Fate of Trichoderma harzianum in the olive rhizosphere: time course of the root colonization process and interaction with the fungal pathogen Verticillium dahliae
- 763 Downloads
Trichoderma harzianum Rifai is a well-known biological control agent (BCA) effective against a wide range of phytopathogens. Since colonization and persistence in the target niche is crucial for biocontrol effectiveness we aimed to: (i) shed light on the olive roots colonization process by T. harzianum CECT 2413, (ii) unravel the fate of its biomass upon application, and (iii) study the in planta interaction with the soil-borne pathogen Verticillium dahliae Kleb. Fluorescently-tagged derivatives of CECT 2413 and V. dahliae and confocal laser scanning microscopy were used. In vitro assays showed for the first time mycoparasitism of V. dahliae by T. harzianum, evidenced by events such as hyphal coiling. In planta assays revealed that CECT 2413 profusely colonized the rhizoplane of olive roots. Interestingly, biomass of the BCA was visualized mainly as chlamydospores. This observation was independent on the presence or absence of the pathogen. Evidence of inner colonization of olive roots by CECT 2413 was not obtained. These results suggest that CECT 2413 is not able to persist in a metabolically-active form when applied as a spore suspension. This may have strong implications in the way this BCA should be introduced and/or formulated to be effective against Verticillium wilt of olive.
KeywordsChlamydospores Confocal laser scanning microscopy Mycoparasitism Olea europaea L. Trichoderma harzianum Rifai Root colonization Verticillium dahliae Kleb. Verticillium wilt
We are very grateful to M. N. Casa Adán for the help with CLSM at the University of Jaén facilities, and to M. Maldonado-González and A. Valverde-Corredor for their technical assistance. We appreciate the collaboration of NUTESCA SL in this project. This work was supported by European Regional Development Fund-cofinanced grants from the Spanish Ministry of Economy and Competitiveness [Project number BIO2012-33904] and ‘Junta de Andalucía’ [Project number AGR-6038].
- Barroso Albarracín JB, Carreras Egaña A, Valderrama Rodríguez R, Chaki M, Begara Morales J, Mercado-Blanco J, Pérez Artés E, Rincón Romero A, Carballo Codón A, Benítez Fernández T, Valverde Corredor A, Guevara Pezoa F, Rodríguez Palero MJ, Dueñas Sánchez R, Fierro Risco J, López García A (2014) Cepa de Trichoderma útil para el tratamiento y/o prevención de infecciones provocadas por hongos pertenecientes al género Verticilium. Spanish Patent ES2393728Google Scholar
- Chet I, Benhamou N, Haran S (1998) Mycoparasitism and lytic enzymes. In: Harman GE, Kubicek CP (eds) Trichoderma & Gliocladium. Enzymes, biological control and commercial applications, vol 2. Taylor and Francis Ltd, London, UK, pp 153–172Google Scholar
- Cohen SD, Lewis JA, Papavizas GC, Bean GA (1983) Chlamydospore formation by Trichoderma spp. in organic-matter amended soil. Phytopathology 73(5):820Google Scholar
- Contreras-Cornejo HA, Ortiz-Castro R, López-Bucio J (2013) Promotion of plant growth and the induction of systemic defence by Trichoderma: physiology, genetics and gene expression. In: Mukherjee PK, Horwitz BA, Singh US, Mukherjee M, Schmoll M (eds) Trichoderma: biology and applications. CABI, Walingford, UK, pp 173–194CrossRefGoogle Scholar
- Harman GE, Kubicek CP (1998) Trichoderma & Gliocladium: enzymes, biological control and commercial applications, vol 2. Taylor & Francis Ltd, London, UKGoogle Scholar
- Jiménez-Díaz RM, Trapero-Casas JL, Boned J, Landa del Castillo BB, Navas-Cortés JA (2009) Uso de Bioten para la protección biológica de plantones de olivo contra la Verticilosis causada por el patotipo defoliante de Verticillium dahliae. Bol San Veg. Plagas, 35:595–615 (with an abstract in English)Google Scholar
- Kredics L, Hatvani L, Naeimi S, Körmöczi P, Manczinger L, Vágvölgyi C, Druzhinina I (2014) Chapter 1: biodiversity of the genus Hypocrea/Trichoderma in different habitats. In: Gupta VK, Schmoll M, Herrera-Estrella A, Upadhyay RS, Druzhinina I, Tuohy M (eds) Biotechnology and biology of Trichoderma. Elsevier, Amsterdam, The Netherlands, pp 3–24CrossRefGoogle Scholar
- Lorito M, Woo S (2015) Trichoderma: A multi-purpose tool for integrated pest management. In: Lugtenberg B (ed) Principles of plan-microbe interactions. Microbes Sustain Agric, Springer, USA, pp 345–353Google Scholar
- Prieto P, Navarro-Raya C, Valverde-Corredor A, Amyotte SG, Dobinson KF, Mercado-Blanco J (2009) Colonization process of olive tissues by Verticillium dahliae and its in planta interaction with the biocontrol root endophyte Pseudomonas fluorescens PICF7. Microb Biotechnol 2(4):499–511CrossRefPubMedPubMedCentralGoogle Scholar
- Rincón AM, Chaki M, Fierro-Risco J, Valverde-Corredor A, Carreras A, Pérez-Artés E, Begara JC, Valderrama R, Barroso JB, Mercado-Blanco J (2014) Biological control of Verticillium wilt of olive by Trichoderma harzianum. In: XII Meeting of the IOBC/WPRS Working Group, Biological control of fungi and bacterial plant pathogens. Upsala, Sweden, p 78Google Scholar