BRANCHED SILKLESS mediates the transition from spikelet to floral meristem during Zea mays ear development
BRANCHED SILKLESS mediates the transition from spikelet to floral meristem during Zea mays ear development
复制标题
DOI：
10.1046/j.1365-313x.1998.00300.x
复制
发表时间：
1998-11-01
期刊：
影响因子：
7.2
通讯作者：
Pè, ME
中科院分区：
文献类型：
--
作者：
Colombo, L;Marziani, G;Pè, ME
本文对拟南芥和牛头草等典型双子叶植物花序和花发育的分子和遗传调控进行了较详细的研究。相比之下，人们对单子叶植物中这些重要的发育步骤知之甚少。本文报道了玉米突变体分枝无丝1-2 （bd1-2）与bd1等位基因的分析，并以此作为研究玉米从小穗到小花发育转变的工具。bd1-2植株的小花发育在雌花（穗）中受阻，而在雄花（穗状花序）中小花发育几乎正常。详细的表型分析表明，在bd1-2突变体中，穗状花序的形成正常启动，但小穗分生组织不能继续形成小花分生组织。穗小穗，在花期，包含不同数量的小穗状分生组织和颖片状结构。此外，经常观察到从耳基部开始生长的分枝。表达分析表明，在bd1-2突变体的穗部小花中不表达具有花特异性的MADS盒子基因Zea mays AGAMOUS1 （ZAG1）、ZAG2和ZMM2，而在穗部小花中的表达与野生型相似。综上所述，这些数据表明，雌雄同株玉米穗部和穗部对小穗向小花分生组织的发育有差异控制，BRANCHED SILKLESS在玉米雌花发育过程中对小穗向花分生组织的转变起着重要的调节作用。
The molecular and genetic control of inflorescence and flower development has been studied in great detail in model dicotyledonous plants such as Arabidopsis and Antirrhinum. in contrast, little is known about these important developmental steps in monocotyledonous species. Here we report the analysis of the Zea mays mutant branched silkless1-2 (bd1-2), allelic to bd1, which we have used as a tool to study the transition from spikelet to floret development in maize. Floret development is blocked in the female inflorescence (the ear) of bd1-2 plants, whereas florets develop almost normally in the male inflorescence (the tassel). Detailed phenotypic analyses indicate that in bd1-2 mutants ear inflorescence formation initiates normally, however, the spikelet meristems do not proceed to form floret meristems. The ear spikelets, at anthesis, contain various numbers of spikelet-like meristems and glume-like structures. Furthermore, growth of branches from the base of the ear is often observed. Expression analyses show that the floral-specific MADS box genes Zea mays AGAMOUS1 (ZAG1), ZAG2 and Zea mays MADS 2 (ZMM2) are not expressed in ear florets in bd1-2 mutants, whereas their expression in tassel florets is similar to that of wild type. Taken together, these data indicate that the development from spikelet to floret meristem is differentially controlled in the ear and tassel in the monoecious grass species Zea mays, and that BRANCHED SILKLESS plays an important role in regulating the transition from spikelet meristem to floral meristem during the development of the female inflorescence of maize.