Abstract
The shoot organs such as leaves and flowers arise from the shoot apical meristem (SAM). Organ primordia emerge in regions where auxin is highly concentrated in the peripheral region of the SAM. The Ser/Thr kinase PINOID (PID) is involved in establishment of auxin distribution through regulating cellular localization of PIN-FORMED1 (PIN1), an auxin efflux facilitator. To identify additional genes involved in this process, we carried out a screen for pid enhancers, named macchi-bou (mab). We identified four loci, MAB1~4. mab3 was a novel pin1 allele. The MAB1 and MAB4 genes were cloned by map-based approach. These genes encode a mitochondrial pyruvate dehydrogenase E1 beta subunit and a novel protein that belongs to the NONPHOTOTROPIC HYPOCOTYL 3 (NPH3) family, respectively. A possible role of the MAB genes in organogenesis will be discussed.
