<i>TaCol-B5</i> modifies spike architecture and enhances grain yield in wheat.

Abstract

Spike architecture influences grain yield in wheat. We report the map-based cloning of a gene determining the number of spikelet nodes per spike in common wheat. The cloned gene is named <i>TaCOL-B5</i> and encodes a CONSTANS-like protein that is orthologous to <i>COL5</i> in plant species. Constitutive overexpression of the dominant <i>TaCol-B5</i> allele but without the region encoding B-boxes in a common wheat cultivar increases the number of spikelet nodes per spike and produces more tillers and spikes, thereby enhancing grain yield in transgenic plants under field conditions. Allelic variation in <i>TaCOL-B5</i> results in amino acid substitutions leading to differential protein phosphorylation by the protein kinase <i>Ta</i>K4. The <i>TaCol-B5</i> allele is present in emmer wheat but is rare in a global collection of modern wheat cultivars.