Origin of strigolactones in the green lineage.
The aims of this study were to investigate the appearance of strigolactones in the green lineage and to determine the primitive function of these molecules. We measured the strigolactone content of several isolated liverworts, mosses, charophyte and chlorophyte green algae using a sensitive biological assay and LC-MS/MS analyses. In parallel, sequence comparison of strigolactone-related genes and phylogenetic analyses were performed using available genomic data and newly sequenced expressed sequence tags. The primitive function of strigolactones was determined by exogenous application of the synthetic strigolactone analog, GR24, and by mutant phenotyping. Liverworts, the most basal Embryophytes and Charales, one of the closest green algal relatives to Embryophytes, produce strigolactones, whereas several other species of green algae do not. We showed that GR24 stimulates rhizoid elongation of Charales, liverworts and mosses, and rescues the phenotype of the strigolactone-deficient Ppccd8 mutant of Physcomitrella patens. These findings demonstrate that the first function of strigolactones was not to promote arbuscular mycorrhizal symbiosis. Rather, they suggest that the strigolactones appeared earlier in the streptophyte lineage to control rhizoid elongation. They may have been conserved in basal Embryophytes for this role and then recruited for the stimulation of colonization by glomeromycotan fungi.
Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, UPS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.|CNRS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.
Pierre-Marc
PM
Delaux
Weed Science Centre, Utsunomiya University, Utsunomiya 321-8505, Japan.
Xiaonan
X
Xie
Cell Biology and Molecular Genetics, 2108 Biosciences Research Bldg., and the Maryland Agricultural Experiment Station, University of Maryland, College Park, MD 20742, USA.
Ruth E
RE
Timme
Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, UPS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.|CNRS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.
Virginie
V
Puech-Pages
Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, UPS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.|CNRS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.
Christophe
C
Dunand
Université de Toulouse, UPS, EDB (Laboratoire Evolution et Diversité Biologique), 118 route de Narbonne, F-31062, Toulouse, France.|CNRS, EDB (Laboratoire Evolution et Diversité Biologique), F-31062, Toulouse, France.
Emilie
E
Lecompte
Cell Biology and Molecular Genetics, 2108 Biosciences Research Bldg., and the Maryland Agricultural Experiment Station, University of Maryland, College Park, MD 20742, USA.
Charles F
CF
Delwiche
Weed Science Centre, Utsunomiya University, Utsunomiya 321-8505, Japan.
Koichi
K
Yoneyama
Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, UPS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.|CNRS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.
Guillaume
G
Bécard
Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, UPS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.|CNRS, UMR 5546, BP 42617, F-31326, Castanet-Tolosan, France.|Present address: UMR5245 ECOLAB, ENSAT, Av de l'Agrobiopole, F-31326 Auzeville, Castanet-Tolosan, France.
Nathalie
N
Séjalon-Delmas
D020418:Algal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D019068:Bryopsida / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D000460:Chlorophyta / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D002853:Chromatography, Liquid; D019143:Evolution, Molecular; D017343:Genes, Plant / Q000235:genetics; D035926:Hepatophyta / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D007783:Lactones / Q000378:metabolism* / Q000494:pharmacology; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
D020418:Algal Proteins; D007783:Lactones