Cloning and Characterization of the BcTuR3 Gene Related to Resistance to Turnip Mosaic Virus (TuMV) from Non-heading Chinese Cabbage

A cDNA clone for the turnip mosaic virus (TuMV)-induced gene in non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino cv. Duanbaigeng) was isolated and characterized. The full-length cDNA clone, designated BcTuR3, was isolated during resistance response to TuMV. Sequence analysis of the cDNA clone confirmed that the translation product of the gene is homologous to other plant resistance proteins. Genomic DNA Southern blot analysis indicated that the gene represented a small multi-gene family. Northern hybridizations confirmed its elevated expression in the resistant “Duanbaigeng” and the susceptible “Aijiaohuang.” Upon inoculation with TuMV, the BcTuR3 transcript was rapidly accumulated in the infected leaves and stems. Tissue-specific expression of the gene showed that higher levels of the BcTuR3 transcript were observed in the TuMV-infected leaves, and later in the stems and roots of the resistant and susceptible varieties. These data showed that the BcTuR3 gene may be involved in plant resistance against TuMV pathogen infection.