Sucrose transport and metabolism control carbon partitioning between stem and grain in rice

Abstract Source–sink relationships are key to overall crop performance. Detailed understanding of the factors that determine source–sink dynamics is imperative for balance biomass and grain yield in plants. We investigated differences between a cultivated rice, Oryza sativa cv. Nipponbare, wild australiensis, which show striking yield. accumulates higher biomass, not only showed photosynthesis per unit leaf area but also exported more sucrose from leaves compared with Nipponbare. However, features sugar content suggested limited mobilization grains rice due vasculature transporter functions. Low cell wall invertase activity high synthase cleavage followed by expression cellulose genes O. australiensis stem indicated it utilized photosynthates preferentially synthesis structural carbohydrates, resulting biomass. In contrast, favored Nipponbare via accumulation transitory starch stem, biosynthetic genes, mobilized panicles at filling stage. Thus, vascular features, transport, functions metabolic enzymes explained australiensis.