A key step during crop domestication is the loss of seed shattering. Here, we show that seed shattering in sorghum is controlled by a single gene, Shattering1 (Sh1), which encodes a YABBY transcription factor. Domesticated sorghums harbor three different mutations at the Sh1 locus. Variants at regulatory sites in the promoter and intronic regions lead to a low level of expression, a 2.2-kb deletion causes a truncated transcript that lacks exons 2 and 3, and a GT-to-GG splice-site variant in the intron 4 results in removal of the exon 4. The distributions of these non-shattering haplotypes among sorghum landraces suggest three independent origins. The function of the rice ortholog (OsSh1) was subsequently validated with a shattering-resistant mutant, and two maize orthologs (ZmSh1-1 and ZmSh1-5.1+ZmSh1-5.2) were verified with a large mapping population. Our results indicate that Sh1 genes for seed shattering were under parallel selection during sorghum, rice and maize domestication.
Bibliographical noteFunding Information:
This work was supported by an Agriculture and Food Research Initiative Competitive Grant (201103587 to J.Y. and T.T.T.) from the US Department of Agriculture (USDA) National Institute of Food and Agriculture, the Plant Genome Research Program of the National Science Foundation (DBI0820610 to J.Y., DBI0820619 to J.D. and DBI1027527 to P.S.S.), the Plant Feedstock Genomics Program of the US Department of Energy (DESC0002259 to J.Y.), the USDAARS (M.L.W. and G.B.), the Targeted Excellence Program of Kansas State University and the Kansas State University Center for Sorghum Improvement.