The suppression subtractive hybridization was employed to elucidate the resistance mechanism in Brassica oleracea var. capitata upon infection with Xanthomonas campestris pv. campestris. A cDNA library was constructed enriched in differentially expressed transcripts in the resistant cultivar Pusa mukta. A total of 150 unigenes were classified into five functional categories. The present study indicates that the defense-related unigenes accounted for the 35 % of the total unigenes studied. Confirmation of defense-specific representation genes through semiquantitative RT-PCR revealed their increased expression in the resistant cultivar which was validated by qPCR. The resistant cultivar elicited a strong hypersensitive response upon attack by black rot pathogen. The study is first of its kind where the resistant cultivar Pusa mukta in India has been assessed for its resistance to the bacterial pathogen.
Keywords: Black rot; Cabbage; Disease resistance; Gene expression; Plant genomics; Pusa mukta.