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The epidemic of stripe rust, caused by the pathogen Puccinia striiformis f. sp. tritici (Pst), would reduce wheat (Triticum aestivum) yields seriously. Traditional experimental methods are difficult to discover the interaction between wheat and Pst. Multi-omics data analysis provides a new idea for efficiently mining the interactions between host and pathogen. We used 140 wheat-Pst RNA-Seq data to screen for differentially expressed genes (DEGs) between low susceptibility and high susceptibility samples, and carried out Gene Ontology (GO) enrichment analysis. Based on this, we constructed a gene co-expression network, identified the core genes and interacted gene pairs from the conservative modules. Finally, we checked the distribution of Nucleotide-binding and leucine-rich repeat (NLR) genes in the co-expression network and drew the wheat NLR gene co-expression network. In order to provide accessible information for related researchers, we built a web-based visualization platform to display the data. Based on the analysis, we found that resistance-related genes such as TaPR1, TaWRKY18 and HSP70 were highly expressed in the network. They were likely to be involved in the biological processes of Pst infecting wheat. This study can assist scholars in conducting studies on the pathogenesis and help to advance the investigation of wheat-Pst interaction patterns. [ABSTRACT FROM AUTHOR]

Tobacco (Nicotiana tabacum L.) is an economic crop and a model organism for studies of plant biology and genetics. As an allotetraploid plant generated from interspecific hybridization, tobacco has a massive genome (4.5 Gb). Recently, a genetic map with 45,081 single nucleotide polymorphism (SNP) markers was constructed using whole-genome sequencing data for a tobacco population including 274 individuals. This provides a basis for quantitative trait locus (QTL) mapping and genomic selection, which have been widely applied to other crops but have not been feasible in tobacco. Based on this high-density genetic map, we identified QTLs associated with important agronomic traits, chemical compounds in dry leaves, and hazardous substances in processed cigarettes. The LOD values for major QTLs were highest for agronomic traits, followed by chemical compounds and hazardous substances. In addition to the identification of molecular markers, we evaluated genomic selection models and found that BayesB had the highest prediction accuracy for the recombinant inbred line population. Our results offer new insights into the genetic mechanism underlying important traits, such as agronomic traits and quality-related chemical compounds in tobacco, and will be able to support the application of molecular breeding to tobacco. [ABSTRACT FROM AUTHOR]

Despite recent advancements in waste management technologies, landfills remain the dominant approach for the final disposal of solid waste (SW) around the world. However, landfills are associated with adverse environmental and health-related impacts. This study is primarily applied to Dar es Salaam, a city in the East African region that has failed to follow appropriate approaches for site selection and that the methods used to select the current sites are manually operated. The study used a geographical information system (GIS) combined with multicriteria decision analysis (MCDA) to objectively determine the optimal landfill sites. A comprehensive list of assessment criteria was examined through a computerized site selection procedure based on GIS to analyze the ground that was surveyed and to remotely obtain data. Analytical hierarchy process (AHP)—one of the best MCDA approaches—was used to assign relative weight and evaluate each criterion. Finally, the study computed site suitability indices (SSIs), which aids in the identification of site suitability levels (SSLs) for the entire region. The final suitability map produced by overlaying the criteria map layers showed that a large part of the study area (60.92%) was completely unsuitable for landfill siting. The remaining areas consisted of land with varying suitability level, which were grouped into four classes: very low (30.92%), low (2.05%), moderate (5.65%), and high (0.46). To this end, only the high suitability class (0.46%) was of acceptable suitability levels (ASLs) (SSI ≥ 2.0). From the numerous identified sites with ASL, only three sites were suggested. Due to concerns regarding the lifespan and environment-related risks associated with these suggested sites, there is a need to further study new environmentally friendly techniques, considering the importance of circular economy agenda of waste to resource/energy for sustainable solid waste management. [ABSTRACT FROM AUTHOR]

As a major agricultural province in China, it is necessary to study the content of heavy metals in farmland soil and crop in Jilin Province and to evaluate the risks to ecology and human health. This study presented the work completed on 79 soil samples, 10 rice samples, 66 maize samples and 15 soybean samples collected from Jilin Province farmland and evaluated six heavy metals (Zn, Cu, Pb, Cd, Hg and As) concentrations. The results showed that the concentrations of the six heavy metals in farmland soil and crop samples from Jilin Province basically met the soil standards and food health standards of China. The agricultural soil pollution spatial distribution was the most serious in the south of Jilin Province and the lightest in the west. The non-carcinogenic risks faced by children eating crops were higher than those of adults, but the carcinogenic risks were lower than those of adults. Both of the two health risks to adults and children from eating crops were very limited. The results would help determine the heavy metals pollution in farmland soil in Jilin Province efficiently and accurately and helped decision makers to achieve a balance between production and environmental regulation. [ABSTRACT FROM AUTHOR]

Grassland fire disaster is one of the most destructive grassland disasters, which is sudden, destructive, and hard to handle. It caused a great threat to the humanity and property in pastoral. In this study, a dynamic risk assessment model was built based on the data of prairie fire statistics and related meteorological data from 1994 to 2005 in the six livestock counties of Hulunbuir grassland. Logistic regression model was used in the identification of the key factors influence grassland fire disaster risk. In the calculation of the weight of individual indicators, analytic hierarchy through scoring by experts was used. Grid GIS technology combined with regression analysis was used in the spatial distribution of indicators which has higher resolution than counties. Assessment factors of endogenous and exogenous sources of warning signs of grassland fires were analyzed through weighted comprehensive analysis. Fire disasters from 1994 to 2004 were taken as the sample cases to determine the threshold of risk level by using optimal partition method. Taking the grassland fires in 2005 as examples to validate the dynamic risk assessment model, results shown high risk areas coincide well with the distribution of fire points, this proved the accuracy of the model. The dynamic risk assessment results could be used to guide and manage the mitigation of grassland fire disaster and rescue goods distribution. [ABSTRACT FROM AUTHOR]

Tobacco ( Nicotiana tabacum) is one of the most economically important nonfood crops, and flue-cured tobacco accounts for approximately 80% of world tobacco production. An extremely narrow genetic diversity in the tobacco pool has led to a low efficiency of PCR-based molecular markers (such as AFLP and SSR). Diversity Arrays Technology (DArT) is a high-throughput hybridisation-based marker system that has been developed in many plants including wheat, which, like tobacco, has a complex genome. In this study, we developed a tobacco DArT chip that included 7680 representative sequence tags based on typical tobacco accessions. The 1076 DArT markers of flue-cured tobacco were identified and most (82.1%) of their polymorphism information contents (PICs) were greater than 0.4. An integrated linkage map that included 851 markers (238 DArT and 613 SSR), which is the highest density map of flue-cured tobacco to date, was constructed. This chip-based DArT system provides an alternative in high-throughput marker genotyping for tobacco. [ABSTRACT FROM AUTHOR]

The traditional studies on drought disaster risk were based on the ground point data, which were unable to realize the continuity of space and the timeliness. It is shown that the monitoring and evaluation precision on drought were reduced significantly. However, remote sensing data in adequate spatial and temporal resolution can overcome these limitations. It can better monitor the crop in large area dynamically. This study presents a methodology for dynamic risk analysis and assessment of drought disaster to maize production in the northwest of Liaoning Province based on remote sensing data and GIS from the viewpoints of climatology, geography and disaster science. The model of dynamic risk assessment of drought disaster was established based on risk formation theory of natural disaster, and the expression of risk by integrating data came from sky, ground and space. The risk indexes were divided into four classes by data mining method, and the grade maps of drought disaster risk were drawn by GIS. It is shown that the spatial and temporal risk distributions of maize at each growth stage changed over time. The model has been verified against reduction in maize yield caused by drought. It demonstrated the reasonability, feasibility and reliability of the model and the methodology. The dynamic risk assessment of regional drought disaster for maize can be used as a tool, which can timely monitor the status (the possibility and extent of drought) and trends of regional drought disaster. The results obtained in this study can provide the latest information of regional drought disaster and the decision-making basis of disaster prevention and mitigation for government management and farmers. [ABSTRACT FROM AUTHOR]

Med8, a subunit of mediator complex, has proved to possess crucial functions in many organisms from yeast to human. In plant, the med8 mutant of Arabidopsis thaliana displayed delayed anthesis and increased number of leaves during the vegetative period. However, the roles of Med8 in other flowering plants are still unknown. To investigate the function of Med8 ortholog in tobacco ( Nicotiana tabacum L.; named as Nt Med8), we created transgenic tobacco plants with repressed Nt Med8 expression mediated by RNA interference (RNAi). Compared with the wild type, the Nt Med8-RNAi plants exhibited: more leaves with smaller but thicker blades; larger cells and vascular bundles with lower stomata density in leaves; swelled chloroplasts with thicker and lumen-enlarged thylakoids; weaker root system with fewer lateral roots; larger flowers and floral organs; flowering earlier under long day, but later under short day conditions; and male sterile with larger but less germinable pollens. In addition, quantitative RT-PCR indicated that Nt Med8 is expressed in both vegetative and floral tissues. Subcellular localization analysis by transient expression of fusion protein in Nicotiana benthamiana leaves showed that NtMed8 was located in both plasma membrane and nucleus. These results suggest that Nt Med8 plays important roles in both vegetative and reproductive development, and the function of Med8 appears to be, at least partially, conserved in flowering plants. [ABSTRACT FROM AUTHOR]

The seedlings of indica rice cultivar Dular are susceptible to chlorosis under low temperature conditions. Our previous studies indicated that low temperature-induced seedling chlorosis is controlled by a recessive gene, located between SSR markers RM257 and RM242, on the long arm of chromosome 9. We temporarily named the gene cisc(t). Using a large F2 population derived from a cross between Dular and the japonica cultivar Lemont, which displays a normal green color at low temperatures, cisc(t) was fine mapped to within a 12-kb interval. There is only one annotated gene in this interval, which encodes a pentatricopeptide repeat (PPR) protein. Sequence analysis indicated that 8 bases were deleted at the 60th base in the Dular allele, resulting in a frame-shift mutation and loss of function of the gene. This is consistent with the chlorosis mutant phenotype of Dular. In addition, previous studies have shown that many chlorosis mutants of seedlings are related to PPR proteins. Hence, we presume that the PPR gene is the candidate for cisc(t). [ABSTRACT FROM AUTHOR]