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许多生物和物理作用。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。该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，并确定其控制表达的因素。PRPs在特定的细胞类型中表达，并通过在特定的植物组织中受伤而诱导。此外，这些蛋白质在细胞壁内交联，这一过程似乎是由物理损伤刺激的。然而，这些基因的转录调控所需的序列或对它们在细胞壁内的不溶性很重要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，这些区域是大豆中这些基因伤口诱导表达所必需的，并确定在细胞壁内这些蛋白质的不溶化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能够区分在发育期间和对物理损伤作出反应时调节这些基因表达的序列。此外，Tierney博士将能够研究受伤组织中的哪种细胞类型能够对伤口诱导的信号做出反应，最终导致SbPRP1和2的表达。她还将研究对细胞壁内这些蛋白质的不溶化很重要的特定氨基酸。“合成”PRPs的使用将使鉴定能够在细胞壁内形成交联的氨基酸、所涉及的相互作用类型以及这些氨基酸对所有细胞类型中这些蛋白质的不溶化是否重要成为可能。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.