Three ancient hormonal cues co-ordinate shoot branching in a moss

0446640 - ÚEB 2016 RIV GB eng J - Journal Article
Coudert, Y. - Palubicki, W. - Ljung, K. - Novák, Ondřej - Leyser, O. - Harrison, C.J.
Three ancient hormonal cues co-ordinate shoot branching in a moss.
eLife. Roč. 4, MAR 25 (2015). ISSN 2050-084X. E-ISSN 2050-084X
R&D Projects: GA MŠMT(CZ) LO1204
Institutional support: RVO:61389030
Keywords : EARLY LAND PLANTS * AUXIN TRANSPORT * APICAL DOMINANCE
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 8.282, year: 2015

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.
Permanent Link: http://hdl.handle.net/11104/0248609