title: Diversity of Cultivated Fungi Associated with Conventional and Transgenic Sugarcane and the Interaction between Endophytic Trichoderma virens and the Host Plant.
abstract: Plant-associated fungi are considered a vast source for biotechnological processes whose potential has been poorly explored. The interactions and diversity of sugarcane, one of the most important crops in Brazil, have been rarely studied, mainly concerning fungal communities and their interactions with transgenic plants. Taking this into consideration, the purpose of this study was, based on culture dependent strategy, to determine the structure and diversity of the fungal community (root endophytes and rhizosphere) associated with two varieties of sugarcane, a non-genetically modified (SP80-1842) variety and its genetically modified counterpart (IMI-1, expressing imazapyr herbicide resistance). For this, the sugarcane varieties were evaluated in three sampling times (3, 10 and 17 months after planting) under two crop management (weeding and herbicide treatments). In addition, a strain of Trichoderma virens, an endophyte isolated from sugarcane with great potential as a biological control, growth promotion and enzyme production agent, was selected for the fungal-plant interaction assays. The results of the isolation, characterization and evaluation of fungal community changes showed that the sugarcane fungal community is composed of at least 35 different genera, mostly in the phylum Ascomycota. Many genera are observed at very low frequencies among a few most abundant genera, some of which were isolated from specific plant sites (e.g., the roots or the rhizosphere). An assessment of the possible effects upon the fungal community showed that the plant growth stage was the only factor that significantly affected the community's structure. Moreover, if transgenic effects are present, they may be minor compared to other natural sources of variation. The results of interaction studies using the Green fluorescent protein (GFP)-expressing T. virens strain T.v.223 revealed that this fungus did not promote any phenotypic changes in the host plant and was found mostly in the roots where it formed a dense mycelial cover and was able to penetrate the intercellular spaces of the root epidermis upper layers. The ability of T. virens to colonize plant roots suggests a potential for protecting plant health, inhibiting pathogens or inducing systemic resistance.
authors.affiliation: Department of Genetics, Escola Superior de Agricultura "Luiz de Queiroz"(ESALQ), University of São Paulo, São Paulo, Brazil.
authors.forename: Aline Silva
authors.initials: AS
authors.lastname: Romão-Dumaresq
authors.affiliation: Department of Genetics, Escola Superior de Agricultura "Luiz de Queiroz"(ESALQ), University of São Paulo, São Paulo, Brazil.|Laboratory of Molecular Biology and Microbial Ecology, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Manuella Nóbrega
authors.initials: MN
authors.lastname: Dourado
authors.affiliation: Department of Genetics, Escola Superior de Agricultura "Luiz de Queiroz"(ESALQ), University of São Paulo, São Paulo, Brazil.|Brazilian Agricultural Research Corporation, Embrapa Agroenergy, Brasília, Distrito Federal, Brazil.
authors.forename: Léia Cecilia de Lima
authors.initials: LC
authors.lastname: Fávaro
authors.affiliation: Department of Genetics, Escola Superior de Agricultura "Luiz de Queiroz"(ESALQ), University of São Paulo, São Paulo, Brazil.|Brazilian Agricultural Research Corporation, Embrapa Environment, Jaguariuna, São Paulo, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Mendes
authors.affiliation: Department of Genetics, Escola Superior de Agricultura "Luiz de Queiroz"(ESALQ), University of São Paulo, São Paulo, Brazil.|Brazilian Agricultural Research Corporation, Embrapa Agrosilvopastoral, Sinop, Mato Grosso, Brazil.
authors.forename: Anderson
authors.initials: A
authors.lastname: Ferreira
authors.affiliation: Department of Genetics, Escola Superior de Agricultura "Luiz de Queiroz"(ESALQ), University of São Paulo, São Paulo, Brazil.|Laboratory of Molecular Biology and Microbial Ecology, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Welington Luiz
authors.initials: WL
authors.lastname: Araújo
mesh_terms: D044822:Biodiversity; D000069599:Crop Production; D004271:DNA, Fungal / Q000235:genetics; D060026:Endophytes / Q000502:physiology*; D053209:Herbicide Resistance / Q000235:genetics; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D058441:Rhizosphere; D031786:Saccharum / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D017422:Sequence Analysis, DNA; D013559:Symbiosis / Q000235:genetics / Q000502:physiology; D014242:Trichoderma / Q000235:genetics / Q000502:physiology*
chemical_list: D004271:DNA, Fungal