Identification and function analysis of spectrin-like protein in pollen tubes of lily (Lilium davidii Duch)

The elongation of pollen tube is an important process of sex- ual reproduction in higher plant. Cytoskeleton plays a major regulatory role in the elongation of pollen tubes. But whether membrane skeleton is involved in the pollen tube elongation is not clear. In this study, imuno- chemical detection of spectrin-like protein has been carried out in pollen tubes. By use of 2-dimensional electrophoresis(2DE) and western blotting, two spectrin-like proteins are found, one is 150 kD, and the other is 105 kD, with pI being 4.54 and 4.39, respectively. 150 kD spec- trin-like protein is located in plasma membrane of pollen tube and 105 kD spectrin-like protein is located in cytoplasm, probably functioning as a subunit to form a dimmer (210 kD) in vivo. The elongation of pollen tubes is inhibited after spectrin antibody was injected into a growing pollen tube. These results suggest that spectrin-like proteins exist in pollen tube and play an important regulating role in the elongation proc- ess of pollen tubes from lily.