National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, ChinaKey Laboratory of Plant Stress Research of Shandong Province, College of Life Sciences, Shandong Normal University, Jinan 250014, ChinaState Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
J Integr Plant Biol. 2011 Oct;53(10):770-82. doi: 10.1111/j.1744-7909.2011.01072.x.
Previous studies have demonstrated that petal shape and size in legume flowers are determined by two separate mechanisms, dorsoventral (DV) and organ internal (IN) asymmetric mechanisms, respectively. However, little is known about the molecular mechanisms controlling petal development in legumes. To address this question, we investigated petal development along the floral DV axis in Lotus japonicus with respect to cell and developmental biology by comparing wild-type legumes to mutants. Based on morphological markers, the entire course of petal development, from initiation to maturity, was grouped to define 3 phases or 13 stages. In terms of epidermal micromorphology from adaxial surface, mature petals were divided into several distinct domains, and characteristic epidermal cells of each petal differentiated at stage 9, while epidermal cells of all domains were observed until stage 12. TCP and MIXTA-like genes were found to be differentially expressed in various domains of petals at stages 9 and 12. Our results suggest that DV and IN mechanisms interplay at different stages of petal development, and their interaction at the cellular and molecular level guides the elaboration of domains within petals to achieve their ideal shape, and further suggest that TCP genes determine petal identity along the DV axis by regulating MIXTA-like gene expression.
先前的研究表明，豆科植物花的花瓣形状和大小分别由两个独立的机制决定，即背腹（DV）和器官内（IN）不对称机制。然而，对于控制豆科植物花瓣发育的分子机制知之甚少。为了解决这个问题，我们通过比较野生型豆科植物和突变体，从细胞和发育生物学的角度研究了豌豆花瓣沿花 DV 轴的发育。基于形态学标记，将花瓣从起始到成熟的整个发育过程分为 3 个阶段或 13 个时期。从腹面表皮微形态学来看，成熟的花瓣分为几个不同的区域，在第 9 期，每个花瓣的特征性表皮细胞分化，而所有区域的表皮细胞则一直观察到第 12 期。在第 9 期和第 12 期，在花瓣的不同区域发现了 TCP 和 MIXTA 样基因的差异表达。我们的结果表明，DV 和 IN 机制在花瓣发育的不同阶段相互作用，它们在细胞和分子水平上的相互作用指导着花瓣内部区域的精细化，以实现其理想的形状，并进一步表明 TCP 基因通过调节 MIXTA 样基因的表达来决定花瓣在 DV 轴上的身份。
