Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Plant Cell. 2012 Jan;24(1):80-95. doi: 10.1105/tpc.111.094797. Epub 2012 Jan 27.
The meristem initiates lateral organs in a regular manner, and proper communication between the meristem and the lateral organs ensures the normal development of plants. Here, we show that mutation of the rice (Oryza sativa) gene TONGARI-BOUSHI1 (TOB1) results in pleiotropic phenotypes in spikelets, such as the formation of a cone-shaped organ instead of the lemma or palea, the development of two florets in a spikelet, or premature termination of the floret meristem, in addition to reduced growth of the lemma or palea and elongation of the awn. These phenotypes seem to result from not only failure in growth of the lateral organs, but also defects in maintenance and organization of the meristem. For example, the cone-shaped organ develops as a ring-like primordium from an initial stage, suggesting that regulation of organ initiation in the meristem may be compromised. TOB1 encodes a YABBY protein, which is closely related to FILAMENTOUS FLOWER in Arabidopsis thaliana, and is expressed in the lateral organ primordia without any patterns of polarization. No TOB1 expression is detected in the meristem, so TOB1 may act non-cell autonomously to maintain proper meristem organization and is therefore likely to play an important role in rice spikelet development.
分生组织以规则的方式启动侧生器官，分生组织和侧生器官之间的适当交流确保了植物的正常发育。在这里，我们表明，水稻（Oryza sativa）基因 TONGARI-BOUSHI1（TOB1）的突变导致小穗中出现多种表型，例如形成锥形器官而不是外稃或内稃、小穗中形成两个小花、或小花分生组织过早终止，以及外稃或内稃生长减少和芒伸长。这些表型似乎不仅是由于侧生器官的生长失败，而且还与分生组织的维持和组织缺陷有关。例如，锥形器官从小穗的初始阶段开始作为环状原基发育，这表明分生组织中器官起始的调节可能受到影响。TOB1 编码一个 YABBY 蛋白，与拟南芥中的 FILAMENTOUS FLOWER 密切相关，并且在侧生器官原基中表达，没有任何极化模式。在分生组织中检测不到 TOB1 的表达，因此 TOB1 可能以非细胞自主的方式发挥作用来维持适当的分生组织组织，因此可能在水稻小穗发育中发挥重要作用。
