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Controlled auxin biosynthesis and transport are important for developmental decisions in the early diverging land plant Physcomitrella patens

Pederson, Eric R. A. (2014). Controlled auxin biosynthesis and transport are important for developmental decisions in the early diverging land plant Physcomitrella patens. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2014:107
ISBN 978-91-576-8162-1
eISBN 978-91-576-8163-8
[Doctoral thesis]

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Abstract

The aim of this thesis was to increase our understanding of the importance of the plant hormone auxin in land plant evolution. The role of a number of auxin regulatory network components in developmental decisions during the haploid phase of the life cycle of the model moss Physcomitrella patens, which belongs to the early diverging bryophyte group of land plants, was investigated. We show that the role of SHI/STY transcriptional activators in the regulation of auxin biosynthesis rates in seed plants is conserved in moss. The amount and rates of auxin synthesis are reduced in PpSHI knockout mutants, defects in these mutants can be mimicked by reducing active auxin in the PpSHI expression domain, and several moss homologues of YUC and TAA1/TAR genes, which encode the main auxin biosynthesis enzymes in seed plants, were activated in moss when PpSHI2 was transiently expressed. Our data reveal that these moss YUC and TAA1/TAR genes can induce auxin biosynthesis, and that their expression domains largely overlap with that of the two PpSHIs in certain stages of the moss life cycle. PpSHI2 also directly or indirectly activates homologues of genes involved in polar auxin transport (PAT) in seed plants, PpPINA, PpPINB and PpLAXB. We show that the auxin efflux function of PIN proteins have been conserved during the evolution of land plants, and that they, together with the PpSHI auxin biosynthesis regulators, are important for determining developmentally regulated decisions, such as the switch between two cell types of the filamentous stage in moss. In addition, PIN-mediated distribution of auxin synthesised in the leaves plays an important role in determining a developmentally regulated wave of cell expansion. PpSHI regulated local auxin biosynthesis is crucial for several steps in reproductive organ development, such as egg cell maturation, clearance of a canal to the egg cavity, as well as apical opening of both male and female reproductive organs allowing sperm release and entrance into the egg cavity. If polar auxin transport plays a role during these stages remains to be studied. This demonstrates that regulated distribution of auxin was operational in cell-fate decisions already in the early land plants, and that auxin has played a key role in the evolution of complex land plant structures.

Authors/Creators:Pederson, Eric R. A.
Title:Controlled auxin biosynthesis and transport are important for developmental decisions in the early diverging land plant Physcomitrella patens
Series/Journal:Acta Universitatis agriculturae Sueciae (1652-6880)
Year of publishing :2014
Depositing date:18 November 2014
Volume:2014:107
Number of Pages:76
Papers/manuscripts:
NumberReferences
I.Eklund DM, Thelander M, Landberg K, Ståldal V, Nilsson A, Johansson M, Valsecchi I, Pederson ERA, Kowalczyk M, Ronne H & Sundberg E. (2010) Homologues of the Arabidopsis thaliana SHI/STY/LRP1 genes control auxin biosynthesis and affect growth and development in the moss Physcomitrella patens. Development 137(3), 1275-1284.
II.Landberg K, Pederson ERA, Viaene T, Bozorg B, Friml J, Jönsson H, Thelander M & Sundberg E. (2013) The moss Physcomitrella patens reproductive organ development is highly organized, affected by the two SHI/STY genes and by the level of active auxin in the SHI/STY expression domain. Plant Physiology 162, 1406-1419.
III.Pederson ERA, Lagercranz U, Thelander M, Landberg K, Schwarzbach S & Sundberg E. (2014) The Physcomitrella patens SHI2 protein modulates the expression of genes involved in hormonal homeostasis and cell wall modification when transiently induced. (manuscript).
IV.Pederson ERA, Landberg K, Thelander M, Viaene T, Vyas P, Sanchez V, & Sundberg E. (2014) Auxin biosynthesis is developmentally regulated by spatiotemportal control of TAR and YUC genes in Physcomitrella patens. (manuscript).
V.Viaene T, Landberg K, Thelander M, Medvecka E, Pederson ERA, Feraru E, Cooper ED, Karimi M, Delwiche CF, Ljung K, Geisler M, Sundberg E, and Friml J. (2014) Directional auxin transport mechanisms in early diverging land plants. Current Biology, doi:10.1016/j.cub.2014.09.056
Place of Publication:Uppsala
Publisher:Department of Plant Biology, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8162-1
ISBN for electronic version:978-91-576-8163-8
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
F Plant production > F62 Plant physiology - Growth and development
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Developmental Biology
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Evolutionary Biology
Agrovoc terms:bryophyta, auxins, biosynthesis, plant developmental stages, life cycle, plant reproductive organs, genes, gene expression, gene fusion, plants, evolution
Keywords:Physcomitrella patens, auxin, SHI/STY-family
URN:NBN:urn:nbn:se:slu:epsilon-e-2228
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2228
ID Code:11656
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Department of Plant Biology (from 140101)
External funders:Swedish Research Council and Kungliga Fysiografiska Sällskapet i Lund
Deposited By: Eric RA Pederson
Deposited On:19 Nov 2014 14:23
Metadata Last Modified:14 Dec 2014 08:23
Project info:
Name:Evolutionary pathways in plant development, from moss to flowering plants
ID:621-2008-5458
Programme:Project research grant

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