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ABSTRACT: This study aimed to provide new information about phyto-toxicology of nano-TiO2 on plant systems. To contribute to the evaluation of the potential harmful effects of the nanoparticles on monocots and dicots
we considered their effects on seed germination and root elongation applying a concentration range from 0.2 to 4.0‰ in the
plants Zea mays L. and Vicia narbonensis L. Moreover, we achieved a genotoxicity study at cytological level in root meristems by means of traditional cytogenetic
approach, to evidence possible alterations in mitotic activity, chromosomal aberrations, and micronuclei release. From these
analyses it comes out that nano-TiO2 particles, after short-term exposure and under our experimental conditions, delayed germination progression for the first
24h in both materials. Root elongation was affected only after treatment with the higher nano-TiO2 concentration. Further significant effects were detected showing mitotic index reduction and concentration-dependent increase
in the aberration emergence that evidenced a nano-TiO2-induced genotoxic effect for both species.
KeywordsChromosome aberrations–Genotoxicity–Mitotic activity–Nanoparticles–Nanotechnology EHS
Journal of Nanoparticle Research 04/2012; 13(6):2443-2449. · 3.29 Impact Factor
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ABSTRACT: In order to investigate the biological hazard of effluents from textile industries of Fez-Boulmane region in Morocco, mutagenicity and phytotoxicity tests were performed on different biological systems. Moreover, the efficiency of a Sequencing Batch Reactor (SBR) system, working by activated sludge on a laboratory scale, was estimated by comparing the ecotoxicity results observed before and after wastewater treatment. Evaluation of the genotoxic potential was investigated by means of classic mutagenicity tests on D7 strain of Saccharomyces cerevisiae and by phytotoxicity tests on Allium sativum L., Vicia faba L. and Lactuca sativa L., estimating micronuclei presence, mitotic index and cytogenetic anomalies. The results obtained by testing untreated wastewater demonstrated major genotoxicity effects in S. cerevisiae and various levels of phytotoxicity in the three plant systems, while after SBR treatment no more ecotoxicological consequences were observed. These data confirm the effectiveness of the SBR system in removing toxic substances from textile wastewaters in Fez-Boulmane region.
Ecotoxicology and Environmental Safety 08/2011; 74(8):2275-83. · 2.29 Impact Factor
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ABSTRACT: The Helianthus annuus LEAFY COTYLEDON1-LIKE (HaL1L) gene encodes a heme-activated protein 3 subunit of the CCAAT box-binding factor. The phylogenetic analysis indicates that HaL1L is closely related to LEAFY COTYLEDON1 (LEC1)-type of Arabidopsis thaliana. In particular, the peptide results homologous to the LEC1-LIKE gene of A. thaliana, with which it shares a high amino acid sequence identity (56%). HaL1L transcripts are accumulated primarily at an early stage of sunflower embryogenesis. High levels of HaL1L messenger RNA (mRNA) have been detected in the developing embryo proper, suspensor, endosperm, integument, and integumentary tapetum cells, while in unfertilized ovules, HaL1L mRNA was present at rather low levels. In an attempt to examine the involvement of HaL1L on somatic embryogenesis, a somaclonal variant of H. annuus x H. tuberosus (EMB-2) that produces ectopic embryo- and shoot-like structures, arranged in clusters along leaf veins, was used. We found that the epiphyllous proliferation of ectopic embryos on EMB-2 leaves was associated to HaL1L mRNA accumulation. The detection of HaL1L transcripts was evident in somatic embryos at the heart- and early cotyledon-stage. On the contrary, no signal related to HaL1L transcript accumulation was observed in EMB-2 leaves characterized by the presence of shoot-like structures. Together, these results support the conclusion that the transcription of the HaL1L gene is maintained both in zygotic and in somatic embryogenesis. In addition, the ectopic accumulation of HaL1L mRNA in parenchymal cells around the vascular bundles of epiphyllous leaves opens the possibility that HaL1L could also be involved in switching somatic cell fate towards embryogenic competence.
Archiv für Entwickelungsmechanik der Organismen 06/2006; 216(5):253-64. · 1.77 Impact Factor
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ABSTRACT: We have isolated PcGA3ox1, a cDNA clone from developing runner bean (Phaseolus coccineus) seeds that shows significant amino acid homology with the gibberellin (GA) 3-oxidases. A recombinant fusion protein of PcGA3ox1 converted GA20 and GA9 to GA1 and GA4, respectively. In situ hybridization results showed that transcripts of this gene accumulate specifically within the suspensor of globular-stage embryos. PcGA3ox1 mRNA begins to accumulate in the epidermal cells of the embryo proper and is also detectable in the endosperm during the transition from globular- to heart-stage embryos. PcGA3ox1 transcripts were localized exclusively in the cotyledons from the early cotyledonary stage up to the cotyledonary stage. Transcripts of the previously cloned GA 2-oxidase (PcGA2ox1) from developing seeds of runner bean were found primarily within the suspensor neck region from the late globular stage up to the heart stage. PcGA2ox1 mRNA was detectable in the whole suspensor from the early cotyledonary stage, and was found in the inner layer of integuments at the cotyledonary stage. Soluble enzyme preparations made from suspensors and embryos at two stages of embryogenesis (the heart and cotyledonary stages) were incubated with [14C]GA20 and [14C]GA1. Only young suspensor preparations converted GA20 to GA1 and GA5. Both suspensor preparations converted GA1 to GA8. Both embryo preparations converted GA20 to GA1, but were unable to convert GA1 to GA8.
Plant and Cell Physiology 08/2005; 46(7):1116-24. · 4.70 Impact Factor
