Floristic and vegetation structure of a grassland plant community on shallow basalt in southern Brazil

Few studies have adequately described the floristic and structural features of natural grasslands associated with shallow basalt soils in southern Brazil. This study was carried out on natural grazing land used for livestock production in the municipality of Santana do Livramento, in the Campanha region of the state of Rio Grande do Sul, Brazil. The aim of the study was to describe the floristic and structural diversity of the area. The floristic list obtained comprises 229 plant taxa from 40 botanical families, with a predominance of the families Poaceae (62), Asteraceae (28), Fabaceae (16) and Cyperaceae (12). The estimated diversity and evenness in the community were 3.00 and 0.874, respectively. Bare soil and rock outcrops accounted for 19.3% of the area, resulting in limited forage availability. Multivariate analysis revealed two well-defined groups among the sampling units. One group showed a high degree of internal aggregation, associated with deep soils, and was characterized by the presence of tussocks, whereas the other was less aggregate and was characterized by prostrate species growing on shallow soil. Ordination analysis indicated a gradient of moisture and of soil depth in the study area, resulting in different vegetation patterns. These patterns were analogous to the vegetation physiognomies described for Uruguayan grasslands. Overall, the grassland community studied is similar to others found throughout southern Brazil, although it harbors more winter forage species. In addition, the rare grass Paspalum indecorum Mez is locally dominant in some patches, behaving similarly to P. notatum Fl., a widespread grass that dominates extensive grassland areas in southern Brazil

Draft genome sequence data of Cercospora kikuchii, a causal agent of Cercospora leaf blight and purple seed stain of soybeans

Cercospora kikuchii (Tak. Matsumoto & Tomoy.) M.W. Gardner 1927 is an ascomycete fungal pathogen that causes Cercospora leaf blight and purple seed stain on soybean. Here, we report the first draft genome sequence and assembly of this pathogen. The C. kikuchii strain ARG_18_001 was isolated from soybean purple seed collected from San Pedro, Buenos Aires, Argentina, during the 2018 harvest. The genome was sequenced using a 2 × 150 bp paired-end method by Illumina NovaSeq 6000. The C. kikuchii protein-coding genes were predicted using FunGAP (Fungal Genome Annotation Pipeline). The draft genome assembly was 33.1 Mb in size with a GC-content of 53%. The gene prediction resulted in 14,856 gene models/14,721 protein coding genes. Genomic data of C. kikuchii presented here will be a useful resource for future studies of this pathosystem. The data can be accessed at GenBank under the accession number VTAY00000000 https://www.ncbi.nlm.nih.gov/nuccore/VTAY00000000.Fil: Sautua, Francisco José. Universidad de Buenos Aires (UBA). Facultad de Agronomía. Catedra de Fitopatología; Argentina.Fil: González, Sergio A. Instituto Nacional de Tecnología Agropecuaria (INTA). Investigación en Ciencias Veterinarias y Agronómicas (CICVYA). Instituto De Investigación Biotecnología; Argentina.Fil: González, Sergio A. Instituto Nacional de Tecnología Agropecuaria (INTA) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Agrobiotecnología y Biología Molecular (IABIMO); ArgentinaFil: Doyle, Vinson P. Louisiana State University Agricultural Center (LSU AgCenter). Department of Plant Pathology and Crop Physiology; United States.Fil: Berretta, Marcelo F. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Berretta, Marcelo F. Instituto Nacional de Tecnología Agropecuaria (INTA). Investigación en Ciencias Veterinarias y Agronómicas (CICVYA). Instituto de Microbiología y Zoología Agrícola (IMyZA); Argentina.Fil: Gordó, Manuela. Laboratorio Agrícola Río Paraná; Argentina.Fil: Scandiani, María Mercedes. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Referencia de Micología (CEREMIC); Argentina.Fil: Rivarola, Máximo L. Instituto Nacional de Tecnología Agropecuaria (INTA). Investigación en Ciencias Veterinarias y Agronómicas (CICVYA). Instituto De Investigación Biotecnología; Argentina.Fil: Rivarola, Máximo L. Instituto Nacional de Tecnología Agropecuaria (INTA) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Agrobiotecnología y Biología Molecular (IABIMO); Argentina.Fil: Rivarola, Máximo L. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Fernández, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Investigación en Ciencias Veterinarias y Agronómicas (CICVYA). Instituto De Investigación Biotecnología; Argentina.Fil: Fernández, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Agrobiotecnología y Biología Molecular (IABIMO); Argentina.Fil: Fernández, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Fernández, Paula. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentina.Fil: Carmona, Marcelo Aníbal. Universidad de Buenos Aires (UBA). Facultad de Agronomía. Catedra de Fitopatología; Argentina

A thermostable laccase from Thermus sp. 2.9 and its potential for delignification of Eucalyptus biomass

Laccases are multicopper oxidases that are being studied for their potential application in pretreatment strategies of lignocellulosic feedstocks for bioethanol production. Here, we report the expression and characterization of a predicted laccase (LAC_2.9) from the thermophilic bacterial strain Thermus sp. 2.9 and investigate its capacity to delignify lignocellulosic biomass. The purified enzyme displayed a blue color typical of laccases, showed strict copper dependence and retained 80% of its activity after 16 h at 70 °C. At 60 °C, the enzyme oxidized 2,2′-azino-di-(3-ethylbenzthiazoline sulfonate) (ABTS) and 2,6-dimethoxyphenol (DMP) at optimal pH of 5 and 6, respectively. LAC_2.9 had higher substrate specificity (kcat/KM) for DMP with a calculated value that accounts for one of the highest reported for laccases. Further, the enzyme oxidized a phenolic lignin model dimer. The incubation of steam-exploded eucalyptus biomass with LAC_2.9 and 1-hydroxybenzotriazole (HBT) as mediator changed the structural properties of the lignocellulose as evidenced by Fourier transform infrared (FTIR) spectroscopy and thermo-gravimetric analysis (TGA). However, this did not increase the yield of sugars released by enzymatic saccharification. In conclusion, LAC_2.9 is a thermostable laccase with potential application in the delignification of lignocellulosic biomass.Science, Faculty ofNon UBCMicrobiology and Immunology, Department ofReviewedFacult