| Poplar has the advantages of fast growth,easy reproduction,easy to grow forests,and wide use of wood.It is used for fast-growing and high-yield forests,industrial timber forest construction,Windbreak and Sand-fixation,etc.It is widely introduced and cultivated and plays an important role in our country’s economy and ecology.However,with the deterioration of soil salinization and drought,it restricts the development of our country’s forestry and seriously affects the ecological and environmental balance.Improving the stress resistance of poplars through genetic engineering breeding is a current research hotspot.In this study,wild-type Populus hopeiensis was used as a control,the changes of the physiological indexes of resistance to reverse were measured after salt stress and drought stress,and the expression of PtWOX11/12a gene in leaves and roots was measured under different stress gradients.Besides,its salt tolerance and drought resistance were preliminarily evaluated.the main results were as follows:（1）PCR and RT-PCR were used to identify the transgenic plants from DNA and RNA levels.The results showed that 760 BP bands were amplified from 1,3,4 and 12lines,which preliminarily proved that the target gene PtWOX11/12a gene had been successfully transformed into the genome of 1,3,4 and 12 lines,and the relative expression level of PtWOX11/12a gene in plant line 12 was the highest,which was 1770times that of wild-type plant.（2）Under 300mmol·L-1NaCl stress,RT-PCR detection showed that the PtWOX11/12a gene expression level in the root of transgenic 1,3,4 and 12 lines were significantly up-regulated,indicating that PtWOX11/12a gene actively responded to salt stress through the root;The related physiological indexes showed that the plant height,average growth of ground diameter,chlorophyll a content,chlorophyll b content,SOD activity,and POD activity of the transgenic 1,3,4 and 12 lines were higher than wild type,and the MDA content was lower than wild type,which indicated that PtWOX11/12a can significantly increase Plant salt tolerance.（3）Under 10%PEG 6000 stress,RT-PCR detection showed that the PtWOX11/12a gene expression level in the roots of the transgenic 1,3,4 and 12 lines were significantly up-regulated,indicating that the PtWOX11/12a gene actively responded to drought stress through the roots;The related physiological indexes showed that the average growth of plant height and ground diameter of the transgenic 1,3,4 and 12 lines significantly higher than wild type,and with the increase of drought intensity,the content of chlorophyll a,chlorophyll b,SOD,and POD were significantly higher than wild type.While the content of MDA was lower than the wild type,which indicated that PtWOX11/12a can significantly improve the drought resistance of plants. |
