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Pine wilt disease has caused great economic loss and become an ecological threat since it was introduced into East Asia. In China, Pinus massoniana Lamb. is highly susceptible. The pathogenic of this disease is linked to the invasion of P. massoniana by the pine wood nematode (PWN, Bursaphelenchus xylophilus), leading to various physiological activities. However, the migration pathway of PWN and the defense mechanisms of P. massoniana tissue structure following invasion remain unclear. This knowledge is vital for understanding the pathogenesis of pine wood nematode disease. To address this issue, we analyzed the tissue structure damage, horizontal and vertical migration pathways, and histochemical reactions of P. massoniana after PWN inoculation. The results are as follows: susceptible P. massoniana exhibited more tissue structure damage compared to highly resistant P. massoniana. PWN reproduced and migrated by feeding on and damaging cells. In susceptible P. massoniana, PWN propagated and migrated throughout the entire plant. Highly resistant P. massoniana displayed limited horizontal and vertical migration of PWN, making it challenging for PWNs to move from cambium to xylem. After P. massoniana was damaged by PWNs, a protein cross-linking phenomenon appeared rapidly, with highly resistant P. massoniana exhibiting less protein cross-linking than the susceptible variety. Lignin synthesis is a crucial factor in the tissue defense of P. massoniana. Protein crosslinking provides time for lignin synthesis and is an vital component of tissue defense. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Seeing that Shanghai implemented mandatory household waste sorting system (referred as Shanghai Model) in 2019 and achieved remarkable improvements, the study focuses on how to localize it in second-tier cities. Specifically, by applying system dynamics method, a qualitative Basic Model and a quantitative Shanghai Model simulating residents' waste related behavior are built. Combined Theory of Planned Behavior and the Split-Core Model are adopted. Data of Zhengzhou is inputted and simulated to representatively deliver policy implications to second-tier cities. The result shows that improving transactional context can lift the weight of willingness and depress the weight of opportunism in behavior decision makings. Shanghai Model significantly improves the legal transaction context of waste sorting which make residents actively sort the wastes under the promotion of willingness. For second-tier cities of China, improving transactional context to reduce opportunism and conquering the short board of willingness to promote active participation are indispensable. And, waste reducing measures like the unit pricing system are recommended to make up the shortage of the Shanghai Model. The study puts forward a synthetic analyzing framework of waste related behaviors and builds a portable policy analyzing system of waste management for both China and other developing countries. • Basic model combing Theory of Planned Behavior and Split-Core Model is built. • Waste generation, reducing, recycling, and sorting system dynamics model is built. • Shanghai Model can improve household waste sorting and recycling. • Zhengzhou is recommended to improve facility level before adopting Shanghai Model. • The study provides a policy making tool for household waste management. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are widely detected in wetlands as emerging pollutants of global concern. Co-occurrence of MPs and trace metals in wetlands is common and the vector effects of MPs on other environmental pollutants have been increasingly reported. However, the interaction of different MPs and trace metals under environmentally realistic conditions is not well understood. Here, we investigated the adsorption capacity of MPs for metals under simulated conditions of Poyang Lake wetlands in Jiang Xi, China, a Ramsar site of international importance for conservation and sustainable use. ICP-MS was used to quantify the amount of adsorbed metals onto different types of MPs. SEM-EDS and micro-FTIR were used to examine the morphological and chemical characteristics of MPs before and after metal adsorption. The influence of internal (polymer types and particle sizes of MPs) and external factors (water pH values, organic matters, ion strength, and sediment) on metal adsorption was systematically investigated. Metal adsorption equilibrium was most achieved at 72 h. The adsorption capacity of MP types to metal ions tended to decrease as PP > PE > PS, and the amount of adsorbed metals decreased as Cu > Pb > Cd. The amount of adsorbed metals generally decreased with the increase of particle size of MPs. With the increase of water pH and K+ strength, the adsorption of metals by MPs showed an increasing and then decreasing trend; the adsorption capacity of MPs increased with the increase of fulvic acid. Under the simulated sedimentary conditions, the adsorption of different metals by MPs also tended to be Cu > Pb > Cd, which was mainly determined by metal concentrations in the sediments collected in situ. The results of this study improve our understanding of metal-MP interaction under simulated environmental conditions, shedding new light on the environmental behavior of MPs and metals in wetlands. [Display omitted] • Metal adsorption by MPs is studied under simulated Poyang Lake wetland conditions. • Particle size and polymer type of MPs significantly affect metal adsorption. • PP MPs show higher adsorption capacity for metals than PE and PS MPs. • Water pH, ionic strength, organic matter, and sediment influence metal adsorption. • The knowledge of metal-MPs interaction in natural wetlands is still limited. [ABSTRACT FROM AUTHOR]