Abstract: We used transgenic technology to cultivate stress-resistant varieties of Populus ussuriensis Kom, which was one of the most significant means of molecular breeding.With three expressed LbDREB lines and one wild type(WT), under the condition of PEG6000, which simulated the treatment of the drought stress, we investigated the growth of different lines, and the relative expression levels of LbDREB and biochemical indicators.With the increase of PEG stress time, the root phytomass of expressed LbDREB line was more than wild type.Meanwhile, the variational trends of SOD and POD were similar to the LbDREB expression level, which presented the upward trend, the downward trend and eventually beingrising.Additionally, transgenic lines contained stronger protective enzymes activity and proline content than wild type.However, the MDA accumulation and relative conductivity of transgenic lines were less than wild type.The drought tolerance ability of transgenic lines was superior to wild type, furthermore, the up-regulated expression of LbDREB probably played an important role in drought resistant in plant.The transgenic line named Dr2 was perfect in the different index of drought resistant, which could be preliminary screened as the excellent drought resistant clones of P.ussuriensis Kom.

Key words: Populus ussuriensis Kom., LbDREB gene, drought stress, transient expression