TRANSGENE AND MUTATIONAL CONTROL OF SEXUALITY IN MAIZE AND RELATED GRASSES

摘要

The present invention pertains to genetically modified plants, particularly maize, sorghum and rice, with an all pistillate or all staminate phenotype and methods of the same. The survival of functional pistils in maize requires the action of the sk1 gene. SK1 encodes a glycosyltransferase (GT) that protects pistils from tasselseed-mediated cell death. sk1-dependent pistil protection at a developing floret gives rise to stamen arrest at the same floret, and so determines the pistillate floral fate. This is the first single gain-of-function gene known to control sexuality. The present invention further provides a direct strategy to extend hybrid technologies to related cereals such as sorghum and rice. Tasselseed and silkless genes represent major sex determination genes in maize, a pathway that permits the efficient production of hybrid seed and the associated benefits of heterosis - increased yield, resistance to pathogens, etc. Except for maize, current hybrid systems in cereals are fraught with genetic and environmental limitations. Genotype-independent hybrid cereal technology could potentially increase crop yields as much as 20-40% without placing additional land under agricultural production. This has profound implications for food security and the environmental impact of agriculture in some of the poorest regions of the world.