Molecular factors affecting plant architecture

植物的所有气生组织都来源于存在于顶端或茎尖分生组织的少量干细胞。当这些细胞分裂时，它们被推离它们的起源，中心区，进入外周区，在那里它们遇到不同的分子环境并被诱导进行分化。根据植物生命周期中发生这种情况的时间和地点，侧向器官被精心制作，采取花，叶或茎的形式。我们现在知道了一些控制干细胞增殖和分化的分子成分，我们对花、叶和根的发育也有了相当多的了解。目前明显缺乏的是对茎发育的描述。 几年前，我的实验室开始了这样一个项目，选择专注于模式植物拟南芥的短梗突变体。 这种突变体表现出许多发育缺陷。这是一个半侏儒，我们已经表明，细胞分裂的过程是妥协。该突变体还表现出两种不同类型的“弯曲”：一种在茎分支点，另一种在花分支点。此外，支持花的短茎，花梗，非常短（因此有突变体的绰号）。BP基因编码一个调节因子，许多证据表明，它有助于促进生长能力的状态，这样，在它的情况下，生长和分化是compromised.My实验室取得了重大进展，了解茎和花梗的发展，拟议的研究旨在进一步了解BP如何调节（和调节）其他基因控制形态发生。 我们将使用一系列的遗传，分子，生物化学和细胞学工具，以确定相互作用的合作伙伴和解剖的生化和信号转导途径，介导BP行动。这些研究将巩固我们对植物结构如何在细胞和分子水平上指定的理解，并可用于考虑对具有农学价值的植物进行定向改变，例如提高其生产力。这项研究提供了机会，以培养一些科学家，准备他们的职业生涯中的基础和应用研究。

All aerial tissues of plants are derived from a small number of stem cells present at the apex, or shoot apical meristem. As these cells divide, they are pushed away from their origin, the central zone, into the peripherial zone, where they encounter a different molecular environment and are induced to undergo differentiation. Depending on when and where this occurs during the plant life cycle a lateral organ is elaborated, taking the form of a flower, a leaf, or a stem. We now know some of the molecular components that govern stem cell proliferation and differentiation and we know quite a lot about floral, leaf and root development. What has been conspicuously lacking is a description of stem development.  Several years ago my laboratory embarked on such a project, choosing to focus on the brevipedicellus (bp) mutant of the model plant Arabidopsis thaliana.  This mutant exhibits a number of developmental defects. It is a semi-dwarf and we have shown that the process of cell division is compromised. The mutant also exhibits two distinct types of 'bends': one at stem branch points, and the other at floral branch points. In addition, the short stem that supports the flower, the pedicel, is very short (hence the mutant moniker). The BP gene encodes a regulatory factor, and many lines of evidence suggest that it serves to promote a growth competent state, such that in its absence, growth and differentiation are compromised.My laboratory has made significant inroads towards understanding stem and pedicel development, and the proposed research is aimed at furthering our knowledge of how BP regulates (and is regulated by) other genes that control morphogenesis.  We will use a battery of genetic, molecular, biochemical and cytological tools to identify interacting partners and dissect the biochemical and signal transduction pathways that mediate BP action. These studies will solidify our understanding of how plant architecture is specified at the cellular and molecular levels, and may be used to contemplate directed changes to plants of agronomic value such as to increase their productivity. This research affords the opportunity to train a number of scientists, preparing them for careers in basic and applied research.