Analysis of Expressed Proteins in the Pollen Tube Occurring Self-Incompatible Response Using Mass or Single-Culture System of Mature Pollen in Citrus

摘要

To analyze the protein expression of pollen grains and tubes having self-incompatible reactions in Hyuganatsu (Citrus tamurana Hort. ex Tanaka), we cultured mature pollen and treated it with crude extracts from the styles using a mass or single liquidculture system, and we collected pollen grains and tubes for proteome analysis. The relative expression of each identified protein was quantified by an imager and revealed as a value relative to the pollen grain. Eleven identified proteins were remarkably up-regulated (above 1.2-fold) or down-regulated (under 0.8-fold) in treatment with self-incompatible reactions. Eight of these proteins were predicted to be self-incompatible-related proteins with the reported functions. In this study, F-box protein was identified as showing minimum expression in the treatment with crude extracts from styles of Hyuganatsu (self-incompatible reactions). The S-locus gene product expressed in pollen has been identified as an F-box protein in Solanaceae and Rosaceae. Itis not clear whether a mechanism similar to that of Solanaceae and Rosaceae exists in the self-incompatible reaction in Hyuganatsu; however, the reduced expression of F-box protein may induce a self-incompatible reaction.