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EFFECT OF MYCORRHIZAL INFECTION ON RESPIRATION AND ACTIVITY OF SOME OXIDASE ENZYMES OF ORCHID PROTOCORMS
Author(s) -
BLAKEMAN J. P.,
MOKAHEL M. A.,
HADLEY G.
Publication year - 1976
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1976.tb04663.x
Subject(s) - polyphenol oxidase , biology , fungus , catalase , peroxidase , orchidaceae , endophyte , botany , rhizoctonia , mycelium , respiration , mycorrhiza , catechol oxidase , rhizoctonia solani , symbiosis , enzyme , biochemistry , bacteria , genetics
S ummary Infection of protocorms of Dactylorhiza purpurella and a Cymbidium hybrid by an endophytic mycorrhizal fungus ( Rhizoctonia sp.) led to a marked stimulation of respiration. Peak oxygen uptake often coincided with formation and digestion of pelotons. Treatment of protocorms with culture filtrates or mycelial extracts of the mycorrhizal fungus also enhanced oxygen uptake. Activities of polyphenol oxidase, ascorbic acid oxidase, peroxidase and catalase were greatly increased in infected protocorms. Peak activity often coincided with peak oxygen uptake and digestion of pelotons, except for peroxidase where peak activity occurred earlier. The orchid/endophyte system is compared with host/pathogen interactions in terms of the possible relationship between changes in enzyme activity and defence mechanisms.