NON-CELL AUTONOMOUS YABBY ACTIVITY IN RICE SPIKELET DEVELOPMENT
Communication between the meristem and lateral organ primordia plays a critical role in plant development. Tanaka et al. (pages 80–95) characterize the tongari-boushi1 (tob1) mutant in rice (Oryza sativa), which shows defects in the maintenance and organization of the spikelet meristem and in the initiation and development of spikelet organs such as the lemma and palea. TOB1 encodes a YABBY protein, Os YABBY5, which is expressed in the lateral organs but not in the meristem per se. Thus, TOB1 is likely to act non–cell autonomously to maintain proper meristem organization in rice spikelet development. The cover shows a developing tob1 mutant spikelet, which forms a cone-shaped organ instead of the lemma and palea.