title: Involvement of pachybasin and emodin in self-regulation of Trichoderma harzianum mycoparasitic coiling.
abstract: Our aim was to determine the effects of two secondary metabolites secreted by Trichoderma harzianum, pachybasin and emodin, on the mycoparasitic coiling behavior and cAMP content of T. harzianum. The number of T. harzianum coils around Nylon 66 fiber was increased in the presence of R. solani. The number of T. harzianum coils around R. solani hyphae and Nylon 66 fiber were significantly increased in the presence of pachybasin and emodin. The cAMP level in T. harzianum was significantly increased by close contact with R. solani and much higer cAMP level in the presence of exogenous pachybasin and emodin. A cAMP inhibitor diminished the effect of pachybasin and emodin on T. harzianum coiling around Nylon 66 fiber. The results suggest that pachybasin and emodin mediate the increase in the number of Trichoderma mycoparasitic coils via cAMP signaling. This is the first report to suggest that pachybasin and emodin play roles in the biocontrol mechanism of Trichoderma.
authors.affiliation: Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien, Taiwan.
authors.forename: Yi-Ruu
authors.initials: YR
authors.lastname: Lin
authors.forename: Chaur-Tsuen
authors.initials: CT
authors.lastname: Lo
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Liu
authors.forename: Kou-Cheng
authors.initials: KC
authors.lastname: Peng
mesh_terms: D000880:Anthraquinones / Q000378:metabolism / Q000494:pharmacology*; D000242:Cyclic AMP / Q000032:analysis / Q000037:antagonists & inhibitors; D004642:Emodin / Q000378:metabolism / Q000494:pharmacology*; D025282:Mycelium / Q000187:drug effects / Q000502:physiology; D014242:Trichoderma / Q000187:drug effects / Q000502:physiology*
chemical_list: D000880:Anthraquinones; C573277:pachybasin; D000242:Cyclic AMP; D004642:Emodin