Physiological and transcriptome analyses of Chinese cabbage in response to drought stress1

Chinese cabbage is an important leafy vegetable crop with high water demand and susceptibility to drought stress. To explore the molecular mechanisms underlying the response to drought, we performed a transcriptome analysis of drought-tolerant and -sensitive Chinese cabbage genotypes under drought stress, and uncovered core drought-responsive genes and key signaling pathways. A co-expression network was constructed by a weighted gene co-expression network analysis (WGCNA) and candidate hub genes involved in drought tolerance were identified. Furthermore, ABA biosynthesis and signaling pathways and their drought responses in Chinese cabbage leaves were systemically explored. We also found that drought treatment increased the antioxidant enzyme activities and glucosinolate contents significantly. These results substantially enhance our understanding of the molecular mechanisms underlying drought responses in Chinese cabbage.