Involvement of reactive oxygen species during early stages of ectomycorrhiza establishment between Castanea sativa and Pisolithus tinctorius.
Evidence for the participation of reactive oxygen species (ROS) and antioxidant systems in ectomycorrhizal (ECM) establishment is lacking. In this paper, we evaluated ROS production and the activities of superoxide dismutase (SOD) and catalase (CAT) during the early contact of the ECM fungus Pisolithus tinctorius with the roots of Castanea sativa (chestnut tree). Roots were placed in contact with P. tinctorius mycelia, and ROS production was evaluated by determining the levels of H(2)O(2) and O(2) (.-) during the early stages of fungal contact. Three peaks of H(2)O(2) production were detected, the first two coinciding with O(2) (.-) bursts. The first H(2)O(2) production peak coincided with an increase in SOD activity, whereas CAT activity seemed to be implicated in H(2)O(2) scavenging. P. tinctorius growth was evaluated in the presence of P. tinctorius-elicited C. sativa crude extracts prepared during the early stages of fungal contact. Differential hyphal growth that matched the H(2)O(2) production profile with a delay was detected. The result suggests that during the early stages of ECM establishment, H(2)O(2) results from an inhibition of ROS-scavenging enzymes and plays a role in signalling during symbiotic establishment.
Baptista
Paula
P
CIMO/ESAB, Escola Superior Agrária de Bragança, Quinta de Sta Apolónia, Apartado 1172, 5301-855, Bragança, Portugal. pbaptista@ipb.pt.
Martins
Anabela
A
CIMO/ESAB, Escola Superior Agrária de Bragança, Quinta de Sta Apolónia, Apartado 1172, 5301-855, Bragança, Portugal.
Pais
Maria Salomé
MS
Unidade de Biologia Molecular e Biotecnologia Vegetal, Instituto de Ciência Aplicada e Tecnologia, Edifício ICAT, Campo Grande, 1749-016, Lisboa, Portugal.
Tavares
Rui M
RM
Departamento de Biologia, Laboratório de Bioquímica e Fisiologia Molecular de Plantas, Centro de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
Lino-Neto
Teresa
T
Departamento de Biologia, Laboratório de Bioquímica e Fisiologia Molecular de Plantas, Centro de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
D001487:Basidiomycota / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure; D002374:Catalase / Q000378:metabolism; D002448:Cell Adhesion; D029962:Fagaceae / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D038821:Mycorrhizae / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013559:Symbiosis
D017382:Reactive Oxygen Species; D002374:Catalase; D013482:Superoxide Dismutase