A gain-of-function mutation in IAA18 alters Arabidopsis embryonic apical patterning.

ABSTRACT: Lateral organ emergence in plant embryos and meristems depends on spatially coordinated auxin transport and auxin response. Here, we report the gain-of-function iaa18-1 mutation in Arabidopsis, which stabilizes the Aux/IAA protein IAA18 and causes aberrant cotyledon placement in embryos. IAA18 was expressed in the apical domain of globular stage embryos, and in the shoot apical meristem and adaxial domain of cotyledons of heart stage embryos. Mutant globular embryos had asymmetric PIN1:GFP expression in the apical domain, indicating that IAA18-1 disrupts auxin transport. Genetic interactions among iaa18-1, loss-of-function mutations in ARF (Auxin response factor) genes and ARF-overexpressing constructs suggest that IAA18-1 inhibits activity of MP/ARF5 and other ARF proteins in the apical d

SUBMITTER: Ploense SE 

PROVIDER: S-EPMC2674258 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature