Multiple Metabolic Enzymes Can Be Involved in Cross-Resistance to 4-Hydroxyphenylpyruvate-Dioxygenase-Inhibiting Herbicides in Wild Radish.

A wild radish population (R) has been recently confirmed to be cross-resistant to 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides without previous exposure to these herbicides. This cross-resistance is endowed by enhanced metabolism. Our study identified one 2-oxoglutarate/Fe(II)-dependent dioxygenase gene (Rr2ODD1) and two P450 genes (RrCYP704C1 and RrCYP709B1), which were significantly more highly expressed in R versus susceptible (S) plants. Gene functional characterization using Arabidopsis transformation showed that overexpression of RrCYP709B1 conferred a modest level of resistance to mesotrione. Ultra-performance liquid chromatography-tandem mass spectrometry analysis showed that tissue mesotrione levels in RrCYP709B1 transgenic Arabidopsis plants were significantly lower than that in the wild type. In addition, overexpression of Rr2ODD1 or RrCYP704C1 in Arabidopsis endowed resistance to tembotrione and isoxaflutole. Structural modeling indicated that mesotrione can bind to CYP709B1 and be easily hydroxylated to form 4-OH-mesotrione. Although each gene confers a modest level of resistance, overexpression of the multiple herbicide-metabolizing genes could contribute to HPPD-inhibiting herbicide resistance in this wild radish population.

Monitoring the Health of Coastal Environments in the Pacific Region-A Review.

Coastal areas provide important ecological services to populations accessing, for example, tourism services, fisheries, minerals and petroleum. Coastal zones worldwide are exposed to multiple stressors that threaten the sustainability of receiving environments. Assessing the health of these valuable ecosystems remains a top priority for environmental managers to ensure the key stressor sources are identified and their impacts minimized. The objective of this review was to provide an overview of current coastal environmental monitoring frameworks in the Asia-Pacific region. This large geographical area includes many countries with a range of climate types, population densities and land uses. Traditionally, environmental monitoring frameworks have been based on chemical criteria set against guideline threshold levels. However, regulatory organizations are increasingly promoting the incorporation of biological effects-based data in their decision-making processes. Using a range of examples drawn from across the region, we provide a synthesis of the major approaches currently being applied to examine coastal health in China, Japan, Australia and New Zealand. In addition, we discuss some of the challenges and investigate potential solutions for improving traditional lines of evidence, including the coordination of regional monitoring programs, the implementation of ecosystem-based management and the inclusion of indigenous knowledge and participatory processes in decision-making.

Characterization of lodging variation of weedy rice.

Weedy rice (Oryza spp.), one of the most notorious weeds of cultivated rice, evades eradication through stem lodging and seed shattering. Many studies have focused on seed shattering, whereas variations in lodging have received less attention and the underlying mechanisms that cause the differences in lodging between weedy and cultivated rice have not been studied in detail. Here, we compared lodging variation among diverse Chinese weedy rice strains and between weedy rice and co-occurring cultivated rice. The chemical composition of basal stems was determined, and transcriptome and methylome sequencing were used to assess the variation in expression of lodging-related genes. The results showed that the degree of lodging varied between indica-derived weed strains with high lodging levels, which occurred predominantly in southern China, and japonica-derived strains with lower lodging levels, which were found primarily in the north. The more lodging-prone indica weedy rice had a smaller bending stress and lower lignin content than non-lodging accessions. In comparison to co-occurring cultivated rice, there was a lower ratio of cellulose to lignin content in the lodging-prone weedy rice. Variation in DNA methylation of lignin synthesis-related OsSWN1, OsMYBX9, OsPAL1, and Os4CL3 mediated the differences in their expression levels and affected the ratio of cellulose to lignin content. Taken together, our results show that DNA methylation in lignin-related genes regulates variations in stem strength and lodging in weedy rice, and between weed strains and co-occurring cultivated rice.

Interactions between hydroxylated polycyclic aromatic hydrocarbons and serum albumins: multispectral and molecular docking analyses.

Hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) can bind to serum albumin and influence their distribution and elimination in organisms. Here, multispectral analysis and molecular docking methods were used to investigate the binding mechanism of two OH-PAHs, 1-hydroxyphenanthrene (1-OHPhe) and 9-hydroxyphenanthrene (9-OHPhe), with two homologous serum albumins, human serum albumin (HSA) and bovine serum albumin (BSA). The quenching constants of HSA with 1-OHPhe and 9-OHPhe were much larger than those for BSA. Energy transfer from the tryptophan (Trp) residues in HSA to 1-OHPhe and 9-OHPhe was more probable than from Trp in BSA. The interactions of 1-OHPhe and 9-OHPhe with Trp in HSA and BSA altered the microenvironment of Trp. Molecular docking results revealed that the binding modes and binding forces of 1-OHPhe and 9-OHPhe with HSA and BSA were different. The two OH-PAHs were used as fluorescent probes to analyze the microenvironmental hydrophobicities of HSA and BSA, which were distinctly different. The structural difference between HSA and BSA induced significant variations in their binding behaviour with 1-OHPhe and 9-OHPhe. Moreover, HSA was more susceptible to 1-OHPhe and 9-OHPhe than BSA. This work suggests that the differences between the two serum albumins should be considered in related studies.

Microstructure and Morphology Control of Potassium Magnesium Titanates and Sodium Iron Titanates by Molten Salt Synthesis.

Titanates materials have attracted considerable interest due to their unusual functional and structural properties for many applications such as high-performance composites, devices, etc. Thus, the development of a large-scale synthesis method for preparing high-quality titanates at a low cost is desired. In this study, a series of quaternary titanates including K0.8Mg0.4Ti1.6O4, Na0.9Mg0.45Ti1.55O4, Na0.75Fe0.75Ti0.25O2, NaFeTiO4, and K2.3Fe2.3Ti5.7O16 are synthesized by a simple molten salt method using inexpensive salts of KCl and NaCl. The starting materials, intermediate products, final products, and their transformations were studied by using TG-DSC, XRD, SEM, and EDS. The results show that the grain size, morphology, and chemical composition of the synthesized quaternary titanates can be controlled simply by varying the experimental conditions. The molar ratio of mixed molten salts is critical to the morphology of products. When KCl:NaCl = 3:1, the morphology of K0.8Mg0.4Ti1.6O4 changes from platelet to board and then bar-like by increasing the molar ratio of molten salt (KCl-NaCl) to raw materials from 0.7 to 2.5. NaFeTiO4 needles and Na0.75Fe0.75Ti0.25O2 platelets are obtained when the molar ratio of molten salt (NaCl) to raw materials is 4. Pure phase of Na0.9Mg0.45Ti1.55O4 and K2.3Fe2.3Ti5.7O16 are also observed. The formation and growth mechanisms of both potassium magnesium titanates and sodium iron titanates are discussed based on the characterization results.

Expression of novel cancer/testis antigen TMEM31 increases during metastatic melanoma progression.

Cancer/testis (CT) antigens are promising targets for immunotherapy due to their restricted expression in the germ cells of the testis in healthy tissue and high immunogenicity. The aim of the present study was to determine whether transmembrane protein 31 (TMEM31) is a CT antigen and to investigate the pattern of TMEM31 expression during the progression of melanoma. The pattern of expression of human TMEM31 mRNA in multiple human tissues was determined through reverse transcription-polymerase chain reaction analysis. TMEM31 protein expression was analyzed in the human testis, in addition to 128 primary melanoma and 64 metastatic melanoma samples through immunohistochemistry analysis. TMEM31 was identified to be predominantly expressed in the testis and weakly expressed in the placenta. In addition, TMEM31 protein expression was detected in 120/190 (63.16%) melanoma samples (primary and metastatic). The intensity of TMEM31 staining in metastatic and primary melanomas was determined through semiquantitative integrated optical density (IOD) analysis, and identified to be significantly increased in metastatic melanoma compared with primary melanoma (0.24±0.03 vs. 0.09±0.01 IOD/area; P<0.001). The expression of TMEM31 protein was significantly increased in metastatic compared with primary melanoma samples (76.56 vs. 56.35%; P=0.017). The results of the present study suggest that TMEM31 is a novel CT antigen that serves an essential role in melanoma metastasis, in addition to being a potential immunotherapeutic target for the treatment of patients with melanoma.

Evaluation of the antioxidant capacity of natural polyphenolic compounds using a macrocyclic Ni-(II) complex-catalysed Briggs-Rauscher reaction.

This paper reports a method for evaluating antioxidant capacity based on the inhibitory effects of a macrocyclic Ni(II) complex-catalysed Briggs-Rauscher reaction. The macrocyclic Ni(II) complex NiL(ClO4)2, in which L is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene, is a porphyrin-like compound, the structure of which can be found in certain enzymes. The experiments indicated that three natural compounds could temporarily quench the oscillations for a period of time prior to regeneration of oscillations. The inhibition time was related to the compound type and concentration; thus, procedures for evaluating the antioxidant activities of polyphenolic compounds were successfully established. Three polyphenolic compounds were tested to evaluate their antioxidant activities: protocatechuic acid, rutin hydrate and procyanidin. Of these three naturally occurring compounds, procyanidin was found to be the most efficient antioxidant. We have also discussed the reaction of the antioxidant with the hydroperoxyl radical (HOO) present in the oscillating system.