Honys, David; Twell, D.
In Encyclopedia of Plant & Crop Science. New York : Marcel Dekker Inc. : 341-346, 2004

Keywords: microsporogenesis; gametophyte; haploid
Abstract: The haploid male gametophytes of higher plants play a vital role in plant fertility and crop production through the generation and transport of the male gametes to ensure fertilization and seed set. There has been an evolutionary tendency toward reduction of the male gametophyte and its increasing functional dependence on the sporophyte. This trend is most acute within flowering plants, such that the male gametophyte consists of just two or three cells when shed as pollen grains. Despite its diminuitive form, the functional specialization of the male gametophyte is thought to be a key factor in the evolutionary success of flowering plants through mechanisms that promote rigorous selection of superior haploid genotypes and outbreeding. This article describes the sequential phases of angiosperm pollen development—microsporogenesis and microgametogenesis—emphasizing the vital role of the cell wall interface and sporophytic-gametophytic interactions. This article further describes recent progress in genomewide studies of haploid gene expression, genetic approaches that are being used to identify genes required for key cellular processes, and aspects of pollen biotechnology in crop improvement.
DOI: IEB authors: David Honys