Asian Citrus Psyllid Expression Profiles Suggest Candidatus Liberibacter Asiaticus-Mediated Alteration of Adult Nutrition and Metabolism, and of Nymphal Development and Immunity

PLoS One. 2015 Jun 19;10(6):e0130328. doi: 10.1371/journal.pone.0130328. eCollection 2015.

Abstract

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is the insect vector of the fastidious bacterium Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus greening disease, or Huanglongbing (HLB). The widespread invasiveness of the psyllid vector and HLB in citrus trees worldwide has underscored the need for non-traditional approaches to manage the disease. One tenable solution is through the deployment of RNA interference technology to silence protein-protein interactions essential for ACP-mediated CLas invasion and transmission. To identify psyllid interactor-bacterial effector combinations associated with psyllid-CLas interactions, cDNA libraries were constructed from CLas-infected and CLas-free ACP adults and nymphs, and analyzed for differential expression. Library assemblies comprised 24,039,255 reads and yielded 45,976 consensus contigs. They were annotated (UniProt), classified using Gene Ontology, and subjected to in silico expression analyses using the Transcriptome Computational Workbench (TCW) (http://www.sohomoptera.org/ACPPoP/). Functional-biological pathway interpretations were carried out using the Kyoto Encyclopedia of Genes and Genomes databases. Differentially expressed contigs in adults and/or nymphs represented genes and/or metabolic/pathogenesis pathways involved in adhesion, biofilm formation, development-related, immunity, nutrition, stress, and virulence. Notably, contigs involved in gene silencing and transposon-related responses were documented in a psyllid for the first time. This is the first comparative transcriptomic analysis of ACP adults and nymphs infected and uninfected with CLas. The results provide key initial insights into host-parasite interactions involving CLas effectors that contribute to invasion-virulence, and to host nutritional exploitation and immune-related responses that appear to be essential for successful ACP-mediated circulative, propagative CLas transmission.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animal Nutritional Physiological Phenomena / immunology
  • Animals
  • Citrus / microbiology
  • Citrus / parasitology
  • Contig Mapping
  • DNA Transposable Elements
  • Gene Expression Regulation, Developmental / immunology
  • Gene Ontology
  • Genes, Insect
  • Hemiptera / growth & development
  • Hemiptera / immunology
  • Hemiptera / microbiology*
  • Host-Pathogen Interactions
  • Immunity, Innate
  • Insect Vectors / microbiology*
  • Insect Vectors / physiology
  • Molecular Sequence Annotation
  • Nymph / microbiology
  • Nymph / physiology
  • Plant Diseases / microbiology*
  • Rhizobiaceae / physiology*
  • Signal Transduction
  • Transcriptome

Substances

  • DNA Transposable Elements

Grants and funding

The authors gratefully acknowledge the United States Department of Agriculture National Institute of Food and Agriculture Coordinated Agricultural Project (Award No. 2012-51181-20086), the Citrus Research and Development Foundation (CRDF) and Florida Citrus Advanced Technology Program, Contracts 21 and 510, respectively for providing generous financial and professional support for this research. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.