Abstract
The TIR1/AFB auxin co-receptors mediate diverse responses to the plant hormone auxin. The Arabidopsis genome encodes six TIR1/AFB proteins representing three of the four clades that were established prior to angiosperm radiation. To determine the role of these proteins in plant development we performed an extensive genetic analysis involving the generation and characterization of all possible multiply-mutant lines. We find that loss of all six TIR1/AFB proteins results in early embryo defects and eventually seed abortion, and yet a single wild-type allele of TIR1 or AFB2 is sufficient to support growth throughout development. Our analysis reveals extensive functional overlap between even the most distantly related TIR1/AFB genes except for AFB1. Surprisingly, AFB1 has a specialized function in rapid auxin-dependent inhibition of root growth and early phase of root gravitropism. This activity may be related to a difference in subcellular localization compared to the other members of the family.
| Original language | English (US) |
|---|---|
| Article number | e54740 |
| Journal | eLife |
| Volume | 9 |
| DOIs | |
| State | Published - Feb 2020 |
Bibliographical note
Funding Information:We thank Yingluo Wang and Diane Le for technical assistance, Brian Crawford for help with embryo microscopy, and the Arabidopsis Biological Resource Center and the US National Plant Germplasm System for seeds. This work was supported by a grant from the NIH (GM43644 to ME) and by start-up funds from the Salk Institute of Biological Studies (WB). MP was supported by a long-term postdoctoral fellowship (LT000340/2019 L) by the Human Frontier Science Program Organization, and NK was supported in part through a UC San Diego Biological Sciences Eureka! Summer Research Scholarship. RB was supported by BBSRC Discovery and Future Food Beacon Nottingham Research Fellowships.
Funding Information:
We thank Yingluo Wang and Diane Le for technical assistance, Brian Crawford for help with embryo microscopy, and the Arabidopsis Biological Resource Center and the US National Plant Germplasm System for seeds. This work was supported by a grant from the NIH (GM43644 to ME) and by start-up funds from the Salk Institute of Biological Studies (WB). MP was supported by a long-term post-doctoral fellowship (LT000340/2019 L) by the Human Frontier Science Program Organization, and NK was supported in part through a UC San Diego Biological Sciences Eureka!Summer Research Scholarship. RB was supported by BBSRC Discovery and Future Food Beacon Nottingham Research Fellowships.
Publisher Copyright:
© Prigge et al.