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Pan Y.,Chongqing University | Pan Y.,University of Nottingham | Seymour G.B.,University of Nottingham | Lu C.,University of Nottingham | And 3 more authors.
Plant Cell Reports | Year: 2012

A novel member of the AP2/ERF transcription factor family, SlERF5, was identified from a tomato mature leaf cDNA library screen. The complete DNA sequence of SlERF5 encodes a putative 244-amino acid DNA-binding protein which most likely acts as a transcriptional regulator and is a member of the ethylene responsive factor (ERF) superfamily. Analysis of the deduced SlERF5 protein sequence showed that it contained an ERF domain and belonged to the class III group of ERFs proteins. Expression of SlERF5 was induced by abiotic stress, such as high salinity, drought, flooding, wounding and cold temperatures. Over-expression of SlERF5 in transgenic tomato plants resulted in high tolerance to drought and salt stress and increased levels of relative water content compared with wild-type plants. This study indicates that SlERF5 is mainly involved in the responses to abiotic stress in tomato. © 2011 Springer-Verlag. Source

Deng L.,Chongqing University | Pan Y.,Chongqing University | Chen X.,Beijing Agro Biotechnology Research Center | Chen G.,Chongqing University | Hu Z.,Chongqing University
Plant Physiology and Biochemistry | Year: 2013

Homozygous state-associated co-suppression is not a very common phenomenon. In our experiments, two transgenic plants 3A29 and 1195A were constructed by being transformed with the constructs pBIN-353A and pBIN119A containing nptII gene as a marker respectively. The homozygous progeny from these two independent transgenic lines 3A29 and 1195A, displayed kanamycin-sensitivity and produced a short main root without any lateral roots as untransformed control (wild-type) seedlings when germinated on kanamycin media. For the seedlings derived from putative hemizygous plants, the percentage of the seedlings showing normal growth on kanamycin media was about 50% and lower than the expected percentage (75%). Southern analysis of the genomic DNA confirmed that the homozygous and hemizygous plants derived from the same lines contained the same multiple nptII transgenes, which were located on the same site of chromosome. Northern analysis suggested that the marker nptII gene was expressed in the primary and the hemizygous transformants, but it was silenced in the homozygous transgenic plants. Further Northern analysis indicated that antisense and sense small nptII-derived RNAs were present in the transgenic plants and the blotting signal of nptII-derived small RNA was much higher in the homozygous transgenic plants than that of hemizygous transgenic plants. Additionally, read-through transcripts from the TRAMP gene to the nptII gene were detected. These results suggest that the read-through transcripts may be involved in homozygous state-associated silencing of the nptII transgene in transgenic tomato plants and a certain threshold level of the nptII-derived small RNAs is required for the homozygous state-associated co-suppression of the nptII transgene. © 2013 Elsevier Masson SAS. Source

Hu Z.-L.,Chongqing University | Deng L.,Chongqing University | Yan B.,Chongqing University | Pan Y.,Chongqing University | And 4 more authors.
Biologia Plantarum | Year: 2011

The full-length cDNA of LeSGR1 was cloned from tomato by RT-PCR and RACE. The cDNA encoded a protein of 272 amino acid residues and was deposited in GenBank (accession No. DQ100158). Northern analysis suggests that LeSGR1 gene specifically expresses in senescent leaves and mature fruits of tomatoes. Desiccation and flooding induce the expression of LeSGR1 in tomato leaves and stems. Both in ethylene-insensitive mutants (Nr) and ripening inhibitor mutants (rin), the expression of LeSGR1 is markedly decreased compared with that in the wild type. Alignment of the nucleotide sequence of SGR1 cloned from the tomato green flesh (gf) mutant with that from the wild type tomato shows a single nucleotide change leading to an amino acid substitution in gf mutant. Furthermore, LeSGR1 gene silencing by RNA interference results in inhibited chlorophyll degradation similar to the phenotype in gf mutant. Thus, we conclude that LeSGR1 is crucial to chlorophyll degradation and the mutation of SGR1 protein might be responsible for gf tomato properties. © 2011 Springer Science+Business Media B.V. Source

Wang L.-H.,University of Science and Technology Beijing | Wang L.-H.,Handan College | Wang Q.,University of Science and Technology Beijing | Cai W.,University of Science and Technology Beijing | Sun X.,Beijing Agro Biotechnology Research Center
Biosystems Engineering | Year: 2012

The solid-state anaerobic co-digestion (AC) of distiller's grains (DG) and food waste (FW) for biogas production was investigated. The effects of different DG/FW (TS) ratios (10/1, 8/1, 6/1, 4/1, 1/0, and 0/1) were examined. Co-digestion with the above DG/FW ratios was found to be superior to that of mono-digestion. The AC of DG and FW had a good synergistic effect of the lower range of propionate/acetate ratio and VFA/alkalinity ratio. No methane was produced when the propionate/acetate ratio was >0.1 ± 0.01, but this inhibition was reversible. When the propionate/acetate ratio was <0.08 ± 0.01, methane production began to recover. When the volatile fatty acids (VFA)/alkalinity ratios were <0.9 ± 0.05, the AC of the influents successfully proceeded in a stable manner. However, when the VFA/alkalinity and propionate/acetate ratios were >1.25 ± 0.21 and 0.1 ± 0.01, respectively, the AC system reached an acidification crisis and failed. Therefore, the propionate/acetate and VFA/alkalinity ratios may be used as important indices for controlling anaerobic digestion (AD). © 2012 IAgrE. Source

Zhang L.,Northeast Dianli University | Zhuang Y.,Northeast Dianli University | Wang X.,Beijing Agro Biotechnology Research Center | Zhang H.,Northeast Dianli University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2016

It is well accepted that nitrogen and phosphorus are the predominant compounds for the promotion of algae growth, and the removal of nitrogen and phosphorus involved in the wastewater has received a world-wide attention. In the biological wastewater treatment process, temperature is one of the most important physical factors, which will influence the metabolic activity and growth of microorganisms and thus their conversion capabilities in the carbonaceous, nitrogen and phosphorus compounds. The effects of temperature variations on the removal efficiencies of chemical oxygen demand (COD), nitrogen and phosphorus were investigated with an anaerobic-aerobic-anoxic process (AOA) (i.e., modified A2/O process). Compared to the conventional anaerobic-anoxic-aerobic process (i.e., A2/O process), the modified A2/O process could utilize the internal carbon contained in poly-β-hydroxybutyric acid (PHB) of the phosphorus accumulation organisms (PAOs) as the carbon source in the anoxic stage for denitrification. The AOA process could avoid the problem induced by the lack of carbon source in denitrification and the completion of carbon source between microorganisms for nitrogen and phosphorus removal. Besides, the environmental conditions created under the AOA process could promote the reproduction and growth of the denitrifying phosphorus accumulation organisms (DPAOs). The effects of temperature variations on PHB degradation rate, NO3 --N reduction rate and phosphorus uptake rate were also discussed. Furthermore, the effects of temperature on the kinetics of anoxic metabolism were analyzed. The present research could provide theoretical guidance and technical supports for the engineering application of the simultaneous removal process of nitrogen and phosphorus. The results showed that temperature had a significant impact on the denitrifying phosphorus removal system. When the temperature declined from 12 to 9℃, the removal efficiency of COD declined from 86.76% to 81.19% and the removal efficiency of total nitrogen (TN) declined from 61.44% to 59.39%, whereas the change of the removal efficiency of PO4 3--P was slight. According to the performance tests with the denitrifying phosphorus removal sludge, too high or too low temperature could lead to the changes of phosphorus release and absorption rate. The rates of anaerobic phosphorus release, aerobic phosphorus uptake and anoxic phosphorus uptake reached the maximum values at 27℃ and were 7.38, 9.18 and 5.15 mg/(g·h), respectively. The temperature also had a great influence on the proportion of DPAOs in the activated sludge. When the temperature was 27℃, the ratio of DPAOs/PAOs reached its maximum value of 56.16%. The effects of temperature on phosphorus uptake rate, NO3 --N reduction rate and PHB degradation rate were quite remarkable in the denitrifying phosphorus removal process. When the temperature was 27℃, the rates of the phosphorus uptake, nitrate reduction and PHB oxidation were the highest, which were 5.15 mg/(g·h), 7.13 mg/(g·h) and 0.81 mmol/(g·h), respectively. By using the extended Arrhenius equation, the temperature kinetic coefficients of the anoxic stage were 1.120-1.164 and 1.137-1.153, respectively, which indicated that all the anoxic stoichiometry parameters were sensitive to temperature changes. In conclusion, in the field application, measures should be taken to maintain an appropriate temperature range in order to enhance the simultaneous removal of nitrogen and phosphorus. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved. Source

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