ANALYSIS OF AUXIN SIGNAL TRANSDUCTION PATHWAYS

生长素信号转导途径分析

• 批准号: 6525568
• 负责人: Reeta Prusty Rao
• 金额: $ 4.42万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6525568
• 关键词: Arabidopsis; biological signal transduction; gene mutation; gravity; indoleacetate; membrane proteins; plant genetics; root

The gravitropic response of roots involves perception of the 'gravistimulus' by root-cap cells, transduction of this physical information into biochemical signals, followed by their transmission to cells in the expansion zone. This ultimately results in an appropriate curvature response of the root. Indole-3-acetic acid (IAA), the major form of auxins in higher plants, is directly involved in providing directionality to plants in response to stimuli such as light, gravity and even obstacles in the path of growth but its mechanism of action has not been elucidated. Plants bearing mutant alleles of EIR1, which encodes a plasma membrane protein, have phenotypes that suggest it is an auxin efflux pump involved in transport of auxin from the root tip to the elongation zone. These mutants have long roots with compromised ability to form root hairs and the roots do not respond to light or gravity. These mutants resemble plants grown in the presence of auxin transport inhibitors. The focus of this proposal is: 1) to further characterize Eir1p, a key component involved in the gravitropic response of roots; and 2) to identify proteins that affect activity of the EIR1 pump. These studies will provide insight regarding the previously uncharacterized auxin signaling pathway involved in the gravitronic response.

根的向重力反应涉及根冠细胞对“重力刺激”的感知，将该物理信息转导为生化信号，然后将其传输到扩张区的细胞。 这最终导致根部具有适当的曲率响应。吲哚-3-乙酸（IAA）是高等植物生长素的主要形式，直接参与为植物提供方向性，以响应光、重力甚至生长路径中的障碍等刺激，但其作用机制尚未阐明。携带 EIR1（编码质膜蛋白）突变等位基因的植物的表型表明它是参与生长素从根尖到伸长区运输的生长素外排泵。 这些突变体具有长根，形成根毛的能力受损，并且根对光或重力没有反应。 这些突变体类似于在生长素转运抑制剂存在下生长的植物。 该提案的重点是：1）进一步表征Eir1p，Eir1p是参与根系向地性响应的关键成分； 2) 识别影响 EIR1 泵活性的蛋白质。 这些研究将提供有关先前未表征的涉及重力电子反应的生长素信号通路的见解。