Krizek Beth Yang Haibing Murphy Angus S Gilroy Simon Li Jisheng 121-5 Peer Wendy Ann Khodakovskaya Mariya 16210544 Richter Gregory Titapiwantakun Boosaree Arabidopsis H+-PPase AVP1 regulates auxin-mediated organ development. 5745 2005 Oct Li Jisheng et al. 2005 Oct. Science 310(5745):121-5. Bandyopadhyay Anindita 310 Gaxiola Roberto Undurraga Soledad The transport of auxin controls developmental events in plants. Here, we report that in addition to maintaining vacuolar pH, the H+-pyrophosphatase, AVP1, controls auxin transport and consequently auxin-dependent development. AVP1 overexpression results in increased cell division at the onset of organ formation, hyperplasia, and increased auxin transport. In contrast, avp1-1 null mutants have severely disrupted root and shoot development and reduced auxin transport. Changes in the expression of AVP1 affect the distribution and abundance of the P-adenosine triphosphatase and Pinformed 1 auxin efflux facilitator, two proteins implicated in auxin distribution. Thus, AVP1 facilitates the auxin fluxes that regulate organogenesis. Richards Elizabeth L Blakeslee Joshua