An-2 Encodes a Cytokinin Synthesis Enzyme that Regulates Awn Length and Grain Production in Rice

An-1 encodes a basic helix-loop-helix protein that regulates awn development, grain size, and grain number in rice.

Long awns are important for seed dispersal in wild rice (Oryza rufipogon), but are absent in cultivated rice (Oryza sativa). The genetic mechanism involved in loss-of-awn in cultivated rice remains unknown. We report here the molecular cloning of a major quantitative trait locus, An-1, which regulates long awn formation in O. rufipogon. An-1 encodes a basic helix-loop-helix protein, which regul...

The Rice HGW Gene Encodes a Ubiquitin-Associated (UBA) Domain Protein That Regulates Heading Date and Grain Weight

Heading date and grain weight are two determining agronomic traits of crop yield. To date, molecular factors controlling both heading date and grain weight have not been identified. Here we report the isolation of a hemizygous mutation, heading and grain weight (hgw), which delays heading and reduces grain weight in rice. Analysis of hgw mutant phenotypes indicate that the hemizygous hgw mutati...

The QTL GNP1 Encodes GA20ox1, Which Increases Grain Number and Yield by Increasing Cytokinin Activity in Rice Panicle Meristems

Cytokinins and gibberellins (GAs) play antagonistic roles in regulating reproductive meristem activity. Cytokinins have positive effects on meristem activity and maintenance. During inflorescence meristem development, cytokinin biosynthesis is activated via a KNOX-mediated pathway. Increased cytokinin activity leads to higher grain number, whereas GAs negatively affect meristem activity. The GA...

Erect panicle2 encodes a novel protein that regulates panicle erectness in indica rice.

Rice (Oryza sativa L.) inflorescence (panicle) architecture is an important agronomic trait for rice breeding. A number of high-yielding japonica rice strains, characterized by an erect panicle (EP) of their architecture, have been released as commercial varieties in China. But no EP-type indica varieties are released so far. Here, we identified two allelic erect-panicle mutants in indica rice,...

ERECT PANICAL2 Encodes a Novel Protein that Regulates Panicle Erectness in Indica Rice