Transformation of rice with the Arabidopsis floral regulator LEAFY causes early heading

Onset of flowering, or heading date, is an important agronomic trait of cer eal crops such as rice and early-heading varieties are required for certain regions in which rice is cultivated. Since the floral control gene LEAFY f rom Arabidopsis can dramatically accelerate flowering in dictoyledonous pla nts, the usefulness of LEAFY for manipulating heading date in rice has been tested. Constitutive expression of LEAFY from the cauliflower mosaic virus 35S promoter caused early flowering in transgenic rice, with a heading dat e that was 26-34 days earlier than that of wild-type plants. Early flowerin g was accompanied by a small yield penalty and some panicle abnormality. Th ese observations suggest that floral regulatory genes from Arabidopsis are useful tools for heading date improvement in cereal crops.