RUI: Cellular Mechanisms of Paraheliotropism

RUI：副向日光性的细胞机制

• 批准号: 9507385
• 负责人: Virginia Berg
• 金额: $ 2.52万
• 依托单位: University of Northern Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-10-01 至 1998-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9507385&HistoricalAwards=false
• 关键词: RUI; Cellular; Mechanisms; Paraheliotropism

9507385 Berg Light-avoiding leaf movement (paraheliotropism) is an important stress response that allows some plants to reduce water loss, lower leaf temperature and decreases photodamage to leaves under hot, dry, bright condition. The capacity to reduce light interception is one of the properties that confers drought resistance on some legumes. While the factors known to stimulate paraheliotropism are well described (high temperature, drought, high light intensity), almost nothing is known about the cellular mechanisms underlying the movement of leaves. The movement involves the swelling and shrinking of cells of the motor organ at the base of leaves, requiring a consideration of ion channels, osmotic properties, cell size change, and physical forces. The proposed project has three principal objectives: 1) to compare how the stimuli known to cause paraheliotropism act differently upon excised tissue, isolated cells and protoplaqts from the motor organ; 2) to determine the fate of the cytoskeleton when motor cells change size; and 3) to determine which ion channels are are involved in cell size change associated with paraheliotropism. This project will advance scientific knowledge by establishing the functional relationships between the two major groups of reversibly expandable plant cells, one well studied, the other barely examined at this time. It will determine the mechanisms that underlie paraheliotropism, a stress response important for the survival and projectivity of native species and agronomically important plants.

避光叶片运动（拟向日性）是一种重要的胁迫反应，可使某些植物在高温、干燥、强光条件下减少水分流失、降低叶片温度和减少叶片的光损伤。减少光拦截的能力是赋予某些豆科植物抗旱性的特性之一。虽然已知的刺激向日性的因素（高温、干旱、高光强）已经被很好地描述，但对叶子运动背后的细胞机制几乎一无所知。这种运动涉及叶片基部运动器官细胞的膨胀和收缩，需要考虑离子通道、渗透特性、细胞大小变化和物理力。该项目有三个主要目标：1)比较已知的引起向阳旁视的刺激对运动器官的切除组织、分离细胞和原生质体的不同作用；2)确定运动细胞大小变化时细胞骨架的命运；3)确定哪些离子通道参与了与准向日性相关的细胞大小变化。该项目将通过建立可逆可扩展植物细胞的两大群体之间的功能关系来推进科学知识，其中一组研究得很好，另一组目前几乎没有研究过。它将确定准向日性的机制，准向日性是一种对本地物种和重要农艺植物的生存和投射性很重要的应激反应。