Sequence Analysis of Herbicide Target Genes in Herbicide-Tolerant Rice

The tolerance of mutagenized rice (Oryza sativa) lines to selector herbicides was investigated and the sequence of ALS gene was analyzed in plants that survived treatment with 4x the label rate of imazethapyr herbicide. This was done to determine if insensitivity to imazethapyr is due to mutation(s) in the herbicide binding site. Seedlots previously treated with ethyl-methyl sulfonate were planted in the field and 3-leaf seedlings were treated with various herbicides to screen for herbicide-tolerant mutants. Seeds from survivors composed the rice lines tested in the current research. Seeds were planted in the greenhouse and 3-leaf seedlings were treated with either 4x the recommended rate of imazethapyr, 4x mesotrione, 2x topramezone, 1x fluridone, 1x fluazifop, or 1x clethodim with their respective recommended adjuvants. Rice injury was assessed visually 14 days after treatment, leaf tissue samples were collected from survivors, and processed for sequencing of herbicide target genes. RNA was extracted from frozen plant tissues and converted to cDNA. PCR primers were designed to amplify the target genes for mesotrione (HPPD) and imazethapyr (ALS), respectively. The expected PCR product was isolated via gel electrophoresis, purified, and sent off for sequencing. Attempts to amplify HPPD failed; therefore, only ALS was sequenced. ALS sequence analysis revealed a mutation, Ser653Asn. This is one of the ALS point mutations that confer high resistance to imidazolinone (i.e. imazethapyr) and broad cross resistance to other ALS-inhibitor herbicide families including sulfonylurea8

Experimental Methods to Study Gene Flow

Herbicide resistance is an exceptional marker to quantify gene flow. Quantification of pollen-, seed-, and vegetative propagule-mediated gene flow provides key weed biology information. Pollen-mediated gene flow influences the genetic variance within a population, the frequency of multiple or polygenic herbicide resistance, and the evolutionary dynamics of a species. Seed-mediated gene flow predominates in self-pollinating species. Gene flow quantification may enable the estimation of herbicide resistance epicenter, the comparison of the relative importance of gene flow pathways, and prediction of future distribution of resistance traits. Gene flow studies using herbicide resistance also can provide insight into the rates and importance of hybridization.This is the publisher’s final pdf. The published article is copyrighted by Weed Science Society of America and can be found at: https://doi.org/10.1614/WS-D-13-00064.

Herbicide Resistance: Toward an Understanding of Resistance Development and the Impact of Herbicide-Resistant Crops

Development of herbicide-resistant crops has resulted in significant changes to agronomic practices, one of which is the adoption of effective, simple, low-risk, crop-production systems with less dependency on tillage and lower energy requirements. Overall, the changes have had a positive environmental effect by reducing soil erosion, the fuel use for tillage, and the number of herbicides with groundwater advisories as well as a slight reduction in the overall environmental impact quotient of herbicide use. However, herbicides exert a high selection pressure on weed populations, and density and diversity of weed communities change over time in response to herbicides and other control practices imposed on them. Repeated and intensive use of herbicides with the same mechanisms of action (MOA; the mechanism in the plant that the herbicide detrimentally affects so that the plant succumbs to the herbicide; e.g., inhibition of an enzyme that is vital to plant growth or the inability of a plant to metabolize the herbicide before it has done damage) can rapidly select for shifts to tolerant, difficult-to-control weeds and the evolution of herbicide-resistant weeds, especially in the absence of the concurrent use of herbicides with different mechanisms of action or the use of mechanical or cultural practices or both.This is the publisher’s final pdf. The published article is copyrighted by the Weed Science Society of America and can be found at: http://wssajournals.org/loi/wee

Prevalencia de enteroparasitosis humanas en un área vulnerable de la provincia de Buenos Aires

El barrio “El Molino”, ubicado en el Municipio de Ensenada, Provincia de Buenos Aires, República Argentina (34° 49′ S, 57° 58′ W), alberga una población precarizada con conductas higiénico-sanitarias inadecuadas para la salud. El equipo de trabajo, integrado por docentes y alumnos de 4 Facultades de la UNLP, desarrolla un proyecto de Extensión Universitaria destinado a contribuir en el diagnóstico y prevención de zoonosis parasitarias, desde el año 2005 ininterrumpidamente. El objetivo del presente estudio es diagnosticar las parasitosis intestinales zoonóticas (de carácter desatendido) en la población de un área de riesgo sanitario y analizar su relación con las costumbres de las familias.Facultad de Ciencias Veterinaria

Prevalencia de enteroparasitosis humanas en un área vulnerable de la provincia de Buenos Aires

El barrio “El Molino”, ubicado en el Municipio de Ensenada, Provincia de Buenos Aires, República Argentina (34° 49′ S, 57° 58′ W), alberga una población precarizada con conductas higiénico-sanitarias inadecuadas para la salud. El equipo de trabajo, integrado por docentes y alumnos de 4 Facultades de la UNLP, desarrolla un proyecto de Extensión Universitaria destinado a contribuir en el diagnóstico y prevención de zoonosis parasitarias, desde el año 2005 ininterrumpidamente. El objetivo del presente estudio es diagnosticar las parasitosis intestinales zoonóticas (de carácter desatendido) en la población de un área de riesgo sanitario y analizar su relación con las costumbres de las familias.Facultad de Ciencias Veterinaria

Prevalencia de enteroparasitosis humanas en un área vulnerable de la provincia de Buenos Aires

El barrio “El Molino”, ubicado en el Municipio de Ensenada, Provincia de Buenos Aires, República Argentina (34° 49′ S, 57° 58′ W), alberga una población precarizada con conductas higiénico-sanitarias inadecuadas para la salud. El equipo de trabajo, integrado por docentes y alumnos de 4 Facultades de la UNLP, desarrolla un proyecto de Extensión Universitaria destinado a contribuir en el diagnóstico y prevención de zoonosis parasitarias, desde el año 2005 ininterrumpidamente. El objetivo del presente estudio es diagnosticar las parasitosis intestinales zoonóticas (de carácter desatendido) en la población de un área de riesgo sanitario y analizar su relación con las costumbres de las familias.Facultad de Ciencias Veterinaria

Prevalencia Dioctophyme renale en un área vulnerable de la provincia de Buenos Aires

Desde el año 2005 a la fecha, de manera ininterrumpida, el grupo de trabajo realiza tareas en un área vulnerable de la Prov. de Bs. As., barrio “El Molino” en la localidad Punta Lara, municipio de Ensenada. El excesivo desmonte y posterior antropización originaron un área suburbana inundable y de elevada vulnerabilidad social y sanitaria, ya que los vecinos vuelcan sus efluentes cloacales sin tratamiento previo. Se estudiaron 692 caninos y 257 personas de la zona, tomando muestras de orina para verificar la presencia de huevos de Dioctophyme renale.Facultad de Ciencias Veterinaria