9305165 Bedinger Plant cell walls are dynamic structures that both determine morphological structure and mediate cell-cell interactions in plant development. Cell wall proteins are likely to participate actively in both roles. The relatively simple structure of pollen and the known pollen "recognition partners" for cell-cell interactions (stigma and stylar canal) make pollen an ideal system for the study of plant cell wall proteins and cell-cell recognition. Dr. Bedinger has identified two novel classes of extracellular matrix proteins specific to pollen. One class of proteins is tightly associated with the outer pollen wall, or exine, and may be involved with establishing the species specific pattern of exine ornamentation, or in pollen-pistil recognition. The second class of protein(s) may be structural components of the pollen tube wall, or may act as sexual agglutinins to mediate the interaction of the pollen tube with female tissues. Dr. Bedinger proposes to isolate full length genes encoding these proteins, localize the proteins within the pollen or pollen tube, and investigate the role of the proteins in male-female recognition. The data obtained from the proposed studies will enable us to propose testable models for the functions of these proteins in plant reproduction. ***
