Functional analysis of the FIERY1 Signaling Network

干旱、极端温度和高土壤盐度是常见的不利环境条件，可以极大地损害作物生产力。了解植物如何感知和应对这些非生物胁迫，将有助于培育或设计新一代的抗逆性作物。植物对非生物胁迫的一个早期反应是激活应激反应基因。这些基因的产物可以共同增强植物的抗逆性。为了找出这些基因的表达是如何被调控的，对模式植物拟南芥进行了遗传研究。FIERY1基因在这些研究中被鉴定为应激基因表达的负调控因子。它还需要对冷却、冷冻和盐胁迫的耐受性。然而，FIERY1蛋白非常复杂，因为它在体外具有肌醇多磷酸1-磷酸酶活性和二磷酸核苷酸酶活性；这些活动及其在信号转导中的作用尚不清楚。目前的研究将1)结合细胞生物学、分子生物学、生物化学和生理学的方法来定义FIERY1的细胞功能；2)导致FIERY1网络中介导植物激素信号和植物发育适应胁迫的信号成分的分离。该项目将深入了解调节植物发育和对环境反应的重要细胞信号传导过程。这项研究还可能确定更好的策略来设计作物，以增强对不利环境条件的耐受性。更广泛的影响FIERY1基因在生物体中广泛保守。FIERY1的人类同源物被认为是锂治疗双相情感障碍的治疗靶点，双相情感障碍严重影响约1%的美国人口。因此，了解FIERY1在植物中的功能对确定治疗人类抑郁症的新靶点具有重要意义。在人力资源方面，PI将支持定期在丹佛斯中心举行的公共教育活动。本科生和高中生也将参与这项研究。这些外展活动将帮助公众认识到植物生物学研究对美国和全世界农业的重要性。

Drought, extreme temperatures, and high soil salinity are common adverse environmental conditions that can greatly impair crop productivity. Understanding how plants sense and respond to these abiotic stresses will help in the breeding or engineering of a new generation of stress-tolerant crop plants. One early response of plants to abiotic stress is the activation of stress-responsive genes. The products of these genes can collectively enhance plant stress tolerance. To find out how the expression of these genes is regulated, genetic studies were conducted with the model plant Arabidopsis. The FIERY1 gene was identified in these studies as a negative regulator of stress gene expression. It is also required for tolerance to chilling, freezing, and salt stresses. However, the FIERY1 protein is very complex in that it possesses both an inositol polyphosphate 1-phosphatase activity and a bisphosphate nucleotidase activity in vitro; these activities and their role in signal transduction are unclear. The current study will 1) define the cellular functions of FIERY1 using a combination of cell biology, molecular biology, biochemistry and physiological approaches; and 2) result in the isolation of signaling components in the FIERY1 network that mediate phytohormone signaling and plant developmental adaptations to stress. This project will yield insights into important cell-signaling processes that regulate plant development and response to the environment. The study may also define better strategies to engineer crop plants for enhanced tolerance to adverse environmental conditions.Broader ImpactsThe FIERY1 gene is widely conserved in organisms. The human homolog of FIERY1 is thought to be a therapeutic target of lithium treatment for bipolar disease, which seriously affects about one percent of the U.S. population. Thus, understanding the function of FIERY1 in plants has implications for the identification of new therapeutic targets for treating depression in humans. Concerning human resources, the PI will support public education activities that are regularly held at the Danforth Center. Undergraduate and high school students will also participate in the study. These outreach activities will help the public to appreciate the importance of plant biology research to agriculture in the U.S. and throughout the world.