Farmyard manure, a potential organic additive to reclaim copper and Macrophomina phaseolina stress responses in mash bean plants

Chitosan-mediated copper nanohybrid attenuates the virulence of a necrotrophic fungal pathogen Macrophomina phaseolina

This study reported the synthesis and characterization of chitosan-copper nanoparticles (Ch-CuNPs) using a 1% copper sulfate solution in 0.2% w/v chitosan. The Ch-CuNPs, displaying a stable brick-red hue, showed an absorption peak at 572 nm, indicative of monodisperse nanoparticle formation and surface plasmon resonance. X-ray diffraction confirmed the face-centered cubic structure with peaks at 36.78°, 43.38°, 50.56°, and 74.26°, and an average particle size of 87-89 nm. FTIR analysis showed interactions between chitosan and copper, particularly around 3370 -3226 cm⁻¹, 1633 cm⁻¹, and 680 cm⁻¹. In vitro assays revealed that Ch-CuNPs inhibited Macrophomina phaseolina growth by 18-71% at 0.03-0.09% concentrations, achieving complete inhibition at 0.12-0.15%, with PCA analysis confirming that growth peaked at lower concentrations and sharply declined at higher levels. Ch-CuNPs also altered fungal morphology and enzyme activity, with notable degradation at higher concentrations. The Cu uptake by the fungus peaked at 29.9% with 0.03% Ch-CuNPs and decreased at higher concentrations. FTIR analysis showed shifts and disappearance of peaks in fungal biomass treated with Ch-CuNPs, indicating molecular interactions and potential structural changes. This study underscores the potential of Ch-CuNPs as an effective antifungal agent and elucidates their interaction mechanisms.

Research Progress on Plant Responses to Stress Combinations in the Context of Climate Change

In the context of climate change, the frequency and intensity of extreme weather events are increasing, environmental pollution and global warming are exacerbated by anthropogenic activities, and plants will experience a more complex and variable environment of stress combinations. Research on plant responses to stress combinations is crucial for the development and utilization of climate-adaptive plants. Recently, the concept of stress combinations has been expanded from simple to multifactorial stress combinations (MFSCs). Researchers have realized the complexity and necessity of stress combination research and have extensively employed composite gradient methods, multi-omics techniques, and interdisciplinary approaches to integrate laboratory and field experiments. Researchers have studied the response mechanisms of plant reactive oxygen species (ROS), phytohormones, transcription factors (TFs), and other response mechanisms under stress combinations and reached some generalized conclusions. In this article, we focus on the research progress and methodological dynamics of plant responses to stress combinations and propose key scientific questions that are crucial to address, in the context of plant responses to stress assemblages, conserving biodiversity, and ensuring food security. We can enhance the search for universal pathways, identify targets for stress combinations, explore adaptive genetic responses, and leverage high-technology research. This is in pursuit of cultivating plants with greater tolerance to stress combinations and enabling their adaptation to and mitigation of the impacts of climate change.