Ferrándiz C, Gu Q, Martienssen R, Yanofsky M F
Department of Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA.
Development. 2000 Feb;127(4):725-34. doi: 10.1242/dev.127.4.725.
The transition from vegetative to reproductive phases during Arabidopsis development is the result of a complex interaction of environmental and endogenous factors. One of the key regulators of this transition is LEAFY (LFY), whose threshold levels of activity are proposed to mediate the initiation of flowers. The closely related APETALA1 (AP1) and CAULIFLOWER (CAL) meristem identity genes are also important for flower initiation, in part because of their roles in upregulating LFY expression. We have found that mutations in the FRUITFULL (FUL) MADS-box gene, when combined with mutations in AP1 and CAL, lead to a dramatic non-flowering phenotype in which plants continuously elaborate leafy shoots in place of flowers. We demonstrate that this phenotype is caused both by the lack of LFY upregulation and by the ectopic expression of the TERMINAL FLOWER1 (TFL1) gene. Our results suggest that the FUL, AP1 and CAL genes act redundantly to control inflorescence architecture by affecting the domains of LFY and TFL1 expression as well as the relative levels of their activities.
拟南芥发育过程中从营养生长阶段向生殖生长阶段的转变是环境因素和内源因素复杂相互作用的结果。这种转变的关键调节因子之一是LEAFY（LFY），其活性阈值水平被认为介导花的起始。密切相关的APETALA1（AP1）和CAULIFLOWER（CAL）分生组织特征基因对花的起始也很重要，部分原因是它们在上调LFY表达中发挥作用。我们发现，FRUITFULL（FUL）MADS盒基因的突变与AP1和CAL的突变相结合时，会导致一种显著的不开花表型，即植物持续发育出多叶枝条而不是花。我们证明这种表型是由LFY上调缺失和TERMINAL FLOWER1（TFL1）基因的异位表达共同引起的。我们的结果表明，FUL、AP1和CAL基因通过影响LFY和TFL1的表达域及其活性的相对水平，在控制花序结构方面发挥冗余作用。
