Bangabandhu Sheikh Mujibur Rahman Agricultural University

Plastic pollution, particularly microplastics (MPs) and nanoplastics (NPs), has emerged as a critical environmental challenge, with Asia serving as a global epicenter of plastic production and mismanaged waste. These particles act as carriers for hazardous chemical pollutants, including heavy metals, persistent organic pollutants, and emerging contaminants. This systematic review supports decision optimization by synthesizing current evidence on the role of plastics as vectors for chemical pollutants in marine environments across South Asia, Southeast Asia, and East Asia, while evaluating how region-specific environmental drivers, tropical temperatures (>25-30 degrees C), monsoonal salinity gradients (0 parts per thousand to 35 parts per thousand), and high UV radiation, modulate pollutant adsorption-desorption mechanisms. MP concentrations across Asia exhibit pronounced spatial variability, ranging from 0.05 to 7.32 particles g(-1) in biota, 9.97 to 21 items m(-3) in water, and 13.1 to 866.59 items kg(-1) in sediment. Asian marine systems function as high-flux reactors where monsoonal pulses accelerate plastic weathering, and MPs traversing salinity gradients may release approximately 10-30% of their adsorbed pollutant load upon entering marine waters. Critical knowledge gaps persist regarding nanoplastic-emerging pollutant interactions, deep-sea accumulation, transboundary transport dynamics, and the effectiveness of existing regulatory interventions. To enable optimized environmental decision-making, future priorities should include coordinated monitoring across major river-estuary systems and the development of integrated frameworks that combine data-driven risk assessment, policy optimization, and sustainability education tailored to Asian coastal communities, where seafood provides 50-80% of animal protein. This review establishes a scientific basis for decision optimization strategies aimed at mitigating chemical pollutant transport by plastics and strengthening evidence-based management of marine pollution in Asia.

Wheat blast caused by the fungus Magnaporthe oryzae Triticum (MoT) pathotype is a catastrophic disease that threatens global food security. Recently, Rmg8 was discovered as a blast resistance gene in wheat genotype S615. However, although Rmg8 has recently been cloned, the precise underlying biochemical and molecular mechanisms by which this gene confers resistance against MoT remain to be fully elucidated. This study investigated the antioxidant defense mechanisms in the wheat genotype S615, which carries the blast resistance gene Rmg8 against MoT infection, compared with the blast-susceptible wheat variety BARI Gom-26 (BG26). Artificial inoculation of wheat heads with MoT followed by biochemical analyses revealed that the levels of hydrogen peroxide (H2O2), lipoxygenases (LOXs), and malondialdehyde (MDA) in rachis tissues increased significantly until 48 h after inoculation in both S615 and BG26. However, LOX and MDA concentrations were substantially lower in S615 than in BG26. These biochemical alterations may have contributed to less damage to photosynthetic pigments, such as chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the rachis of S615. The S615 genotype exhibited significantly higher levels of several enzymatic (superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, glutathione reductase, dehydroascorbate reductase, and monodehydroascorbate reductase) and non-enzymatic (e.g., proline) antioxidants in the MoT-inoculated rachis tissues than in those of BG26. To the best of our knowledge, this study biochemically demonstrates for the first time that the blast resistance in S615 is, in part, correlated with its strong antioxidant defense responses to MoT infection, providing a physiological basis for this resistance mechanism.

Marine renewable energy (MRE), including offshore wind, tidal, wave, thermal, and biomass resources, can support decarbonization while advancing blue economy objectives, but its deployment requires coordinated ecological, technical, and social strategies. This study synthesizes the interdisciplinary nexus among marine science, blue economy, energy analytics, and sustainability education, and maps the research development using a PRISMA-guided bibliometric review of Scopus-indexed literature. Bibliometric indicators (publications, citations, and collaboration networks) were analysed in order to map research development trends. Findings indicate a rapid growth in MRE research with strong international collaborations, mainly led by offshore wind and tidal technologies, together with persistent concerns related to habitat disturbance, biodiversity impacts, and spatial conflicts. Energy analytics (forecasting, optimization, and grid integration) emerges as key enabler for managing variability and improving system reliability, while sustainability education supports the public understanding, social acceptance, and development of workforce capacity. Accelerating sustainable MRE adoption requires marine spatial planning, robust environmental safeguards, and data-driven grid and system management aligned with equitable governance of blue economy.

Wheat blast, caused by the hemibiotrophic fungus Magnaporthe oryzae Triticum (MoT), is a destructive disease that poses a severe threat to global wheat production. The 2NS chromosomal translocation, introgressed from Aegilops ventricosa into the Bangladeshi wheat variety BARI Gom 33 (BG33), was found to confer moderate-to-high resistance to MoT under field conditions. Despite the deployment of 2NS chromosomal segment for providing resistance to wheat blast, the underlying mechanisms remain largely unknown. This study aimed to elucidate the physiological and biochemical bases of resistance in BG33, specifically regarding its capacity to nullify infection-induced oxidative stress. Comparative analysis between the resistant variety (BG33) and a susceptible variety (BARI Gom 26, BG26) revealed that BG33 maintained significantly lower accumulation of reactive oxygen species (ROS), including hydrogen peroxide (H₂O₂), and exhibited reduced lipid peroxidation (malondialdehyde, MDA) and lipoxygenase (LOX) activity post-inoculation. BG33 also retained higher photosynthetic pigment integrity (chlorophyll and carotenoids), indicating superior protection against oxidative cellular damage. Most importantly, BG33 displayed enhanced antioxidant activity both constitutively and in response to MoT-induced oxidative stress. Basal levels of catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX), ascorbate peroxidase (APX), glutathione-S-transferase (GST), and proline were 1.3–2.5-fold higher in BG33 than in BG26. Upon MoT infection, BG33 further upregulated enzymatic antioxidants, including superoxide dismutase, CAT, APX, GPX, glutathione reductase, dehydroascorbate reductase, and monodehydroascorbate reductase and proline by 1.2–2.0-fold, establishing a robust state of redox homeostasis that was absent in BG26. These findings suggest that a multi-tiered antioxidant defense system mitigating the oxidative burst in the 2NS translocation, may in part be responsible for preserving cellular function and thus reduces fungal prolifearation. This study also provides evidence that the wheat genotype possessing enhanced constitutive or inducible antioxidant potentially through 2NS translocation can contribute to the resistance against wheat blast compared to ones lacking 2NS translocation. Future research should focus on identifying and cloning the key 2NS regulatory genes governing these antioxidant pathways.

Landslide susceptibility mapping is one of the most effective tools for sustainable development and management in hilly regions of countries, particularly in the Chittagong Hill Tracts (CHT) of Bangladesh. An innovative approach has been taken to create a landslide inventory, and a geospatial technique has been applied to map susceptible areas using the Information Value method. The research area has been classified into five categories ranging from very low to very high susceptibility by integrating information values. The analysis reveals that high and very high susceptibility classes in the study area are influenced by higher slopes, relatively high topography, concave curvature, proximity to roads and streams, sandy and loamy soils, and exposed Tipam Sandstone and Bokabil Formation. 31.9% and 34.9% of the Rangamati Sadar Upazila area are classified as high and very highly susceptible, while 7.2% are moderately susceptible. Among the seven unions, Balukhali Union is the most susceptible to landslide occurrence, followed by Kutuk Chhari and Sapchhari, where a large portion of the area falls under high and very high susceptibility classes. The results also show that landslide occurrence is strongly controlled by the interaction of topographic, geological, hydrological, and anthropogenic factors, including road construction and deforestation. Model validation using a confusion matrix demonstrates high predictive performance, with an overall accuracy of 93.5% and a Kappa coefficient of 0.87, confirming the reliability of the susceptibility map. Due to dense vegetation, low-quality google images, and satellite viewing angles, landslides are difficult to identify from imagery alone, making detailed field surveys the most reliable technique. These findings provide a scientifically stranded framework for risk-sensitive landuse planning and disaster risk reduction in the CHT region.