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Advanced innovations for combating variants of aggressive breast cancer and overcoming drug resistance are desired. In cancer treatment, ZnO nanoparticles (NPs) have the capacity to specifically and compellingly activate apoptosis of cancer cells. There is also a pressing need to develop innovative anti-cancer therapeutics, and recent research suggests that ZnO nanoparticles hold great potential. Here, the in vitro chemical effectiveness of ZnO NPs has been tested. Zinc oxide (ZnO) nanoparticles were synthesized using Citrullus colocynthis (L.) Schrad by green methods approach. The generated ZnO was observed to have a hexagonal wurtzite crystal arrangement. The generated nanomaterials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-visible spectroscopy. The crystallinity of ZnO was reported to be in the range 50-60 nm. The NPs morphology showed a strong absorbance at 374 nm with an estimated gap band of 3.20 eV to 3.32 eV. Microscopy analysis proved the morphology and distribution of the generated nanoparticles to be around 50 nm, with the elemental studies showing the elemental composition of ZnO and further confirming the purity of ZnO NPs. The cytotoxic effect of ZnO NPs was evaluated against wild-type and doxorubicin-resistant MCF-7 and MDA-MB-231 breast cancer cell lines. The results showed the ability of ZnO NPs to inhibit the prefoliation of MCF-7 and MDA-MB-231 prefoliation through the induction of apoptosis without significant differences in both wild-type and resistance to doxorubicin.
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Neoplasias de la Mama , Nanopartículas , Óxido de Zinc , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Tecnología Química Verde/métodos , Humanos , Nanopartículas/química , Extractos Vegetales/química , Difracción de Rayos X , Óxido de Zinc/químicaRESUMEN
AIM: To investigate the potential anti-inflammatory and biochemical effects of Moringa peregrina leaf extracts on testosterone-induced benign prostatic hyperplasia (BPH) in rats. METHODS: Six groups of rats (each group included 5 rats) were included in this study. The groups included: 1) the control group, 2) the testosterone-induced BPH group, 3) with 50 mg/kg bwt (bodyweight) oil-treated BPH, 4) with 100 mg/kg bwt. oil-treated BPH, 5) with 500mg/kg bwt. ethanol treated BPH and 6) with 1,000 mg/kg bwt. aqueous treated BPH group. Biochemical markers were measured to evaluate the effect of M. peregrina leaf extracts. RESULTS: Our results showed a significant improvement in the thickness of epithelial cells of the BPH glandular tissues when treated with different M. peregrina extracts (p < 0.05). In addition, M. peregrina extracts showed anti-inflammatory, anti-proliferative and anti-angiogenesis effects on the BPH tissues by reduction of IL-6, PCNA and VEGF-A, respectively. CONCLUSION: Our preclinical study concluded that M. peregrina leaf extracts showed a significant effect on BPH by reducing inflammation, proliferation, and angiogenic processes with no signs of toxicity.
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Inhibidores de la Angiogénesis/farmacología , Antiinflamatorios/farmacología , Proliferación Celular/efectos de los fármacos , Moringa , Extractos Vegetales/farmacología , Hiperplasia Prostática/tratamiento farmacológico , Animales , Modelos Animales de Enfermedad , Masculino , Hojas de la Planta , Hiperplasia Prostática/inducido químicamente , Ratas , TestosteronaRESUMEN
Salt stress is a major abiotic stress causing adverse effects on plant growth and development. The aim of this study was to investigate the effect of NaCl stress on growth, stress indicator parameters (lipid peroxidation, chlorophyll content and proline content), yield, and the expression of heat shock proteins genes (Hsp17.8, Hsp26.3, Hsp70 and Hsp101) of five Jordanian durum wheat (Triticum durum) landraces. Plants were irrigated with tap water as control or 200 mM NaCl. Significant differences among the 5 Triticum durum landraces in terms of growth parameters, stress indicator parameters, and expression of heat shock proteins genes were observed. Salt stressed landraces demonstrated decreased growth, increased levels of stress indicator parameters, and upregulation in Hsp17.8, Hsp26.3, Hsp70 and Hsp101 expression. Landraces T11 and M23 showed the highest growth, lowest levels of stress indicator parameters, and high expression of heat shock protein genes under NaCl stress. Whereas, J2 and A8 landraces showed the lowest growth, highest levels of stress indicator parameters and low expression of heat shock protein genes under NaCl stress. In conclusion, NaCl stress caused significant reduction in growth parameters, increased level of lipid peroxidation and proline content and upregulation in heat shock proteins gene expression levels. Growth, stress indicator parameters and gene expression results suggest that T11 and M23 landraces are the most NaCl stress tolerant landraces and could be used to enhance the gene pool in wheat breeding programs.
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Vitamin B12 (Cobalamin) deficiency, due to improper internalization of cobalamin, is a metabolic disorder prevalent in impoverished and elderly populations and is associated with megaloblastic anemia and dementia. It has been suggested that mutations in transcobalamin II (TCN2) or gastric intrinsic factor (GIF) proteins can alter their binding efficiency to cobalamin or reduce the ability of their receptors to internalize them. In this case-control study, the correlation between vitamin B12 deficiency and alternative alleles of TCN2 and GIF was investigated in a Jordanian population. One hundred individuals with vitamin B12 deficiency (B12 < 200 mg/mL) were enrolled in our study to evaluate the TCN2 and GIF polymorphisms. The control group (B12 > 200 mg/mL) included 100 individuals. Our results indicated a significant association between the homologous variant of the TCN2 gene (G776G) and vitamin B12 deficiency, and an intermediate phenotype in heterozygous individuals (p < 0.001, OR = 5.6, 95% CI = 2.95 to 10.63). The GIF gene, however, showed no correlation between the A68G variant and vitamin B12 deficiency (p = 0.2). This study expounds the association of TCN2 polymorphism with cobalamin levels in a Jordanian population and highlights the necessity of further studies to elucidate the molecular basis and impact of TCN2 and GIF genes polymorphisms on vitamin B12 deficiency and associated disorders.
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Transcobalaminas , Deficiencia de Vitamina B 12/sangre , Vitamina B 12/sangre , Anciano , Estudios de Casos y Controles , Humanos , Prevalencia , Transcobalaminas/genética , Vitamina B 12/química , Vitamina B 12/metabolismo , Deficiencia de Vitamina B 12/complicaciones , Deficiencia de Vitamina B 12/genéticaRESUMEN
Male infertility is commonly associated with sperm abnormalities including asthenozoospermia. The molecular basis of asthenozoospermia was linked to mitochondrial DNA (mtDNA) mutations. The 4,977-bp human mtDNA deletion is one of the most common mutations of spermatozoa and results in loss of about 33% of the mitochondrial genome. In this preliminary study, we aimed to investigate the presence of 4,977-bp mtDNA deletion in asthenozoospermic infertile men in Jordan. Semen specimens of 120 asthenozoospermic infertile men and 80 normozoospermic individuals were collected at the in vitro fertilization unit. MtDNA was extracted after the enrichment of spermatozoa; then, polymerase chain reaction was performed using 4,977-bp mtDNA deletion-specific primers. The deletion of 4,977-bp mtDNA was detected in 79.2% of asthenozoospermic patients compared to 10% in normozoospermic controls. The results showed a significant association between the presence of 4,977-bp mtDNA deletion and the asthenozoospermia and infertility (OR = 34.2000, 95% CI = 14.57-80.26, p-value < .001). In conclusion, our findings underscored a strong association between 4,977-bp mtDNA deletion and asthenozoospermia in the Jordanian population.
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Astenozoospermia/genética , ADN Mitocondrial/genética , Eliminación de Secuencia , Motilidad Espermática/genética , Espermatozoides/patología , Astenozoospermia/diagnóstico , Astenozoospermia/patología , Secuencia de Bases/genética , Estudios de Casos y Controles , ADN Mitocondrial/aislamiento & purificación , Humanos , Jordania , MasculinoRESUMEN
Vitamin B12, folate, and ferritin are vital for the development of the nervous system, blood formation, and diverse metabolic functions. The aim of the current study is to evaluate the status of vitamin B12, folate and ferritin in the Jordanian population across distinct geographical locations. In this retrospective study, the cohort population included 2,880 Jordanian individuals with an average age of 47 y for males and 34 y for females (January 2014-December 2016). Vitamin B12, folate, and ferritin were measured in the blood samples by immunoassay on an automated instrument. Prevalence of low levels of vitamin B12 among males and females was similar across the four regions (24%). Equivalently high levels of folate were reported in males (24.4%) and females (23.4%). Additionally, 37.4% of males and 20.4% of females showed low levels of ferritin. Pearson's correlations did not show any association between age, vitamin B12, folate, and ferritin levels in both sexes. Univariate odd ratio (OR) and age-adjusted OR in males showed a significant decrease in low vitamin B12 risk in the region of Tafela when compared to Irbid. In conclusion, our results showed a significant difference in vitamin B12 levels between populations according to their geographical locations. Ferritin levels were low in almost a quarter of the Jordanian population with a high prevalence in males and females in Irbid and Maan, respectively. These differences might be associated with the genetic, dietary and lifestyle situation which requires further studies to elucidate the risk factors for vitamin B12 and ferritin deficiency.
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Ferritinas/sangre , Ferritinas/deficiencia , Ácido Fólico/sangre , Deficiencia de Vitamina B 12/epidemiología , Vitamina B 12/sangre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Jordania/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores Sexuales , Adulto JovenRESUMEN
Plant DNA is damaged by exposure to solar radiation, which includes ultraviolet (UV) rays. UV damaged DNA is repaired either by photolyases, using visible light energy, or by nucleotide excision repair (NER), also known as dark repair. NER consists of two subpathways: global genomic repair (GGR), which repairs untranscribed DNA throughout the genome, and transcription-coupled repair (TCR), which repairs transcribed DNA. In mammals, CSA, CSB, UVSSA, USP7, and TFIIS have been implicated in TCR. Arabidopsis homologs of CSA (AtCSA-1/2) and CSB (CHR8) have previously been shown to contribute to UV tolerance. Here we examine the role of Arabidopsis homologs of UVSSA, USP7 (UBP12/13), and TFIIS (RDO2) in UV tolerance. We find that loss of function alleles of UVSSA, UBP12, and RDO2 exhibit increased UV sensitivity in both seedlings and adults. UV sensitivity in atcsa-1, uvssa, and ubp12 mutants is specific to dark conditions, consistent with a role in NER. Interestingly, chr8 mutants exhibit UV sensitivity in both light and dark conditions, suggesting that the Arabidopsis CSB homolog may play a role in both NER and light repair. Overall our results indicate a conserved role for UVSSA, USP7 (UBP12), and TFIIS (RDO2) in TCR.
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Jordan relies heavily on reservoirs building and development to cope with water supply challenges, where monitoring and assessment of reservoir water quality are critically important for the sustainable use of these water supplies. Mujib Dam is an important water supply source in central western Jordan. Evaluation of water quality parameters and their spatial distributions (vertical and horizontal) showed near-neutral pH values with nearly similar values from surface to bottom. The vertical profile of DO and TDS in the dammed reservoir showed slight decreasing trends with increasing depth. Although Ca, Mg, Na, and K concentrations varied slightly with depths, their variations showed no trends. Similarly, the vertical and horizontal distribution patterns of Cl, SO4, HCO3, NO3, and PO4 in Mujib reservoir water showed insignificant variations in surface water layer and relatively unchanged values or decreasing trends through the water column. Higher values of TN have been observed, especially in the western part, suggesting that agricultural activities and livestock farming in the upstream catchment are impacting water quality. Results revealed that weathering and dissolution of rocks are the major source of water chemistry. The majority of trace metal levels (Cd, Cr, Cu, Fe, Mn, Pb, Zn, Co, Ni, Sr, and B) in water showed relatively similar surface and bottom values. The concentrations of COD and BOD5 in surface water were relatively low with higher concentrations observed in the northwestern corner, coincided with higher levels of chlorophyll a. The average ratio of TN to TP in surface water suggests that phosphorus is the limiting factor for the algal blooms, whereas the average chlorophyll a level in surface water indicates oligo-mesotrophic water.
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Agua Potable/química , Monitoreo del Ambiente/métodos , Fósforo/análisis , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Agricultura/métodos , Clorofila A/análisis , Agua Potable/análisis , Eutrofización , Jordania , Abastecimiento de AguaRESUMEN
BACKGROUND: Blepharis constitutes an important part of the vegetation of the Jordanian arid and semi-arid regions, yet whether one or more species of this genus occurs in the Jordanian area is uncertain. We addressed this question by assessing morphological characters and testing Inter-Simple Sequence Repeat (ISSR) markers from three populations of Blepharis: two northern (lower slopes of Kufranjah valley and the Dead Sea region) and one southern (Wadi al Yutm). RESULTS: Shoots from randomly chosen Blepharis plants were harvested from each of the three populations for morphological and molecular analyses. In the northern populations, spikes were lax and bract width was significantly shorter than length of the longest lateral spine compared to the southern population. A multivariate linear discriminant analysis distinguished the northern populations from the southern one by internode length, bract width, longest lateral spine length, and bract width to spine length ratio. The ISSR analysis revealed that 44 markers across eight primers were polymorphic with major allele frequency of 83.6% and an average of 5.5 polymorphic markers per primer. The genetic resemblance among individuals ranged from 0.27 to 0.96. The three Blepharis populations were accordingly clustered into two distinct groups, similar to the analysis of morphological differences and corresponding with the "northern" and "southern" population designations. CONCLUSIONS: Our results strongly indicate the occurrence of two discrete Blepharis species in Jordan and reject the hypothesis that the genus is represented by only one species. We propose that the Blepharis species in Jordan are B. attenutata Napper (represented by the northern populations) and B. ciliaris (L.) B. L. Burtt (represented by the southern population). These findings are important for informing and revising floristic work within the region and an updated key has been included in our findings.
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KEY MESSAGE: Arabidopsis det1 mutants exhibit salt and osmotic stress resistant germination. This phenotype requires HY5, ABF1, ABF3, and ABF4. While DE-ETIOLATED 1 (DET1) is well known as a negative regulator of light development, here we describe how det1 mutants also exhibit altered responses to salt and osmotic stress, specifically salt and mannitol resistant germination. LONG HYPOCOTYL 5 (HY5) positively regulates both light and abscisic acid (ABA) signalling. We found that hy5 suppressed the det1 salt and mannitol resistant germination phenotype, thus, det1 stress resistant germination requires HY5. We then queried publically available microarray datasets to identify genes downstream of HY5 that were differentially expressed in det1 mutants. Our analysis revealed that ABA regulated genes, including ABA RESPONSIVE ELEMENT BINDING FACTOR 3 (ABF3), are downregulated in det1 seedlings. We found that ABF3 is induced by salt in wildtype seeds, while homologues ABF4 and ABF1 are repressed, and all three genes are underexpressed in det1 seeds. We then investigated the role of ABF3, ABF4, and ABF1 in det1 phenotypes. Double mutant analysis showed that abf3, abf4, and abf1 all suppress the det1 salt/osmotic stress resistant germination phenotype. In addition, abf1 suppressed det1 rapid water loss and open stomata phenotypes. Thus interactions between ABF genes contribute to det1 salt/osmotic stress response phenotypes.
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Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Germinación/genética , Proteínas Nucleares/genética , Arabidopsis/genética , Proteínas de Arabidopsis/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/fisiología , Péptidos y Proteínas de Señalización Intracelular , Mutación , Proteínas Nucleares/fisiología , Presión Osmótica , Estrés FisiológicoRESUMEN
This study aimed to assess genotoxicity in wild plants grown in Jordan as a pollution bioindicator. Comet assay was used to evaluate the level of DNA damage in plants collected from different areas in Jordan. Significant differences in plant DNA damage index and frequency were observed among sites of collection. Results show that plants collected from Aqaba back road and Ghour Assaal had significantly higher damage values. In contrast, plants collected from Wadi Rum, Al Naqab Heights, Swaimeh/Deadsea and Alshoneh Aljanobyeh showed low levels of DNA damage. A similar trend was observed for lipid peroxidation rates. Furthermore, heavy metal analysis showed that plants collected from Aqaba back road and Aqaba airport had the highest Al, Cr, Fe, Cu, Zn, Cd and Pb contents. A significant correlation was observed between DNA Damage Index, DNA Damage Frequency, lipid peroxidation rate, soil Cu, Cd and Pb biomarkers, indicating that heavy metals pollution is a major source for genotoxicity in these plant species. Finally, our results approved the feasibility of using plants and Comet assay system as a diagnostic tool for pollution in any environment adversely affected by different pollution sources.
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Drought is considered one of the major constraints of plant growth and productivity worldwide. Plants respond to drought through different mechanisms including physiological, biochemical, and gene expression modulation. Studying these mechanisms will provide better understanding of drought response mechanisms and will help breeders in developing new cultivars. In this study, growth, biochemical, and molecular responses of four wheat (Triticum durum Desf.) landraces to drought stress (300 mM mannitol) were investigated at the seedling stage. Reverse transcription-polymerase chain reaction was used to assess gene expression level for a drought stress responsive gene (DHN15.1). Germination percentage, shoot length, root length, and root number for all T. durum landraces were decreased significantly under drought stress. However, drought stress caused an increase in proline content, lipid peroxidation level, and DHN15.1 transcript level. According to the studied traits, the Karak landrace showed long shoots (48% relative to its control), the longest roots (45% relative to its control) and the highest proline content (483% relative to its control). The results indicate that from the landraces studied, Karak may be selected as the most tolerant wheat landrace and may help in wheat breeding programs for adaptation to drought-prone environments.
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This paper focuses on characterizing the current status of physiochemical properties of Mujib Dam sediments. Five types of granulometric textural facies were observed for the bottom sediments of Mujib reservoir bed; these are clayey facies, clayey-silt facies, sand-silt-clay facies, sand facies, and granule facies. This average grain size will likely play a vital role in adsorption-desorption of the majority trace metals to the reservoir lake. Other sediment parameters including the total averages were 5.9% (total organic matter (TOM)), 7.5 (pH), 25.8% (CaCO3), and 88.0 meq/100 g (cation exchange capacity), with dominant mineralogical constituents of quartz, calcite, dolomite, and minor feldspar and with variability in clay mineral types. The vast majority of trace metals in sediment exhibited values in the range or near the upper limit of the normal worldwide soil ranges. TOM and grain size of sediment are major factors governing the trace metal concentrations. The calculated geoaccumulation index (I geo) and enrichment factor (EF) of metals in sediments of Mujib Dam were ranked as follows: cadmium (Cd) > copper (Cu) > zinc (Zn) > lead (Pb) > cobalt (Co) > iron (Fe) > chromium (Cr) > nickel (Ni) > manganese (Mn) > Sr based on the I geo and Cd > Zn > Pb > Co > Cr > Cu > Sr > Ni > Mn according to the EF values. The estimated percentage loss in volumetric capacity of the reservoir due to sedimentation was 1.55% per year, indicating that the sediment currently occupied 18.63% of the original reservoir storage capacity. The maximum life span of reservoir is about 64.46 years.
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Monitoreo del Ambiente , Sedimentos Geológicos/química , Centrales Eléctricas , Contaminantes Químicos del Agua/análisis , Cadmio/análisis , Cromo/análisis , Cobalto , Cobre/análisis , Hierro/análisis , Jordania , Manganeso/análisis , Metales/análisis , Metales Pesados/análisis , Níquel , Suelo , Calidad del Agua , Zinc/análisisRESUMEN
Plants like other organisms are affected by environmental factors. Cadmium, copper and zinc are considered the most important types of pollutants in the environment. In this study, a comparison of growth and biochemical parameters between the crop wild relative (CWR) Solanum nigrum versus its cultivated relative Solanum lycopersicum to different levels of Cu, Zn and Cd stress were investigated. The presence of ZnSO4 and CuSO4 in Murashige and Skoog medium affected severely many growth parameters (shoot length, number of roots and leaves, and fresh weight) of both S. nigrum and S. lycopersicum at high levels. On the other hand, CdCl2 significantly reduced most of the studied growth parameters for both species. S. nigrum exhibited higher tolerance than S. lycopersicum for all types of stress. In addition, results show that as stress level increased in the growing medium, proline content of both S. nigrum and S. lycopersicum increased. A significant difference was observed between the two species in proline accumulation as a result of stress. In addition, a higher accumulation rate was observed in the crop wild relative (S. nigrum) than in cultivated S. lycopersicum. Changes in Inter-simple sequence repeat (ISSR) pattern of CuSO4 treated S. nigrum and S. lycopersicum plants were also observed. In conclusion, based on growth and biochemical analysis, S. nigrum showed higher level of metals tolerance than S. lycopersicum which indicates the possibility of using it as a crop wild relative for S. lycopersicum.
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Moringa peregrinais an endangered species of Moringaceae.M. peregrinais a multipurpose tree with a wide variety of potential uses including its medicinal activity. In our study, a rapid and efficient micropropagation protocol for M. peregrina has been established. In vitro germinated seedlings were cultured on Murashige and Skoog (MS) medium supplemented with different levels of either 6-benzyladenine (BA) or kinetin (Kin). The maximum shoot proliferation of 6.5 shoots per explant with 100 % shoot proliferation rate was observed on MS medium supplemented with 1.0 mg/l BA. On the other hand, MS medium supplemented with 1 mg/l indole-3-butyric acid (IBA) resulted in the maximum number of roots. Micropropagated plants were successfully acclimatized. Genetic stability of micropropagated plants was assessed using Inter-Simple Sequence Repeat (ISSR). The amplification products were monomorphic in all in vitro grown plants. No polymorphism was detected indicating the genetic integrity of in vitro propagated plants. This micropropagation protocol could be useful for raising genetically uniform plants for plant propagation and commercial cultivation.
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The effect of plant space and time of harvesting on yield and quality of Thymus vulgaris was evaluated in Jordan. Thyme was cultivated in rows of 50 cm apart with inter-row spacing of 15, 30 or 45 cm and was grown at various development stages. Plants were harvested during different growth stages including vegetation, beginning of blooming, full blooming and fruit maturation. Results indicated that oil yields of thyme were affected by growth stage and inter-row spacing. The maximum oil yields was obtained by harvesting at the early growth stage, which was found superior to oil yield corresponding to the later stages of collection. With 45 cm inter-row spacing, the maximum oil yield was recorded when the samples were collected at growth stage. Indicated results showed that the chemical composition during various growth stages was characterised by high percentage of carvacrol and its corresponding monoterpenic hydrocarbon precursors ρ-cymene and γ-terpinene, and ether 1,4-cineol.
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Aceites Volátiles/análisis , Estaciones del Año , Thymus (Planta)/química , Monoterpenos Ciclohexánicos , Ciclohexanoles/análisis , Cimenos , Eucaliptol , Jordania , Monoterpenos/análisisRESUMEN
Damaged DNA Binding protein 1 (DDB1) is a conserved protein and a component of multiple cellular complexes. Arabidopsis has two homologues of DDB1: DDB1A and DDB1B. In this study we examine the role of DDB1A in Arabidopsis UV tolerance and DNA repair using a DDB1A null mutant (ddb1a) and overexpression lines. DDB1A overexpression lines showed higher levels of UV-resistance than wild-type in a range of assays as well as faster DNA repair. However a significant difference between wild-type plants and ddb1a mutants was only observed immediately following UV treatment in root length and photoproduct repair assays. DDB1A and DDB1B mRNA levels increased 3 h after UV exposure and DDB1A is required for UV regulation of DDB1B and DDB2 mRNA levels. In conclusion, while DDB1A is sufficient to increase Arabidopsis UV tolerance, it is only necessary for immediate response to UV damage.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica de las Plantas , Rayos Ultravioleta , Adaptación Fisiológica/genética , Adaptación Fisiológica/efectos de la radiación , Alquilantes/farmacología , Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/metabolismo , Reparación del ADN , Proteínas de Unión al ADN/metabolismo , Peróxido de Hidrógeno/farmacología , Mitomicina/farmacología , Mutación , Oxidantes/farmacología , Estabilidad del ARN/efectos de la radiación , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de TiempoRESUMEN
Damaged DNA-binding proteins 1 and 2 (DDB1 and DDB2) are subunits of the damaged DNA-binding protein complex (DDB). DDB1 is also found in the same complex as DE-ETIOLATED 1 (DET1), a negative regulator of light-mediated responses in plants. Arabidopsis has two DDB1 homologs, DDB1A and DDB1B. ddb1a single mutants have no visible phenotype while ddb1b mutants are lethal. We have identified a partial loss-of-function allele of DDB2. To understand the genetic interaction among DDB2, DDB1A, and DET1 during Arabidopsis light signaling, we generated single, double, and triple mutants. det1 ddb2 partially enhances the short hypocotyl and suppresses the high anthocyanin content of dark-grown det1 and suppresses the low chlorophyll content, early flowering time (days), and small rosette diameter of light-grown det1. No significant differences were observed between det1 ddb1a and det1 ddb1a ddb2 in rosette diameter, dark hypocotyl length, and anthocyanin content, suggesting that these are DDB1A-dependent phenotypes. In contrast, det1 ddb1a ddb2 showed higher chlorophyll content and later flowering time than det1 ddb1a, indicating that these are DDB1A-independent phenotypes. We propose that the DDB1A-dependent phenotypes indicate a competition between DDB2- and DET1-containing complexes for available DDB1A, while, for DDB1A-independent phenotypes, DDB1B is able to fulfill this role.