BpAP1转基因白桦中开花相关基因的时序表达

Quantitative Expression Analysis of Several Flowering-related Genes in Bp AP1 Transgenic Birch( Betula platyphylla×Betula pendula)

为揭示白桦(Betula platyphylla×B.pendula)中Bp AP1转录因子的调控机理,以Bp AP1过表达、抑制表达转基因白桦以及非转基因对照白桦(NT)为试材,对前期获得的Bp AP1转基因白桦中的6条开花相关基因(BpPI、Bp MADS4、Bp MADS5、FT、TFL1和LFY)进行了定量PCR分析,探讨了白桦Bp AP1转录因子与这6条开花基因的表达调控关系以及它们对白桦提早开花的影响。结果表明:非转基因对照与Bp AP1抑制表达转基因白桦叶片中Bp AP1、Bp PI、Bp MADS4、Bp MADS5、FT、TFL1和LFY的相对表达量在不同发育时期变化均不显著。Bp AP1过表达转基因白桦叶片和雄花序中这7条基因的表达量在不同发育时期均显著高于NT和Bp AP1抑制表达转基因白桦。在Bp AP1过表达转基因白桦中,除Bp AP1和TFL1外,其他5条基因在各个时期的雄花序中表达量均为最高,多数基因的表达高峰出现在6月15日;另外,Bp AP1、Bp MADS4、Bp MADS5和Bp PI在8月15日的雄花序中表达量也很高;TFL1的相对表达量在9月1日的叶片中显著上调;LFY基因在生长发育最旺盛的6、7月份的雄花序中达到了表达高峰。Bp AP1与Bp PI、Bp MADS4、Bp MADS5、FT、TFL1、LFY这6条开花相关基因之间均呈极显著的正相关。

We used quantitative real-time PCR （qRT-PCR） of several flowering related genes in BpAP1 transgenic birch to study the regulation relationship between BpAP1 transcription factor and other six flowering related genes for revealing regulation mechanism of BpAP1 transcription factor. By qRT-PCR, BpAP1 overexpression lines, BpAP1 suppression lines and non- transgenic line （NT） were used to analyze the expression of BpAP1, BpPI, BpMADS4, BpMADSS, FT, TFL1 and LFY at the eight developmental stages, and the correlation analysis were employed to reveal the regulation relationship between BpAP1 and other six flowering genes for their effect on early flowering in birch. There was no significant change in expres- sion of BpAP1, BpPI, BpMADS4, BpMADSS, FT, TFL1 and LFY in leaves of NT and BpAP1 suppression lines at different developmental stages. However, expression of these seven genes in leaves and male inflorescences of BpAP1 overexpression lines was significantly higher than that in NT and BpAP1 suppression lines at different developmental stages. BpMADS4, BpMADSS, FT, BpPI and LFY all ectopically expressed in male inflorescences at the eight developmental stages, and the expression peak of most of genes appeared in 15th June. The expression of BpAP1, BpMADS4, BpMADS5 and BpPI was dramatically increased in male inflorescences in 15th August. Relative expression of TFL1 was significantly upregulated in leaves in 1st September. Expression of LFY in male inflorescences appeared peak in June and July. There is a significant positive correlation between BpAP1 and BpPI, BpMADS4, BpMADS5, FT, TFL1, LFY.