Format

Send to:

Choose Destination
See comment in PubMed Commons below
Plant Cell. 2011 Jun;23(6):2184-95. doi: 10.1105/tpc.111.086355. Epub 2011 Jun 3.

Gibberellin regulates PIN-FORMED abundance and is required for auxin transport-dependent growth and development in Arabidopsis thaliana.

Author information

  • 1Department of Plant Systems Biology, Center for Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany.

Abstract

Plants integrate different regulatory signals to control their growth and development. Although a number of physiological observations suggest that there is crosstalk between the phytohormone gibberellin (GA) and auxin, as well as with auxin transport, the molecular basis for this hormonal crosstalk remains largely unexplained. Here, we show that auxin transport is reduced in the inflorescences of Arabidopsis thaliana mutants deficient in GA biosynthesis and signaling. We further show that this reduced auxin transport correlates with a reduction in the abundance of PIN-FORMED (PIN) auxin efflux facilitators in GA-deficient plants and that PIN protein levels recover to wild-type levels following GA treatment. We also demonstrate that the regulation of PIN protein levels cannot be explained by a transcriptional regulation of the PIN genes but that GA deficiency promotes, at least in the case of PIN2, the targeting of PIN proteins for vacuolar degradation. In genetic studies, we reveal that the reduced auxin transport of GA mutants correlates with an impairment in two PIN-dependent growth processes, namely, cotyledon differentiation and root gravitropic responses. Our study thus presents evidence for a role of GA in these growth responses and for a GA-dependent modulation of PIN turnover that may be causative for these differential growth responses.

PMID:
21642547
[PubMed - indexed for MEDLINE]
PMCID:
PMC3160035
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk