Identification and characterization of a β-1, 3-glucanase gene, TcLr19Glu, involved in wheat resistance against Puccinia triticina

Abstract

β-1,3-glucanases represent a group of pathogenesis-related proteins (PRs) that have been extensively reported to be involved in plant defense response towards fungal pathogens infection. However, it remains unknown how these genes are involved in wheat against leaf rust pathogen Puccinia triticina. Here, we present the cloning and expression analysis of a full length β-1,3-glucanase gene, TcLr19Glu, from the near isogenic wheat line TcLr19 infected by leaf rust pathogen. TcLr19Glu encodes a 342 amino acid protein with deduced molecular weight of 34.86 kDa that contains a conserved glycoside hydrolase family 17 domain widely existing in β-1,3-glucanases family. The expression profile of TcLr19Glu detected by quantitative real-time PCR showed that the transcript was induced by P. triticina both in the compatible and incompatible interactions, but the accumulation level of transcript was statistically significant in the incompatible interaction compared with that in the compatible interaction. Subsequently, we demonstrated that the accumulation of TcLr19Glu transcript significantly differentiates in tested wheat organs and TcLr19Glu was noticeably induced by the signaling molecules including abscisic acid (ABA) and salicylic acid (SA). Furthermore, induction and quantification of TcLr19Glu protein in compatible and incompatible interactions was measured and the amount of protein was higher in the incompatible interaction than compatible interaction. All these results allow us to conclude that TcLr19Glu is involved in the Lr19-mediated defense response against rust pathogen.