低磷条件下过表达OsPHF1基因对粳稻农艺性状的影响

Agronomic Traits of Marker-free Transgenic japonica Rice with Overexpression of OsPHF1 Under Low Phosphorus Environment

【目的】磷酸盐转运体运输协助因子(PHF1)通过转录后调节特定磷转运蛋白,影响磷酸盐的利用效率。本研究通过培育过表达OsPHF1的无选择标记转基因粳稻空育131,研究在不同磷浓度环境中OsPHF1的过表达对粳稻空育131产量的影响,为培育可商品化的磷高效转基因水稻品种提供依据。【方法】利用双T-DNA方法构建OsPHF1的过表达载体,通过农杆菌侵染法和后续筛选获得了无选择标记的转基因空育131纯合株系,通过对T_3和T_4代转基因植株的田间试验,研究转基因品系在低磷浓度(75或112.5 kg/hm^2过磷酸钙)、中低磷浓度(225或300 kg/hm^2过磷酸钙)和正常磷浓度(450 kg/hm^2过磷酸钙)下的农艺性状。【结果】获得了3个无筛选标记的纯合OsPHF1过表达转基因空育131株系F18-18、F22-32和F25-6。其中,F22-32和F25-6的OsPHF1的表达量远高于野生型。大田试验显示,F22-32和F25-6株系的T_3代在中低磷(300kg/hm^2过磷酸钙)环境中,分蘖数比对照分别增加了55%和25%,增产幅度分别为38%和34%;F22-32和F25-6株系T_4代在低磷条件下(112.5kg/hm^2过磷酸钙)产量的增幅最大,增产了30%～35%;在中低磷条件下(225 kg/hm^2过磷酸钙)分蘖数和产量也有明显增加。【结论】双T-DNA法能用于培育过表达OsPHF1的无筛选标记转基因水稻。田间试验显示,高表达OsPHF1的转基因株系在中低磷条件下(112.5、225或300 kg/hm^2过磷酸钙)分蘖数和产量稳定增加。

【Objective】PHF1(phosphate transporter assistance factor)regulates specific phosphorous transporters after transcriptional regulation and affects the utilization efficiency of phosphate.The main purpose is to develop selective-marker-free OsPHF1-overexpressed japonica rice(Kongyu 131),and study the agronomic traits of transgenic rice at different low phosphorus concentrations.It contributes to the cultivation of transgenic rice varieties with high phosphorus utilization efficiency.【Method】Marker-free OsPHF1-overexpressed transgenic lines were obtained by using double T-DNA methods,Agrobacterium-mediated infection and subsequent screening.The field experiments for T3 and T4 generations of transgenic plants were carried out under low phosphorus concentration(75 or 112.5 kg/hm2 calcium superphosphate)medium-to-low phosphorus concentrations(225 or 300 kg/hm2 calcium superphosphate)and normal phosphorus concentration(450 kg/hm2 calcium superphosphate).【Result】Three marker-free homozygous transgenic lines F18-18,F22-32 and F25-6 were obtained.The expression levels of OsPHF1 in lines F22-32 and F25-6 were much higher than that of wild type.Field experiments showed that compared with the wild type,the tiller number of F22-32 and F25-6(T3 generation)were increased by 55%and 25%,respectively and the yield per plant of F22-32 and F25-6 were increased by 38%-34%,respectively under medium-to-low phosphorus environment(300 kg/hm2 calcium superphosphate).The yield of F22-32 and F25-6 transgenic lines(T4)increased by 30%to 35%,the biggest improvement under low phosphorus(112.5 kg/hm2 calcium superphosphate).Meantime,the tiller number and yield of F22-32 and F25-6(T4)also showed obvious boost under medium-to-low phosphorus(225 kg/hm2 calcium superphosphate)levels.【Conclusion】Marker-free OsPHF1 transgenic lines were cultivated using double T-DNA method.Two generation of homozygous transgenic lines showed significantly increased tiller number and yield at medium-to-low phosphorus level(112.5,225 or 300 kg/hm2 calcium superphosphate).