THE MOLECULAR-BIOLOGY OF ANTHER DIFFERENTIATION

This review attempts to summarise recent progress in our understanding of androgenesis in plants. There are two major divisions within this work. The first is a cytomorphological description of anther development and gametogenesis in model hermaphrodite plants. This is intended as a background against which to view the molecular biological information; this aspect constitutes the second main division in this chapter. The approach taken in describing these recent advances is intended to reflect, more or less, how these were made in practice. Gene cloning via cDNA library construction from whole anther organs or microspores represents the main technique, and therefore the merits of this approach, as applied to the developing anther, are discussed. In particular, the influence of cDNA library construction and screening methods on the type or class of genes identified to date are highlighted. The information generated from gene cloning is divided roughly into three sections. The first of these describes how the synthesis of specific mRNAs has provided valuable insights into the physiology and ontogeny of anther development. The physical and functional properties of cloned cDNAs cognate to mRNAs expressed within the anther are the subject of the second section. The third of these sections deals with anther-expressed genes, including analysis in transgenic plants. Finally, the commercial spin-off from this part of plant science, artificial male sterility, is discussed.