To address the issue of poor phytoremediation in Cd-contaminated saline soil caused by the biotoxicity of Cdsalinity, we constructed a symbiotic system of arbuscular mycorrhizal fungi (AMF) and the hyperaccumulator Solanum nigrum, and systematically elucidated the response strategies of Solanum nigrum and the enhancement mechanism of AMF for plant tolerance through cytological, physiological, and transcriptomic methods. The findings showed that Cd-salinity stress had synergistic aggravated Cd/Na enrichment, ultrastructural damage, photosynthetic inhibition, water loss, and reactive oxygen species (ROS) accumulation in plants. In response to the heterogeneity of Cd/salinity stress, AMF smartly regulated the Cd/salinity tolerance of host plants: AMF decreased intercellular CO2 concentration (Ci) under Cd stress to alleviate non-stomatal limitation induced by Cd, but increased Ci under salinity stress to alleviate the stomatal limitation induced by salinity; the role of AMF in strengthening the osmoregulation system was more prominent under salinity stress, thereby alleviated the more severe osmotic imbalance induced by salinity. AMF also enhanced signal transduction to consolidate resistance defense, upregulated antioxidant genes to activate antioxidant enzymes, and strengthened the AsAGSH cycle to mitigate oxidative damage. The enhancement of tolerance improved plant growth and Cd enrichment. Under high Cd-high salinity combined stress, Cd concentrations in shoots and roots increased by 14.28 % and 38.85 %, respectively, and the biomass also increased by over 30.00 % after AMF inoculation. In summary, inoculation with AMF serves as an effective and sustainable phytoremediation enhancement strategy that improves the host plants' stress resistance through multiple pathways, thereby increasing the phytoremediation potential.

Environmental stresses, particularly drought and salinity, significantly impair plant growth and productivity. This study explores the novel synergistic interaction between biochar and arbuscular mycorrhizal fungi (AMF) in enhancing the resilience of sweet pepper plants subjected to the individual or combined stresses of drought and salinity. The impact of these biostimulants on growth parameters, photosynthetic efficiency, and biochemical traits was assessed. Sweet pepper plants were subjected to drought stress (35 and 75% of field capacity (FC)), salinity (0 and 150 mM NaCl), and their combined effects (150 mM NaCl +35% of FC), with treatments including biochar (2.5 g/kg soil), AMF, and their combination. Under drought stress, the dual application of biochar and AMF notably improved plant growth indicators such as shoot fresh weight, shoot height, and number of leaves by 50, 14, and 3%, respectively compared to the control plants. Under drought and salinity combined, this combination also enhanced photosynthetic pigments content by 144% for Chl a, 316% for Chl b, 212% for Chl T and 302% for carotenoids content respectively compared to the control plants. Additionally, AMF and Biochar combined reduced the oxidative effect of malondialdehyde (MDA) by 37% and hydrogen peroxide (H2O2) by 43%, indicating a reduction in oxidative damage. Furthermore, a significant increase in antioxidant enzyme activities was observed, with peroxidase activity (POX) rising by 33% and polyphenol oxidase activity (PPO) increasing by 212%, indicating enhanced stress tolerance. This study underscores the efficacy of using biochar and AMF together to bolster sweet pepper plant resilience, offering a viable strategy for improving plant performance under challenging environmental conditions.

To comprehensively understand the toxic effects and ecological risks of microplastics on major economic tree species, a pot experiment was conducted using polylactic acid (mPLA) microplastics as the test object to explore the effects of different concentrations (0.1%, 0.5%, 1%, 5%, 10%, w/w, mass fraction) of microplastics on the growth and physiological characteristics of mulberry trees. The study results showed that, compared with the control group, the biomass, total chlorophyll content, and net photosynthetic rate of mulberry trees in the mPLA treatment group were significantly reduced under high concentration (10%) treatment; the activities of SOD and CAT and the MDA content were significantly increased by 50.00%, 47.83%, and 60.87%, respectively, at a 10% concentration. The results indicate that the toxic effects of microplastic addition on mulberry trees are related to the type and concentration of microplastics. High concentrations of mPLA can damage the photosynthetic system of plants, affecting photosynthesis, causing oxidative damage and thus inhibiting the growth of mulberry plants.

Climate change not only leads to high temperatures, droughts, floods, storms and declining soil quality, but it also affects the spread and mutation of pests and diseases, which directly influences plant growth and constitutes a new challenge to food security. Numerous hormones like auxin, ethylene and melatonin, regulate plant growth and development as well as their resistance to environmental stresses. To mitigate the impact of diverse biotic and abiotic stressors on crops, single or multiple phytohormones in combination have been applied. Melatonin is a multifunctional signaling molecule engaged in the development and stress response of plants. In the current review, we discuss the synthesis and action of melatonin, as well as its utilization for plant resistance to different stresses from the perspective of practical application. Simultaneously, we elucidate the regulatory effects and complex mechanisms of melatonin and other plant hormones on the growth of plants, explore the practical applications of melatonin in combination with other phytohormones in crops. This will aid in the planning of management strategies to protect plants from damage caused by environmental stress.

In this study, the phytoremediation efficiency of Arabidopsis halleri L. in response to mechanical injury were compared between those irrigated with magnetized water and those irrigated with normal water. Under normal irrigation treatment, wounding stress increased malondialdehyde (MDA) concentrations and hydrogen peroxide (H2O2) levels in A. halleri leaves significantly, by 46.7-86.1% and 39.4-77.4%, respectively, relative to those in the intact tissues. In addition, wounding stresses decreased the content of Cd in leaves by 26.8-52.2%, relative to the control, indicating that oxidative damage in plant tissues was induced by mechanical injury, rather than Cd accumulation. There were no significant differences in MDA and H2O2 between A. halleri irrigated with magnetized water and with normal water under wounding conditions; however, the activities of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) in the leaves of plants treated with magnetized water were significantly increased by 25.1-56.7%, 47.3-183.6%, and 44.2-109.4%, respectively. Notably, under the magnetic field, the phytoremediation effect of 30% wounded A. halleri nearly returned to normal levels. We find that irrigation with magnetized water is an economical pathway to improve the tolerance of A. halleri to inevitable mechanical injury and may recover its phytoremediation effect.

A rich diversity of radiation-resistant (Rr) and desiccation-resistant (Dr) bacteria has been found in arid habitats of the world. Evidence from scientific research has linked their origin to reactive oxygen species (ROS) intermediates. Rr and Dr. bacteria of arid regions have the potential to regulate imbalance radicals and evade a higher dose of radiation and oxidation than bacterial species of non-arid regions. Photochemical-activated ROS in Rr bacteria is run through photo-induction of electron transfer. A hypothetical model of the biogeochemical cycle based on solar radiation and desiccation. These selective stresses generate oxidative radicals for a short span with strong reactivity and toxic effects. Desert-inhibiting Rr bacteria efficiently evade ROS toxicity with an evolved antioxidant system and other defensive pathways. The imbalanced radicals in physiological disorders, cancer, and lung diseases could be neutralized by a self-sustaining evolved Rr bacteria antioxidant system. The direct link of evolved antioxidant system with intermediate ROS and indirect influence of radiation and desiccation provide useful insight into richness, ecological diversity, and origin of Rr bacteria capabilities. The distinguishing features of Rr bacteria in deserts present a fertile research area with promising applications in the pharmaceutical industry, genetic engineering, biological therapy, biological transformation, bioremediation, industrial biotechnology, and astrobiology.

Strigolactones (SLs), the newest group of phytohormones, are involved in a wide range of functions, including the regulation of plant growth and physiology. Besides, emerging evidence suggests that SLs also participate in the promotion of plant environmental stress resilience through mediation of different metabolic genes/pathways. However, thus far little is known about SL-mediated transcriptional changes in rice (Oryza sativa), compared to other model plants. To meet this objective, we analyzed the RNA-seq-based comparative transcriptome data sets of rice SL-deficient dwarf l7 (d17) mutant line and its respective wild-type (WT), obtained from the National Center for Biotechnology Information GenBank. Both, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, in order to identify genes/pathways which function downstream of SLs. With respect to the WT, a large number of functional GO terms, mainly stress-associated terms such as 'response to stress', 'response to stimulus', 'response to chemical', 'response to oxidative stress' and 'reactive oxygen species metabolic process' were significantly suppressed in the d17 mutant plants. In addition, KEGG metabolic pathways such as cvaline, leucine and isoleucine degradation', 'plant hormone signal transduction', 'galactose metabolism', 'fatty acid degradation' and 'phenylalanine metabolism' were also remarkably undermined in the d17 lines relative to the WT. These results imply a possible involvement of rice SLs in the regulation of distinct stress-related metabolic genes/pathways, which may function in environmental stress tolerance of plants. Taken together, the study provides new opportunities to broaden our limited understanding of SL-regulated downstream pathways, especially in rice.

The Granger Causality (GC) statistical test explores the causal relationships between different time series variables. By employing the GC method, the underlying causal links between environmental drivers and global vegetation properties can be untangled, which opens possibilities to forecast the increasing strain on ecosystems by droughts, global warming, and climate change. This study aimed to quantify the spatial distribution of four distinct satellite vegetation products' (VPs) sensitivities to four environmental land variables (ELVs) at the global scale given the GC method. The GC analysis assessed the spatially explicit response of the VPs: (i) the fraction of absorbed photosynthetically active radiation (FAPAR), (ii) the leaf area index (LAI), (iii) solar-induced fluorescence (SIF), and, finally, (iv) the normalized difference vegetation index (NDVI) to the ELVs. These ELVs can be categorized as water availability assessing root zone soil moisture (SM) and accumulated precipitation (P), as well as, energy availability considering the effect of air temperature (T) and solar shortwave (R) radiation. The results indicate SM and P are key drivers, particularly causing changes in the LAI. SM alone accounts for 43%, while P accounts for 41%, of the explicitly caused areas over arid biomes. SM further significantly influences the LAI at northern latitudes, covering 44% of cold and 50% of polar biome areas. These areas exhibit a predominant response to R, which is a possible trigger for snowmelt, showing more than 40% caused by both cold and polar biomes for all VPs. Finally, T's causality is evenly distributed amongst all biomes with fractional covers between similar to 10 and 20%. By using the GC method, the analysis presents a novel way to monitor the planet's ecosystem, based on solely two years as input data, with four VPs acquired by the synergy of Sentinel-3 (S3) and 5P (S5P) satellite data streams. The findings indicated unique, biome-specific responses of vegetation to distinct environmental drivers.