Genome-wide identification, cloning and characterization of SNARE genes in bread wheat (Triticum aestivum L.) and their response to leaf rust

SNAREs (soluble N-ethylmaleimide sensitive factor adaptor protein receptors) are small polypeptides characterized by a particular domain called the SNARE motif. Compared with the genome of other eukaryotes, monocotyledonous and dicotyledonous plants have more SNAREs indicating their important roles in higher plant species. Higher plants have the capability to form SNARE complexes that are important in determining the precise process of vesicle fusion for intracellular trafficking pathways. SNAREs have been reported to be engaged in the delivery of cell wall precursors to the newly formed cell plate during cytokinesis. The role of SNARE genes in response to plant-pathogen interaction is still not well understood. We found 35 SNARE genes in the wheat genome using a Hidden Markov Model. In this study with combined usage of in silico and molecular cloning technologies, we identified and characterized three SNARE genes (SNARE3, SNARE5 and SNARE6). The deduced amino acid sequences of these SNARE genes contained two characteristic conserved domains - a SNARE motif and a transmembrane domain, and they showed a high degree of homology with other eukaryotic SNARE genes. Phylogenetic analysis and three dimensional structures built with the help of Modeller software confirmed the presence of SNARE motifs in the proteins. The spatio-temporal expression profiling studies exemplify the positive role of SNARE transcripts have in resistant and susceptible wheat plants during incompatible and compatible interaction respectively, in response to Puccinia triticina induced leaf-rust infection. Taken together, our study suggests a role for SNARE genes in vesicle mediated resistance to leaf rust in wheat.