title: The tomato CAROTENOID CLEAVAGE DIOXYGENASE8 (SlCCD8) regulates rhizosphere signaling, plant architecture and affects reproductive development through strigolactone biosynthesis.
abstract: Strigolactones are plant hormones that regulate both above- and belowground plant architecture. Strigolactones were initially identified as rhizosphere signaling molecules. In the present work, the tomato (Solanum lycopersicum) CAROTENOID CLEAVAGE DIOXYGENASE 8 (SlCCD8) was cloned and its role in rhizosphere signaling and plant physiology assessed by generating knock-down lines. Transgenic SlCCD8 plants were generated by RNAi-mediated silencing. Lines with different levels of strigolactone reduction--confirmed by UPLC-MS/MS--were selected and their phenotypes investigated. Lines exhibiting reduced SlCCD8 levels displayed increased shoot branching, reduced plant height, increased number of nodes and excessive adventitious root development. In addition, these lines exhibited reproductive phenotypes such as smaller flowers, fruits, as well as fewer and smaller seeds per fruit. Furthermore, we show that strigolactone loading to the xylem sap is possibly restricted to orobanchol. Infestation by Phelipanche ramosa was reduced by 90% in lines with a relatively mild reduction in strigolactone biosynthesis and secretion while arbuscular mycorrhizal symbiosis, apical dominance and fruit yield were only mildly affected. This demonstrates that reduction of strigolactone biosynthesis could be a suitable tool in parasitic weed management. Furthermore, our results suggest that strigolactones are involved in even more physiological processes than so far assumed.
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.|Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, D-50829, Cologne, Germany.
authors.forename: Wouter
authors.initials: W
authors.lastname: Kohlen
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
authors.forename: Tatsiana
authors.initials: T
authors.lastname: Charnikhova
authors.affiliation: Business Unit Bioscience, Plant Research International, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
authors.forename: Michiel
authors.initials: M
authors.lastname: Lammers
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
authors.forename: Tobia
authors.initials: T
authors.lastname: Pollina
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.|Department of Plant Protection, Slovak Agricultural University, A. Hlinku 2, 94976, Nitra, Slovakia.
authors.forename: Peter
authors.initials: P
authors.lastname: Tóth
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
authors.forename: Imran
authors.initials: I
authors.lastname: Haider
authors.affiliation: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), Prof. Albareda 1, 18008, Granada, Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: Pozo
authors.affiliation: Business Unit Bioscience, Plant Research International, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.|Centre for Biosystems Genomics, PO Box 98, 6700 AB, Wageningen, The Netherlands.
authors.forename: Ruud A
authors.initials: RA
authors.lastname: de Maagd
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.|Business Unit Bioscience, Plant Research International, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
authors.forename: Carolien
authors.initials: C
authors.lastname: Ruyter-Spira
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.|Centre for Biosystems Genomics, PO Box 98, 6700 AB, Wageningen, The Netherlands.
authors.forename: Harro J
authors.initials: HJ
authors.lastname: Bouwmeester
authors.affiliation: Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.|Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), Prof. Albareda 1, 18008, Granada, Spain.
authors.forename: Juan A
authors.initials: JA
authors.lastname: López-Ráez
mesh_terms: D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D003001:Cloning, Molecular; D035264:Flowers / Q000033:anatomy & histology; D005638:Fruit / Q000033:anatomy & histology; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D007783:Lactones / Q000737:chemistry / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000033:anatomy & histology* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D013058:Mass Spectrometry; D008954:Models, Biological; D008969:Molecular Sequence Data; D053147:Plant Exudates / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D018520:Plant Shoots / Q000033:anatomy & histology / Q000201:enzymology; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012098:Reproduction; D058441:Rhizosphere; D012639:Seeds / Q000033:anatomy & histology; D015398:Signal Transduction
chemical_list: D007783:Lactones; D053147:Plant Exudates; D010940:Plant Proteins; D012333:RNA, Messenger