Proteome analysis of tea pollen (Camellia sinensis) under different storage conditions

The protein complement of tea pollen collecting from tea tree (Camellia sinensis) was compared under different storage conditions. Protein was partially identified using a combination of the 2D-PAGE, MALDI-TOF/MS, MASCOT, and Xproteo search engine. Two hundred and sixty-nine and 396 proteins were detected in pollen stored at room temperature (RT) and -20 degrees C, respectively. Forty-three of the identified proteins were assigned to defense-related functions, energy metabolism, cytoskeleton, nucleic acid metabolism, membrane transport, amino acid metabolism, stress response, protein metabolism, transcription, fat metabolism, others, and function unknown proteins. The abundance analysis showed that more proteins related to stress response, nucleic acid metabolism, fat metabolism, and membrane transport are lost at RT than at -20 degrees C, while proteins related to defense and energy metabolism showed a reverse relation. For the others, no differences were found between the two storage conditions. During the determination of the peptides mass fingerprinting (PMF) of each spot, 35 proteins were identified in tea pollen for the first time. Thus, our data present an initial molecular picture of bee collected tea pollen, and our results suggest that freezing is the best way to maintain the quality of tea pollen.