EPF2 and the Molecular Regulation of Stomatal Development

气孔是叶片表面的气孔，它允许植物内部和大气之间通过蒸腾交换光合作用的气体和损失水蒸气。人们普遍认为，气孔的进化以及它们控制水分流失的能力，是植物对陆地的殖民以及随后它们在陆地环境中传播的基础。今天，气孔行为支撑着我们的作物生产力，了解控制气孔发育和功能的途径从未像现在这样重要。虽然众所周知，植物通过关闭气孔来适应干旱等逆境，但在长期暴露于环境变化的情况下，它们通过调整新叶上发育的气孔数量来进一步适应。为了让叶子有效地发挥作用，它们的气孔频率和间距必须是最佳的，植物科学家已经开始识别一些调节这一点的遗传因素。我们最近鉴定了一种因子，它和哺乳动物激素胰岛素一样，是一种分泌肽。缺乏该肽的植物形成额外的气孔，在叶表面形成许多额外的气孔前体细胞。被操控过多生产这种多肽的植物几乎不会形成气孔，生长缓慢。因此，我们研究的多肽是一种气孔发育的抑制因子。在这个项目中，我们将更多地了解这种肽信号是如何工作的。我们将找出这种多肽是否与其他被确定为调节气孔发育的因素一起起作用，我们还将调查它是否像胰岛素一样被一种酶激活，这种酶首先将它分解成更小的片段。

Stomata are pores on the surface of leaves which allow exchange of gas for photosynthesis and loss of water vapour via transpiration between the interior of the plant and the atmosphere. The evolution of stomata, and their ability to control water loss, is widely believed to have underpinned the colonisation of the land by plants and their subsequent spread throughout terrestrial environments. Today, stomatal behaviour underpins our crop productivity, and it has never been more important to understand the pathways that control stomatal development and function. Although plants are well known to adapt to stresses such as drought by closing their stomata, under longer term exposure to environmental change they adapt further by adjusting the number of stomata that develop on their new leaves. For leaves to function efficiently the frequency and spacing of their stomata must be optimal, and plant scientists have begun to identify some of the genetic factors that regulate this. We have recently characterised a factor which like the mammalian hormone insulin, is a secreted peptide. Plants lacking this peptide develop extra stomata, and many extra stomatal precursor cells are formed in the leaf surface. Plants manipulated to overproduce the peptide develop almost no stomata and grow slowly. Thus, the peptide we have studied is an inhibitor of stomatal development. In this project we will find out more about how this peptide signal works. We will find out whether the peptide works together with other factors identified as regulating stomatal development, and we will investigate whether it, like insulin, is activated by an enzyme that first breaks it into smaller fragments.