The Roles Of A Gene Encoding Glyoxalase From Banana (Musa Ssp.) Under Abiotic Stresses

Banana is a typical tropical fruit. It Mainly distributes in the north and south latitude 30°within the tropical and subtropical regions.In our country, bananas are mainly distributed in Guangdong, Guangxi, Fujian, Taiwan, Yunnan and Hainan.Guizhou, Sichuan, Chongqing, also a small amount of cultivation. Banana growth and development were impacted by climate-sensitive factor,such as low temperature, drought, and typhoons. With the deterioration of the natural environment, soil salinization has also seriously affected the growth and development of bananas, these environmental factors seriously affect plant growth and development, resulting in a large number of cuts.In the previous study, we have cloned a cDNA sequence encoding glyoxalaseⅠ(GLO I) from a banana fruit. The full length of MaGLO14 cDNA was 1195bp with an open reading frame encoding 292 amino acids. the sequence has the second signature patterns of glyoxalase I. It located in the central section of the protein and contains a conserved histidine that could be implicated in the binding of the zinc atom. The amino acid sequence is GT.. GFGHFAIASED, at 92-104.Phylogenetic analysis showed that it has closest relationship with rice glyoxalase I and furthest genetic relationship with Ralstonia solanacearum, Named Maglol4, RT-PCR analysis showed that MaGLO14 expressed in all organs, including roots, stems, leaves, flowers and fruits. The expression level was higher in leaves, flowers and fruits than other organs. Previous studies show that the glyoxalase closely related with salt and heavy metal Zn.In order to study the response of Maglol4 to abiotic stresses, banana seedlings have been treated with NaCl, chilling, injury, ethylene, drought and waterlogging. RT-PCR analysis showed that Maglo14 expression was up-regulated by NaCl, Chilling, injury, ethylene while no significant difference under drought and waterlogging stress.To further study the function of Maglo14, a plant expression vector named pCAMBIA1304-Maglol4 was constructed and transformed tobobacco. The transgenic plants were obtained by Agrobacterium mediated transformation of leaf discs, we obtained a total of five molecular detection of transgenic tobacco. After treated with 400mM and 800mM of NaCl, transgenic tobacco has greater tolerance than the wild type. Determination of chlorophyll content also showed that the chlorophyll content of transgenic tobacco was higher than wild-type tobacco. Preliminary experiments demonstrated that transgenic tobacco has higher salt tolerance than the wild-type tobacco.Another yeast expression vector was constructed named pYES2-Maglo14.The transgenic yeast were obtained by lithium chloride transformation method. Similarly, after inducing 30h at 30℃with Induction medium containing galactose,transgenic yeast was treated with NaCl, NaHCO3, Na2CO3, drought, high temperature (53℃), freezing (-20℃) and the ultraviolet radiation stress, the results of experiment showed that the survival rate of transgenic yeast is higher than wild-type yeast under salt, drought, freezing (-20) stresses,but no difference under high temperature (53℃) and ultraviolet radiation stress. At the same time, yeast cells were treated with Al and then stained with FDA-PI. The result showed that the transgenic yeast had stronger tolerance than the wild-type.