Function and mechanism of action of plant-specific LINC complexes in pollen tube and guard cell biology.

该项目探索了一类新的植物蛋白质的功能，这些蛋白质参与了细胞核与植物细胞的定位。细胞核的位置影响植物细胞功能的方式对于它们的生命周期和它们对变化的环境条件的反应是重要的。该项目将首先探索细胞核位置在花粉管中的控制机制，花粉管是受精所必需的结构，因此是开花植物随后产生种子的关键。该项目还将探索细胞核位置的作用，这些细胞控制植物叶片中孔（气孔）的打开和关闭，调节二氧化碳从空气进入植物的运动，以及植物叶片进入空气中的水分（作为蒸汽）的损失。植物从空气中吸收二氧化碳和从植物中损失水分对于日益频繁的气候事件如干旱、极端温度和大气中二氧化碳含量的上升具有额外的意义。植物特异性外核被膜蛋白（KASH蛋白）是核骨架和细胞骨架连接体（LINC）复合物的动物KASH蛋白的功能等价物。该项目将剖析KASH蛋白如何在植物雄性育性和保卫细胞功能中发挥作用。一个植物特异性LINC复合体需要移动营养核通过花粉管，并且其破坏影响花粉管终止和雄性育性。这一新发现的过程与已知的花粉管功能信号通路的联系将被确定。第二种植物特异性LINC复合物参与将细胞核锚定在保卫细胞中，其破坏改变保卫细胞肌动蛋白组织、非生物胁迫反应和保卫细胞动力学。保卫细胞核的位置，皮层肌动蛋白模式和孔径调节生物和非生物信号之间的联系将被调查。数学建模和有针对性的遗传和生物化学方法将用于识别电机，阐明力的要求，并定义控制花粉管和保卫细胞中的核运动的机制。

This project explores the function of a new class of plant proteins that are involved in positioning the nucleus with the plant cell. The manner in which the position of the nucleus affects the function of plant cells is important for their life cycle and for their response to changing environmental conditions. This project will first explore the mechanisms by which nuclear position is controlled in the pollen tube, a structure that is essential for fertilization and thus the subsequent seed production in flowering plants. This project will also explore the role of the nuclear position in the cells that control the opening and closing of apertures (stomata) in the leaf of the plant, which regulate the movement of carbon dioxide from the air into the plant, and the loss of water (as vapor) from plant leaves into the air. The uptake of carbon dioxide from the air and the loss of water from the plant are of added significance in the face of increasingly frequent climate events such as drought, temperature extremes and the rising levels of carbon dioxide in the earth's atmosphere.Plant-specific outer nuclear envelope proteins (KASH proteins) are the functional equivalent of animal KASH proteins of the linker of nucleoskeleton and cytoskeleton (LINC) complexes. This project will dissect how KASH proteins function in plant male fertility and guard cell function. One plant specific LINC complex is required to move the vegetative nucleus through the pollen tube and its disruption affects pollen tube termination and male fertility. The connection of this newly discovered process to known signaling pathways of pollen tube function will be determined. A second plant-specific LINC complex is involved in anchoring the nucleus in guard cells and its disruption changes guard cell actin organization, abiotic stress responses, and guard cell dynamics. The connection between guard cell nuclear position, cortical actin patterns and aperture regulation by biotic and abiotic signals will be investigated. Mathematical modeling and targeted genetic and biochemical approaches will be used to identify the motors, clarify the force requirements and define the mechanisms that control nuclear movement in pollen tube and guard cells.