1.The bile acid Deoxycholate Elicits defenses in Arabidopsis and reduces bacterial infection.
Zarattini M1,2, Launay A1,3, Farjad M1, Wénès E1, Taconnat L4, Boutet S1, Bernacchia G2, Fagard M1. Mol Plant Pathol. 2016 Apr 16. doi: 10.1111/mpp.12416. [Epub ahead of print]
Crop yield loss is significantly affected by disease. Considering that the worldwide demand for agricultural products is increasing, there is a need to pursue the development of new methods to protect crops from disease. One mechanism of plant protection is through the activation of its immune system. By exogenous application, "plant activator molecules" with elicitor properties, can be used to activate the plant immune system. These defense-inducing molecules represent a powerful and often environment-friendly toolset to fight pathogens. We show that the secondary bile acid deoxycholic acid (DCA) induces defense in Arabidopsis and reduces the proliferation of two bacterial phytopathogens, Erwinia amylovora and Pseudomonas syringae pv. tomato. We describe the global defense response triggered by this new plant activator in Arabidopsis at the transcriptional level. Several induced genes were selected for further analysis by qRT-PCR: we describe the kinetics of their induction and we show that abiotic stress, such as moderate drought or nitrogen limitation, does not impede DCA induction of defense.
2.Effect of alkyl polyglucoside and nitrilotriacetic acid combined application on lead/pyrene bioavailability and dehydrogenase activity in co-contaminated soils.
Chen T1, Liu X2, Zhang X1, Chen X1, Tao K1, Hu X1. Chemosphere. 2016 Apr 13;154:515-520. doi: 10.1016/j.chemosphere.2016.03.127. [Epub ahead of print]
At present, few research focus on the phytoremediation for organic pollutants and heavy metals enhanced by surfactants and chelate agents in the combined contaminated soils or sediments. In this study, the effect of a novel combined addition of alkyl polyglucoside (APG) and nitrilotriacetic acid (NTA) into pyrene and lead (Pb) co-contaminated soils on bioaccessiblity of pyrene/Pb and dehydrogenase activities (DHA) was studied. Through the comparison of the results with the alone and combined application, synergistic effect on bioaccessiblity of pyrene and Pb was found while APG and NTA was applied together. Results also indicated a significant promotion on the DHA in mixed addition of APG and NTA. In addition, correlation and principal component analysis were performed to better understand the relationship among APG/NTA, bioaccessiblity of pyrene/Pb and the DHA. Results showed that APG and NTA can affect DHA directly by themselves but also can affect DHA indirectly by changing bioaccessible pyrene and exchangeable Pb.
3.Isolation and identification of oxidation products of syringol from brines and heated meat matrix.
Bölicke SM1, Ternes W2. Meat Sci. 2016 Apr 5;118:108-116. doi: 10.1016/j.meatsci.2016.03.029. [Epub ahead of print]
In this study we developed new extraction and detection methods (using HPLC-UV and LC-MS), making it possible to analyze the smoke phenol syringol and its oxidation products nitrososyringol, nitrosyringol, and the syringol dimer 3,3',5,5'-tetramethoxy-1,1'-biphenyl-4,4'-diol, which were identified in heated meat for the first time. Preliminary brine experiments performed with different concentrations of ascorbic acid showed that high amounts of this antioxidant also resulted in almost complete degradation of syringol and to formation of the oxidation products when the brines were heated at low pH values. Heat treatment (80°C) and subsequent simulated digestion applied to meat samples containing syringol, ascorbic acid and different concentrations of sodium nitrite produced 3,3',5,5'-tetramethoxy-1,1'-biphenyl-4,4'-diol even at a low nitrite level in the meat matrix, while nitroso- and nitrosyringol were isolated only after the digestion experiments.
4.Chlorination of oxybenzone: Kinetics, transformation, disinfection byproducts formation, and genotoxicity changes.
Zhang S1, Wang X1, Yang H2, Xie YF3. Chemosphere. 2016 Apr 13;154:521-527. doi: 10.1016/j.chemosphere.2016.03.116. [Epub ahead of print]
UV filters are a kind of emerging contaminant, and their transformation behavior in water treatment processes has aroused great concern. In particular, toxic products might be produced during reaction with disinfectants during the disinfection process. As one of the most widely used UV filters, oxybenzone has received significant attention, because its transformation and toxicity changes during chlorine oxidation are a concern. In our study, the reaction between oxybenzone and chlorine followed pseudo-first-order and second-order kinetics. Three transformation products were detected by LC-MS/MS, and the stability of products followed the order of tri-chloro-methoxyphenoyl > di-chlorinated oxybenzone > mono-chlorinated oxybenzone. Disinfection byproducts (DBPs) including chloroform, trichloroacetic acid, dichloroacetic acid and chloral hydrate were quickly formed, and increased at a slower rate until their concentrations remained constant.