QUANTITATIVE-ANALYSIS OF LIPIDS AND PROTEIN FROM THE POLLEN OF BRASSICA-NAPUS L

Brassica napus L. pollen lipids and proteins are divided into two spatially distinct domains by the plasma membrane of the vegetative cell. The extracellular lipid and protein fractions can be separated from the internal cytoplasmic fractions by differential solvent and buffer extraction because the pollen grain wall and plasma membrane act as barriers to both lipid and protein extraction. Mature pollen is composed of 25.4% lipids and 26.0% protein (dry weight). The extracellular pollen-coat is estimated to contain 27.1% of the total lipids and between 9.6 and 19.6% of total protein depending upon the extraction method. We conclude that for assured determination of pollen grain lipid and protein content, the pollen should be fractured during extraction.