水稻丙酮酸激酶基因OsPK1的过表达转基因株系的获得与鉴定

Generation and Characterization of Overexpression Lines of a Rice Pyruvate Kinase Gene OsPK1

利用农杆菌介导的转化方法研究OsPK1过表达对水稻的影响。将CaMV 35S启动子驱动的OsPK1的全长CDS序列导入到日本晴基因组中。选择3个过表达转基因系作为代表进行鉴定和分析。结果显示,过表达植株在株高、分蘖数、穗长和千粒重四方面接近野生型水稻,结实率略下降,但每穗饱满种子数明显增加。通过定量RT-PCR分析,发现有4个代谢酶在过表达植株嫩叶中表达存在着上调或下调。用GC-MS方法检测糖含量,显示OsPK1过表达株系中葡萄糖、果糖、半乳糖和蔗糖的含量与野生型差异不大。总之,对OsPK1过表达株系的鉴定,有助于更好了解OsPK1的功能,并且每穗饱满种子数明显增加具潜在的应用价值。

We have reported that downregulation of OsPK1, a rice pyruvate kinase, causes dwarfism, reduced seed set and so on. Therefore,the aim in this study is to explore the effect of the overexpression of OsPK1 on rice. The construct containing a CaMV 35S-driven full-length CDS of OsPK1 was introduced into the genome of wild-type （WT） Nipponbare via an Agrobacterium-mediated method. Three overexpression lines were selected for further char- acterization and analysis. Statistics showed that these overexpression plants approach WT plants in plant height,tiller number, panicle length and thousand seed weight, while present slightly reduced seed set and significantly increased viable seed number per panicle. Quantitative RT-PCR results exhibited that the expressions of four metabolic en- zymes were downregulated or upregulated in the young leaves of overexpression plants. The sugar contents were measured using GC-MS, and the results indicated that the contents of glucose, fructose, galactose and sucrose in Os- PK1 overexpression plants showed few differences compared with those of WT plants. Together,the characterization of OsPK1 overexpression plants can help us better understand the role of OsPK1 ,and increased viable seed number per panicle should be a prospective application.