Genome-wide identification and characterization of thaumatin-like protein family genes in wheat and analysis of their responses to Fusarium head blight infection

Abstract

Thaumatin-like proteins (TLPs) play potential roles in plant resistance to various diseases. Identifying TLPs is necessary to determine their function and apply them to plant disease resistance. However, limited information is available about TLP-family genes in wheat, especially regarding their responses to Fusarium species, which cause Fusarium head blight in wheat. In this study, we conducted a comprehensive genome-wide survey of TLP genes in wheat and identified 129 TLP genes in the wheat genome, which were unevenly distributed on 21 wheat chromosomes, with 5A containing the highest number. Phylogenetic analysis showed that these 129 wheat TLP genes together with 24 Arabidopsis TLPs were classified into 7 groups based on the protein sequences. We systematically analyzed the genes in terms of their sequence characterization, chromosomal locations, exon–intron distribution, duplication (tandem and segmental) events and expression profiles in response to Fusarium infection. Furthermore, we analyzed differentially expressed TLP genes based on publicly available RNA-seq data obtained from a resistant near isogenic wheat line at different time points after Fusarium graminearum inoculation. Then, the expression of 9 differentially expressed TLP genes was confirmed by real-time PCR, and these 9 genes were all upregulated in the resistant Sumai 3 variety, which was generally consistent with the RNA-seq data. Our results provide a basis for selecting candidate wheat TLP genes for further studies to determine the biological functions of the TLP genes in wheat.Graphical