SSD1, which encodes a plant-specific novel protein, controls plant elongation by regulating cell division in rice

Plant, height is one of the important traits in crop improvement. Therefore revealing the mechanism of plant elongation and controlling plant, height, in accordance with breeding object is important. In this study we analyzed a novel dwarf mutant, ssd1, of which phenotype is different from typical GA- or BR-related dwarf phenotype, ssd1 exhibits pleiotropic defects ill elongation of various organs such as steins, roots, leaves and flowers, ssd1 also snows abnormal cell files and shapes, which suggests defects of normal cell division in die mutant. Map-based cloning and complementation test demonstrated that, the dwarf phenotype in ssd1 mutant was caused by insertion of retrotransposon ill a gene. which encodes plant-specific protein with unknown biochemical function. A BLAST search revealed that SSD1-like genes exist in diverse plant species, including monocots and dicots, but not fern and moss. Our results demonstrate that SSD1 controls plant elongation by controlling cell division in higher plants.