The Arabidopsis Polycomb Repressive Complex 1 (PRC1) components AtBMI1A, B and C impact gene networks throughout all stages of plant development.

Polycomb Group regulation in Arabidopsis (Arabidopsis thaliana) is required to maintain cell differentiation and allow developmental phase transitions. This is achieved by the activity of three PcG repressive complex 2s (PRC2s) and the participation of a yet poorly defined PRC1. Previous results showed that apparent PRC1 components perform discrete roles during plant development, suggesting the existence of PRC1 variants; however, it is not clear in how many processes these components participate. We show that AtBMI1 proteins are required to promote all developmental phase transitions and to control cell proliferation during organ growth and development, expanding their proposed range of action. While AtBMI1 function during germination is closely linked to B3 domain transcription factors VAL1/2 possibly in combination with GT-box binding factors, other AtBMI1 regulatory networks require participation of different factor combinations. Conversely, EMF1 and LHP1 bind many H3K27me3 positive genes up-regulated in atbmi1a/b/c mutants; however, loss of their function affects expression of a different subset, suggesting that even if EMF1, LHP1, and AtBMI1 exist in a common PRC1 variant, their role in repression depends on the functional context

Ethnic characterization of a population of children exposed to high doses of arsenic via drinking water and a possible correlation with metabolic processes

Because the ratio between the two major arsenic metabolites is related to the adverse health effects of arsenic, numerous studies have been performed to establish a relationship between the ability to metabolically detoxify arsenic and other variables, including exposure level, gender, age and ethnicity. Because ethnicity may play a key role and provide relevant information for heterogeneous populations, we characterized a group of 70 children from rural schools in the Argentinean provinces of Chaco and Santiago del Estero who were exposed to high levels of arsenic. We used genetic markers for maternal, paternal and bi-parental ancestry to achieve this goal. Our results demonstrate that the Amerindian maternal linages are present in 100% of the samples, whereas the Amerindian component transmitted through the paternal line is less than 10%. Informative markers for autosomal ancestry show a predominantly European ancestry, in which 37% of the samples contained between 90 and 99% European ancestry. The native American component ranged from 50 to 80% in 15.7% of the samples, and in all but four samples, the African component was less than 10%. Correlation analysis demonstrated that the ethnicity and the ratio of the excreted arsenic metabolites monomethyl arsenic and dimethyl arsenic are not associated, dismissing a relationship between ethnic origin and differential metabolism.Fil: Bobillo, Maria Cecilia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Navoni, Julio A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Olmos, Valentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Merini, Luciano Jose. Instituto Nacional de Tecnología Agropecuaria. Centro Regional la Pampa-San Luis. Estación Experimental Agropecuaria Anguil; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Villaamil Lepori, Edda. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Corach, Daniel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Phytostabilization of Pb and Cd polluted soils using Helianthus petiolaris as pioneer aromatic plant species

The area of soils polluted with heavy metals is increasing due to industrialization and globalization. Aromatic plant species can be a suitable alternative way for agricultural valorization and phytomanagement of such soils by the commercialization of essential oils avoiding risks for the food chain. The potential of growing Helianthus petiolaris in heavy metal polluted soils was assessed in pot experiments using spiked soils and soils from a shooting range. In terms of phytostabilization, H. petiolaris could grow in soils containing 1000 mg/kg Pb2þ, 50 mg/kg Cd2þ, accumulating more than three times the soil Cd content in the aerial parts and translocating significant amounts of Pb to the aerial parts when growing in soils polluted with up to 500 mg/kg Pb. When phytostabilization is considered, phytotoxicity of heavy metals strongly depends on the rhizospheric microbial communities, either by mitigating trace element phytotoxicity or promoting plant growth via phytohormone production. So, the effects of heavy metals on the diversity of the rhizospheric bacterial community were assessed using DNA-fingerprinting.Fil: Saran, Anabel. Instituto Nacional de Tecnología Agropecuaria; Argentina. Hasselt University; BélgicaFil: Fernandez, L.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Cora, F.. Universidad Nacional de La Pampa; ArgentinaFil: Savio, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Thijs, S.. Hasselt University; BélgicaFil: Vangronsveld, J.. Hasselt University; Bélgica. Maria Curie-Sklodowska; PoloniaFil: Merini, Luciano Jose. Instituto Nacional de Tecnología Agropecuaria; Argentina. Gobierno de la Provincia de la Pampa.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin