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.
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.
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.
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.