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1.  The Comparative Photodegradation Activities of Pentachlorophenol (PCP) and Polychlorinated Biphenyls (PCBs) Using UV Alone and TiO2-Derived Photocatalysts in Methanol Soil Washing Solution 
PLoS ONE  2014;9(9):e108765.
Photochemical treatment is increasingly being applied to remedy environmental problems. TiO2-derived catalysts are efficiently and widely used in photodegradation applications. The efficiency of various photochemical treatments, namely, the use of UV irradiation without catalyst or with TiO2/graphene-TiO2 photodegradation methods was determined by comparing the photodegadation of two main types of hydrophobic chlorinated aromatic pollutants, namely, pentachlorophenol (PCP) and polychlorinated biphenyls (PCBs). Results show that photodegradation in methanol solution under pure UV irradiation was more efficient than that with either one of the catalysts tested, contrary to previous results in which photodegradation rates were enhanced using TiO2-derived catalysts. The effects of various factors, such as UV light illumination, addition of methanol to the solution, catalyst dosage, and the pH of the reaction mixture, were examined. The degradation pathway was deduced. The photochemical treatment in methanol soil washing solution did not benefit from the use of the catalysts tested. Pure UV irradiation was sufficient for the dechlorination and degradation of the PCP and PCBs.
PMCID: PMC4177926  PMID: 25254664
2.  Overexpression of VP, a vacuolar H+-pyrophosphatase gene in wheat (Triticum aestivum L.), improves tobacco plant growth under Pi and N deprivation, high salinity, and drought 
Journal of Experimental Botany  2014;65(2):683-696.
Establishing crop cultivars with strong tolerance to P and N deprivation, high salinity, and drought is an effective way to improve crop yield and promote sustainable agriculture worldwide. A vacuolar H+-pyrophosphatase (V-H+-PPase) gene in wheat (TaVP) was functionally characterized in this study. TaVP cDNA is 2586-bp long and encodes a 775-amino-acid polypeptide that contains 10 conserved membrane-spanning domains. Transcription of TaVP was upregulated by inorganic phosphate (Pi) and N deprivation, high salinity, and drought. Transgene analysis revealed that TaVP overexpression improved plant growth under normal conditions and specifically under Pi and N deprivation stresses, high salinity, and drought. The improvement of growth of the transgenic plants was found to be closely related to elevated V-H+-PPase activities in their tonoplasts and enlarged root systems, which possibly resulted from elevated expression of auxin transport-associated genes. TaVP-overexpressing plants showed high dry mass, photosynthetic efficiencies, antioxidant enzyme activities, and P, N, and soluble carbohydrate concentrations under various growth conditions, particularly under the stress conditions. The transcription of phosphate and nitrate transporter genes was not altered in TaVP-overexpressing plants compared with the wild type, suggesting that high P and N concentrations regulated by TaVP were caused by increased root absorption area instead of alteration of Pi and NO3 − acquisition kinetics. TaVP is important in the tolerance of multiple stresses and can serve as a useful genetic resource to improve plant P- and N-use efficiencies and to increase tolerance to high salinity and drought.
PMCID: PMC3904725  PMID: 24474810
Abiotic stresses; gene expression; physiological and biochemical property; plant growth; transgene analysis; vacuolar H+-pyrophosphatase.
3.  A novel Omega-class glutathione S-transferase gene in Apis cerana cerana: molecular characterisation of GSTO2 and its protective effects in oxidative stress 
Cell Stress & Chaperones  2013;18(4):503-516.
Oxidative stress may be the most significant threat to the survival of living organisms. Glutathione S-transferases (GSTs) serve as the primary defences against xenobiotic and peroxidative-induced oxidative damage. In contrast to other well-defined GST classes, the Omega-class members are poorly understood, particularly in insects. Here, we isolated and characterised the GSTO2 gene from Apis cerana cerana (AccGSTO2). The predicted transcription factor binding sites in the AccGSTO2 promoter suggested possible functions in early development and antioxidant defence. Real-time quantitative PCR (qPCR) and western blot analyses indicated that AccGSTO2 was highly expressed in larvae and was predominantly localised to the brain tissue in adults. Moreover, AccGSTO2 transcription was induced by various abiotic stresses. The purified recombinant AccGSTO2 exhibited glutathione-dependent dehydroascorbate reductase and peroxidase activities. Furthermore, it could prevent DNA damage. In addition, Escherichia coli overexpressing AccGSTO2 displayed resistance to long-term oxidative stress exposure in disc diffusion assays. Taken together, these results suggest that AccGSTO2 plays a protective role in counteracting oxidative stress.
Electronic supplementary material
The online version of this article (doi:10.1007/s12192-013-0406-2) contains supplementary material, which is available to authorized users.
PMCID: PMC3682018  PMID: 23382010
Apis cerana cerana; GSTO2; Gene expression pattern; Oxidative stress; Biochemical properties
4.  Cotton GhMKK1 Induces the Tolerance of Salt and Drought Stress, and Mediates Defence Responses to Pathogen Infection in Transgenic Nicotiana benthamiana 
PLoS ONE  2013;8(7):e68503.
Mitogen-activated protein kinase kinases (MAPKK) mediate a variety of stress responses in plants. So far little is known on the functional role of MAPKKs in cotton. In the present study, Gossypium hirsutum MKK1 (GhMKK1) function was investigated. GhMKK1 protein may activate its specific targets in both the nucleus and cytoplasm. Treatments with salt, drought, and H2O2 induced the expression of GhMKK1 and increased the activity of GhMKK1, while overexpression of GhMKK1 in Nicotiana benthamiana enhanced its tolerance to salt and drought stresses as determined by many physiological data. Additionally, GhMKK1 activity was found to up-regulate pathogen-associated biotic stress, and overexpression of GhMKK1 increased the susceptibility of the transgenic plants to the pathogen Ralstonia solanacearum by reducing the expression of PR genes. Moreover, GhMKK1-overexpressing plants also exhibited an enhanced reactive oxygen species scavenging capability and markedly elevated activities of several antioxidant enzymes. These results indicate that GhMKK1 is involved in plants defence responses and provide new data to further analyze the function of plant MAPK pathways.
PMCID: PMC3700956  PMID: 23844212
5.  Refining the diagnosis of Huntington disease: the PREDICT-HD study 
Participants with the gene expansion for Huntington disease (HD) but not yet diagnosed were evaluated annually. Unidimensional diagnosis (UD) was a motor diagnosis defined as a diagnostic confidence level (DCL) of 4 (unequivocal motor signs, ≥99% confidence) on the standardized motor exam of the Unified Huntington Disease Rating Scale (UHDRS). Multidimensional diagnosis (MD) was defined as answering yes on Question 80 (Q80) of the UHDRS, ≥99% confidence of manifest HD based on the entire UHDRS. Motor, cognitive, and behavioral measures of phenotype at first diagnosis were compared by t-tests between participants diagnosed via motor exam (UD) and those diagnosed via multidimensional input (MD). Cluster analysis identified clusters based on UHDRS domains.186 participants received a diagnosis of HD during a maximum of 6.4 years of follow-up. In 108 (58.1%) the diagnosis by MD and UD occurred simultaneously, while in 69 (37.1%) the diagnosis by MD occurred prior to UD. Participants who were diagnosed by MD prior to UD were less impaired on motor (12.2 ± 6.7 vs. 22.4 ± 9.3, p < 0.0001), and cognitive (290.7 ± 56.2 vs. 258.0 ± 53.7, p = 0.0002), but not behavioral measures (16.3 ± 21.2 vs. 18.6 ± 22.1, p = 0.49) when compared with those diagnosed simultaneously. Cluster analysis identified three clusters that represented primarily cognitively impaired, behaviorally impaired, and cognitively preserved phenotypes. A multidimensional method results in an earlier diagnosis with less motor and cognitive impairment than a motor diagnosis. Findings have implications for designing preventive trials and providing clinical care in prodromal HD.
PMCID: PMC3613616  PMID: 23565093
Huntington's disease; trinucleotide repeat diseases; cohort studies; natural history studies; outcome research
6.  Indexing Disease Progression at Study Entry with Individuals At-Risk for Huntington Disease 
The identification of clinical and biological markers of disease in persons at risk for Huntington Disease (HD) has increased in efforts to better quantify and characterize the epoch of prodrome prior to clinical diagnosis. Such efforts are critical in the design and implementation of clinical trials for HD so that interventions can occur at a time most likely to increase neuronal survival and maximize daily functioning. A prime consideration in the examination of prodromal individuals is their proximity to diagnosis. It is necessary to quantify proximity so that individual differences in key marker variables can be properly interpreted. We take a data-driven approach to develop an index that can be viewed as a proxy for time to HD diagnosis known as the CAG-Age Product Scaled or CAPS. CAPS is an observed utility variable computed for all genetically at-risk individuals based on age at study entry and CAG repeat length. Results of a longitudinal receiver operating characteristic (ROC) analysis showed that CAPS had a relatively strong ability to predict individuals who became diagnosed, especially in the first 2 years. Bootstrap validation provided evidence that CAPS computed on a new sample from the same population could have similar discriminatory power. Cutoffs for the empirical CAPS distribution can be used to create a classification for mutation-positive individuals (Low-Med-High) that is useful for comparison with the naturally occurring mutation-negative Control group. The classification is an improvement over the one currently in use as it is based on observed data rather than model-based estimated values.
PMCID: PMC3174494  PMID: 21858921
survival analysis; prodromal Huntington disease; PREDICT-HD Study
7.  GhWRKY15, a member of the WRKY transcription factor family identified from cotton (Gossypium hirsutum L.), is involved in disease resistance and plant development 
BMC Plant Biology  2012;12:144.
As a large family of regulatory proteins, WRKY transcription factors play essential roles in the processes of adaptation to diverse environmental stresses and plant growth and development. Although several studies have investigated the role of WRKY transcription factors during these processes, the mechanisms underlying the function of WRKY members need to be further explored, and research focusing on the WRKY family in cotton crops is extremely limited.
In the present study, a gene encoding a putative WRKY family member, GhWRKY15, was isolated from cotton. GhWRKY15 is present as a single copy gene, and a transient expression analysis indicated that GhWRKY15 was localised to the nucleus. Additionally, a group of cis-acting elements associated with the response to environmental stress and plant growth and development were detected in the promoter. Consistently, northern blot analysis showed that GhWRKY15 expression was significantly induced in cotton seedlings following fungal infection or treatment with salicylic acid, methyl jasmonate or methyl viologen. Furthermore, GhWRKY15-overexpressing tobacco exhibited more resistance to viral and fungal infections compared with wild-type tobacco. The GhWRKY15-overexpressing tobacco also exhibited increased RNA expression of several pathogen-related genes, NONEXPRESSOR OF PR1, and two genes that encode enzymes involved in ET biosynthesis. Importantly, increased activity of the antioxidant enzymes POD and APX during infection and enhanced expression of NtAPX1 and NtGPX in transgenic tobacco following methyl viologen treatment were observed. Moreover, GhWRKY15 transcription was greater in the roots and stems compared with the expression in the cotyledon of cotton, and the stems of transgenic plants displayed faster elongation at the earlier shooting stages compared with wide type tobacco. Additionally, exposure to abiotic stresses, including cold, wounding and drought, resulted in the accumulation of GhWRKY15 transcripts.
Overall, our data suggest that overexpression of GhWRKY15 may contribute to the alteration of defence resistance to both viral and fungal infections, probably through regulating the ROS system via multiple signalling pathways in tobacco. It is intriguing that GhWRKY15 overexpression in tobacco affects plant growth and development, especially stem elongation. This finding suggests that the role of the WRKY proteins in disease resistance may be closely related to their function in regulating plant growth and development.
PMCID: PMC3489871  PMID: 22883108
GhWRKY15; Cotton; Disease resistance; SA; ROS; Plant development
8.  Cotton GhMKK5 affects disease resistance, induces HR-like cell death, and reduces the tolerance to salt and drought stress in transgenic Nicotiana benthamiana  
Journal of Experimental Botany  2012;63(10):3935-3951.
Mitogen-activated protein kinase (MAPK) cascades are involved in various processes from plant growth and development to biotic and abiotic stress responses. MAPK kinases (MAPKKs), which link MAPKs and MAPKK kinases (MAPKKKs), play crucial roles in MAPK cascades to mediate a variety of stress responses in plants. However, few MAPKKs have been functionally characterized in cotton (Gossypium hirsutum). In this study, a novel gene, GhMKK5, from cotton belonging to the group C MAPKKs was isolated and characterized. The expression of GhMKK5 can be induced by pathogen infection, abiotic stresses, and multiple defence-related signal molecules. The overexpression of GhMKK5 in Nicotiana benthamiana enhanced the plants’ resistance to the bacterial pathogen Ralstonia solanacearum by elevating the expression of pathogen resistance (PR) genes, including PR1a, PR2, PR4, PR5, and NPR1, but increased the plants’ sensitivity to the oomycete pathogen Phytophthora parasitica var. nicotianae Tucker. Importantly, GhMKK5-overexpressing plants displayed markedly elevated expression of reactive oxygen species-related and cell death marker genes, such as NtRbohA and NtCDM, and resulted in hypersensitive response (HR)-like cell death characterized by the accumulation of H2O2. Furthermore, it was demonstrated that GhMKK5 overexpression in plants reduced their tolerance to salt and drought stresses, as determined by statistical analysis of seed germination, root length, leaf water loss, and survival rate. Drought obviously accelerated the cell death phenomenon in GhMKK5-overexpressing plants. These results suggest that GhMKK5 may play an important role in pathogen infection and the regulation of the salt and drought stress responses in plants.
PMCID: PMC3388830  PMID: 22442420
Abiotic stress tolerance; cell death; cotton; disease resistance; mitogen-activated protein kinase kinase

Results 1-8 (8)