Arsenophonus GroEL interacts with CLCuV and is localized in midgut and salivary gland of whitefly B. tabaci

PLoS One. 2012;7(8):e42168. doi: 10.1371/journal.pone.0042168. Epub 2012 Aug 10.

Abstract

Cotton leaf curl virus (CLCuV) (Gemininiviridae: Begomovirus) is the causative agent of leaf curl disease in cotton plants (Gossypium hirsutum). CLCuV is exclusively transmitted by the whitefly species B. tabaci (Gennadius) (Hemiptera: Alerodidae). B. tabaci contains several biotypes which harbor dissimilar bacterial endo-symbiotic community. It is reported that these bacterial endosymbionts produce a 63 kDa chaperon GroEL protein which binds to geminivirus particles and protects them from rapid degradation in gut and haemolymph. In biotype B, GroEL protein of Hamiltonella has been shown to interact with Tomato yellow leaf curl virus (TYLCV). The present study was initiated to find out whether endosymbionts of B. tabaci are similarly involved in CLCuV transmission in Sriganganagar (Rajasthan), an area endemic with cotton leaf curl disease. Biotype and endosymbiont diversity of B. tabaci were identified using MtCO1 and 16S rDNA genes respectively. Analysis of our results indicated that the collected B. tabaci population belong to AsiaII genetic group and harbor the primary endosymbiont Portiera and the secondary endosymbiont Arsenophonus. The GroEL proteins of Portiera and Arsenophonus were purified and in-vitro interaction studies were carried out using pull down and co-immunoprecipitation assays. In-vivo interaction was confirmed using yeast two hybrid system. In both in-vitro and in-vivo studies, the GroEL protein of Arsenophonus was found to be interacting with the CLCuV coat protein. Further, we also localized the presence of Arsenophonus in the salivary glands and the midgut of B. tabaci besides the already reported bacteriocytes. These results suggest the involvement of Arsenophonus in the transmission of CLCuV in AsiaII genetic group of B. tabaci.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / metabolism*
  • Begomovirus / genetics
  • Begomovirus / metabolism*
  • Biodiversity
  • Chaperonin 60 / metabolism*
  • DNA, Mitochondrial / genetics
  • Enterobacteriaceae / classification
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / metabolism
  • Escherichia coli Proteins / metabolism
  • Gastrointestinal Tract / microbiology
  • Gossypium / virology
  • Hemiptera / classification
  • Hemiptera / genetics
  • Hemiptera / microbiology*
  • Hemiptera / virology
  • Phylogeny
  • Plant Diseases / virology
  • Protein Binding
  • RNA, Ribosomal, 16S / genetics
  • Salivary Glands / microbiology
  • Symbiosis
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / isolation & purification
  • Viral Envelope Proteins / metabolism

Substances

  • Bacterial Proteins
  • Chaperonin 60
  • DNA, Mitochondrial
  • Escherichia coli Proteins
  • RNA, Ribosomal, 16S
  • Viral Envelope Proteins

Grants and funding

This work has been funded by 1. University of Delhi Faculty Research Grant and 2. National Agricultural Innovation Project (NAIP) grant of the Indian Council for Agricultural Research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.