高等植物器官是由多种分化细胞按特定空间分层排列组成，如叶片包括表皮、皮层和叶脉等多层细胞。气孔是所有陆生植物地上部重要表皮细胞结构，调控着气体交换和水分蒸发，直接影响了植物光合作用和水分有效利用效率。CHALLAH和STOMAGEN是茎、叶内层细胞产生的EPF家族分泌多肽，通过未知的层间细胞间信号传递途径与表皮细胞中EPF多肽竞争结合TOO MANY MOUTHS（TMM）和ERECTA家族受体，从而影响表皮气孔发生和分布格局。已知STOMAGEN表达受到生长素信号途径ARF5调控。我们前期也发现油菜素内酯可通过BRASSINAZOLE RESISTANT1负调控CHALLAH亚家族基因表达，从而导致tmm突变体茎表皮气孔簇形成。本项目拟进一步探讨器官发育中内层组织信号对表皮气孔发育动态作用模式，揭示植物发育中激素信号调控层间细胞间通讯和细胞分裂、分化协同的分子细胞生物学机制。

Higher plant organs consist of multiple types of differentiated cells that are organized in layers, such as a leaf including a several layers of cells from epidermis, cortex and veins. Coordination of cell division and differentiation between different layers is critical for the proper organ morphogenesis and physiological functions. Stomata are specialized cell structure in epidermis of the aboveground parts of all land plants, controlling gas exchange and water evaporation, directly affecting the efficiency of photosynthesis and water using. CHALLAH and STOMAGEN, which are EPF family peptides secreted by inner layer cells in stems and leaves, can change stomatal production and distribution via a competition with epidermal EPFs on binding TMM-ERf receptors. It was found that STOMAGEN expression is regulated by ARF5 in auxin signaling pathway. Our previous study demonstrated that brassinosteroid induced stomatal clusters in tmm stems through a BRASSINAZOLE RESISTANT1-mediated suppression of CHALLAH subfamily genes. In this project, we will further investigate the dynamic effects of signals from interior tissue on stomatal development in epidermis, and the cellular and molecular mechanisms of phytohormones in cell communications and coordination of cell division and differentiation during the plant development.