Genome-wide identification and characterization of the TPS gene family in wheat (Triticum aestivum L.) and expression analysis in response to aphid damage

Abstract

Terpene synthase (TPS) gene family is ubiquitous in land plants and plays an important role in regulating various biological processes in plants, especially in pathogen and herbivore defense mechanisms. Also, little is known about this gene family in wheat. In this research, 153 TaTPS genes were identified and named according to their chromosome location. Phylogenetic analysis of TaTPS proteins and other homologous proteins corresponded to a six-subgroup classification. The analysis of gene structure and motif showed that the TaTPS gene was highly conserved in each subgroup, which suggested that whole genome duplication and segmental duplication events were the main expansion way of the TaTPS gene family. Nineteen tandem duplication gene pairs and 91 homologous genes on different chromosomes were produced by segmental duplication. Expression profiles derived from transcriptome data results indicated that TaTPS genes may contribute to defense responses of wheat to pests such as aphids. The cis-regulatory elements (CREs) of TaTPS were found to be diversified indicating that TaTPS gene may participate in many physiological processes of wheat growth and development. Each TaTPS gene contains at least two or more defense or hormone-related CREs, suggesting an important role in wheat pest defense through hormone pathways. This study can provide valuable clues for elucidating the evolutionary relationship of the TaTPS gene family. Also, it may provide a research basis for functional investigations related to wheat development, particularly to plant–pest interactions and further breeding for new wheat varieties with aphid resistance.