Abstract
Pollen coat is a surface structure of Arabidopsis pollen grains, which consists mainly of proteins and lipids. These components are synthesized in tapetal cells and are deposited on the pollen surface after the tapetal cells are ruptured. Pollen coat is significant in fertilization. The EXTRACELLULAR LIPASE4 (EXL4) and EXL6 are abundant proteins in Arabidopsis pollen coat. Here we examined the EXL4 and EXL6 function. By the TEM and SEM observations, it was appeared that the pollen grains of exl4-RNAi exl6 plant lacked normal pollen coat and thus they showed the difficulty in water absorption from stigma. Proteomic analysis revealed that the pollen coat lacked most major proteins. The EXL4-GFP and EXL6-GFP were localized in unidentified granules in the tapetal cells. These results suggested that the EXL4 and EXL6 are required for the formation of pollen coat components in tapetal cells.
