Auxin Regulates the Initiation and Radial Position of Plant Lateral Organs

摘要: Leaves originate from the shoot apical meristem, a small mound of undifferentiated tissue at tip stem. Leaf formation begins with selection group founder cells in so-called peripheral zone flank followed by initiation local growth and finally morphogenesis resulting bulge into differentiated leaf. Whereas mechanisms controlling switch between meristem propagation leaf are being identified genetic molecular analyses, radial positioning leaves, known as phyllotaxis, remains poorly understood. Hormones, especially auxin gibberellin, to influence but their specific role determination organ position is not clear. We show that inhibition polar transport blocks vegetative tomato pinlike naked stems an intact tip. Microapplication natural indole-3-acetic acid (IAA) apex such pins restores formation. Similarly, exogenous IAA induces flower on Arabidopsis pin-formed1-1 inflorescence apices, which blocked because mutation putative protein. Our results required for sufficient induce organogenesis both meristem. In this study, always strictly coincided site application dimension, whereas apical–basal occurred fixed distance summit propose determines size lateral organs or identity induced structures.