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Oligochitosan and sodium alginate enhance stilbene production and induce defense responses in Vitis vinifera cell suspension cultures

100%

Xu A. , Zhan J.-C. , Huang W.-D.

Acta Physiologiae Plantarum

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2015

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tom 37

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nr 08

EN

Vitis vinifera L. cv. Cabernet Sauvignon cell suspension cultures were treated with oligochitosan (OCS) and sodium alginate (NaAlg) at various concentrations for different exposure times to investigate the effects on stilbene biosynthesis. In this study, adding optimal concentrations of OCS (100 mg l-1) and NaAlg (100 mg l-1) significantly enhanced both stilbene production inside the cells and trans-resveratrol accumulation in the culture medium without loss of biomass. OCS and NaAlg markedly increased total intracellular stilbene production (1212.05 ± 36.83 and 990.74 ± 24.24 lg g-1 DW; 96.32 and 60.48 % higher than in untreated cells, respectively), and trans-resveratrol release into the culture medium was induced to the maximum of 3.26 ± 0.14 and 2.76 ± 0.12 mg l-1, respectively. Total phenolics and total flavonoids contents were also highly increased after the application of the two elicitors. The expression levels of genes involved in stilbene and flavonoid biosynthesis were significantly up-regulated in the presence of OCS and NaAlg. Further, the expression levels and enzyme activities of two pathogenesis-related proteins, chitinase and β-1,3- glucanase, were induced after the addition of elicitors. The results suggest that OCS and NaAlg can significantly enhance the production of stilbene in V. vinifera cell cultures and may induce the defense responses by the upregulation of chitinase and β-1,3-glucanase at transcript and enzyme activity levels.

2

Effect of boron on ZSM-5 catalyst for methanol to propylene conversion

88%

Xu A. , Ma H. , Zhang H. , Ying W. , Fang D.

Polish Journal of Chemical Technology

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2013

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tom Vol. 15, nr 4

95-101

EN

B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-desorption, Fourier Transform Infrared spectrometry (FT-IR), 27Al and 11B MAS NMR spectra. The results revealed that the weak acidity of catalysts was significantly increased by modification. The catalytic activity was measured in a fixed bed at 460°C for methanol to propylene (MTP) reaction. The results of MTP reaction showed a great increment of the propylene selectivity for the boron modified samples, especially for the directly synthesized B-ZSM-5 which also displayed high activity and selectivity towards C2 =-C4 = olefins. It was found that the remarkable selectivity strongly depended on the intensity of weak acidity.

3

Drought stress condition increases root to shoot ratio via alteration of carbohydrate partitioning and enzymatic activity in rice seedlings

75%

Xu W. , Cui K. , Xu A. , Nie L. , Huang J. , Peng S.

Acta Physiologiae Plantarum

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2015

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tom 37

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nr 02

EN

To understand the underlying mechanism for plasticity in root to shoot ratio (R/S) in response to drought stress, two rice cultivars, Zhenshan97 (drought susceptible) and IRAT109 (drought resistant), were grown hydroponically, and R/S, carbohydrate concentration and partitioning, and activities of enzymes for sucrose conversion in seedlings exposed to drought stress condition (DS) imposed by polyethylene glycol 6000 were investigated. The R/S significantly increased under DS in comparison with that under well-watered condition. The proportion of dry matter and soluble sugar of roots markedly increased under DS. The R/S was negatively correlated with proportion of soluble sugar in stems, and positively with the proportions of soluble sugar and starch in roots. Drought stress condition significantly increased leaf sucrose-phosphate synthase (EC 2.4.1.14) activity and root acid and neutral/ alkaline invertase (EC 3.2.1.26) activity. The R/S was positively correlated with leaf sucrose-phosphate synthase and root acid invertase activity, and negatively with leaf sucrose synthase activity in the cleavage direction. Our results indicate that the increase in R/S in response to DS is closely associated with the higher proportion of dry matter and soluble sugar in roots, and this occurs via an increase in leaf sucrose-phosphate synthase and root invertase activity, and thus more sucrose is available for transport from leaves to roots.

4

Inhibition of endometrial fundocervical wave by phloroglucinol and the outcome of in vitro fertilization

75%

Xu A. , Li Y. , Zhu L. , Tian T. , Hao J. , Zhao J. , Zhang Q.

Reproductive Biology

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2013

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tom 13

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nr 1

5

IgG silencing induces apoptosis andsuppresses proliferation, migration and invasion in LNCaP prostate cancer cell

63%

Xu Y. , Chen B. , Zheng S. , Wen Y. , Xu A. , Xu K. , Li B. , Liu C.

Cellular and Molecular Biology Letters

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2016

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tom 21