Abstract
Inflorescence architecture is an important agronomic trait because it is reflected in grain yield in rice. Little is known how inflorescence morphology is determined.
Characterization of the rice aberrant panicle organization 1 (apo1) mutant revealed that the decreased number of spikelet results from precocious transition of meristem identity from inflorescence to spikelet in apo1. Smaller main axis inflorescence meristem causes abnormal phyllotaxy of lateral inflorescence meristem.
In apo1 , lodicules replace stamens and carpels are indeterminately differentiated. APO1 also regulates floral organ identity and determinacy. Double mutants analyses and spatial expression patterns analyses of floral organ identity genes demonstrate that APO1 positively regulates Class C floral organ identity gene. APO1, FLORAL ORGAN NUMBER 1 and FON1 and FON2 cooperatively regulate cell proliferation and determinacy in rice floral meristem. We identified APO1 gene by map-based approach and we discuss its functions.
