glucose attenuation of auxin-mediated bimodality in lateral root formation is partly coupled by the heterotrimeric g protein complex葡萄糖的衰减auxin-mediated侧根形成双峰性部分heterotrimeric g蛋白耦合的复杂.pdfVIP

Glucose Attenuation of Auxin-Mediated Bimodality in Lateral Root Formation Is Partly Coupled by the Heterotrimeric G Protein Complex 1 2 1 1,3 Katherine S. Booker , John Schwarz , Michelle B. Garrett , Alan M. Jones * 1 Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America, 2 Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America, 3 Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America Abstract Background: Auxin and glucose are both essential elements in normal root development. The heterotrimeric G protein complex in Arabidopsis thaliana, defined as containing alpha (AtGPA1), beta (AGB1), and gamma (AGG) subunits and a GTPase accelerating protein called Regulator of G Signaling 1 protein (AtRGS1), are involved in glucose signaling and regulate auxin transport. Methodology/Principal Findings: A systems approach was used to show that formation of lateral roots, a process requiring coordinated cell division followed by targeted cell expansion, involves a signaling interaction between glucose and auxin. We dissected the relationship between auxin and glucose action using lateral root formation as the biological context. We found that auxin and glucose act synergistically to yield a complex output involving both stimulatory and antagonist glucose effects on auxin responsiveness. Auxin-induced, lateral-root formation becomes bimodal with regard to auxin dose in the presence of glucose. This bimodality is mediated, in part, by the G protein complex defined above. Conclu