Pollination in Lilium Longiflorum and Arabidopsis Thaliana: The Role of Adhesion Molecules in Tube Cell Movement in the Style

本研究的目的是描述相容授粉过程中花粉管和花柱之间的相互作用，描述花柱和花筒细胞在这种相互作用中的特征，并了解它们在花柱中管细胞运动中的作用。目的是分离参与引导管细胞到胚珠的粘附分子，并描述伴随这种引导的管细胞运动的机制。来自百合的结构和生化证据表明，在花柱传递道中运动的管状细胞在行为、形态、蛋白质组成、mRNA谱和细胞骨架特征上与培养的花粉管不同。将描述在体内和体外培养的花粉管结构的差异，包括百合和拟南芥管细胞中的细胞外基质(ECM)-质膜-细胞骨架复合物。从百合中提取的花柱渗出物被用于开发体外人工花柱基质，其具有粘附性。花粉管在离体时附着在基质上，在体内时生长。这种渗出物的粘合成分的表征正在进行中。这表明管细胞和花柱传递通道ECM之间的粘附事件触发了管细胞中的基因表达，导致H携带的精子细胞有效地转移到胚珠中。有证据表明花粉管细胞基因及其产物是通过与花柱接触而诱导或不调节的。二维蛋白质图谱和mRNA差异显示表明，百合体内花粉管的基因表达和蛋白质合成与体外花粉管有显著差异。粘附试验现在可以用来确定这些差异中粘附的作用。多年来，人们一直试图在许多物种中完善花粉管的离体系统，但还没有确定的培养基允许管的生长速度、形态或体内系统的行为。缺失的元素被认为是花粉管传导束的ECM，这是一个必须分离的结合物质的基质，以保证花粉管细胞在体外的正常行为。Lord博士已经开发出这种用于体外花粉管生长的人工ECM，并希望进一步对其进行修改，以作为一种粘附试验，以正确研究百合花粉管的体外生长。

Lord 9603826 The aim in this study of plant reproduction is to describe the interaction between the pollen tube and the style during compatible pollination, to characterize the styler and tube cell components involved in this interaction and to understand their role in tube cell movement in the style. The goal is to isolate the adhesive molecules involved in guiding the tube cell to the ovule and to describe the mechanism of tube cell movement that accompanies this guidance. There is structural and biochemical evidence from lily that tube cells moving in the transmitting tract of the style differ in behavior, morphology, protein composition, mRNA profiles and cytoskeletal features from pollen tubes grown in culture. Differences in the structure of in vivo- and in vitro-grown pollen tubes, including the extracellular matrix (ECM)-plasma membrane-cytoskeletal complex in the tube cell in lily and Arabidopsis, will be described. Stylar exudates extracted from lily have been used to develop an in vitro artificial styler matrix that exhibits adhesive qualities. Pollen tubes adhere to this matrix in vitro and grow as in vivo. Characterization of the adhesive components of this exudate is in progress. The suggestion is that the adhesion event between the tube cell and the styler-transmitting tract ECM triggers gene expression in the tube cell, resulting in efficient transfer of the sperm cells H carries to the ovule. There is evidence that pollen tube cell genes and their products are induced or unregulated by contact with the style. Results from 2-D protein profiles and mRNA differential display show that both gene expr ession and protein synthesis in in vivo pollen tubes differ significantly from that in in vitro-grown pollen tubes in lily. The adhesion assay can now be used to establish the role of adhesion in these differences. Years have been spent trying to perfect an in vitro system for pollen tubes in many species, but no defined medium yet allows for the tube growth rates, morphology, or be havior of the in vivo system. The missing element is proposed to be the ECM of the styler transmitting tract, which is a matrix of bound substances that must be isolated for proper in vitro behavior of pollen tube cells. Dr. Lord has developed such an artificial ECM for pollen tube growth in vitro and wants to modify it further for use as an adhesion assay to properly study lily pollen tube growth in vitro.