AtCPL1调控拟南芥开花的机制

RNA聚合酶II CTD磷酸化酶1 (CPL1)作为影响RNA聚合酶II磷酸化水平的重要因子, 在植物逆境响应、离子吸收以及成花诱导等生命过程中扮演重要角色。为深入探究CPL1参与植物开花时间调控的作用机制, 以拟南芥(Arabidopsis thaliana) AtCPL1突变体cpl1-3和fry2-1为研究材料, 观察了长日照条件下突变体与野生型的开花时间, 并利用荧光定量PCR技术对突变体中开花相关基因的表达情况进行了检测。结果表明: 在长日照条件下, 突变体cpl1-3和fry2-1抽薹时的莲座叶数目均显著多于野生型, 且表现出明显的开花时间延迟现象; 荧光定量PCR分析显示, 突变体cpl1-3和fry2-1中开花抑制因子miR156a、TOEs和SMZ基因的表达量较野生型显著升高, 而开花促进因子FT、FD、CO和miR172基因的表达量则显著降低。由此推测, AtCPL1通过调控miR156和miR172的表达水平进而影响下游开花相关基因TOEs、SMZ、FT、FD及CO等的表达, 从而实现对拟南芥开花时间的调控。

Mechanism of AtCPL1 in Regulating Flowering of Arabidopsis

CTD-phosphatase-like 1 (CPL1), the RNA polymerase II, plays an important role in plant stress responses, ion absorption and floral induction by regulating the phosphorylation of RNA polymerase II. To study the mechanism of CPL1 involved in regulation of flowering, two AtCPL1 mutants, cpl1-3 and fry2-1, were used for observing differences in flowering phenotype. Deletion of AtCPL1 caused flowering delay in Arabidopsis under long-day conditions. Moreover, the expression of genes related to flowering regulatory pathways in cpl1-3 and fry2-1 mutants were analyzed by qRT-PCR. The expression of FT, FD, CO and miR172 was significantly upregulated in cpl1-3 and fry2-1 mutants, but that of miR156a, TOEs and SMZ was significantly downregulated. AtCPL1 may be involved in the regulation of flowering in Arabidopsis as a positive regulatory factor, perhaps by regulating the expression of miR156 and miR172, which affect the expression of flowering-related genes.