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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Microbiol. | doi: 10.3389/fmicb.2019.02419

Anti-plant defense response strategies mediated by the secondary symbiont Hamiltonella defensa in the wheat aphid Sitobion miscanthi

 Li Qian1, Jingxuan Sun1,  Jia Fan2,  Yong Zhang2,  Maolin Hou1 and Julian Chen1*
  • 1Institute of Plant Protection, Chinese Academy of Agricultural Sciences, China
  • 2Chinese Academy of Agricultural Sciences , Institute of Plant Protection , Beijing , China, China

Bacterial symbionts are omnipresent in insects, particularly aphids, and often exert important effects on the host ecology; however, examples of symbionts that mediate herbivore-plant interactions remain limited. Here, three clones with identical genetic backgrounds were established: Hamiltonella defensa free clone, H. defensa infected clone and H. defensa cured clone. H. defensa infection was found to increase the fitness of S. miscanthi, which increased the total number of offspring and decreased the age of first reproduction. Furthermore, gene expression studies and phytohormone measurement showed that feeding by the Hamiltonella-infected clone suppressed the salicylic acid (SA)- and jasmonic acid (JA)-related defense pathways and accumulation in wheat plants relative to feeding by the other two clones. Additionally, after feeding by the Hamiltonella-infected clone, the activity levels of the defense-related enzymes polyphenol oxidase (PPO) and peroxidase (POD) in wheat plants were significantly decreased compared with the levels observed after feeding by the other two clones. Taken together, these data reveal for the first time the potential role of H. defensa of S. miscanthi in mediating the anti-plant defense responses of aphids.

Keywords: Hamiltonella defensa, Sitobion miscanthi, anti-plant defense, Defense pathway, enzyme

Received: 16 Aug 2019; Accepted: 07 Oct 2019.

Copyright: © 2019 Qian, Sun, Fan, Zhang, Hou and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Prof. Julian Chen, Chinese Academy of Agricultural Sciences, Institute of Plant Protection, Beijing, Beijing Municipality, China, chenjulian@caas.cn