Human disturbance in the Arctic is increasing. Abrupt changes in vegetation may be expected, especially when spots without vegetation are made available; additionally, climate change alters competition between species. We studied whether 34- to 35-year-old seismic operations had left imprints on local vegetation and whether changes could be related to different soil characteristics. The study took place in Jameson Land in central east Greenland where winter seismic operations in search of oil took place from 1985 to 1989. This area is dominated by continuous dwarf shrub heath with Cassiope tetragona, Betula nana, and Vaccinium uliginosum as dominant species. Using point frame analyses, we registered vascular plants and other surface types in frames along 10-m transects in vehicle tracks (hereafter damages) and in undisturbed vegetation parallel to the track (hereafter references) at eleven study sites. We also measured temperature and pH and took soil samples for analysis. Damaged and reference vegetation types were compared with S & oslash;rensen similarity indices and detrended correspondence analyses. Although most vascular plant species were equally present in damaged vegetation and in references the detrended correspondence analyses showed that at ten out of eleven study sites the damages and references still differed from each other. Graminoids and the herb Polygonum viviparum had the highest occurrence in damages. Shrubs and the graminoid Kobresia myosuroides had the highest occurrence in references. Cassiope tetragona was negatively impacted where vehicles had compacted the snow. Moss, organic crust or biocrust, soil, and sand occurred more often in damages than in references, whereas lichens and litter had the highest occurrence in references. The richness of vascular plant species varied between the eleven study sites, but between damages and references the difference was only up to four species. Temperature was the soil parameter with the most significant differences between damages and references. Total recovery of the damaged vegetation will most likely not occur within several decades. The environmental regulations were important to avoid more serious impacts.

Biogrouting has been proposed for improving mechanical properties of soils and rocks, whose performance greatly depends on the location of biocement at pore-scale. To enhance the performance of biogrouting, many strategies were proposed, including the addition of assistants, controlling curing moisture degree, and flocculation of bacteria. Clay is one such assistant which has been proven to be effective, with an assumption of increasing active biocement, i.e. those located between soil particles. In this work, we employed microfluidics to directly observe whether clay minerals can certainly control the location of precipitates and how they function. First of all, the capacity of bentonite and kaolin for adsorbing bacteria were investigated. Then, the location of CaCO3 crystals with and without clay minerals were visually observed using microfluidics. Pore-filling ratios and CaCO3 ratios, which are closely related to permeability and strength of biocemented soils, were quantitatively analyzed from collected images. Finally, the effects of bentonite and kaolin and their dosages on the location of biocement were comprehensively discussed. The results demonstrated that the performance of bentonite and kaolin on adsorbing bacteria and regulating biocement location is distinct due to differences in the morphologies of clays. These findings can help us to improve biogrouting performance on soil stabilization and propose new strategies in various practical applications, such as CO2 sequestration, heavy metal remediation, and oil recovery enhancement, all with a foundational understanding of their mechanisms.

This study investigates the potential of green-fabricated manganese dioxide (MnO2) nanoparticles (NPs) to mitigate chromium (Cr) toxicity in wheat, presenting a novel approach to enhancing ion homeostasis and physiological resilience under Cr stress. Chromium contamination in agricultural soils is a significant concern, severely impacting crop productivity and disrupting the physiological homeostasis of wheat. Chromium exposure compromises nutrient uptake, induces oxidative stress, and impairs plant growth and yield. This study explored the use of green-fabricated MnO2NPs to mitigate Cr-induced oxidative stress in two bread wheat cultivars, Borlaug-16 and SKD-1. Seed nano-priming with MnO2NPs (100, 250, and 500 mg kg-1) was applied, followed by Cr (100 mg kg-1) exposure, and key physiological, biochemical, and ionomic responses were evaluated. Manganese dioxide nanoparticles significantly reduced Cr uptake and improved ion transport. In Borlaug-16, NP250 enhanced seedling height by 74 %, while NP100 reduced H2O2and TBARS by 60.28 % and 50.17 %, respectively, indicating improved oxidative stress tolerance. SKD-1 exhibited greater Cr stress tolerance, with NP250 improving root length by 31.03 % and relative water content by 56.66 %, supporting better water retention. Additionally, MnO2NP treatments boosted antioxidant enzyme activities, increasing APX and GPX by up to 12.47 %, and restored root and leaf anatomy, reversing Cr-induced structural damage. Furthermore, MnO2NPs enhanced the uptake of essential nutrients such as calcium, potassium, and magnesium, while restricting Cr translocation, improving overall nutrient efficiency. These findings emphasize the potential of MnO2NPs as an eco-friendly strategy for enhancing crop resilience and promoting sustainable agriculture in Cr-contaminated soils.

Soil salinity is a severe abiotic stress that damages plant growth and development. As an antioxidant and free radical scavenger, melatonin is well known for helping plants survive abiotic conditions, including salinity stress. Here, we report that the salt-related gene MsSNAT1, encoding a rate-limiting melatonin biosynthesis enzyme, is located in the chloroplast and contributes to salinity stress tolerance in alfalfa. We found that the MsSNAT1 overexpressing alfalfa lines exhibited higher endogenous melatonin levels and increased tolerance to salt stress by promoting antioxidant systems and improving ion homeostasis. Furthermore, through a combination of transcriptome sequencing, dual-luciferase assays and transgenic analysis, we identified that the basic leucine zipper (bZIP) transcription factor, MsbZIP55, is associated with salt response and MsSNAT1 expression. EMSA analysis and ChIP-qPCR uncovered that MsbZIP55 can recognize and directly bind to the MsSNAT1 promoter in vitro and in vivo. MsbZIP55 acts as a negative regulator of MsSNAT1 expression, thereby reducing melatonin biosynthesis. Morphological analysis revealed that overexpressing MsbZIP55 conferred salt sensitivity to transgenic alfalfa through a higher Na+/K+ ratio and lower antioxidant activities, which could be alleviated by applying exogenous melatonin. Silencing of MsbZIP55 by RNA interference in alfalfa resulted in higher expression of MsSNAT1 and promoted salt tolerance by enhancing the antioxidant system enzyme activities and ion homeostasis. Our findings indicate that the MsbZIP55-MsSNAT1 module plays a crucial role in regulating melatonin biosynthesis in alfalfa while facilitating protection against salinity stress. These results shed light on the regulatory mechanism of melatonin biosynthesis related to the salinity stress response in alfalfa.

Inappropriate fertilization and poor management practices in citrus orchards can cause soil acidification, which may result in potential proton (H+) toxicity to citrus roots. It has been reported that boron (B) can mediate H+ detoxification in citrus; however, the mechanisms remain limited. Herein, a hydroponic experiment was employed to unravel the alleviation mechanism of B on H+ toxicity at pH 4 in trifoliate (Poncirus trifoliate (L.) Raf.) seedlings. H+ toxicity reduced cytoplasmic pH from 7.2 (control) to 6.9 and vacuolar pH from 5.6 (control) to 5.4. This severely damaged the plasma membrane (PM) and inhibited root activity by 35%. However, B supplementation restored cytoplasmic pH to 7.1 and vacuolar pH to 5.6, enhancing root activity by 52% and reducing membrane permeability (relative conductivity decreased by 28%). Mechanistically, B upregulated phosphorylated-type adenosine triphosphatase activity by 14%; conversely, it suppressed vacuolar-type adenosine triphosphatase hyperactivity by 9% to stabilize vacuolar pH. Furthermore, B restored PM integrity by increasing phospholipid (40%), glycolipid (50%) and sulfhydryl group (28%) content, critical for membrane structure and function. It is concluded that B can alleviate root growth inhibition induced by H+ toxicity via increasing the content of key components of PM, which not only repairs the damaged PM but also maintains cellular pH homeostasis through enzyme regulation. The improvement of citrus growth correspondingly safeguards the production capacity.

Germinating seeds undergo elaborate de-etiolation developmental transitions upon initial soil emergence. As central transcription factors promoting cotyledon greening, the abundance of ETHYLENE-INSENSITIVE 3 (EIN3) and PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) are strictly controlled by physically associating themselves with the EIN3-BINDING F BOX PROTEINS 1 and 2 (EBF1/2) for ubiquitination. Here, we report that the B-box zinc-finger protein BBX32, as a positive regulator during seedling de-etiolation. BBX32 is robustly elevated during the dark-to-light transitions. Constitutively expressing BBX32 ultimately protects against severe photobleaching damage by synchronizing the accumulation of protochlorophyllide (Pchlide) and the differentiation of etioplast-chloroplast apparatus in buried seedlings. Specifically, BBX32 directly interacts with EIN3, PIF3 and EBF1/2. These associations disrupt the assembly of the SCFEBF1/2-EIN3/PIF3 E3 ligation protein complexes, thus dampening E3 ligase activity and robustly controlling EIN3/PIF3 stability. Under soil conditions, BBX32-ox largely rescues the greening deficiency of EBF1ox, and all EIN3ox/bbx32 seedlings override the bbx32 mutant defect and successfully turn green. Both biochemical findings and genetic evidence reveal a novel regulatory paradigm by which the B-box protein dampens the E3 ligase binding activity to achieve green seedlings upon changes in light or soil environmental conditions.

Salinity is a common environmental stress that disrupts physiological and biochemical processes in plants, inhibiting growth. Silicon is a key element that enhances plant tolerance to such abiotic stresses. This study examined the effects of silicon supplementation on physiological, biochemical, and molecular responses of GF677 and GN15 rootstocks under NaCl-induced salinity stress. The experiment was conducted in a greenhouse using a factorial design with two rootstocks, three NaCl concentrations (0, 50, and 100 mM), and three silicon levels (0, 1, and 2 mM) in a randomized complete block design with three replicates. Salinity significantly reduced growth parameters, including shoot and root fresh and dry weights, RWC, and photosynthetic activity, with GN15 being more sensitive to salt stress than GF677. Silicon supplementation, especially at 2 mM, alleviated NaCl-induced damage, enhancing biomass retention and RWC under moderate and high NaCl levels. Additionally, silicon reduced electrolyte leakage, lipid peroxidation, and hydrogen peroxide accumulation, suggesting a protective role against oxidative stress. Biochemical analyses showed that silicon increased the accumulation of osmolytes such as proline, soluble sugars, glycine betaine, and total soluble protein, particularly in GF677. Silicon also boosted antioxidant enzyme activities, mitigating oxidative damage. In terms of mineral nutrition, silicon reduced Na+ and Cl- accumulation in leaves and roots, with the greatest reduction observed at 2 mM Si. Gene expression analysis indicated that NaCl stress upregulated key salt tolerance genes, including HKT1, AVP1, NHX1, and SOS1, with silicon application further enhancing their expression, particularly in GF677. The highest levels of gene expression were found in plants treated with both NaCl and 2 mM Si, suggesting that silicon improves salt tolerance by modulating gene expression. In conclusion, this study demonstrates the potential of silicon as an effective mitigator of NaCl stress in GF677 and GN15 rootstocks, particularly under moderate to high salinity conditions. Silicon supplementation enhances plant growth, osmotic regulation, reduces oxidative damage, and modulates gene expression for salt tolerance. Further research is needed to assess silicon's effectiveness under soil-based conditions and its applicability to other rootstocks and orchard environments. This study is the first to concurrently evaluate the physiological, biochemical, and molecular responses of GF677 and GN15 rootstocks to silicon application under salt stress conditions.

BackgroundSoybean (Glycine max L. Merrill), a vital source of edible oil and protein, ranks seventh in global agricultural production, yet its productivity is significantly hindered by potential toxic metal/liods (PTM) stress. Arsenic (As), a highly toxic soil contaminant, poses substantial risks to both plants and humans, even at trace concentrations, particularly in China.ResultsThis research endeavor delves into the combined effect of arsenate (AsV), a common form of As in soil, and nano-selenium (nSe), on the transcriptional regulation of key genes and the modulation of signaling and metabolic cascades in young soybean seedlings. Our findings indicate that nSe mitigates AsV toxicity by modulating hormonal signaling cascades, particularly the phenylalanine and salicylic acid pathways, thereby augmenting antioxidant defenses and mitigating the damaging effects of reactive oxygen species (ROS) on soybean roots.ConclusionThis study offers valuable insights into the molecular mechanisms underlying metalloid tolerance in soybean, opening avenues for the development of strategies to bolster As resistance in contaminated soils. Nevertheless, further investigation is imperative to elucidate the intricate interplay of hormonal signaling in soybean roots during nSe supplementation under As stress conditions.

Regulations on chemicals aim to protect public health and the environment. However, owing to the nature of this chemical, it is difficult to determine its impact pathway. Thus, it is difficult to investigate the damage caused by chemicals. However, it is essential to evaluate the costs and benefits of chemicals to establish reasonable chemical regulations. Therefore, this study analyzes the benefits of strengthening the regulation of chemical substances in Korea using the conditional valuation method. In particular, this study evaluated the public benefit of the chemical regulation of arsenic, which is a carcinogen. Data were collected from 1000 households in Korea, and a one-and-one-half-bound dichotomous choice spike model was used. The results show that the average annual willingness to pay for additional income tax payments over 10 years to reduce the incidence of arsenic-related diseases is 4314 Korean won (3.67 USD), with 57.5% of households refusing to pay. Additional analysis indicates that females are more willing to pay, and a higher education level, knowledge of arsenic, and experience in using arsenic-free products and hand sanitizers lead to a higher willingness to pay. The results of this study can be used to establish an efficient level of arsenic regulations and determine their effect on the related market.

Pectin blended with cellulose nanofiber (CNF) sourced from wood pulp has excellent potential for modified atmosphere packaging (MAP), as demonstrated with refrigerated or sliced fruits enclosed in parchment coated with pectin-CNF composites. Addition of sodium borate (NaB) augments the antioxidant capacity of the composite, most likely through the generation of unsaturated pectic acid units. Packaging materials coated with pectin-CNF-NaB composites demonstrate better humidity regulation in refrigerated spaces over a 3-week period relative to uncoated controls (50% less variation), with improved preservation of strawberries as well as a reduction in the oxidative browning of sliced apples. Pectin-CNF films are both biorenewable and biodegradable as confirmed by their extensive decomposition in soil over several weeks, establishing their potential as a sustainable MAP material. Lastly, self-standing films are mechanically robust at 80% RH with tensile strength and toughness as high as 150 MPa and 8.5 MJ/m2 respectively. These values are on par with other bioplastic composites and support the practical utility of pectin-CNF composites in functional packaging applications.