2,426 research outputs found

    The histone binding capacity of SPT2 controls chromatin structure and function in Metazoa

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    Histone chaperones control nucleosome density and chromatin structure. In yeast, the H3-H4 chaperone Spt2 controls histone deposition at active genes but its roles in metazoan chromatin structure and organismal physiology are not known. Here we identify the Caenorhabditis elegans ortholog of SPT2 (CeSPT-2) and show that its ability to bind histones H3-H4 is important for germline development and transgenerational epigenetic gene silencing, and that spt-2 null mutants display signatures of a global stress response. Genome-wide profiling showed that CeSPT-2 binds to a range of highly expressed genes, and we find that spt-2 mutants have increased chromatin accessibility at a subset of these loci. We also show that SPT2 influences chromatin structure and controls the levels of soluble and chromatin-bound H3.3 in human cells. Our work reveals roles for SPT2 in controlling chromatin structure and function in Metazoa.</p

    A Pinus strobus transcription factor PsbHLH1 activates the production of pinosylvin stilbenoids in transgenic Pinus koraiensis calli and tobacco leaves

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    Transcription factors (TFs) play an important role in regulating the biosynthesis of secondary metabolites. In Pinus strobus, the level of methylated derivatives of pinosylvin is significantly increased upon pine wood nematode (PWN) infection, and these compounds are highly toxic to PWNs. In a previous study, we found that the expression of a basic helix-loop-helix TF gene, PsbHLH1, strongly increased in P. strobus plants after infection with PWNs. In this study, we elucidated the regulatory role of the PsbHLH1 gene in the production of methylated derivatives of pinosylvin such as pinosylvin monomethyl ether (PME) and dihydropinoylvin monomethyl ether (DPME). When PsbHLH1 was overexpressed in Pinus koraiensis calli, the production of PME and DPME was significantly increased. Overexpression of the stilbene synthase (PsSTS) and pinosylvin methyl transferase (PsPMT) genes, known as key enzymes for the biosynthesis of methylated pinosylvins, did not change PME or DPME production. Moreover, PME and DPME were not produced in tobacco leaves when the PsSTS and PsPMT genes were transiently coexpressed. However, the transient expression of three genes, PsSTS, PsPMT, and PsbHLH1, resulted in the production of PME and DPME in tobacco leaves. These results prove that PsbHLH1 is an important TF for the pinosylvin stilbene biosynthesis in pine plants and plays a regulatory role in the engineered production of PME and DPME in tobacco plants

    Inocellia (Amurinocellia) calida (Raphidioptera, Inocelliidae) was first observed as a predator of Monochamus saltuarius (Coleoptera, Cerambycidae) in China, the vector of Bursaphelenchus xylophilus (Aphelenchida, Aphelenchoididae)

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    Monochamus saltuarius Gebler (Coleoptera, Cerambycidae) serves as the primary carrier of Bursaphelenchus xylophilus (Steiner &amp;amp; Buhrer) (Aphelenchida, Aphelenchoididae) in the middle-temperate zone of China. Pine wilt disease caused by B. xylophilus leads to serious losses to pine forestry around the world. It is necessary to study the biological control of M. saltuarius to effectively prevent the further spread of B. xylophilus. To explore the insect resources that act as natural enemies of M. saltuarius, investigations were conducted on natural enemy insects by splitting Pinus koraiensis Siebold &amp;amp; Zucc (Pinales, Pinaceae) damaged by M. saltuarius and dissecting their trunks in Yingpan Village, Fushun County, Fushun City, Liaoning Province, China, in 2023. A larva of Inocellia (Amurinocellia) calida (H. Aspöck &amp;amp; U. Aspöck) (Raphidioptera, Inocelliidae) was discovered in the trunk of an infested P. koraiensis. Additionally, the feeding habits of I. calida were preliminarily examined under indoor conditions and a description of its morphological characteristics was provided. When placed in an indoor environment, the I. calida larva began pupating after a period of 21 days, during which time it consumed and attacked a total of 23 M. saltuarius larvae. Ultimately, after a pupal period of ten days, the I. calida larva emerged successfully as an adult. This discovery marks the first recorded presence of I. calida in Liaoning Province and the first documentation of I. calida in China, serving as a natural predatory enemy of M. saltuarius

    Perspective Chapter: Microorganisms and Their Relationship with Tree Health

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    The health of plants depends on numerous environmental factors. All plants, including trees, live in close relationship with microorganisms. Plants harbor microbial communities in above- and below-ground tissues, where plant-associated microbial communities are influenced by environmental conditions and host genotype. The microbiome of trees is composed of mutualistic, commensal, and pathogenic microorganisms. Mutualistic microorganisms can help trees obtain nutrients (e.g., phosphorus and nitrogen) and defend against plant pathogens. Ecological interactions between different microbial groups directly influence host health, and endophytic microorganisms can inhibit pathogen growth or induce the expression of genes related to tree defense against these adverse organisms. Hence, understanding host-microbiome-environment interactions are crucial for modulating tree health

    Using Machine Learning in Forestry

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    Advanced technology has increased demands and needs for innovative approaches to apply traditional methods more economically, effectively, fast and easily in forestry, as in other disciplines. Especially recently emerging terms such as forestry informatics, precision forestry, smart forestry, Forestry 4.0, climate-intelligent forestry, digital forestry and forestry big data have started to take place on the agenda of the forestry discipline. As a result, significant increases are observed in the number of academic studies in which modern approaches such as machine learning and recently emerged automatic machine learning (AutoML) are integrated into decision-making processes in forestry. This study aims to increase further the comprehensibility of machine learning algorithms in the Turkish language, to make them widespread, and be considered a resource for researchers interested in their use in forestry. Thus, it was aimed to bring a review article to the national literature that reveals both how machine learning has been used in various forestry activities from the past to the present and its potential for use in the future

    Exploring Common Hyperspectral Features of Early-Stage Pine Wilt Disease at Different Scales, for Different Pine Species, and at Different Regions

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    Pine wilt disease (PWD) is a devastating forest disease and has been listed as a quarantine pest in 52 countries around the world. Early identification of the affected trees and timely removal of them from the forest is crucial to control the spread. This study aims to explore the potential of hyperspectral data on early identification of PWD and exhibit the common spectral features, from early-infected tree crowns and needles, and from different species located in different regions. Two types of hyperspectral data were used and compared. One was using drone-based hyperspectral images with a spectral range of 400 – 1 000 nm and a resolution of 0.11 m. The images were analyzed at the individual-tree level. The other was using hyperspectral reflectance from sampled needles with a spectral range of 350 – 2 500 nm. It was used for the analysis at the needle level. We used linear discriminant analysis (LDA) to quantify the separability of spectral reflectance and first-derivative reflectance from the healthy and early-infected samples. The results showed that the red-edge bands were more sensitive than the other bands at both individual-tree and needle levels, and the first-derivative of red-edge bands achieved the best early recognition of the disease with 0.78, 0.72, and 0.85 accuracy at the individual-tree level for Chinese red pine and at the needle level for Japanese pine and Korean pine. We concluded that red-edge bands were the most informative bands with stable sensitivity at different scales and for different species

    Comparative effects of two in situ hybridization methods for the pinewood nematode (Bursaphelenchus xylophilus)

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    The gene localization technique of Bursaphelenchus xylophilus (pinewood nematode, PWN) is used for study gene expression in PWNs. Two in situ hybridization methods, namely, whole-mount in situ hybridization and the cut-off method are used widely. To compare the effects of these two in situ hybridization methods, the present study investigated the patterns of two functional genes expression in PWNs. The Bx-vap-2 gene (GenBank accession number: OR228482), related to pathogenicity, and the fem-2 gene (GenBank accession number: OR228481), related to sex determination, were selected to map related genes in the whole-mount and amputated PWNs at different ages using these in situ hybridization methods. Based on the overall statistical comparison, we found that compared to the cut-off method, the whole-mount method exhibited higher staining rates and correct staining rates for the fem-2 gene and Bx-vap-2 gene. However, considering the correct staining aspect, the cut-off method yielded better staining effects on pinewood nematode sections than the whole-mount method, with clearer hybridization signal locations and less non-specific staining. In other words, the cut-off method demonstrated more precise gene localization. Both methods are applicable for gene localization, but considering the overall staining pattern, analysis of experimental results, and comprehensive experimental operations, we believe that the whole-mount method is more suitable for gene localization and expression analysis of development-related genes in pinewood nematodes. This is because intact pinewood nematodes are better suited for showcasing the continuous developmental process of development-related genes. On the other hand, considering the experimental time, accuracy of staining site, and the amount of non-specific staining, the cut-off method is more suitable for disease-related genes. Additionally, to achieve better performance, the cut-off method can be selectively applied to samples during the experimental process

    Investigation of molecular and cellular aspects of cotton black root rot disease and the potential for biological control

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    The worldwide demand for high quality cotton has increased with time, and cotton production is now one of the most important rural industries in Australia. However, cotton growers face significant challenges in dealing with diseases that impact on crop yields. One of the most important diseases impacting cotton producers in Australia is black root rot disease, caused by the pathogenic fungi Berkeleyomyces spp. While a number of management practices have been suggested to help control this pathogen, there is not currently a complete solution to this problem. The main aims of this study were to gain a better understanding of the factors that affect disease severity, and explore the use of the bacterium Azospirillum brasilense as a biological control option for black root rot disease in cotton. The distribution and abundance of Berkeleyomyces spp. in different soil samples from cotton farms (collected prior to planting) was investigated using quantitative polymerase chain reaction (qPCR). The incidence of the pathogen was higher in organically fertilised cotton fields compared to fields treated with mineral fertiliser. The relationship between crop rotation and pathogen abundance was also examined. Crop rotation with wheat and mung bean did not show any decrease in the soil load of Berkeleyomyces spp. However, soil properties, including iron and manganese levels, appeared to impact on the abundance of Berkeleyomyces spp. in soils. The relationship between cotton cultivar, temperature and disease severity was also investigated, using Berkeleyomyces rouxiae BRIP40192 (a cotton isolate) and five cotton cultivars (Sicot 730, and the genetically modified cultivars Sicot 74BRF, Sicot 71BRF, Sicot 43BRF and Sicot 714B3F). Temperature had an influence on the proportion of root affected by black root rot lesions, and the water content of shoots, supporting the findings of previous studies that indicate temperature is a significant factor impacting disease severity and, consequently, plant growth. At higher temperatures (25°C) soil collected from the rhizosphere for all genetic modified cultivars (Sicot 74BRF, Sicot 71BRF, Sicot 43BRF and Sicot 714B3F) showed a significant decrease in the levels of B. rouxiae BRIP40192 recovered, compared to recovery at lower temperature (20°C). To better understand the processes involved in disease, in vitro pathogenicity testing was carried out to examine the ability of B. rouxiae BRIP40192 to perceive and respond to signalling molecules produced by the roots of cotton seedlings. The results demonstrated that cotton root exudates stimulate the directional growth of B. rouxiae, although the strength of this attraction varied between cotton cultivars. The inclusion of the bacterium Azospirillum brasilense in the test was able to prevent this directional growth and stop spore germination. This finding suggests that there may be a role for A. brasilense as a potential biological control agent for B. rouxiae. Interaction tests between B. rouxiae BRIP40192 and A. brasilense strains showed that that the two were not antagonistic to each other, although A. brasilense strains showed a high capability to interact with B. rouxiae BRIP40192 hyphae. The interaction between B. rouxiae BRIP40192, A. brasilense and cotton was investigated, focusing on the role played by border cells of the cotton root. Cotton border cells of all cultivars tested failed to trap B. rouxiae BRIP40192, however, A. brasilense strains, proposed as a potential biocontrol organisms, showed a high level of interaction with border cells of the five cotton cultivars and with border cells from wheat (often used in crop rotation on cotton farms). The colonisation of border cells by A. brasilense may assist with the suppression of germination of B. rouxiae BRIP40192 spores and retard directional growth in the rhizosphere, thus protecting seedlings from infection. The results of this study help improve understanding of factors, such as temperature, cotton cultivar and farm management practices, which influence the distribution and severity of black root rot disease in Australian cotton farms. The results of this study also suggest that A. brasilense could be considered as a potential biological control agent to block or suppress the growth of black root rot disease in cotton fields

    Comprehensive Analysis and Functional Verification of the Pinus massoniana NBS-LRR Gene Family Involved in the Resistance to Bursaphelenchus xylophilus

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    Pinus massoniana Lamb. is a crucial timber and resin conifer in China, but its plantation industry is threatened by outbreaks of pine wilt disease (PWD) caused by Bursaphelenchus xylophilus (pinewood nematode; PWN). However, as of yet, there is no comprehensive analysis of NBS-LRR genes in P. massoniana involved in its defense against PWN. In this study, 507 NBS genes were identified in the transcriptome of resistant and susceptible P. masoniana inoculated with the PWN. The phylogenetic analysis and expression profiles of resistant and susceptible P. massoniana revealed that the up-regulated PmNBS-LRR97 gene was involved in conferring resistance to PWN. The results of real-time quantitative PCR (qRT-PCR) showed that PmNBS-LRR97 was significantly up-regulated after PWN infection, especially in the stems. Subcellular localization indicated that PmNBS-LRR97 located to the cell membrane. PmNBS-LRR97 significantly activated the expression of reactive oxygen species (ROS)-related genes in P. massoniana. In addition, the overexpression of PmNBS-LRR97 was capable of promoting the production of ROS, aiding in plant growth and development. In summary, PmNBS-LRR97 participates in the defense response to PWN and plays an active role in conferring resistance in P. massoniana. This finding provides new insight into the regulatory mechanism of the R gene in P. massoniana
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