Genetic Transformation Of ZxZF Gene And The Evaluation Of Drought Tolerance In Populus×Euramericana Cl.’Bofeng1’

Species in genus Populus are important for forestry industry in China. However the large area with arid or semi arid climate limit the plantation of poplar. In order to produce poplar varieties with high tolerance to drought stress, the Zygophyllum xanthoxylum Zinc finger protein gene ZxZF was transformed into Populus×euramericana cl.’Bofeng1’. The integration of transgene in transgenic plants was confirmed by southern blot analysis and the expression of ZxZF was monitored using qRT-PCR. Drought tolerance was evaluated by analysis of transgenic trees treated with polyethylene glycol (PEG). The results are as following:More than1500positive clones were screened by using kanamycin-resistance selection method, and72of these clones passed the PCR assay. Five transgenic clones were finally confirmed by Southern blot analysis on10clones. Four of these clones that showed over-expression of ZxZF were used in the polyethylene glycol stress experiment.Under the drought stress conditions, transgenic clones showed higher and stability of relative water content (RWC) and less decreased chlorophyll content. A higher accumulation of proline content, low level of malondialdehyde (MDA) content, and higher activity of peroxidase (POD) and superoxide dismutase (SOD) were also observed in transgenic plants relative to non-transgenic control trees. These results showed an improved tolerance to drought stress in transgenic poplar, and provide a foundation for future research.