Submitted to: Proteomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 6, 2005
Publication Date: December 1, 2005
Citation: Holmes-Davis, R.A., Tanaka, C.K., Vensel, W.H., Hurkman, W.J., McCormick, S. 2005. Proteome mapping of mature pollen of Arabidopsis thaliana. Proteomics. 5(18):4864-84. Interpretive Summary: The Arabidopsis pollen grain is thought to contain almost all of the mRNAs needed for germination and rapid pollen tube growth. This idea was investigated through the analysis of the Arabidopsis pollen proteome. Mature pollen was collected from Arabidopsis plants and the proteins were isolated. Individual proteins were separated by gel electrophoresis and identified by mass spectrometry. In all, 135 proteins were identified; 125 of these have known functions in cell structure, energy generation or metabolism, and 10 have unknown functions. This analysis of the Arabidopsis pollen proteome complemented and extended recent analyses of the pollen transcriptome.
Technical Abstract: The male gametophyte of Arabidopsis is a 3-celled pollen grain that is thought to contain almost all the mRNAs needed for germination and rapid pollen tube growth. We generated a reference map of the Arabidopsis mature pollen proteome by using multiple protein extraction techniques followed by 2-dimensional gel electrophoresis (2-DE) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). We identified 135 distinct proteins from a total of 179 protein spots. We found that half of the identified proteins are involved in metabolism (20%), energy generation (17%) or cell structure (12%); these percentages are similar to those determined for the pollen transcriptome and this similarity is consistent with the idea that in addition to the mRNAs, the mature pollen grain contains proteins necessary for germination and rapid pollen tube growth. We identified 10 proteins of unknown function, 3 of which are flower or pollen-specific, and we identified 9 proteins whose RNAs were absent from the transcriptome, 7 of which are involved in metabolism, energy generation or cell wall structure. Our work complements and extends recent analyses of the pollen transcriptome.