转ThIPK2基因大豆的农艺性状及光合生理研究

将抗逆基因ThIPK2转入东农50,得到稳定遗传株系,将T4代株系种子正常播种,将转基因植株与对照东农50的生育期、株高、主茎节数、分枝数、主茎荚数、分枝荚数、单株粒数等性状进行比较,研究ThIPK2基因对大豆农艺性状方面的影响。结果表明,在正常条件下,转基因株系和对照植株相比,生育期并没有改变,而株高、主茎荚数、分枝荚数、分枝数和单株粒数农艺性状呈显著或极显著提高,这表明ThIPK2基因对提高大豆产量有利。干旱胁迫导致大豆叶片各项光合生理指标下降;但转ThIPK2基因大豆的各项光合生理指标高于非转基因对照。经干旱胁迫后,转基因植株与对照相比积累了更多的干物质。

ThIPK2基因植物表达载体的构建

为培育高度抗逆和无选择标记的转基因小麦,本研究从NCBI数据库中搜索到ThIPK2基因序列,依据该基因编码的氨基酸序列,参照小麦偏爱的密码子对该基因进行密码子优化,并将重复的和不必要的酶切位点去掉后进行人工合成。将改造后的ThIPK2基因插入到强启动子Ubiquitin和终止子AtSac66之间,然后将其插入到含有玉米Ac/Ds转座子背景骨架的植物表达载体中,获得了具有删除选择标记功能的、由玉米Ubiquitin启动子驱动ThIPK2基因的植物表达载体。经过限制性内切酶分析鉴定,该植物表达载体构建成功。

Heterologous expression of the ThIPK2 gene enhances drought resistance of common wheat

Th IPK2 is an inositol polyphosphate kinase gene cloned from Thellungiella halophila that participates in diverse cellular processes. Drought is a major limiting factor in wheat(Triticum aestivum L.) production. The present study investigated whether the application of the Th IPK2 gene could increase the drought resistance of transgenic wheat. The codon-optimized Th IPK2 gene was transferred into common wheat through Agrobacterium-mediated transformation driven by either a constitutive maize ubiquitin promoter or a stress-inducible rd29 A promoter from Arabidopsis. Molecular characterization confirmed the presence of the foreign gene in the transformed plants. The transgenic expression of Th IPK2 in wheat led to significantly improve drought tolerance compared to that observed in control plants. Compared to the wild type(WT) plants, the transgenic plants showed higher seed germination rates, better developed root systems, a higher relative water content(RWC) and total soluble sugar content, and less cell membrane damage under drought stress conditions. The expression profiles showed different expression patterns with the use of different promoters. The codon-optimized Th IPK2 gene is a candidate gene to enhance wheat drought stress tolerance by genetic engineering.

农杆菌介导的籼稻科恢675快速遗传转化体系的建立

本研究以籼稻科恢675成熟种子为材料进行了农杆菌介导的ThIPK2基因遗传转化。结果显示:持续高温光照培养使得愈伤诱导和继代只需10～14 d,有效缩短了愈伤获得周期,且愈伤诱导率可达95.6%。抗性愈伤率为10.6%,持续高温光照培养使得抗性愈伤继代5～7 d就可大量繁殖,且抗性愈伤分化率达48.8%。经第一次继代后的愈伤转化效率显著高于未经继代的愈伤的转化效率。因此,此转化系统有效缩短了水稻转化周期,优化了籼稻遗传转化,同时为抗逆基因转入籼稻提供了参考。