GENETIC CONTROL OF LEAF EXPANSION IN ARABIDOPSIS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 中心，不一定是研究者的机构。 本项目旨在通过研究生长素（吲哚乙酸）激素指导模式植物拟南芥叶片扩展的分子/遗传机制来增加对发育的理解。已知生长素通过泛素-26S蛋白体途径触发转录因子的选择性降解。目前还不知道，然而，激素的接收如何导致加速转录因子的降解和改变发育生理学，虽然在这个实验室的早期工作表明，生长素相互作用，在转录因子蛋白水解之前，与第二个非生长素生长效应控制叶扩展。 我们将使用突变分析来解决这里提出的具体目标，包括（1）鉴定与假设的生长效应子的产生相关的基因和（2）鉴定负责植物中生长素控制叶扩展的其他信号转导参与者的基因。 了解植物中泛素化的调节可能会为了解人类正向系统的功能提供见解。几种人类癌症是由泛素途径故障引起的。胡萝卜素也被怀疑是内分泌干扰物。这个子项目的结果也可能导致对这些化合物如何干扰哺乳动物发育的理解。 自2005年1月1日开始实施该子项目以来，已经购买并安装了一个大型伸入式生长室（AC-60“Bigfoot”; Enconair，温尼伯，加拿大），这对于建立种植和筛选突变植物的统一条件至关重要。一系列的初步生长实验已经开始，以优化生长条件。大量野生型拟南芥种子（CS 1092; Lehle Seeds，朗德罗克，TX）已经用一定浓度范围的甲磺酸乙酯诱变。已培养突变种子（M1）用于种子（M2）。预期M2细胞含有纯合突变，将对这些突变进行目标表型筛选。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project is intended to increase understanding of development though examination of the molecular/genetic mechanism by which the hormone auxin (indole acetic acid) directs leaf expansion in the model plant Arabidopsis thaliana. Auxin is known to trigger selective degradation of transcription factors via the ubiqutin-26S proteosome pathway. It is not known, however, how hormone reception leads to accelerated transcription factor degradation and altered developmental physiology although earlier work in this laboratory suggests auxin interacts, in advance of transcription factor proteolysis, with a second non-auxin growth effecter in controlling leaf expansion. We will use mutational analysis to address the specific aims proposed here which include (1) identifing the gene(s) associated with production of the hypothesized growth effector and (2) identifying genes responsible for other signal transduction players in auxin control of leaf expansion in plants. Understanding of the regulation of ubiquitination in plants may provide insights into the function of the orthologous human system. Several human cancers result from ubiquitin pathway malfunction. Auxins are also suspected endocrine disrupters. The results of this subproject may also lead to an understanding of how these compounds function in disturbing mammalian development. Since the start date of this sub-project, January 1, 2005, a large reach-in growth chamber (AC-60 "Bigfoot"; Enconair, Winnipeg, Canada), essential for establishing uniform conditions underwhich to grow and screen mutated plants, has been purchased and installed. A series of preliminary growth experiments have been initiated to optimize growth conditions. A large number of wild type Arabidopsis seeds (CS 1092; Lehle Seeds, Round Rock, TX) have been mutagenized with ethyl methane sulfonate at a range of concentrations. Mutated seed (M1) has been grown for seed (M2). The cells of the M2 are expected to contain homozygous mutations which will be screened for phenotypes of interest.