Smith Harley M S, Hake Sarah
Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
Plant Cell. 2003 Aug;15(8):1717-27. doi: 10.1105/tpc.012856.
Plant architecture results from the activity of the shoot apical meristem, which initiates leaves, internodes, and axillary meristems. KNOTTED1-like homeobox (KNOX) genes are expressed in specific patterns in the shoot apical meristem and play important roles in plant architecture. KNOX proteins interact with BEL1-like (BELL) homeodomain proteins and together bind a target sequence with high affinity. We have obtained a mutation in one of the Arabidopsis BELL genes, PENNYWISE (PNY), that appears phenotypically similar to the KNOX mutant brevipedicellus (bp). Both bp and pny have randomly shorter internodes and display a slight increase in the number of axillary branches. The double mutant shows a synergistic phenotype of extremely short internodes interspersed with long internodes and increased branching. PNY is expressed in inflorescence and floral meristems and overlaps with BP in a discrete domain of the inflorescence meristem where we propose the internode is patterned. The physical association of the PNY and BP proteins suggests that they participate in a complex that regulates early patterning events in the inflorescence meristem.
植物形态建成源于茎尖分生组织的活动，茎尖分生组织可形成叶片、节间和腋生分生组织。类KNOTTED1同源异型框（KNOX）基因在茎尖分生组织中以特定模式表达，并在植物形态建成中发挥重要作用。KNOX蛋白与类BEL1（BELL）同源异型域蛋白相互作用，并共同以高亲和力结合靶序列。我们在拟南芥的一个BELL基因PENNYWISE（PNY）中获得了一个突变，该突变在表型上与KNOX突变体短柄（bp）相似。bp和pny都有随机变短的节间，并且腋生分支数量略有增加。双突变体表现出一种协同表型，即极短节间与长节间相间排列且分支增加。PNY在花序和花分生组织中表达，并在花序分生组织的一个离散区域与BP重叠，我们认为该区域是节间模式化的位置。PNY和BP蛋白的物理结合表明它们参与了一个调节花序分生组织早期模式化事件的复合体。
