Control of rice grain-filling and yield by a gene with a potential signature of domestication

Abstract

Grain-filling, an important trait that contributes greatly to grain weight, is regulated by quantitative trait loci and is associated with crop domestication syndrome. However, the genes and underlying molecular mechanisms controlling crop grain-filling remain elusive. Here we report the isolation and functional analysis of the rice GIF1 (GRAIN INCOMPLETE FILLING 1) gene that encodes a cell-wall invertase required for carbon partitioning during early grain-filling. The cultivated GIF1 gene shows a restricted expression pattern during grain-filling compared to the wild rice allele, probably a result of accumulated mutations in the gene's regulatory sequence through domestication. Fine mapping with introgression lines revealed that the wild rice GIF1 is responsible for grain weight reduction. Ectopic expression of the cultivated GIF1 gene with the 35S or rice Waxy promoter resulted in smaller grains, whereas overexpression of GIF1 driven by its native promoter increased grain production. These findings, together with the domestication signature that we identified by comparing nucleotide diversity of the GIF1 loci between cultivated and wild rice, strongly suggest that GIF1 is a potential domestication gene and that such a domestication-selected gene can be used for further crop improvement.

New Insights into Roles of Cell Wall Invertase in Early Seed Development Revealed by Comprehensive Spatial and Temporal Expression Patterns of GhCWIN1 in Cotton

“…Extensive studies have shown essential roles of CWIN in seed filling, probably through regulating Suc unloading and the establishment and maintenance of sink strength (Cheng et al, 1996;Weber et al, 1996;Wang et al, 2008;Jin et al, 2009;Zanor et al, 2009). However, it remains largely unknown how CWIN exerts its regulation early in seed development .…”

“…Therefore, CWINs are central to phloem unloading and carbon partitioning, especially in cellular sites lacking symplasmic (plasmodesmal) connections (Patrick and Offler, 2001;Weschke et al, 2003). A positive correlation between CWIN activity and seed development has been observed in maize (Zea mays; Cheng et al, 1996;Vilhar et al, 2002;Chourey et al, 2006), faba bean (Vicia faba; Weber et al, 1995Weber et al, , 1996, barley (Hordeum vulgare; Weschke et al, 2003;Sreenivasulu et al, 2004), rice (Oryza sativa; Hirose et al, 2002;Wang et al, 2008), and tomato (Solanum lycopersicum; Zanor et al, 2009). With an exception in tobacco (Nicotiana tabacum; Tomlinson et al, 2004), high and low Glc-to-Suc ratios generally favor cell division or promote cell differentiation, respectively, during seed development (for review, see Weber et al, 2005).…”

The Birth of a Black Rice Gene and Its Local Spread by Introgression

“…Several genes related to rice domestication, including sh4, qSH1, PLOG1, qSW5, GIF1, and Rc, have been cloned and the corresponding causal FNPs have also been identified (Konishi et al, 2006;Li et al, 2006;Sweeney et al, 2007;Jin et al, 2008;Shomura et al, 2008;Tan et al, 2008;Wang et al, 2008). Among them, a 14-bp deletion within the Rc gene, which induced a premature stop codon, resulted in the change of pericarp color from red to white.…”

DTH8 Suppresses Flowering in Rice, Influencing Plant Height and Yield Potential Simultaneously

“…Recent studies have shown much progress on exploring the mechanism for regulation of yield potential, plant height, and flowering time in rice. Some genes regulating the rice yield trait have already been identified (Li et al, 2003;Ashikari et al, 2005;Fan et al, 2006;Song et al, 2007;Shomura et al, 2008;Wang et al, 2008;Weng et al, 2008). The control of rice plant height is mostly related to the synthesis and regulation of the phytohormone, such as GA and brassinolide (Ashikari et al, 1999;Yamamuroa et al, 2000;Honga et al, 2003;Sasaki et al, 2002Sasaki et al, , 2003Itoh et al, 2004;Tanabe et al, 2005).…”