欧美杨锌指蛋白转录因子基因(ZxZF)的遗传转化及抗旱性初步分析

Transformation of Zinc Finger Protein Transcription Factor Gene (ZxZF) and Preliminary Evaluation of Drought Tolerance in Populus × euramericana

C2H2型锌指蛋白转录因子在激活胁迫相关基因、增强植物抗逆性方面具有重要的作用。以来自极端抗逆木本植物霸王C2H2型锌指蛋白转录因子基因(ZxZF)为外源基因,利用农杆菌介导法对欧美杨‘渤丰1号’进行遗传转化。经卡那霉素筛选获得80株抗性植株,通过PCR检测获得17株呈阳性植株,Southern印记杂交检测证实外源基因以单拷贝方式整合到5个转基因株系体内,RT-PCR及qRT-PCR分子检测表明,外源基因在4个转基因株系中成功表达。PEG模拟干旱胁迫试验结果初步表明,转基因株系叶片相对含水量和脯氨酸含量均显著高于非转基因植株10%以上,转基因株系抗旱性得到一定程度提高。研究表明ZxZF转录因子基因对提高转基因杨树抗旱能力具有重要作用,在培育抗旱林木优良品种中具有重要育种价值。

The C2H2 zinc finger protein transcription factor plays an important role in the activation of stress-related genes, and increase in plant resistance. In this study, an C2H2 zinc finger protein transcription factor （ZxZF） from shrub Sarcozygium xanthoxylon with strong drought tolerance was used as exogenous gene, and the Agrobacterium-mediated method was applied for transgenie transformation to an elite hybrid clone of Populus x euramericana cl. ＇ Bofengl ＇ A total 80 resistant plants were gained via strict selection by kanamycin. Among them 17 positive transgenic plants were verified by PCR analysis, and five transgbnic plants were finally confirmed with one copy of the exogenous gene by Southern blot analysis. Four of these clones were verified over-expression of ZxZF by RT-PCR and qRT-PCR analysis. Under the drought stress conditions, transgenic clones showed more than 10% significantly higher of relative water content （RWC） and accumulation of proline content, compared with non-transgenic control plants. These results showed an improved tolerance to drought stress in transgenic poplar. Our study suggested that ZxZF transcription factor played a crucial role in transgene poplar response to drought stress and was useful in developing trees with enhanced tolerance to drought.