Down-regulated Lotus japonicus GCR1 plants exhibit nodulation signalling pathways alteration.
G Protein Coupled Receptor (GPCRs) are integral membrane proteins involved in various signalling pathways by perceiving many extracellular signals and transducing them to heterotrimeric G proteins, which further transduce these signals to intracellular downstream effectors. GCR1 is the only reliable plant candidate as a member of the GPCRs superfamily. In the legume/rhizobia symbiotic interaction, G proteins are involved in signalling pathways controlling different steps of the nodulation program. In order to investigate the putative hierarchic role played by GCR1 in these symbiotic pathways we identified and characterized the Lotus japonicus gene encoding the seven transmembrane GCR1 protein. The detailed molecular and topological analyses of LjGCR1 expression patterns that are presented suggest a possible involvement in the early steps of nodule organogenesis. Furthermore, phenotypic analyses of independent transgenic RNAi lines, showing a significant LjGCR1 expression down regulation, suggest an epistatic action in the control of molecular markers of nodulation pathways, although no macroscopic symbiotic phenotypes could be revealed.
Institute of Biosciences and Bioresources, IBBR, CNR, Via P. Castellino 111, 80131 Napoli, Italy.
Alessandra
A
Rogato
Institute of Biosciences and Bioresources, IBBR, CNR, Via P. Castellino 111, 80131 Napoli, Italy.
Vladimir Totev
VT
Valkov
Institute of Biosciences and Bioresources, IBBR, CNR, Via P. Castellino 111, 80131 Napoli, Italy.
Ludovico Martins
LM
Alves
Arterra Bioscience Srl, Via B. Brin 69, 80142 Napoli, Italy.
Fabio
F
Apone
Arterra Bioscience Srl, Via B. Brin 69, 80142 Napoli, Italy.
Gabriella
G
Colucci
Institute of Biosciences and Bioresources, IBBR, CNR, Via P. Castellino 111, 80131 Napoli, Italy. Electronic address: maurizio.chiurazzi@ibbr.cnr.it.
Maurizio
M
Chiurazzi
D015536:Down-Regulation; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D000070116:Lotus / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D012231:Rhizobium / Q000502:physiology*; D053204:Root Nodules, Plant / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D013559:Symbiosis
D010940:Plant Proteins; D043562:Receptors, G-Protein-Coupled
G proteins; GCR1; Nodule organogenesis; Signalling; Symbiotic-nitrogen-fixation