title: Small Ubiquitin-like Modifier protein SUMO enables plants to control growth independently of the phytohormone gibberellin.
abstract: Plants survive adverse conditions by modulating their growth in response to a changing environment. Gibberellins (GAs) play a key role in these adaptive responses by stimulating the degradation of growth-repressing DELLA proteins. GA binding to its receptor GID1 enables association of GID1 with DELLAs. This leads to the ubiquitin-mediated proteasomal degradation of DELLAs and consequently growth promotion. We report that DELLA-dependent growth control can be regulated independently of GA. We demonstrate that when a proportion of DELLAs is conjugated to the Small Ubiquitin-like Modifier (SUMO) protein, the extent of conjugation increases during stress. We identify a SUMO-interacting motif in GID1 and demonstrate that SUMO-conjugated DELLA binds to this motif in a GA-independent manner. The consequent sequestration of GID1 by SUMO-conjugated DELLAs leads to an accumulation of non-SUMOylated DELLAs, resulting in beneficial growth restraint during stress. We conclude that plants have developed a GA-independent mechanism to control growth.
authors.affiliation: School of Biological and Biomedical Sciences, South Road, Durham University, Durham DH1 3LE, UK; Department of Life Sciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy.
authors.forename: Lucio
authors.initials: L
authors.lastname: Conti
authors.affiliation: School of Biological and Biomedical Sciences, South Road, Durham University, Durham DH1 3LE, UK.
authors.forename: Stuart
authors.initials: S
authors.lastname: Nelis
authors.affiliation: School of Biological and Biomedical Sciences, South Road, Durham University, Durham DH1 3LE, UK.
authors.forename: Cunjin
authors.initials: C
authors.lastname: Zhang
authors.affiliation: School of Biological and Biomedical Sciences, South Road, Durham University, Durham DH1 3LE, UK; School of Life Sciences University of Warwick, Gibbet Hill Road, Coventry CV4 7ES, UK.
authors.forename: Ailidh
authors.initials: A
authors.lastname: Woodcock
authors.affiliation: Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Swarup
authors.affiliation: Department of Life Sciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy; Fondazione Filarete, Viale Ortles 22/4, 20139 Milan, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Galbiati
authors.affiliation: Department of Life Sciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Tonelli
authors.affiliation: School of Life Sciences University of Warwick, Gibbet Hill Road, Coventry CV4 7ES, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Napier
authors.affiliation: Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Hedden
authors.affiliation: Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Bennett
authors.affiliation: School of Biological and Biomedical Sciences, South Road, Durham University, Durham DH1 3LE, UK. Electronic address: ari.sadanandom@durham.ac.uk.
authors.forename: Ari
authors.initials: A
authors.lastname: Sadanandom
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D005875:Gibberellins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D025842:SUMO-1 Protein / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; C512225:GID1a protein, Arabidopsis; D005875:Gibberellins; C508468:RGA protein, Arabidopsis; D011956:Receptors, Cell Surface; D012097:Repressor Proteins; D025842:SUMO-1 Protein