Project description:to profile the adverse effects of an emamectin benzoate trunk-injection agent on pine wood nematode Bursaphelenchus xylophilus by analysing differential transcripts from the nematode whole genome through next-generation high-throughput sequencing.
Project description:Bursaphelenchus xylophilus is known as the causative agent of pine wilt disease with complex life cycles. In this research, newly published Bursaphelenchus xylophilus genome data were employed to annotate its miRNAs based on deep sequencing technologies. Four small RNA libraries derived from different infection stages of pine wilt disease were constructed and sequenced. Consequently, we obtained hundreds of evolutionarily conserved miRNAs as well as novel miRNA candidates. The analysis of miRNA expression patterns showed that most miRNAs were expressed at extraordinarily high levels during the middle stage of pine wilt disease. Subsequent stem-loop RT-PCR experiments were carried out to validate our results. Functional analysis proved that expression levels of miR-73 and miR-239 were mutually exclusive with their target GH45 cellulase genes., genes known to be responsible for the degradation of the pine cell walls. In addition, another set of atypical miRNAs, termed mirtrons, were identified from B. xylophilus introns. This discovery has expanded the current knowledgebase of such splicing-derived miRNAs into B. xylophilus. Thus, our research has provided detailed characterization of B. xylophilus miRNAs expression patterns during the pathological process of pine wilt disease. The findings will contribute to more in-depth understanding of this devastating plant disease.
Project description:Bursaphelenchus xylophilus is known as the causative agent of pine wilt disease with complex life cycles. In this research, newly published Bursaphelenchus xylophilus genome data were employed to annotate its miRNAs based on deep sequencing technologies. Four small RNA libraries derived from different infection stages of pine wilt disease were constructed and sequenced. Consequently, we obtained hundreds of evolutionarily conserved miRNAs as well as novel miRNA candidates. The analysis of miRNA expression patterns showed that most miRNAs were expressed at extraordinarily high levels during the middle stage of pine wilt disease. Subsequent stem-loop RT-PCR experiments were carried out to validate our results. Functional analysis proved that expression levels of miR-73 and miR-239 were mutually exclusive with their target GH45 cellulase genes., genes known to be responsible for the degradation of the pine cell walls. In addition, another set of atypical miRNAs, termed mirtrons, were identified from B. xylophilus introns. This discovery has expanded the current knowledgebase of such splicing-derived miRNAs into B. xylophilus. Thus, our research has provided detailed characterization of B. xylophilus miRNAs expression patterns during the pathological process of pine wilt disease. The findings will contribute to more in-depth understanding of this devastating plant disease. For the purposes of this study, we classified the pathogenic process associated with PWD into three stages in order to best characterize the expression patterns of microRNAs during the development of this devastating disease. The following describes the first stage (F): about seven days after pine trees are infected with PWNs, the tips of the pine needles begin to turn brown. Next, the middle stage (M) ensues approximately seven days later, when half of the needles on pine trees turn brown. The last stage (L) occurs another 10 days later and pine needles are complete browning. PWNs cultured on Botrytis cinerea grown on PDA medium served as the control stage (C).
Project description:Pine wilt disease is a worldwide dangerous pine disease. We used Masson pine (Pinus massoniana) clones, selected through traditional breeding and testing for 20 years, with high resistance to study the molecular mechanism of resistance to pine wood nematode (PWN, Bursaphelenchus xylophilus). A total of 3491 proteins were identified from seedling tissue, among which 2783 proteins contained quantitative information. Total 42 proteins were up-regulated and 96 proteins were down-regulated in resistant lines. Of them, function enrichment analysis found that significant differences in proteins with pectin esterase activity or peroxidase activity. Proteins participating in salicylic acid metabolism, antioxidant stress reaction, polysaccharide degradation, glucose acid ester sheath lipid biosynthesis, sugar glycosaminoglycans degradation pathway also changed significantly. PRM results showed that pectin acetyl esterase, carbonic anhydrase, peroxidase and chitinase were significantly down-regulated, while aspartic protease was significantly up-regulated, which was consistent with proteomic data.These results suggested that Masson pine could degrade nematode-related proteins by increasing protease to inhibit their infestation, and enhance the resistance of Masson pine to PWN by down-regulating the carbon metabolism to limit available carbon to PWN or to be involved in cell wall components or tissue softening. Most downregulated proteins seem to take back seats prior to pathogen attacks. The highly resistant Masson pine, very likely, has evolved multiple pathways, both the passive and active, to defense against PWN infestation.
Project description:Primary objectives: The primary objective is to investigate circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Primary endpoints: circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Project description:Bursaphelenchus xylophilus (pinewood nematode, PWN) is a causal agent of pine wilt disease and results in economic and environmental losses in pine forests. The establishment of systemic acquired resistance (SAR) provides positive capacities to control PWN. We selected two SAR elicitors, acibenzolar-S-methyl (ASM) and methyl salicylic acid (MeSA), which effectively inhibited disease symptoms on PWN-infected pine trees. To understand dynamic interactions between pine host and PWN under SAR state, we characterized in vivo transcriptomes of pine trees infected by B. xylophilus according to the ASM and MeSA treatment. After distilled water treatment, pine trees infected by B. xylophilus was used as a negative control.