PTLF-PTAG-IR对转基因烟草开花的抑制效应

PTLF（LEAFY同源基因）和PTAG（AGAMOUS同源基因）是杨树中控制花发育的重要基因,为了解RNA干涉同时抑制PTLF和PTAG对花发育的影响,本研究采用根癌农杆菌（Agrobacterium tumefaciens）介导法将35S：：PTLF-PTAG-IR导入烟草（Nicotiana tabacum）。经PCR检测获得了15株阳性转化株系,进一步的Southern分析证实PTLF-PTAG-IR基因已整合到烟草基因组中。荧光定量分析结果显示,转基因烟草内源NFL（LEAFY同源基因）和NAG1（AGAMOUS同源基因）的表达量均低于野生型。对开花时间调查的结果表明：与野生型烟草相比,53.3%的转基因株系开花受到完全的抑制,26.7%的转基因株系开花时间平均推迟34.3d,仅20%的转基因株系与野生型在同一时期开花。另外,对转基因烟草花器官的观察发现花瓣形态,雄蕊着生方式、数目等方面发生变异,这些研究结果表明过量表达35S：：PTLF-PTAG-IR对烟草花发育起到抑制作用,本研究将为利用转基因手段获得不育材料提供参考。

Repression Effects on Flowering Caused by PTLF-PTAG-IR in Transgenic Tobacco Plants

PTLF（LEAFY homologue gene） and PTAG（AGAMOUS homologue gene） are crucial genes in controlling poplar floral development.To investigate floral inhibition through RNAi of both PTLF and PTAG,RNAi vector of 35S：：PTLF-PTAG-IR was transformed into tobacco（Nicotiana tabacum） via the Agrobacterium tumefaciens-mediated method.The results of PCR showed that we have got 15 transgenic lines.Further Southern analysis approved that the gene of PTLF-PTAG-IR was integrated into tobacco genome.The data of real-time qPCR analysis showed that the expression level of NFL（LFY homologue gene） and NAG1（AGAMOUS homologue gene） were lower than wild type control.The results of the investigation indicated that 53.3% of the 15 transgenic lines did not flower during their life cycles,and flowering time of the 26.7% lines was delayed 34.3 days averagely,while the rest 20% of transgenic lines flowered at the same time with the wild type control.In addition,the flowers of transgenic tobacco lines were also observed,we found that 35S：：PTLF-PTAG-IR in transgenic tobacco plants caused morphological changes of petals and stamens,and numerical change of stamens.All these results of this research suggested that over-expression of 35S：：PTLF-PTAG-IR suppress floral development in tobacco,which would provide a reference for obtaining sterility lines via transgenic engineering.