Characterization of PiCDPK1 Mediated Signaling Pathways Regulating Pollen Tube Tip Growth

种子或果实的生产是大多数农业和园艺实践的目标。在大多数情况下，种子和果实的发育需要胚珠通过花粉传递的精子受精。在大多数开花植物中，胚珠被包在母体组织中。为了穿过这道屏障，花粉产生了一种称为尖端生长的过程，这种过程可以穿透雌性组织。这一过程是如何被调节的还不清楚，但对植物有性生殖是关键，是一个潜在的目标，为受精和seedset.Ca离子的遗传操作在尖端的生长和钙调节酶（PiCDPK1），控制花粉管生长极性，起着重要的调节作用，已被确定。这种酶是一种蛋白激酶，通过将磷酸基团添加到其蛋白质骨架来调节下游信号传导组分。本项目的目标是使用分子遗传学和生物化学方法来表征两种这样的下游组分。初步结果表明，这些成分的磷酸化形式可以介导抑制或促进花粉管生长。这种可能性将详细调查使用转基因的approaches.This研究将显着提高知识的信号事件在花粉管生长，并有望提供分子工具，这一过程可以操纵。此外，这些结果可能对植物细胞信号传导具有更广泛的意义，因为钙参与了植物生长和发育的许多方面。拟议的研究将为一名博士后，一名研究生和几名本科生提供各种细胞和分子生物学技术的培训。通过暑期实习，每年两名高中生将获得最先进的分子生物学技术的宝贵经验。

Production of seeds or fruits is the goal of most agricultural and horticultural practices. In most cases seed and fruit development requires fertilization of ovules by sperm delivered by pollen. In most flowering plants ovules are enclosed within maternal tissues. To traverse this barrier, pollen produce tubes that penetrate the female tissues by a process known as tip-growth. How this process is regulated is not well understood but is key to plant sexual reproduction and is a potential target for the genetic manipulation of fertilization and seed set.Calcium ions play an important regulatory role in tip-growth and a calcium-regulated enzyme (PiCDPK1), which controls pollen tube growth polarity, has been identified. This enzyme is a protein kinase which regulates downstream signaling components by adding phosphate groups to their protein backbones. The objectives of this project are to characterize two such downstream components using molecular genetic and biochemical approaches. Preliminary results suggest that the phosphorylated forms of these components can mediate the inhibition or enhancement of pollen tube growth. This possibility will be investigated in detail using transgenic approaches.This study will significantly enhance knowledge of signaling events in pollen tube growth and is expected to provide molecular tools with which this process can be manipulated. Furthermore, the results may have broader implications for plant cell signaling as calcium is involved in many aspects of plant growth and development.The proposed research will provide training for a post-doctoral, a graduate and several undergraduate students in a variety of cell and molecular biology techniques. Through summer internships, two high school students per year will gain valuable experience in state of the art molecular biology techniques.