Expression and Functional Analysis of a Pathogenesis-Related Protein 1 Gene, TcLr19PR1, Involved in Wheat Resistance Against Leaf Rust Fungus

Abstract

Pathogenesis-related (PR) proteins encoded by plant defense genes play key roles in plant disease-resistance responses, specialized in systemic-acquired resistance. However, their roles in the response of wheat to fungal infection are still not well known. Our earlier studies have reported that a full-length TcLr19PR1 gene (818 bp) was isolated from wheat infected by leaf rust (Puccinia triticina). Here, we showed that TcLr19PR1 was induced earlier and its expression level was higher in the incompatible interaction between seedling stage of wheat and P. triticina than in compatible interactions. TcLr19PR1 was strongly induced after P. triticina inoculation and ABA and SA treatments, in which the expression level of TcLr19PR1 significantly increased and reached the maximum at 12 and 72 h, respectively. Furthermore, the transgenic T1-stable TcLr19PR1 lines generated in the susceptible wheat cultivar Zhengzhou 5389 background exhibited certain extent disease resistance against P. triticina infection by preventing disease development. In addition, Western blotting was conducted to confirm that TcLr19PR1 protein was induced by P. triticina infection in positive transgenic plants at the protein expression level. These findings suggest that TcLr19PR1 gene plays an important role in wheat development and resistance to leaf rust pathogen attack.