| Pear is one of the most widely cultivated friut trees in China.Its annual output is only inferior to that of citrus and apple.The development of pear industry plays a crucial role in the rise of agricultural economy in China.At present,the continuous improvement of people's living standards,the demand for fruit is expanding,and the pear industry has ushered in a huge space for development.In production and cultivation,drought is one of the most common terrain and external environmental factors.It has a crucial impact on the growth and development,geographical distribution and yield of plants.Therefore,how to improve plant drought resistance has been an extremely important research direction in the long term,and it is also the most extensive researched subjects for the breeders research.Although some artificial cultivation methods can improve the drought resistance of plants,the most effective solution is to cultivate new varieties with drought-resistant capacity.As a supplementary means of traditional breeding,the current genetic engineering has been proved to be an effective and feasible new method.However,the premise of genetic engineering breeding is to find genes with drought resistance function.According to previous research reports,that plant WRKY gene plays an very important role in plant drought stress of plants.Therefore,PbrWRKY53 gene was isolated and cloned from Pyrus betulifolia,and its resistance function was identified.The main purpose is to understand the resistance mechanism of PbrWRKY53 gene in order to obtain the pear resistant gene resources with independent intellectual property rights.The experimental results are shown as follows:In this study,we used electronic cloning technology to obtain a PbrWRKY53 gene from the Pyrus betulifolia.The PbrWRKY53 had a complete open reading frame of 1044 bp,encoding 347 amino acids,the molecular weight of this gene is 38.76 KDa,and the isoelectric point(pI)is 5.80.Sequence alignment showed that PbrWRKY53 has high homology with WRKY genes of other species.Subcellular localization of PbrWRKY53 gene in the nucleus.The transcript levels of PbrWRKY53 were up-regulated under various abiotic stresses,particularly dehydration.Over-expression of PbrWRKY53 gene positive tobacco plants enhanced the tolerance of plants to drought stress.In dry water stress under the condition of bad environment,transformation of super positive expression of transgenic tobacco plants with no wild type,by contrast,the former had lower expression of strain ROS acumulants,overexpression of plant gene expression content is higher,over-expression plant chlorophyll content is higher in organizations,and over-expression of three kinds of the activity of antioxidant enzymes in strain organization significantly higher than that of wild type plants.Over-expression PbrWRKY53 Pyrus ussuriensis experiments show that under natural drought condition,over-expression Pyrus ussuriensis plant ROS acumulants was significantly less than the wild type plants of no conversion,over-expression of Pyrus ussuriensis plant chlorophyll content significantly greater than no conversion of wild type plants,as well as the over-expression of three kinds of the activity of antioxidant enzymes in plant organization than the wild type strain controlled significantly improved.The above experimental results show that overexpression of PbrWRKY53 gene can effectively improve the drought resistance of transgenic plants,and the PbrWRKY53 gene is a crucial candidate gene for future genetic engineering drought tolerance breeding. |
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