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Enzymes Associated with Defence against Toxic Oxygen Species in PCNB‐Tolerant and Sensitive Soil Fungi
Author(s) -
Ephraim Cohen Prof.,
Teomi Shoshana
Publication year - 1992
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/j.1439-0434.1992.tb01273.x
Subject(s) - pythium aphanidermatum , trichoderma harzianum , biology , rhizoctonia solani , superoxide dismutase , fusarium oxysporum , glutathione reductase , sclerotium , catalase , rhizopus arrhizus , glutathione peroxidase , microbiology and biotechnology , fungi imperfecti , botany , biochemistry , enzyme , biological pest control , lipase
The specific activities of enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPOX) and glutathione reductase (GR), which are involved in protection against toxic species of oxygen, were determined in mycelia extracts of pentachloronitrobenzene (PCNB)‐tolerant and susceptible soil fungi. The organisms assayed were the highly PCNB‐sensitive Rhizoctonia solani and Rhizopus arrhizus; Sclerotium rolfsii and Trichoderma harzianum , which are moderately susceptible to PCNB, and the fungicide‐tolerant Fusarium oxysporum f. sp. melonis and Pythium aphanidermatum . No GPOX activity was detected in the six examined fungi. Significant differences in the specific activities of the other enzyme systems among the fungi were evident. Remarkably low levels of CAT activities were measured in R. solani . Except for T. harzianum , no meaningful differences regarding SOD, CAT and GR activities with age of the fungi cultures were observed. The electrophoretic patterns of SOD and CAT displayed dissimilarities among the fungi under study. P. aphanidermatum is more polymorphic with respect to both SOD and CAT enzyme systems as compared to the other fungi. The SOD of F. oxysporum f. sp. melonis, R. arrhizus and T. harzianum is a cuprozinc enzyme, while the mangano‐SOD species was detected in S. rolfsii, R. solani and T. harzianum .