Du Y.,Ghent University |
Du Y.,Yunnan Agricultural University |
Tejos R.,Ghent University |
Beck M.,Norwich Research Park |
And 6 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2013
Removal of cargos from the cell surface via endocytosis is an efficient mechanism to regulate activities of plasma membrane (PM)-resident proteins, such as receptors or transporters. Salicylic acid (SA) is an important plant hormone that is traditionally associated with pathogen defense. Here, we describe an unanticipated effect of SA on subcellular endocytic cycling of proteins. Both exogenous treatments and endogenously enhanced SA levels repressed endocytosis of different PM proteins. The SA effect on endocytosis did not involve transcription or known components of the SA signaling pathway for transcriptional regulation. SA likely targets an endocytic mechanism that involves the coat protein clathrin, because SA interfered with the clathrin incidence at the PM and clathrin-deficient mutants were less sensitive to the impact of SA on the auxin distribution and root bending during the gravitropic response. By contrast, SA did not affect the ligand-induced endocytosis of the FLAGELLIN SENSING2 (FLS2) receptor during pathogen responses. Our data suggest that the established SA impact on transcription in plant immunity and the nontranscriptional effect of SA on clathrin-mediated endocytosis are independent mechanisms by which SA regulates distinct aspects of plant physiology.
Agency: European Commission | Branch: FP7 | Program: CP-TP | Phase: KBBE.2013.1.2-04 | Award Amount: 8.53M | Year: 2014
The DROPSA consortium will create new knowledge and understanding of the damage and losses of fruit crops resulting from pests and pathogens, with a specific focus on the new and emerging threats due to Drosophila suzukii and quarantine pathogens Pseudomonas syringae, Xanthomonas fragariae and X. arboricola. The project will deliver a cost effective approach that can be widely implemented by the EU fruit industry. The aims and objectives are to: Determine the pathways of introduction and spread of D. suzukii and pathogens into the EU and develop preventative strategies and recommendations against the introduction of other dangerous fruit pests and pathogens. Determine the biology, ecology and interaction of these pests and diseases in different regions of Europe. This will involve a comprehensive evaluation of the life cycles, host ranges, capacities to disperse, the identification of natural enemies, plant-pathogen interactions as well as the semiochemicals involved in the behaviour of D. suzukii. The biology will provide the platform to develop practical solutions for sustainable pest control. Develop innovative and effective control options using approved chemicals, semiochemicals, novel antimicrobial compounds and biological control agents as well as cultural practices, sterile insect techniques and new mode of action compounds. The most reliable and effective control options will be combined to optimise an integrated pest management (IPM) strategy. Develop forecasting and decision support systems and risk mapping as a component of IPM. The economic viability of proposed strategies for fruit crop protection will be evaluated and used to support decision making in the implementation of IPM strategies to protect the EU fruit sector. To protect intellectual property (IP) and to undertake dissemination and exploitation actions to maximise the impact and up take of the recommended IPM by commercial fruit growers.
Liu H.,Yunnan Agricultural University
Agro Food Industry Hi-Tech | Year: 2017
With the development and importance of critical thinking ability, the cultivation of critical thinking ability in college English teaching has become the key goal of college students' higher education. Therefore, critical thinking gets more and more attention in college English teaching, and English writing which is related to critical thinking has association with key points of college teaching quality and knowledge adoption ability of college students. At present, the problems such as insufficient argument, obsolete conception, and unclear theme often exist in the writing of college students. The self-thinking ability of college students is also ignored in college English teaching, and gradually ossified learning model and mechanical application of teaching template are formed, the sentence structure follows the same pattern with nothing new at all. So, on the basis of understanding of critical thinking, the paper focuses on the practical application ability of college students in the process of English writing.
News Article | March 25, 2016
Biologists at UC San Diego and in China found that an Asian species of honey bee can produce different types of vibrational "stop signals" when attacked by giant Asian hornets. These signals have different effects depending upon type of danger and the context. A bee delivers a stop signal by giving another bee a brief, vibrational pulse, usually through a head-butt. "Surprisingly, this signal encodes the level of danger in its vibrational frequency, its pitch, and the danger context through the duration of each pulse," said James Nieh, a professor of biology at UC San Diego who headed the research team., which was also led by Ken Tan, a professor at Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science. The scientists report their discovery, which they say is the most sophisticated form of alarm signaling found in a social insect, in a paper published this week in the open-access journal PLOS Biology. Six years ago, Nieh discovered that foragers of the European honey bee, Apis mellifera, when attacked at a food source, will return to the nest and deliver stop signals to nestmates recruiting for the dangerous food source. These signals were known to inhibit recruitment, the famous waggle dance of the honey bee, but researchers did not know what triggered stop signals. "Stop signals are usually delivered by a sender butting her head into a recipient. Understanding that these signals can be triggered by danger and reduce recruitment for dangerous food therefore made sense," explained Nieh. Nieh next wanted to find out if other honey bee species also used stop signals. He and his collaborators at the Chinese Academy of Science and Eastern Bee Research Institute in Yunnan Province conducted their experiments at Yunnan Agricultural University using the Asian honey bee, Apis cerana, which occurs throughout southern and eastern Asia, from India to China and Japan. The scientists said this honey bee species is an excellent model for studying the effects of predator threats because A. cerana is attacked by multiple species of giant hornets, which pose a threat according to hornet body size. They studied the world's largest hornet, the "yak-killer" Vespa mandarinia and a smaller, but still formidable hornet, Vespa velutina. Both hornet species are natural enemies of A. cerana. These hornets attack foraging bees and bee nests, and the scientists therefore set up their experiments to see if bees would produce stop signals in both situations. "We hypothesized that bigger predators would pose a bigger threat and would change stop signaling, perhaps by producing more signals when attacked by a large predator," Nieh said. "However, we were very surprised to find that these Asian bees not only produced more stop signals, they also produced different kinds of stop signals." Attacked foragers reduced their waggle dancing and produced stop signals that increased in pitch according to predator size. The larger and more dangerous predator triggered higher pitched stop signals that were more effective at stopping waggle dancing than the lower pitched stop signals triggered by the smaller and less dangerous predator. In addition, guard bees and returning foragers attacked at the nest entrance produced longer duration stop signals to warn nestmates about the imminent danger outside. "Our experiments showed that these different types of stop signals elicited different and appropriate responses. Bees attacked at food sources by bigger hornets produced a kind of stop signal that more effectively inhibited recruitment," said Nieh. "Bees attacked at the nest entrance produced another kind of stop signal that inhibited foragers from exiting the nest and being exposed to the danger outside." According to Nieh, "this is the first demonstration of such sophisticated inhibitory signaling or alarm signaling in an insect." Previously, such referential alarm signals had only been reported in vertebrates like birds and primates.
Luo Q.,Yunnan Agricultural University |
Li Y.,CAS Institute of Genetics and Developmental Biology |
Shen Y.,CAS Institute of Genetics and Developmental Biology |
Cheng Z.,CAS Institute of Genetics and Developmental Biology
Journal of Genetics and Genomics | Year: 2014
Meiosis is the crucial process by which sexually propagating eukaryotes give rise to haploid gametes from diploid cells. Several key processes, like homologous chromosomes pairing, synapsis, recombination, and segregation, sequentially take place in meiosis. Although these widely conserved events are under both genetic and epigenetic control, the accurate details of molecular mechanisms are continuing to investigate. Rice is a good model organism for exploring the molecular mechanisms of meiosis in higher plants. So far, 28 rice meiotic genes have been characterized. In this review, we give an overview of the discovery of rice meiotic genes in the last ten years, with a particular focus on their functions in meiosis. © 2014.
Li S.,University of North Carolina at Charlotte |
Dong X.,University of North Carolina at Charlotte |
Dong X.,Yunnan Agricultural University |
Su Z.,University of North Carolina at Charlotte
BMC Genomics | Year: 2013
Background: Although prokaryotic gene transcription has been studied over decades, many aspects of the process remain poorly understood. Particularly, recent studies have revealed that transcriptomes in many prokaryotes are far more complex than previously thought. Genes in an operon are often alternatively and dynamically transcribed under different conditions, and a large portion of genes and intergenic regions have antisense RNA (asRNA) and non-coding RNA (ncRNA) transcripts, respectively. Ironically, similar studies have not been conducted in the model bacterium E coli K12, thus it is unknown whether or not the bacterium possesses similar complex transcriptomes. Furthermore, although RNA-seq becomes the major method for analyzing the complexity of prokaryotic transcriptome, it is still a challenging task to accurately assemble full length transcripts using short RNA-seq reads.Results: To fill these gaps, we have profiled the transcriptomes of E. coli K12 under different culture conditions and growth phases using a highly specific directional RNA-seq technique that can capture various types of transcripts in the bacterial cells, combined with a highly accurate and robust algorithm and tool TruHMM (http://bioinfolab.uncc.edu/TruHmm_package/) for assembling full length transcripts. We found that 46.9 ~ 63.4% of expressed operons were utilized in their putative alternative forms, 72.23 ~ 89.54% genes had putative asRNA transcripts and 51.37 ~ 72.74% intergenic regions had putative ncRNA transcripts under different culture conditions and growth phases.Conclusions: As has been demonstrated in many other prokaryotes, E. coli K12 also has a highly complex and dynamic transcriptomes under different culture conditions and growth phases. Such complex and dynamic transcriptomes might play important roles in the physiology of the bacterium. TruHMM is a highly accurate and robust algorithm for assembling full-length transcripts in prokaryotes using directional RNA-seq short reads. © 2013 Li et al.; licensee BioMed Central Ltd.
Gong J.-S.,Yunnan Agricultural University |
Tang C.,Yunnan Agricultural University |
Peng C.-X.,Yunnan Agricultural University
Journal of Analytical and Applied Pyrolysis | Year: 2012
Solvent extracts from a type of Pu-erh tea and Dian Hong black tea were characterized by Curie-point pyrolysis-gas chromatography-mass spectroscopy (CP-Py-GC/MS). The ethyl-acetate extracts from both teas showed similar CP-Py-GC/MS results, with main pyrolytic products of carbon dioxide, caffeine, o-phenols, and phthalate esters. During pyrolysis, the n-butanol extract from Pu-erh tea formed carbon dioxide (38.92% of total pyrolytic products), alkaloids (49.7%), and nitrogen oxides (8.38%), as well as a small fraction of esters. The n-butanol extract from Dian Hong tea formed mainly alcohols, amines, esters, phenols, carboxylic acids, and alkaloids. The raw theabrownin extracts (ethanol precipitates) from the two teas produced substantially different CP-Py-GC/MS results. The raw theabrownin extract from Pu-erh tea formed mostly carbon dioxide during pyrolysis, whereas the counterpart extract from Dian Hong tea formed mainly carbon dioxide (48.23%) and nitrogen oxides (35.39%). The 3.5-100 kDa fractions separated from the theabrownin extracts of the two teas showed similar CP-Py-GC/MS results, whereas the fractions <3.5 kDa and >100 kDa formed substantially different pyrolytic products. These results showed that solvent extracts from Pu-erh tea and Dian Hong tea had substantially different chemical compositions and structures. The study suggested that CP-Py-GC/MS can be used to effectively identify chemical differences between tea extracts. © 2012 Elsevier B.V. All rights reserved.
Li X.Y.,Yunnan Agricultural University
Journal of microbiology and biotechnology | Year: 2013
Bacillus subtilis XF-1, a strain with demonstrated ability to control clubroot disease caused by Plasmodiophora brassicae, was studied to elucidate its mechanism of antifungal activity against P. brassicae. Fengycin-type cyclopeptides (FTCPs), a well-known class of compounds with strong fungitoxic activity, were purified by acid precipitation, methanol extraction, and chromatographic separation. Eight homologs of fengycin, seven homologs of dehydroxyfengycin, and six unknown FTCPs were characterized with LC/ESI-MS, LC/ESI-MS/MS, and NMR. FTCPs (250 microg/ml) were used to treat the resting spores of P. brassicae (10(7)/ml) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A(260)) and at 280 nm (A(280)) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be cleaved by the FTCPs of B. subtilis XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol.
Wang T.-F.,Yunnan Agricultural University
Chinese Journal of Biologicals | Year: 2013
Objective: To investigate the form of caffeine and the change of free caffeine content during fermentation of Puer tea Methods: The free and combined caffeine contents in Puer tea samples at six stages of fermentation were determined by precipitation at low pH value followed by HPLC. Results: The content of free caffeine decreased gradually from (2.555 ± 0.104) % to (1.878 ± 0.049) % during fermentation. More the 1/4 of the caffeine were combined with other ingredients in the tea. The content of combined caffeine increased continuously during fermentation, which increased remarkably from 0.084% to 0.647% at stages 4 and 5, and reached the maximum of 0.703% in final product. Conclusion: The content of free caffeine decreased gradually during fermentation of Puer tea, which provided a basis for monitoring the fermentation level and control the quality of the tea.
Liu J.N.,Yunnan Agricultural University
Journal of insect science (Online) | Year: 2010
The white backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae), is a serious pest of rice in Asia. In the present study, inter-simple sequence repeat (ISSR) markers were employed to investigate the genetic diversity and differentiation of 47 populations sampled from 14 prefectures of the Greater Mekong Subregion. A total of 14 selected primers yielded 121 bright and discernible bands, with an average of 8.6 bands per primer. According to the hierarchical analysis of molecular variance (AMOVA), the genetic variation among geographic regions (79.84%) was higher than that of among populations within region (20.16%), and the FST value was 0.72, indicating a high level of genetic differentiation. Neighbor-Joining cluster analysis of the 47 populations showed two major clusters, one consisting of mostly southwestern Yunnan Province and Myanmar populations; and the other one consisting of southeastern and central of Yunnan Province plus Vietnam and Laos populations. No significant positive correlation was observed between genetic and geographic distances by Mantel test (r = 0.2230, p = 0.8448), indicating the role of geographic isolation did not shape the genetic structure of the sampled S. furcifera populations. This paper provides useful data for understanding and speculating the migration of S. furcifera and reveals available information to develop sustainable strategies for manage this long-range migratory pest.