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Chemical biology and digital image processing to unravel complex molecular mechanisms in Arabidopsis

Vain, Thomas (2016). Chemical biology and digital image processing to unravel complex molecular mechanisms in Arabidopsis. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2016:104
ISBN 978-91-576-8711-1
eISBN 978-91-576-8712-8
[Doctoral thesis]

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The sessile life of plant directed their evolution toward multiple adaptive strategies. Rapid protein turn over has been described to be a key regulatory mechanism for plant adaptation. Ubiquitin-modified proteins are targeted for degradation by the 26S-proteasome. A class of ubiquitin-ligases, the Cullin Ring Ligases (CRLs) have been shown to be involved in most Arabidopsis developmental processes. CRLs are stabilized by the covalent binding of the small peptide RELATED TO UBIQUITIN (RUB). The CRLs modification is required for the activity of plant hormones as exemplified by mutants deficient in the RUB-activating enzyme subunit AUXIN-RESISTANT 1 (AXR1). The perception of auxin results in the ubiquitin-mediated degradation of the AUXIN/INDOL-3-ACETIC ACID (Aux/IAA) transcriptional repressors. Aux/IAA proteins control the auxin-mediated transcriptional response. In this work, a forward chemical genomic strategy has been used to identify small synthetic molecules affecting plant development. We used the resistance of the axr1-30 mutants in order to select compounds requiring RUB activation. Among the molecules isolated to alter specific plant developmental processes, three Developmental Regulators (DRs) have been shown to directly interfere with the degradation of the Aux/IAA proteins promoting a rapid induction of specific auxin-related transcriptional responses. Furthermore, we used the molecule DR4, abolishing specifically apical hook formation, to investigate the functional selectivity of auxin perception during apical hook development. A forward genetic screen has been performed to isolate dr4-resistant mutants. Several viable mutants were isolated with different sensitivity to auxin but all resistant to DR4. The isolation of mutants preferentially resistant to the differential growth defect induced by DR4 demonstrates the potential to determine the molecular process mediating the developmental features induced by the selective agonists of auxin. Since the first digital image 60 years ago, imaging techniques are constantly evolving generating more and more digital images. The conversion of images into biologically relevant quantitative data is an essential process to overcome and understand biological variability. In this work, we describe two digital images processing approaches which have been used to semi-automatically describe intracellular structure density and colocalization; the complex shape of the Arabidopsis pavement cells.

Authors/Creators:Vain, Thomas
Title:Chemical biology and digital image processing to unravel complex molecular mechanisms in Arabidopsis
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :25 November 2016
Depositing date:25 November 2016
Number of Pages:48
IVain T., Ferro N., Barange D.K., Kieffer M., Ma Q., Thelander M., Pařízková B., Novák O., Doyle S.M., Ismail A., Enquist P.A., Rigal A., Langowska M., Harborough S.R., Zhang Y., Ljung K., Callis J., Almqvist F., Kepinski S., Estelle M., Pauwels L. and Robert S.. Selective degradation of Aux/IAA proteins modulates plant development (manuscript).
IIVain T., Crowell E.F., Timpano H., Biot E., Desprez T., Mansoori N., Trindade L. M., Pagant S., Robert S., Höfte H., Gonneau M. and Vernhettes S. (2014). The Cellulase KORRIGAN Is Part of the Cellulose Synthase Complex. Plant Physiology. vol(165), 1521-1532.
IIIMajda M., Grones P., Sintorn I.M., Vain T., Milani P., Krupinski P., Zagórska-Marek B., Viotti C., Jönsson H., Mellerowicz E.J., Hamant O. and Robert S.. Mechano-chemical polarization of cell walls drives shape coordination (manuscript).
Place of Publication:Umeå
Publisher:Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8711-1
ISBN for electronic version:978-91-576-8712-8
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
F Plant production > F60 Plant physiology and biochemistry
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 104 Chemical Sciences > Other Chemistry Topics
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Biochemistry and Molecular Biology
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Developmental Biology
Agrovoc terms:arabidopsis thaliana, genomics, genomes, auxins, digital image processing, molecular biology
Keywords:Chemical genomics, Arabidopsis, Auxin
Permanent URL:
ID Code:13771
Faculty:S - Faculty of Forest Sciences
Department:(S) > Dept. of Forest Genetics and Plant Physiology
External funders:SLU fund for internationalisation of postgraduate studies
Deposited By: M Thomas Vain
Deposited On:01 Nov 2016 08:55
Metadata Last Modified:10 Sep 2020 13:41

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