This study analyses expression and sequence characteristics of ORSF21
in S. squalidus and compares the findings with those for
homologous genes in other species to assess possible func-
tions of SF21 in pollen–pistil interactions. Consensus in
expression and sequence data between diverse angiosperm
species indicates that SF21 may be a rare example of a
conserved pollen–pistil gene, and hence play a vital role
during reproduction in angiosperms.