Abstract
Background Glyoxalase I (GLYI) and glyoxalase II (GLYII), two enzymes of the glyoxalase pathway, are responsible for the detoxification of a cytotoxic metabolite methylglyoxal (MG) into the nontoxic S-D-lactoylglutathione, which play crucial roles in stress tolerance in various plant species. Considering the roles of glyoxalases, the GLY gene families have been analyzed in higher plant, such as rice, soybean and Chinese cabbage; however, little is known about them in rapeseed (Brassica napus L.). The B. napus glyoxalase pathway is worth an in-depth investigation about the presence, distribution, localizations, and expression of glyoxalase genes. Result In this study, a total of 35 BnaGLYI and 30 BnaGLYII genes were identified in the B. napus genome, and they were clustered into six and eight subfamilies, respectively. The classifications, chromosomal distributions, gene structures, and conserved motifs were predicted and analyzed. Importantly, these genes were mainly localized in chloroplast and cytoplasm. Moreover, their expression profiles varied among different tissues. For example, BnaGLY genes are expressed in most organs but tend to be highly expressed in a single organ, such as BnaGLYI27 and BnaGLYII19; while some members are only expressed in specific tissues, e.g., BnaGLYI32 only expressed in silique pericarps. Some genes were induced at different germination stages. Notably, a number of BnaGLY genes showed responses to Plasmodiophora brassicae infection. Conclusion This study systematically identifies BnaGLYI and BnaGLYII gene families in B. napus. The different sub-cellular organelles and expression analysis offer insight into their biological roles and function in plant development and stress resistance.