Investigating the Effects of Plant Hormones on Intercellular Trafficking via Plasmodesmata

项目摘要/摘要 胞间连丝(PD)，植物细胞壁中有质膜衬里的毛孔，允许运输 小分子、大分子、代谢物、信号分子和包括来自 从一个植物细胞到另一个植物细胞。已发现几种激素通过PD在细胞之间进行运输。 有趣的是，水杨酸(SA)是一种植物防御激素，它不是通过PD而是通过 质外体。尽管如此，SA是一种关键的激素信号，它负向调节细胞与细胞之间的关系 对病原体感染作出反应的渗透性。先前的研究表明SA对帕金森病有调节作用 通过调节沿毛孔的老茧堆积。帕金森病的第二个作用是诱导 在现有的PD处插入额外的孔导致形成复杂(分支)孔。 由于PD对植物的生长、发育和防御非常重要，我们寻求 了解参与调节帕金森病功能和形成的分子机制。这 研究将集中在研究SA如何调节细胞间的细胞机制 通过调整PD渗透率进行人口贩运。这些研究将结合先进的 研究SA如何连接的显微技术和细胞和分子生物学方法 对烟草表皮叶组织中Pd运输的影响。《公约》的具体目标 研究将确定SA单独或与另一种防御荷尔蒙联合使用的效果， 茉莉酸，对钯的结构和功能的影响。我们还将调查SA的浓度如何 和/或JA在暴露于激素后的不同时间改变PD通透性(目的 1)测定SA处理后组织中Pd的结构和Pd的数量 对照研究激素对帕金森病形成的影响(目标2)；确定SA对帕金森病形成的影响 内吞作用和ER-PM接触部位作为向现有细胞插入新毛孔的过程的一部分 墙，(目标3)。这项研究的结果将促进对荷尔蒙如何 影响细胞间运输和PD，它们将引起基础植物科学家和 农业科学家。

PROJECT SUMMARY/ABSTRACT Plasmodesmata (PD), plasma membrane-lined pores in the plant cell walls, allow trafficking of small molecules, macromolecules, metabolites, signaling molecules and including hormones from one plant cell to another. Several hormones have been found to traffic between cells via PD. Interestingly, salicylic acid (SA), a plant defense hormone, does not traffic via PD but through the apoplast. Nonetheless, SA is a critical hormonal signal that negatively regulates cell-to-cell permeability in response to pathogen infection. Previous studies have shown SA to regulate PD through regulated callose accumulation along the pores. A second effect of PD is to induce the insertion of additional pores at existing PD leading to the formation of complex (branched) pores. Because PD are very important for plant growth, development, and defense, we seek to understand the molecular mechanisms involved in regulating PD function and formation. This study will focus on investigating the cellular mechanisms of how SA regulates intercellular trafficking by adjusting PD permeability. These studies will apply a combination of advanced microscopic techniques and cell and molecular biology approaches to study how SA is connected to PD transport in epidermal leaf tissues of Nicotiana benthamiana. The specific aims of the research will determine the effects of SA alone or in combination with another defense hormone, jasmonic acid, on PD structure and function. We will also investigate how the concentration of SA and/or JA change PD permeability based on various times after exposure to the hormone (Aim 1); determine PD structure and the number of PD in SA-treated tissues relative to untreated controls to examine hormone effects on PD formation (Aim 2); determine the effect of SA on endocytosis and ER-PM contact sites as part of the process inserting new pores into existing cell walls, (Aim 3). The results from this research will advance understanding of how hormones influence intercellular trafficking and PD, and they will be of interest to basic plant scientists and agricultural scientists.