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Trichoderma harzianum
About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.
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TL;DR: Biological control of bunch rot of grape with Trichoderma harzianum can be an effective method of management of this disease.
96 citations
TL;DR: The cell-wall degrading enzymes β-glucanase and chitinase have been suggested to be essential for the mycoparasitic action of Trichoderma species against plant fungal pathogens, and their production in different carbon sources showed an increase parallel to increasing concentrations of either pustulan or chitIn, although the extent of this increase varied with the different enzymes.
Abstract: The cell-wall degrading enzymes β-glucanase and chitinase have been suggested to be essential for the mycoparasitic action of Trichoderma species against plant fungal pathogens. For this reason, the production in different carbon sources of extracellular β-1,3-glucanase, β-1,6-glucanase, chitobiase and chitinase was studied in a mycoparasitic strain of Trichoderma harzianum. Maximal β-glucanase specific activities were detected in media supplemented with either pustulan (β-1,6-glucan), nigeran (α-1,3-glucan alternating with α-1,4-glucan), chitin or Saccharomyces cerevisiae or Botrytis cinerea purified cell walls, whereas the highest chitinase specific activity was obtained in medium supplemented with chitin. Furthermore, β-glucanase, chitobiase and chitinase activities showed an increase parallel to increasing concentrations of either pustulan or chitin added to the cultures, although the extent of this increase varied with the different enzymes. The culture filtrates of T. harzianum grown in these carbon sources also showed lytic activity on purified cell walls of S. cerevisiae and B. cinerea. The enzyme synthesis seemed to be repressed by glucose, 8-hydroxyquinoline, which inhibits transcription, or cycloheximide, an inhibitor of protein synthesis.
95 citations
TL;DR: The synergistic effect of Trichoderma harzianum, exogenous salicylic acid and methyl jasmonate over the response and regulation of the antioxidant defense mechanisms and lipid peroxidation in tomato plants against Fusarium wilt disease is investigated.
Abstract: Plant defense against their pathogens can be induced by a complex network of different inducers. The present study investigates the synergistic effect of Trichoderma harzianum, exogenous salicylic acid (SA) and methyl jasmonate (MeJA) over the response and regulation of the antioxidant defense mechanisms and lipid peroxidation in tomato plants against Fusarium wilt disease. In the present work, tomato plants were infected by Fusarium oxysporum f. sp. lycopersici 3 days after inoculated with T. harzianum and/or sprayed daily for 3 days with chemical inducers (SA and MeJA). Plants were analysed at 0, 24, 48, 72 and 96 h after inoculation with Fusarium oxysporum f. sp. lycopersici. Infection of tomato plants by pathogen led to strong reduction in the dry weight of roots and shoots with the enhanced concentration of H2O2 and varying degree of lipid peroxidation. Concurrently, exogenous SA, when applied with pathogen greatly enhanced H2O2 content as well as activities of antioxidant enzymes except catalase (CAT) and ascorbate peroxidase (APx). The pathogen challenged plants pretreated with T. harzianum and MeJA together exhibited less lipid peroxidation and as well as the elevated level of ascorbic acid and enhanced activities of antioxidant enzymes. All applied treatments protected tomato seedlings against Fusarium wilt disease but the percentage of protection was found higher in plants pretreated with the combination of T. harzianum and chemical inducers.
95 citations
TL;DR: A strong synergistic effect was observed on the inhibition of cyst germination by a combination of the endo-1,3-β-glucanase and the fungicide Fongarid, and Trichoderma appeared to colonize healthy roots only superficially, whereas the mucilage of the root hairs and of distal parts of wounded areas or broken parts of the roots, were extensively colonized.
Abstract: There were indications that endo-1,3-β-glucanase (1,3-(1,3;1,4)-β-D-Glucan 3(4)-glucanohydrolase (EC 3.2.1.6)) and cellulase (1,4-(1,3;1,4)-β-D-Glucan 4-glucanohydrolase (EC 3.2.1.4)) activity of Trichoderma harzianum Rifai isolate T3 were induced in sphagnum peat moss cultivations and dual culture experiments by the presence of Pythium ultimum. Further, P. ultimum stimulated the germination of Trichoderma conidia. Endo-1,3-β-glucanase and cellulase were purified from T. harzianum isolate T3, known to control Pythium damping-off of cucumber seedlings. The enzymes were purified from the culture filtrate of the fungus by gel filtration and isoelectric focusing. The purified endo-1,3-β-glucanase was a small protein with a molecular mass of 17 kilodaltons and a pI of 5.0. Two cellulases were purified to homogeneity and had molecular masses of 40 and 45 kilodaltons respectively, and pI's of 6.4 and 7.6 respectively. Germination of encysted zoospores and elongation of germ tubes of a plant pathogenic Pythium isolate were inhibited by low concentrations of the purified enzymes. A strong synergistic effect was observed on the inhibition of cyst germination by a combination of the endo-1,3-β-glucanase and the fungicide Fongarid. Finally, a time-course study of colonization of the rhizosphere of cucumber seedlings showed that the active fungal mycelial biomass of a GUS-transformant of T. harzianum isolate T3 increased over four weeks. Trichoderma appeared to colonize healthy roots only superficially, whereas the mucilage of the root hairs and of distal parts of wounded areas or broken parts of the roots, were extensively colonized.
95 citations
95 citations