Role of Rop GTPases in Signaling during Male Gametophyte Development

为了使植物种子发育，受精必须发生，即来自雄性的精子细胞必须在胚囊中与雌性细胞结合。由于胚囊在花内，雄性配子体的花粉管必须穿过几个花组织将精细胞运送到这个目的地。它通过感知、解释和处理来自周围花组织的信号来完成这项至关重要的任务。本项目旨在了解雄性配子体发育和与花和胚囊相互作用完成受精的机制。一个信号蛋白家族，Rop GTPases，在协调雄性配子体发育中的作用将被研究。本研究将结合遗传学方法、分子、细胞和生物信息学方法，对拟南芥和玉米这两种模式植物进行研究。这项工作的结果将确定特定玉米Rop gtpase在体内雄性配子体发育的不同阶段的作用。拟蓝花粉管生长、Rop GTPase和局部胞吐作用之间可能存在的联系可能被阐明，玉米和其他禾草作物中可能影响Rop GTPase功能的基因也可能被鉴定出来。这项研究可能会启发新的农业有益的方法来控制雄性配子体的发育，从而在玉米和其他密切相关的作物（水稻、小麦）的植物繁殖。例如，控制雄性配子体可以减少从转基因植物到非转基因植物的不必要的基因流动。波特兰公立学校的外展项目将向公众介绍花粉生物学和生物信息学。这个项目将允许高中生参与科学研究，帮助建立一个植物生物学家广泛感兴趣的网络数据库。

For plant seeds to develop, fertilization must occur, i.e., sperm cells from the male must unite with female cells in the embryo sac. Because the embryo sac is within the flower, the pollen tube of the male gametophyte must transport the sperm cells to this destination by navigating through several floral tissues. It accomplishes this crucial task by perceiving, interpreting and acting upon signals from the surrounding floral tissues. This project seeks to understand the mechanisms by which the male gametophyte develops and interacts with the flower and embryo sac to accomplish fertilization. The roles of a family of signaling proteins, the Rop GTPases, in coordinating the development of the male gametophyte will be investigated. This investigation will combine a genetic approach with molecular, cellular and bioinformatic methods, in two model plants, Arabidopsis thaliana and maize. Results from this work should establish roles for specific maize Rop GTPases in the distinct stages of male gametophyte development in vivo. Possible connections between A. thaliana pollen tube growth, Rop GTPases, and localized exocytosis may be elucidated and genes in maize and other grass crops that may influence Rop GTPase function may also be identified. This research may inspire new agriculturally-beneficial ways for controlling male gametophyte development, and thus plant reproduction, in maize and other closely-related crops (rice, wheat). For example, control of the male gametophyte could reduce unwanted gene flow from transgenic to non-transgenic plants. An outreach program to the Portland Public Schools will inform the public about pollen biology and bioinformatics. This program will allow high school students to participate in scientific research by helping to build a web-accessible database of broad interest to plant biologists.