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171.
172.
Jun-Qing Wang Xin Yin Min-Chen Wu Hui-Min Zhang Shu-Juan Gao Jing-Tu Wei Cun-Duo Tang Jian-Fang Li 《Journal of industrial microbiology & biotechnology》2013,40(1):75-83
A cDNA gene (Auxyn10A), which encodes a mesophilic family 10 xylanase from Aspergillus usamii E001 (abbreviated to AuXyn10A), was amplified and inserted into the XhoI and NotI sites of pPIC9KM vector constructed from a parent pPIC9K. The recombinant expression vector, designated pPIC9KM-Auxyn10A, was transformed into Pichia pastoris GS115. All P. pastoris transformants were spread on a MD plate, and then inoculated on geneticin G418-containing YPD plates for screening multiple copies of integration of the Auxyn10A. One transformant expressing the highest recombinant AuXyn10A (reAuXyn10A) activity of 368.6 U/ml, numbered as P. pastoris GSX10A4-14, was selected by flask expression test. SDS-PAGE assay demonstrated that the reAuXyn10A was extracellularly expressed with an apparent M.W. of 39.8 kDa. The purified reAuXyn10A displayed the maximum activity at pH 5.5 and 50 °C. It was highly stable at a broad pH range of 4.5–8.5, and at a temperature of 45 °C. Its activity was not significantly affected by EDTA and several metal ions except Mn2+, which caused a strong inhibition. The K m and V max, towards birchwood xylan at pH 5.5 and 50 °C, were 2.25 mg/ml and 6,267 U/mg, respectively. TLC analysis verified that the AuXyn10A is an endo-β-1,4-d-xylanase, which yielded a major product of xylotriose and a small amount of xylose, xylotetraose, and xylopentose from birchwood xylan, but no xylobiose. 相似文献
173.
Yanchang Luo Zhongchao Yin 《Molecular breeding : new strategies in plant improvement》2013,32(3):709-721
Rice is a staple food crop for more than half of the world’s population. However, rice production is affected by many types of abiotic and biotic stress. Genetic breeding by utilizing natural resistance or tolerance genes is the most economic and efficient way to combat or adapt to these stresses. Khao Dawk Mali 105 (KDML 105) is an elite cultivar of aromatic rice mainly grown in Thailand. However, the production of KDML 105 is affected by lodging problems due to its tall plant type, regular flash floods or short-term submergence during the monsoon season, and diseases such as blast and bacterial blight. Here we report the pyramiding of semi-dwarf gene sd1, submergence tolerance gene Sub1A, blast resistance gene Pi9 and bacterial blight resistance genes Xa21 and Xa27 in KDML 105 by marker-assisted selection. The improved line, designated T5105, has a semi-dwarf phenotype with improved lodging resistance and a greater harvest index. T5105 survives after 2 weeks of complete submergence without significant loss of viability. T5105 confers high resistance to all five Magnaporthe oryzae isolates tested and provides resistance or moderate resistance to 25 of the 27 Xanthomonas oryzae pv. oryzae strains tested. In addition, T5105 produced higher yield than KDML 105 in two field trials and retains similar good grain quality to KDML 105. The development of T5105 provides a new line to boost the production of high-quality aromatic rice in tropical regions. 相似文献
174.
Fagen Li Fan Yang Qijie Weng Guangtian Yin Mei Li Siming Gan 《Molecular breeding : new strategies in plant improvement》2013,31(4):867-877
Rattans serve as an important source of raw non-wood materials for furniture and handicraft industries worldwide. However, their genomic sequence information in public databases is very limited. In this study, a set of 2,528 good-quality expressed sequence tags (ESTs) were generated from a full-length cDNA library constructed previously with root, stem and male inflorescence tissues of Calamus simplicifolius C. F. Wei, a rattan species native to Hainan Island, China. The ESTs were assembled into 1,588 unigenes, including 1,221 singletons and 367 contigs. BlastX searches against the GenBank non-redundant protein database revealed that 1,248 (78.6 %) unigenes had at least one significant match (E ≤ 10?5). The gene ontology functional classification assigned 991, 669 and 977 of the unigenes to the cellular component, molecular function and biological process categories, respectively. A total of 71 simple sequence repeat (SSR) loci were developed among these ESTs, including 65 polymorphic across 19 rattan species representing three genera. High levels of cross-species/genus transferability were observed for the EST-SSRs. For the polymorphic EST-SSR markers, the number of alleles per locus and polymorphic information content ranged from 2 to 25 (mean 11.1) and from 0.135 to 0.949 (mean 0.695), respectively. The EST sequences and the EST-SSR primers have been deposited in GenBank databases of EST (IDs JK838364–40891) and Probe (IDs Pr16718978–9048, to be assigned). 相似文献
175.
The ergosterol biosynthesis pathway is well understood in Saccharomyces cerevisiae, but currently little is known about the pathway in plant‐pathogenic fungi. In this study, we characterized the Fusarium graminearum FgERG4 gene encoding sterol C‐24 reductase, which catalyses the conversion of ergosta‐5,7,22,24‐tetraenol to ergosterol in the final step of ergosterol biosynthesis. The FgERG4 deletion mutant ΔFgErg4‐2 failed to synthesize ergosterol. The mutant exhibited a significant decrease in mycelial growth and conidiation, and produced abnormal conidia. In addition, the mutant showed increased sensitivity to metal cations and to various cell stresses. Surprisingly, mycelia of ΔFgErg4‐2 revealed increased resistance to cell wall‐degrading enzymes. Fungicide sensitivity tests revealed that ΔFgErg4‐2 showed increased resistance to various sterol biosynthesis inhibitors (SBIs), which is consistent with the over‐expression of SBI target genes in the mutant. ΔFgErg4‐2 was impaired dramatically in virulence, although it was able to successfully colonize flowering wheat head and tomato, which is in agreement with the observation that the mutant produces a significantly lower level of trichothecene mycotoxins than does the wild‐type progenitor. All of these phenotypic defects of ΔFgErg4‐2 were complemented by the reintroduction of a full‐length FgERG4 gene. In addition, FgERG4 partially rescued the defect of ergosterol biosynthesis in the Saccharomyces cerevisiae ERG4 deletion mutant. Taken together, the results of this study indicate that FgERG4 plays a crucial role in ergosterol biosynthesis, vegetative differentiation and virulence in the filamentous fungus F. graminearum. 相似文献
176.
Plant invasion is one of the major threats to natural ecosystems. Phenotypic plasticity is considered to be important for promoting plant invasiveness. High tolerance of stress can also increase survival of invasive plants in adverse habitats. Limited growth and conservation of carbohydrate are considered to increase tolerance of flooding in plants. However, few studies have examined whether invasive species shows a higher phenotypic plasticity in response to waterlogging or a higher tolerance of waterlogging (lower plasticity) than native species. We conducted a greenhouse experiment to compare the growth and morphological and physiological responses to waterlogging of the invasive, clonal, wetland species Alternanthera philoxeroides with those of its co-occurring, native, congeneric, clonal species Alternanthera sessilis. Plants of A. philoxeroides and A. sessilis were subjected to three treatments (control, 0 and 60 cm waterlogging). Both A. philoxeroides and A. sessilis survived all treatments. Overall growth was lower in A. philoxeroides than in A. sessilis, but waterlogging negatively affected the growth of A. philoxeroides less strongly than that of A. sessilis. Alternanthera philoxeroides thus showed less sensitivity of growth traits (lower plasticity) and higher waterlogging tolerance. Moreover, the photosynthetic capacity of A. philoxeroides was higher than that of A. sessilis during waterlogging. Alternanthera philoxeroides also had higher total non-structural and non-soluble carbohydrate concentrations than A. sessilis at the end of treatments. Our results suggest that higher tolerance to waterlogging and higher photosynthetic capacity may partly explain the invasion success of A. philoxeroides in wetlands. 相似文献
177.
Chung-Feng Hwang Li-Yen Shiu Li-Jen Su Yu-Fang Yin Wei-Sheng Wang Shun-Chen Huang Tai-Jan Chiu Chao-Cheng Huang Yen-Yi Zhen Hsin-Ting Tsai Fu-Min Fang Tai-Lin Huang Chang-Han Chen 《PloS one》2013,8(12)
Background
Nasopharyngeal carcinoma (NPC) is known for its high metastatic potential and locoregional recurrence, although the molecular alterations that are driving NPC metastasis remain unclear at this time. This study aimed to examine the expression of fibulin-5 in NPC, correlate the results with clinicopathological variables and survival, and to investigate the role of fibulin-5 in human NPC cell lines.Material and Methods
Standard semi-quantitative-RT-PCR, quantitative-RT-PCR, immunoblotting, and immunohistochemistry were used to investigate the mRNA and protein expression profiles of fibulin-5 in normal and NPC tissues. Immunohistochemistry of fibulin-5 was correlated with clinicopathological characteristics by univariate analyses. NPC cells overexpressing fibulin-5 or fibulin-5-siRNA cells were generated by stable transfection to characterize the molecular mechanisms of fibulin-5-elicited cell growth and metastasis.Results
Our results demonstrated that fibulin-5 overexpression in NPC specimens and significantly correlated with advanced tumor metastasis indicating a poor 5-year overall survival. Fibulin-5 was mainly expressed in the nucleus in human NPC specimens and cell lines. Functionally, fibulin-5 overexpression yielded fast growth in NPC cells. In addition, fibulin-5 promotes cell metastasis in NPC cells through increased FLJ10540 and phosphor-AKT activity. In contrast, siRNA depletion of fibulin-5 suppressed FLJ10540 expression and phosphor-AKT activity. Suppression of either fibulin-5 or FLJ10540 can cause significant inhibition with regards to cell motility in NPC cells. Finally, immunohistochemical analysis of human aggressive NPC specimens showed a significant and positive correlation between fibulin-5 and FLJ10540 expression.Conclusion
Higher fibulin-5 expression is not only an important indicator of poor survival, but also contributes to the development of new therapeutic strategies in the FLJ10540/AKT pathway for NPC treatment. 相似文献178.
Yong Liu Xuesen Yang Tor Paaaske Utheim Chenying Guo Mingchun Xiao Yan Liu Zhengqin Yin Jie Ma 《PloS one》2013,8(12)
Microglial cells, which are immunocompetent cells, are involved in all diseases of the central nervous system. During their activation in various diseases, a variety of soluble factors are released. In the present study, the correlation between cytokine levels and microglial cell migration in the course of retinal degeneration of Royal College of Surgeons (RCS) rats was evaluated. MFG-E8 and CD11b were used to confirm the microglial cells. In the retina of RCS rats, the mRNA expression of seven genes (MFG-E8 and its integrins αυ and ß5, CD11b and the cytokines TNF-α, IL-1ß, and MCP-1) formed almost similar bimodal peak distributions, which were centred at P7 and P45 to P60. In contrast, in rdy rats, which comprised the control group, a unimodal peak distribution centred at P14 was observed. The gene expression accompanied the activation and migration of microglial cells from the inner to the outer layer of the retina during the process of degeneration. Principal component analysis and discriminant function analysis revealed that the expression of these seven genes, especially TNF-α and CD11b, positively correlated with retinal degeneration and microglial activity during retinal degeneration in RCS rats, but not in the control rats. Furthermore, linear regression analysis demonstrated a significant correlation between the expression of these genes and the activation of microglial cells in the dystrophic retina. Our findings suggest that the suppression of microglial cells and the blockade of their cytotoxic effects may constitute a novel therapeutic strategy for treating photoreceptor death in various retinal disorders. 相似文献
179.
Tih-Shih Lee Siau Juinn Alexa Goh Shin Yi Quek Rachel Phillips Cuntai Guan Yin Bun Cheung Lei Feng Stephanie Sze Wei Teng Chuan Chu Wang Zheng Yang Chin Haihong Zhang Tze Pin Ng Jimmy Lee Richard Keefe K. Ranga Rama Krishnan 《PloS one》2013,8(11)
Cognitive decline in aging is a pressing issue associated with significant healthcare costs and deterioration in quality of life. Previously, we reported the successful use of a novel brain-computer interface (BCI) training system in improving symptoms of attention deficit hyperactivity disorder. Here, we examine the feasibility of the BCI system with a new game that incorporates memory training in improving memory and attention in a pilot sample of healthy elderly. This study investigates the safety, usability and acceptability of our BCI system to elderly, and obtains an efficacy estimate to warrant a phase III trial. Thirty-one healthy elderly were randomized into intervention (n = 15) and waitlist control arms (n = 16). Intervention consisted of an 8-week training comprising 24 half-hour sessions. A usability and acceptability questionnaire was administered at the end of training. Safety was investigated by querying users about adverse events after every session. Efficacy of the system was measured by the change of total score from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) before and after training. Feedback on the usability and acceptability questionnaire was positive. No adverse events were reported for all participants across all sessions. Though the median difference in the RBANS change scores between arms was not statistically significant, an effect size of 0.6SD was obtained, which reflects potential clinical utility according to Simon’s randomized phase II trial design. Pooled data from both arms also showed that the median change in total scores pre and post-training was statistically significant (Mdn = 4.0; p<0.001). Specifically, there were significant improvements in immediate memory (p = 0.038), visuospatial/constructional (p = 0.014), attention (p = 0.039), and delayed memory (p<0.001) scores. Our BCI-based system shows promise in improving memory and attention in healthy elderly, and appears to be safe, user-friendly and acceptable to senior users. Given the efficacy signal, a phase III trial is warranted.
Trial Registration
ClinicalTrials.gov NCT01661894相似文献180.
Lu Xu Fan Ping Jinhua Yin Xinhua Xiao Hongding Xiang Christie M. Ballantyne Huaizhu Wu Ming Li 《PloS one》2013,8(12)