Center for Plant Cell Biology, Institute for Integrative Genome Biology, Department of Botany and Plant Sciences, 4202B Genomics, University of California, Riverside, CA 92521, USA.
J Exp Bot. 2011 Jan;62(2):583-93. doi: 10.1093/jxb/erq296. Epub 2010 Oct 11.
In Arabidopsis floral meristems are specified on the periphery of the inflorescence meristem by the combined activities of the FLOWERING LOCUS T (FT)-FD complex and the flower meristem identity gene LEAFY. The floral specification activity of FT is dependent upon two related BELL1-like homeobox (BLH) genes PENNYWISE (PNY) and POUND-FOOLISH (PNF) which are required for floral evocation. PNY and PNF interact with a subset of KNOTTED1-LIKE homeobox proteins including SHOOT MERISTEMLESS (STM). Genetic analyses show that these BLH proteins function with STM to specify flowers and internodes during inflorescence development. In this study, experimental evidence demonstrates that the specification of flower and coflorescence meristems requires the combined activities of FT-FD and STM. FT and FD also regulate meristem maintenance during inflorescence development. In plants with reduced STM function, ectopic FT and FD promote the formation of axillary meristems during inflorescence development. Lastly, gene expression studies indicate that STM functions with FT-FD and AGAMOUS-LIKE 24 (AGL24)-SUPPRESSOR OF OVEREXPRESSION OF CONTANS1 (SOC1) complexes to up-regulate flower meristem identity genes during inflorescence development.
在拟南芥的花分生组织中，由 FLOWERING LOCUS T（FT）-FD 复合物和花分生组织身份基因 LEAFY 的联合作用在花序分生组织的外围被指定。FT 的花分生组织指定活性依赖于两个相关的 BELL1 样同源盒（BLH）基因 PENNYWISE（PNY）和 POUND-FOOLISH（PNF），它们是花诱导所必需的。PNY 和 PNF 与包括 SHOOT MERISTEMLESS（STM）在内的一组 KNOTTED1-LIKE 同源盒蛋白相互作用。遗传分析表明，这些 BLH 蛋白与 STM 一起在花序发育过程中指定花和节间。在本研究中，实验证据表明花和合生分生组织的指定需要 FT-FD 和 STM 的联合活性。FT 和 FD 还调节花序发育过程中的分生组织维持。在 STM 功能降低的植物中，异位 FT 和 FD 在花序发育过程中促进腋生分生组织的形成。最后，基因表达研究表明，STM 与 FT-FD 和 AGAMOUS-LIKE 24（AGL24）-SUPPRESSOR OF OVEREXPRESSION OF CONTANS1（SOC1）复合物一起作用，在花序发育过程中上调花分生组织身份基因。
