Ljung, Karin
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Abstract
Shoot branching is a primary contributor to plant architecture, evolving independently in flowering plant sporophytes and moss gametophytes. Mechanistic understanding of branching is largely limited to flowering plants such as Arabidopsis, which have a recent evolutionary origin. We show that in gametophytic shoots of Physcomitrella, lateral branches arise by re-specification of epidermal cells into branch initials. A simple model co-ordinating the activity of leafy shoot (gametophore) tips can account for branching patterns, and three known and ancient hormonal regulators of sporophytic branching interact to generate the branching pattern-auxin, cytokinin and strigolactone. The mode of auxin transport required in branch patterning is a key divergence point from known sporophytic branching pathways. Although PIN-mediated basipetal auxin transport regulates branching patterns in flowering plants, this is not so in Physcomitrella, where bi-directional transport is required to generate realistic branching patterns. Experiments with callose synthesis inhibitors suggest plasmodesmal connectivity as a potential mechanism for transport.
Published in
eLife
2015, volume: 4, article number: e06808
Publisher: ELIFE SCIENCES PUBLICATIONS LTD
SLU Authors
Novak, Ondrej
- Palacký University Olomouc
UKÄ Subject classification
Botany
Publication identifier
- DOI: https://doi.org/10.7554/eLife.06808
Permanent link to this page (URI)
https://res.slu.se/id/publ/76280