Identification and characterization of caleosin in pollen.

Oil bodies are essential energy storage organelles that are generally present in the seeds of plants. Caleosin protein has been identified in the seed oil bodies of seed. In this study, mature pollen grains were collected from cycad elliptical cones. However, the isolation and identification of oil bodies protein from mature grains have never been experimentally determined. Ultrastructural studies have shown that the oil bodies were present in pollen grains. Lipid analysis showed that oil bodies are predominantly composed of triacylglycerol. Complete cDNA fragments encoding the caleosin were obtained by PCR cloning. Phylogenetic tree analyzes showed that cycad pollen caleosin is closely related to the caleosin of seeds. Fresh pollen grains were allowed to germinate for 48 h in a germination medium containing 2% sucrose and 0.01% HBO Pollen germination were recorded periodically from day one to day 10 and the results showed that the pollen elongate the tube and increasing of triacylglycerol(TAG) after 4 days.