Cloning and Expression Analysis of the Gene Involved in Heat Tolerance in Chinese Kale.

Chinese kale ( var Lei) is an important vegetable crop in South China, valued for its nutritional content and taste. Nonetheless, the thermal tolerance of Chinese kale still needs improvement. Molecular characterization of Chinese kale's heat stress response could provide a timely solution for developing a thermally tolerant Chinese kale variety. Here, we report the cloning of () from Chinese kale (), an ortholog to the key heat stress responsive gene . Phylogenetic analysis showed that is highly similar to the stress-response transcriptional coactivator from (), and the coding region conserves MBF1 and helix-turn-helix (HTH) domains. Moreover, the promoter region of contains three heat shock elements (HSEs) and, thus, is highly responsive to heat treatment. This was verified in leaf tissue using a green fluorescent protein (GFP) reporter. In addition, the expression of can be induced by various abiotic stresses in Chinese kale which indicates the involvement of stress responses. The BocMBF1c-eGFP (enhanced green fluorescent protein) chimeric protein quickly translocated into the nucleus under high temperature treatment in leaf tissue. Overexpression of in results in a larger size and enhanced thermal tolerance compared with the wild type. Our results provide valuable insight for the role of during heat stress in Chinese kale.