L-N Liu1, J-Z Zhang, T Xu. 1. Institute of Biotechnology, Zhejiang University, Hangzhou, China.
Abstract
AIMS: The aim of the study was to investigate the antagonistic interactions of Trichoderma species against Rhizoctonia solani sclerotia by enhanced green fluorescence protein (EGFP)-tagged transformant of Trichoderma virens TY009. METHODS AND RESULTS: An EGFP was used as a report gene for transforming T. virens strain, and a stable EGFP transformant GF5 was obtained with the mycoparasitic activity against sclerotia of R. solani. Observation of parasitized sclerotia by fluorescence microscopy showed hyphae of transformant GF5 was able to invade into sclerotia and its colonization was mainly intercellar with uniformly distributed mycelium in sclerotia. The host cells were colonized, penetrated, and then the whole cells were replaced by transformant GF5 hyphae. Chlamydospores were seen after 10 days but mature ones after 20 days. Sclerotia became soft and decayed after 40 days but a few cells seemed not to be colonized completely. CONCLUSIONS: Trichoderma virens was able to parasitize sclerotia to make sclerotia soft and decayed, and its colonization was mainly intercellar in sclerotial tissues. SIGNIFICANCE AND IMPACT OF THE STUDY: This is first report of parasitism of sclerotia of R. solani by EGFP-tagged transformant, providing useful information for using T. virens as effective biocontrol agent.
AIMS: The aim of the study was to investigate the antagonistic interactions of Trichoderma species against Rhizoctonia solani sclerotia by enhanced green fluorescence protein (EGFP)-tagged transformant of Trichoderma virens TY009. METHODS AND RESULTS: An EGFP was used as a report gene for transforming T. virens strain, and a stable EGFP transformant GF5 was obtained with the mycoparasitic activity against sclerotia of R. solani. Observation of parasitized sclerotia by fluorescence microscopy showed hyphae of transformant GF5 was able to invade into sclerotia and its colonization was mainly intercellar with uniformly distributed mycelium in sclerotia. The host cells were colonized, penetrated, and then the whole cells were replaced by transformant GF5 hyphae. Chlamydospores were seen after 10 days but mature ones after 20 days. Sclerotia became soft and decayed after 40 days but a few cells seemed not to be colonized completely. CONCLUSIONS:Trichoderma virens was able to parasitize sclerotia to make sclerotia soft and decayed, and its colonization was mainly intercellar in sclerotial tissues. SIGNIFICANCE AND IMPACT OF THE STUDY: This is first report of parasitism of sclerotia of R. solani by EGFP-tagged transformant, providing useful information for using T. virens as effective biocontrol agent.