DIVERGENCE OF BRACT SUPPRESSION IN ANGIOSPERMS
Suppression of growth of inflorescence leaves, or bracts, has evolved multiple times in diverse angiosperm lineages. Several genes involved in bract suppression have been identified in Arabidopsis, but it is not known whether homologs of these genes play a similar role in other plants with suppressed bracts. Whipple et al. (pages 565–578) identify maize Tsh1, which encodes a GATA zinc-finger protein that is involved in bract suppression in maize. They show that the bract suppression function of Tsh1 is conserved in the grass family, but not in the homologous Arabidopsis gene HAN, suggesting the evolution of distinct bract suppression mechanisms in these lineages. The cover shows an electron micrograph image of the inflorescence of a barley mutant featured in the article.