Broad spectrum developmental role of Brachypodium AUX 1
- Department of Plant Molecular Biology University of Lausanne Biophore Building CH‐1015 Lausanne Switzerland
- Institute for Plant Cell Biology and Biotechnology Heinrich‐Heine University D‐40225 Duesseldorf Germany
- DOE Joint Genome Institute 2800 Mitchell Dr. Walnut Creek CA 94598 USA
- Umeå Plant Science Center Department of Forest Genetics and Plant Physiology Swedish University of Agricultural Sciences SE‐901 83 Umeå Sweden
Targeted cellular auxin distribution is required for morphogenesis and adaptive responses of plant organs. In Arabidopsis thaliana (Arabidopsis), this involves the prototypical auxin influx facilitator AUX1 and its LIKE-AUX1 (LAX) homologs, which act partially redundantly in various developmental processes. Interestingly, AUX1 and its homologs are not strictly essential for the Arabidopsis life cycle. Indeed, aux1 lax1 lax2 lax3 quadruple knock-outs are mostly viable and fertile, and strong phenotypes are only observed at low penetrance. Here we investigated the Brachypodium distachyon (Brachypodium) AUX1 homolog BdAUX1 by genetic, cell biological and physiological analyses. We report that BdAUX1 is essential for Brachypodium development. Bdaux1 loss-of-function mutants are dwarfs with aberrant flower development, and consequently infertile. Moreover, they display a counter-intuitive root phenotype. Although Bdaux1 roots are agravitropic as expected, in contrast to Arabidopsis aux1 mutants they are dramatically longer than wild type roots because of exaggerated cell elongation. Interestingly, this correlates with higher free auxin content in Bdaux1 roots. Consistently, their cell wall characteristics and transcriptome signature largely phenocopy other Brachypodium mutants with increased root auxin content. Our results imply fundamentally different wiring of auxin transport in Brachypodium roots and reveal an essential role of BdAUX1 in a broad spectrum of developmental processes, suggesting a central role for AUX1 in pooideae.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- DE‐AC02‐05CH11231; AC02-05CH11231
- OSTI ID:
- 1457498
- Alternate ID(s):
- OSTI ID: 1457500; OSTI ID: 1543998; OSTI ID: 1560556
- Journal Information:
- New Phytologist, Journal Name: New Phytologist Vol. 219 Journal Issue: 4; ISSN 0028-646X
- Publisher:
- Wiley-BlackwellCopyright Statement
- Country of Publication:
- United Kingdom
- Language:
- English
Web of Science
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