized. L. apiculatum hexamerin (LaHEX, GeneBank accession no. MH256667) contains an open reading frame of 2199 bp encoding a polypeptide of 733 amino acid residues with a calculated molecular mass of 82.41 kDa. LaHEX protein is more similar to HEX110 than HEX70 from Apis mellifera. Down-regulation of LaHEX was observed throughout ant development. This work represents the first proteome map as well as the first hexamerin characterized from L. apiculatum larvae.
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Affiliation(s)
- José A Huerta-Ocampo
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a Sección, 78216 San Luis Potosí, S.L.P, Mexico; CONACYT-Centro de Investigación en Alimentación y Desarrollo A.C., Carretera a La Victoria Km 0.6, Edificio C, C.P 83304 Hermosillo, Sonora, Mexico
| | - María S García-Muñoz
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Nava No.6, Zona Universitaria, C.P. 78200 San Luis Potosí, S.L.P, Mexico
| | - Aída J Velarde-Salcedo
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a Sección, 78216 San Luis Potosí, S.L.P, Mexico
| | - Eric E Hernández-Domínguez
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a Sección, 78216 San Luis Potosí, S.L.P, Mexico
| | - Jorge L González-Escobar
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a Sección, 78216 San Luis Potosí, S.L.P, Mexico
| | - Alberto Barrera-Pacheco
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a Sección, 78216 San Luis Potosí, S.L.P, Mexico
| | - Alicia Grajales-Lagunes
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Nava No.6, Zona Universitaria, C.P. 78200 San Luis Potosí, S.L.P, Mexico.
| | - Ana P Barba de la Rosa
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a Sección, 78216 San Luis Potosí, S.L.P, Mexico.
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