Auxin fluxes through plasmodesmata modify root-tip auxin distribution

Abstract

© 2020. Published by The Company of Biologists Ltd. Auxin is a key signal regulating plant growth and development. It is well established that auxin dynamics depend on the spatial distribution of efflux and influx carriers on the cell membranes. In this study, we employ a systems approach to characterise an alternative symplastic pathway for auxin mobilisation via plasmodesmata, which function as intercellular pores linking the cytoplasm of adjacent cells. To investigate the role of plasmodesmata in auxin patterning, we developed a multicellular model of the Arabidopsis root tip. We tested the model predictions using the DII-VENUS auxin response reporter, comparing the predicted and observed DII-VENUS distributions using genetic and chemical perturbations designed to affect both carrier-mediated and plasmodesmatal auxin fluxes. The model revealed that carrier-mediated transport alone cannot explain the experimentally determined auxin distribution in the root tip. In contrast, a composite model that incorporates both carrier-mediated and plasmodesmatal auxin fluxes re-capitulates the root-tip auxin distribution. We found that auxin fluxes through plasmodesmata enable auxin reflux and increase total root-tip auxin. We conclude that auxin fluxes through plasmodesmata modify the auxin distribution created by efflux and influx carriers.

Citation

Mellor, N. L., Voß, U., Janes, G., Bennett, M. J., Wells, D. M., & Band, L. R. (2020). Auxin fluxes through plasmodesmata modify root-tip auxin distribution. Development, 147(6), Article dev181669. https://doi.org/10.1242/dev.181669

• Journal Article Type: Article
• Acceptance Date: Feb 17, 2020
• Online Publication Date: Mar 30, 2020
• Publication Date: Mar 15, 2020
• Deposit Date: Feb 19, 2020
• Publicly Available Date: Mar 15, 2020
• Journal: Development (Cambridge, England)
• Print ISSN: 0950-1991
• Electronic ISSN: 1477-9129
• Publisher: Company of Biologists
• Peer Reviewed: Peer Reviewed
• Volume: 147
• Issue: 6
• Article Number: dev181669
• DOI: https://doi.org/10.1242/dev.181669
• Keywords: Auxin transport; Plasmodesmata; Mathematical modelling; Root biology; Developmental Biology; Molecular Biology
• Public URL: https://nottingham-repository.worktribe.com/output/3993205
• Publisher URL: https://dev.biologists.org/content/147/6/dev181669