Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 1 of 1
Full-Text Articles in Molecular Biology
Trp-Dependent Auxin Biosynthesis In Arabidopsis: Involvement Of Cytochrome P450s Cyp79b2 And Cyp79b3, Yunde Zhao, Anna K. Hull, Neeru R. Gupta, Kendrick A. Goss, José Alonso, Joseph R. Ecker, Jennifer Normanly, Joanne Chory, John L. Celenza
Trp-Dependent Auxin Biosynthesis In Arabidopsis: Involvement Of Cytochrome P450s Cyp79b2 And Cyp79b3, Yunde Zhao, Anna K. Hull, Neeru R. Gupta, Kendrick A. Goss, José Alonso, Joseph R. Ecker, Jennifer Normanly, Joanne Chory, John L. Celenza
Jennifer Normanly
The plant hormone auxin regulates many aspects of plant growth and development. Although several auxin biosynthetic pathways have been proposed, none of these pathways has been precisely defined at the molecular level. Here we provide in planta evidence that the two Arabidopsis cytochrome P450s, CYP79B2 and CYP79B3, which convert tryptophan (Trp) to indole-3-acetaldoxime (IAOx) in vitro, are critical enzymes in auxin biosynthesis in vivo. IAOx is thus implicated as an important intermediate in auxin biosynthesis. Plants overexpressing CYP79B2 contain elevated levels of free auxin and display auxin overproduction phenotypes. Conversely, cyp79B2 cyp79B3 double mutants have reduced levels of IAA and …