Transcriptomic analysis reveals polygalacturonase genes in Pachypeltis micranthus

Abstract

The mirid bug, Pachypeltis micranthus Mu et Liu (Hemiptera: Miridae), is a natural enemy of the widespread invasive weed in the tropics, Mikania micrantha. To date, however, there is not any genetic information related to this species. Polygalacturonases (PGs) are one group of pectin hydrolases that are in the saliva of mirid bugs believed to be responsible for the digestion of plant cell wall and involved in causing visible plant injury. This study aims to obtain genetic data and reveal the putative PG genes of P. micranthus. The transcriptome of this species was sequenced using Illumina paired-end sequencing technology. Approximately 5.2 Gbps of sequences were generated, which were assembled into 57 739 unigenes. Of these unigenes, 23 549 non-redundant BlastX hits were identified. In total, 7 048, 8 548 and 16 135 unigenes were respectively subjected to Gene Orthology (GO), Clusters of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, respectivly. Based on the P. micranthus transcriptome, 24 putative PG genes were identified, of which 15 were predicted to be full-length protein sequences. The findings provide valuable information to further exploration of this species from various ecological, biological and physiological aspects at the molecular level, and the role of PGs involved in the interaction between P. micranthus and its host.