Characterisation of sunflower-21 (SF21) genes expressed in pollen and pistil of Senecio squalidus (Asteraceae) and their relationship with other members of the SF21 gene family

摘要

Two related flower-expressed gene copies belonging to the () gene family have been isolated from (Oxford Ragwort, Asteraceae). These gene copies are differentially expressed in pollen and pistil tissues; () is expressed exclusively in mature pollen, whereas () is expressed in the transmitting tissue of the style, where it is developmentally regulated. Despite differences in expression, the coding regions of and are highly similar. Amino acid sequence alignments of genes from a number of angiosperm species indicate that this gene family is conserved in flowering plants and may play an important role in reproductive processes in a wide range of taxa. Phylogenetic analysis of nucleotide sequence alignments supports this theory, and indicates a complicated history of evolution of this gene family in angiosperms. The putative roles of genes in reproduction and pollen–pistil interactions are discussed.