The present invention provides a heat-resistance plant gene JAZ5a and use thereof. The inventors of the present invention isolated for the first time a heat resistance gene from the plant of Brassica spp., which can greatly improve the heat-resistance ability of the plant, especially in the bolting stage. The present invention further provides a protein encoded by said gene and its preparation method, vectors and host cells containing said gene, and a method for preparing a transgenic plant containing said gene.
