Molecular Characterization and Expression Profiles of Polygalacturonase Genes in Apolygus lucorum (Hemiptera: Miridae)

PLoS One. 2015 May 8;10(5):e0126391. doi: 10.1371/journal.pone.0126391. eCollection 2015.

Abstract

Polygalacturonase (PG) is an enzyme in the salivary glands of piercing-sucking mirid bugs (Hemiptera: Miridae) that plays a key role in plant feeding and injury. By constructing a full-length cDNA library, we cloned and characterized 14 PG genes from the salivary glands of Apolygus lucorum, a pestiferous mirid bug in cotton, fruit trees and other crops in China. BLAST search analysis showed that the amino acid sequences deduced from transcripts of the PG genes were closely related to PGs from other mirid bugs. Phylogenetic analysis showed that the PGs of mirid bugs had six main branches, PG1-PG6 (Genbank accession numbers: KF881899~KF881912). We investigated the mRNA expression patterns of the A. lucorum PG genes using real-time PCR. All 14 PGs were expressed significantly higher in the salivary glands than in other tissues (head, thorax, abdomen, leg and wing). For eggs and nymphs, the expression levels of these PGs were much higher in the 5th instar stage than in the egg, and 1st and 3rd instar stages. The PG expression levels in 1-day-old adults were very low, and increased in 5, 20 and 30-day-old adults. Additionally, PG expression levels were generally similar between males and females. The possible physiological functions of PGs in A. lucorum were discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • Evolution, Molecular
  • Female
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Enzymologic
  • Hemiptera / enzymology*
  • Hemiptera / genetics
  • Insect Proteins / genetics*
  • Insect Proteins / metabolism*
  • Male
  • Organ Specificity
  • Phylogeny
  • Polygalacturonase / genetics*
  • Polygalacturonase / metabolism*
  • Salivary Glands / enzymology*

Substances

  • Insect Proteins
  • Polygalacturonase

Grants and funding

This work was supported by the National Natural Science Foundation of China (31171859 and 31321004), and National Basic Research Program of China (2012CB114104). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.