Research On Cold Resistance Transcription Factor Genes PlMBF1b In Poplar

As an important factor, abiotic stresses, especially the extreme temperature, have an influence on plant distribution areas. It is helpful for plants to adapt to the cold weather in winter by improving the resistance of coldness. By this way, we can make effective use of land resources.the transgenosis is an important way to achieve this aim. According to the information of gene BpMBF1 in Arabidopsis genome which was related to the cold resistance,the Blast of NCBI were used to gain the homologous sequence of BpMBF1 in poplar genome.RNA was used for reverse transcription after extracted from Populus×euramericana ‘Neva’.Then the cDNA was used to clone the target gene. After that, it was transformed into the Agrobacterium and the Agrobacterium was used to infect the leaves of Populus×euramericana ‘Neva’. When we gained the transgenic plants, the physiological indexes were tested. The results revealed that:1、PlMBF1b which was in poplar genome(here we named PlMBF1b). The indexes of homlogy was 68 %, respectively. So we chose PlMBF1 b owned 437 bp and encoded144 aa as our target gene.2、After that, we constructed the over-expression vector that contained a fluorescent protein GFP.3、The transgenic plants were tested by agarose gel electrophoresis(AGE). Among them,5 lines were chosen which contained the target gene. qRT-PCR expression analysis were conducted and the results showed that expression levels of 5 lines were 2-fold higher than CK plants.4、As the vector which contained the target gene and GFP was used, subcellular localization were conducted by detecting the fluorescent protein location. The result indicted that the target gene was expressed in the nucleus of cells.5、As the temperature declined, the proline in transgenic plants were increased while the MDA was decreased. The change of the of SOD and POD’s activity were similar. Theactivity of POD in 15 ℃ was higher than other temperatures and the activity of SOD in 20 ℃was higher than other temperatures. When compared the WT, the activity of SOD and POD in transgenic plants were higher.Based on the results above, the PlMBF1 b gene can enhance the cold resistance of Populus×euramericana ‘Neva’ and the results had the practical and theoretical significance.