Genome-wide expression profiles of contrasting inbred lines of Chinese cabbage, Chiifu and Kenshin, under temperature stress

Abiotic stresses such as extreme temperatures frequently limit plant growth and productivity of major crop species. To identify temperature-stress responsive genes in Brassica rapa ssp. pekinensis, we conducted a comparative transcriptome analysis of two contrasting genotypes, the inbred lines Chiifu and Kenshin, under and heat-shock conditions. Of 23,929 unigenes deposited on a Br24K microarray, 17,603 genes were significantly expressed. Chiifu expression profiles were more prevalent under , and those of Kenshin were more prevalent under heat-shock. Previously characterized genes, with little exception, show similar changes to temperature stress. We found that a relatively large number of genes were expressed in response to temperature stress and genotype, amounting to 24 and 126 genes from and heat-shock conditions, respectively. These genes could be used in molecular marker development for either high or low temperature-resistant Brassica spp. Only ten genes, including TCH4 and CBL1, were up-regulated in both genotypes under all stress treatments, implying possible candidates for broad spectrum, stress-resistant crop production.