Abstract:Membrane phospholipids are important sources of intracellular signal messengers and phosphatidic acid (PA) can be catalyzed by phospholipase Ds (PLDs) in response to different stress signals. In this study, we used Bioinformatics to identify and analyze the gene members of PLD gene family in Chinese cabbage; and the qRTPCR to analyze the expression of 18 BrPLD genes in nonheading Chinese cabbage, in order to explore the response mechanism of BrPLD gene family in nonheading Chinese cabbage to high temperature stress. The results showed that: (1) a total of 18 PLD gene family members were identified. Two of them (BrPLD03 and BrPLD09) were replaced by PH/PX domain. Another gene(BrPLD12)lacked its Nterminal conservative domain and was replaced by signal peptide. (2) Depending on the domain of the encoding protein,18 BrPLD genes were classified into three subgroups: 15 C2BrPLD, 2 PH/PXBrPLD and 1 SPBrPLD;analysis of physicochemical properties of amino acids revealed that most of the proteins encoded by the gene family were acidic proteins; 18 genes were distributed on another 8 chromosomes except chromosomes 4 and 7, and showed nonuniform distribution. The deletion of Ca2+ ligand base of BrPLDs protein was also found.(3) Quantitative RTPCR analysis of nonheading Chinese cabbage under high temperature showed that BrPLD gene could respond to high temperature stress, and the expression of BrPLD gene changed significantly. The expression of BrPLD gene was different in heattolerant and heatsensitive varieties. (4) Prediction of cisresponse elements with different functions in BrPLD gene family revealed that all family genes contained lightrelated action elements, 9 genes contained cisresponse elements related to low temperature, 10 genes contained droughtrelated elements, all 18 genes did not predict heatstressrelated cisresponse elements. The results of this study have important reference value for further studying the mechanism of BrPLD gene family responding to high temperature stress.