title: Trichoderma harzianum T-78 supplementation of compost stimulates the antioxidant defence system in melon plants.
abstract: BACKGROUND
  Compost is emerging as an alternative plant growing medium in efforts to achieve more sustainable agriculture. The addition of specific microorganisms such as Trichoderma harzianum to plant growth substrates increases yields and reduces plant diseases, but the mechanisms of such biostimulants and the biocontrol effects are not yet fully understood. In this work we investigated how the addition of citrus and vineyard composts, either alone or in combination with T. harzianum T-78, affects the antioxidant defence system in melon plants under nursery conditions.
  
  
  RESULTS
  Compost application and/or Trichoderma inoculation modulated the antioxidant defence system in melon plants. The combination of citrus compost and Trichoderma showed a biostimulant effect that correlated with an increase in ascorbate recycling enzymes (monodehydroascorbate reductase, dehydroascorbate reductase) and peroxidase. Moreover, the inoculation of both composts with Trichoderma increased the activity of antioxidant enzymes, especially those involved in ascorbate recycling.
  
  
  CONCLUSIONS
  Based on the long-established relationship between ascorbic acid and plant defence responses as well as plant growth and development, it can be suggested that ascorbate recycling activities play a major role in the protection provided by Trichoderma and its biostimulant effect and that these outcomes are linked to increases in antioxidant enzymes. We can conclude that the combination of citrus compost and T. harzianum T-78 constitutes a viable, environmentally friendly strategy for improving melon plant production.
authors.affiliation: Department of Soil and Water Conservation and Organic Waste Management, CEBAS-CSIC, P.O. Box 164, 30100, Espinardo, Murcia, Spain.
authors.forename: Agustina
authors.initials: A
authors.lastname: Bernal-Vicente
authors.affiliation: Department of Soil and Water Conservation and Organic Waste Management, CEBAS-CSIC, P.O. Box 164, 30100, Espinardo, Murcia, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Pascual
authors.affiliation: Centro per la Ricerca e la sperimentazione in Agricoltura, Centro di ricerca per lo studio delle relazioni tra pianta e suolo (CRA-RPS), via della Navicella, 2, 00184, Rome, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Tittarelli
authors.affiliation: Fruit Tree Biotechnology Group, Department of Plant Breeding, CEBAS-CSIC, P.O. Box 164, 30100, Espinardo, Murcia, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Hernández
authors.affiliation: Fruit Tree Biotechnology Group, Department of Plant Breeding, CEBAS-CSIC, P.O. Box 164, 30100, Espinardo, Murcia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Diaz-Vivancos
mesh_terms: D000383:Agriculture / Q000379:methods; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism*; D002957:Citrus; D019662:Cucurbitaceae / Q000254:growth & development / Q000378:metabolism*; D005638:Fruit; D006801:Humans; D010088:Oxidoreductases / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D010935:Plant Diseases; D018517:Plant Roots; D012987:Soil; D012988:Soil Microbiology; D014242:Trichoderma
chemical_list: D000975:Antioxidants; D012987:Soil; D010088:Oxidoreductases; D009195:Peroxidase; C020666:glutathione dehydrogenase (ascorbate); D001205:Ascorbic Acid
keywords: Trichoderma harzianum T-78; antioxidant defence system; ascorbate recycling activities; compost-growing media