A 2-component system is involved in the early stages of the Pisolithus tinctorius-Pinus greggii symbiosis.
Ectomycorrhizal symbiosis results in profound morphological and physiological modifications in both plant and fungus. This in turn is the product of differential gene expression in both co-symbionts, giving rise to specialized cell types capable of performing novel functions. During the precolonization stage, chemical signals from root exudates are sensed by the ectomycorrizal fungus, and vice versa, which are in principle responsible for the observed change in the developmental symbionts program. Little is known about the molecular mechanisms involved in the signaling and recognition between ectomycorrhizal fungi and their host plants. In the present work, we characterized a novel lactone, termed pinelactone, and identified a gene encoding for a histidine kinase in Pisolithus tictorius, which function is proposed to be the perception of the aforementioned metabolites. In this study, the use of closantel, a specific inhibitor of histidine kinase phosphorylation, affected the capacity for fungal colonization in the symbiosis between Pisolithus tinctorius and Pinus greggii, indicating that a 2-component system (TCS) may operate in the early events of plant-fungus interaction. Indeed, the metabolites induced the accumulation of Pisolithus tinctorius mRNA for a putative histidine kinase (termed Pthik1). Of note, Pthik1 was able to partially complement a S. cerevisiae histidine kinase mutant, demonstrating its role in the response to the presence of the aforementioned metabolites. Our results indicate a role of a 2-component pathway in the early stages of ectomycorrhizal symbiosis before colonization. Furthermore, a novel lactone from Pinus greggii root exudates may activate a signal transduction pathway that contributes to the establishment of the ectomycorrhizal symbiosis.
Departamento de Biotecnología y Bioingeniería; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco, México, D.F.; Facultad de Ingeniería; Universidad Autónoma de Baja California; Mexicali B.C. México.
Aseneth
A
Herrera-Martínez
Departamento de Biotecnología y Bioingeniería; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco, México, D.F.
Roberto
R
Ruiz-Medrano
Departamento de Biotecnología y Bioingeniería; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco, México, D.F.
Santiago Valentín
SV
Galván-Gordillo
Departamento de Biotecnología y Bioingeniería; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco, México, D.F.
Roberto
R
Toscano Morales
Escuela Nacional de Ciencias Biológicas; IPN; México D.F.
Lidia
L
Gómez-Silva
Escuela Nacional de Ciencias Biológicas; IPN; México D.F.
María
M
Valdés
Facultad de Ingeniería Química; Benemérita Universidad Autónoma de Puebla; Ciudad Universitaria; Puebla, México.
Jesús
J
Hinojosa-Moya
Departamento de Biotecnología y Bioingeniería; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco, México, D.F.
Beatriz
B
Xoconostle-Cázares
D005656:Fungal Proteins / Q000378:metabolism; D000071677:Histidine Kinase; D007783:Lactones / Q000378:metabolism*; D038821:Mycorrhizae / Q000201:enzymology*; D028223:Pinus / Q000378:metabolism / Q000382:microbiology*; D053147:Plant Exudates / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D012458:Salicylanilides; D013559:Symbiosis; D015026:Zeatin / Q000378:metabolism
D005656:Fungal Proteins; D007783:Lactones; D053147:Plant Exudates; D012458:Salicylanilides; D015026:Zeatin; D011494:Protein Kinases; D000071677:Histidine Kinase; C023342:closantel
2-Component System (TCS); Ectomycorrhiza; Pinelactone