A Cys2/His2 zinc finger protein acts as a repressor of gibberellins biosynthesis by regulating SD1/OsGA20ox2 in rice (Oryza sativa L.)
AbstractGibberellins (GAs) play important roles in the regulation of plant growth and development. The green evolution geneSD1encoding gibberellin 20-oxidase 2 (GA20ox2) has been widely used in modern rice breeding. However, the molecular mechanism of howSD1/OsGA20ox2expression is regulated remains unclear. Here we report a Cys2/His2 zinc finger protein ZFP207 acting as a transcriptional repressor ofOsGA20ox2.ZFP207was mainly accumulated in young tissues and more specifically in culm nodes.ZFP207-overexpression (ZFP207OE) plants displayed semi-dwarfism phenotype and small grains by modulating cell length. RNA interference ofZFP207caused higher plant and longer grains. The endogenous bioactive GA levels were significantly reduced inZFP207OEplants and application of exogenous GA3rescued the semi-dwarf phenotype. Thein vivoandin vitrostudies showed that ZFP207 repressed the expression ofOsGA20ox2via binding to its promoter region. Together, ZFP207 acts as a transcriptional repressor of gibberellins biosynthesis and it may play a critical role in plant growth and development through fine-tuning GA biosynthesis in rice.