Molecular Analysis of PRP Insolubilization and Wound-inducedExpression

植物细胞壁是一种重要的细胞结构，在植物生长过程中具有多种生物学和物理作用。这种结构是动态的，随着生长、细胞分化和与环境的相互作用而变化。这项研究的长期目标是确定富含脯氨酸的细胞壁蛋白(PRPS)在植物生长发育过程中的功能，并确定其可控表达的因素。PRPS在特定的细胞类型中表达，并在特定的植物组织中由伤害诱导。此外，这些蛋白质在细胞壁内发生交叉连接，这一过程似乎受到物理损伤的刺激。然而，这些基因转录调控所需的序列或对它们在细胞壁内的不溶解起重要作用的氨基酸却知之甚少。该奖项的具体目标是确定SbPRP1和SbPRP2启动子内的特定区域，这些区域是这些基因在大豆中的创伤诱导表达所必需的，并确定在这些蛋白质在细胞壁内的不溶解中起关键作用的氨基酸。在稳定转化的植物中使用启动子/GUS将使PI能够区分在发育过程中调节这些基因表达的序列和对物理伤害做出反应的序列。此外，蒂尔尼博士将能够研究创伤组织中的哪些细胞类型能够对创伤诱导的信号做出反应，这些信号最终导致SbPRP1和2的表达。她还将研究特定的氨基酸，这些氨基酸对这些蛋白质在细胞壁内的不溶解很重要。使用“合成的”PRPS将有可能确定能够在细胞壁内形成交联链的氨基酸、所涉及的相互作用的类型，以及这些氨基酸是否对这些蛋白质在所有细胞类型中的不溶解起重要作用。这些研究还将描述参与细胞壁基质形成的关键酶的底物，并将作为鉴定这些蛋白质的起点。

The plant cell wall is an important cellular structure that has numerous biological and physical roles during plant growth. This structure is dynamic and changes as a consequence of growth, cellular differentiation and interactions with the environment. The long term goals of the proposed research are to determine the function of proline-rich cell wall proteins (PRPs) during plant growth and development and to identify the factors responsible for their controlled expresion. PRPs are expressed in specific cell types and are induced by wounding in a specific plant tissues. In addition, these proteins become cross-linked within the cell wall, a process which appears to be stimulated by physical damage. However, the sequences required for the transcriptional regulation of these genes or the amino acids important for their insolubilization within the cell wall are poorly understood. The specific goals of this award to identify specific regions within the SbPRP1 and SbPRP2 promoters which are required for the wound-inducible expression of these genes in soybean and to identify amino acids which play a critical role in the insolubilization of these proteins within the cell wall. The use of promoter/GUS in stably transformed plants will allow PIs to distinguish between sequences which regulate the expression of these genes during development and in response to physical damage. In addition, Dr. Tierney will be able to investigate which cell types within wounded tissue are capable of responding to the wound- induced signals which ultimately result in SbPRP1 and 2 expression. She will also investigate the specific amino acids which are important for the insolubilzation of these proteins within the cell wall. The use of "synthetic" PRPs will make it possible to identify amino acids capable of forming cross-links within the cell wall, the types of interactions involved, and whether these amino acids are important for insolubilization of these proteins in all cell types. These studies will also describe the substrates for key enzymes involved in cell wall matrix formation and will serve as a starting point for the identification of these proteins.