Genome-Wide Identification, Classification, and Expression Analysis of SNARE Genes in Chinese Cabbage (Brassica rapa ssp pekinensis) Infected by Turnip mosaic virus

Turnip mosaic virus (TuMV) is a widely distributed pathogen that seriously affects the yield and quality of brassica crops. The SNARE genes in the host encode proteins that are very important for virus replication and movement. However, systematic and comprehensive analyses of these genes have not been reported for Chinese cabbage. In the present study, 78 BrSNARE genes were identified in Chinese cabbage. We analyzed the classification of these genes, their phylogenetic relationships (including their orthologous and paralogous relationships with those in Arabidopsis and rice), conserved motifs, and distribution on the ten chromosomes of Chinese cabbage. Of the 78 BrSNAREs, 77 were unevenly distributed among ten chromosomes. In the phylogenetic analyses of SNARES from Chinese cabbage, Arabidopsis, and rice, the 78 BrSNAREs were classified into four subfamilies. Analyses of the transcript levels of BrSNAREs in six different tissues revealed tissue-specific expression of some BrSNARE genes. We detected the expression of 55 BrSNAREs and grouped them according to their change trends and subcellular location in different organelles. On the basis of our analyses, we concluded that nine BrSNAREs may be associated with cell-to-cell movement and 15 BrSNAREs may be associated with long-distance transport. These results indicate that many BrSNAREs have evolved in Chinese cabbage and that some of them are related to TuMV infection.