Messenger RNAs in corn pollen and protein synthesis during germination and pollen tube growth

Abstract
Mature ungerminated pollen grains of Zea mays L. contain presynthesized messenger RNAs. This has been demonstrated by the isolation of poly(A)RNA and its translation in the wheat germ and reticulocyte cell free systems into polypeptides many of which are similar to those synthesized in germinating pollen. Each corn pollen grain contains between 352–705 pg of total RNA and 8.9–17.8 pg of poly(A)RNA. During germination of corn pollen at least 260 different polypeptides are synthesized as determined by labeling and 2-dimensional gel electrophoresis. These results are discussed with reference to other plants and the number of different genes expressed during pollen development.