Transcriptome profile analysis of cadmium tolerance in Chinese flowering cabbage

Chinese flowering cabbage (Brassica parachinensis L.) is an important leafy vegetable crop that can accumulate high levels of cadmium (Cd) and can thus be easily contaminated by this heavy metal. In this study, we performed genome-wide transcriptional profiling of Cd tolerance in Cd-tolerant cultivar 'LB70' using Solexa sequencing to identify genes and pathways involved in Cd tolerance in Chinese flowering cabbage. Profiling analysis revealed numerous changes in gene expression in response to Cd treatment, including 1669 genes that were downregulated and 1404 genes that were upregulated. Gene ontology analysis showed that these differentially expressed genes were mainly involved in binding, catalytic processes, metabolism, cellular processes, single-organism processes, biological regulation, localization, and stimulus responses. Several known important Cd tolerance-related genes, such as HMA3, HMA4, and Nramp1, were also identified. Pathway analysis suggested that two potential novel pathways, namely, the viral carcinogenesis and Parkinson's disease pathways, might be involved in Cd tolerance in Chinese flowering cabbage. The genes and pathways identified in this study provide an important basis for future studies on the molecular mechanism of Cd tolerance in Chinese flowering cabbage.