Search Results (69)

Nano-titanium dioxide (nano-TiO₂) can alleviate oxidative damage in plants subjected to abiotic stress, interfere with related gene expression, and change metabolite content. Polylactic acid (PLA) microplastics can inhibit plant growth, induce oxidative stress in plant cells, and alter the biophysical properties of rhizosphere soil. In this study, untargeted metabolomics (LC-MS) and RNA-seq sequencing were performed on radish root cells exposed to nano-TiO₂ and PLA. The results showed that nano-TiO₂ alleviated the growth inhibition of radish roots induced by PLA. Nano-TiO₂ alleviated PLA-induced oxidative stress, and the activities of SOD and POD were decreased by 28.6% and 36.0%, respectively. A total of 1673 differentially expressed genes (DEGs, 844 upregulated genes, and 829 downregulated genes) were detected by transcriptome analysis. Metabolomics analysis showed that 5041 differential metabolites were involved; they mainly include terpenoids, fatty acids, alkaloids, shikimic acid, and phenylpropionic acid. Among them, phenylpropanoid biosynthesis as well as flavone and flavonol biosynthesis were the key metabolic pathways. This study demonstrates that nano-TiO₂ mitigates PLA phytotoxicity in radish via transcriptional and metabolic reprogramming of phenylpropanoid biosynthesis. These findings provide important references for enhancing crop resilience against pollutants and underscore the need for ecological risk assessment of co-existing novel pollutants in agriculture. Full article

Regional increases in atmospheric O₃ are phytotoxic not only to major crops but also to root vegetables such as radish, and their effects can be further modulated by nitrogen (N) addition. To assess how cherry radish responds to elevated O₃ (eO₃) under N addition and to compare the dose–response relationships, we established six open-top chambers with two O₃ levels and two N treatments in Beijing, China, to examine gas exchange, growth, and biomass throughout the growing period. The results showed that: 1. eO₃ had a “priming effect” on photosynthesis rates (Pn) at the beginning of the experiment. N addition alleviated the O₃-induced Pn reduction at the end of the experiment by 6.76% but did not significantly influence the O₃-dose response to Pn; 2. stomatal conductance (gs) did not have a dose response to all treatments while evaporation rates (E) showed strong negative regression with AOT40; 3. N addition reduced the hypocotyl biomass (−47.70%), leaf biomass (−32.22%), and the whole plant biomass reduction caused by O₃ (−38.47%) at the end of the experiment, but N addition did not significantly influence O₃-dose response to biomass. In conclusion, N addition can alleviate O₃-induced reductions in Pn and biomass via non-stomatal mechanisms, but it is ineffective in altering long-term O₃ dose–response relationships. Soil N addition offers a short-term strategy to mitigate O₃ impacts on short-lived root vegetables such as cherry radish but does not influence key functional traits over the long term. This study highlights the potential of N addition to alleviate acute oxidative stress, while underscoring its limitations in mitigating the effects of prolonged O₃ exposure in root vegetables. Full article

Soil heavy-metal pollution is one of the most serious environmental issues in the world. There is an urgent need to develop feasible strategies for the remediation of polluted soil. Biochar has great potential to reduce heavy metal phytotoxicity and promote plant growth, but its mechanisms are still unclear. In this study, phosphoric acid and magnesium composite-modified tea branch biochar (PMB) was prepared and characterized. The effects of PMB at 5% addition on pakchoi growth, Cd/Pb accumulation and subcellular distribution in pakchoi, soil physicochemical characteristics and enzyme activities, Cd/Pb bioavailability, bacterial community structure, and diversity in Cd/Pb co-contaminated soils was investigated by a pot experiment. The results showed that PMB significantly alleviated the phytotoxicity of Cd and Pb. The application of PMB effectively increased the plant height and biomass and Cd and Pb proportion in the cell wall, while reducing Cd and Pb accumulation and their distribution in cytoplasm and organelles in pakchoi plants. PMB significantly improved the activities of urease, invertase, and catalase and reduced the available Cd and Pb contents in soil. Moreover, PMB changed the structure and diversity of the soil bacterial community. The relative abundance of several beneficial microbial phyla, including Acidobacteriota, Bacteroidota, Actinobacteriota, and Gemmatimonadota, increased by 13.81%, 19.02%, 68.09%, and 34.79%, respectively. The Shannon and Chao1 index also increased significantly. This study provides an effective strategy for simultaneous Cd and Pb immobilization in soil, promoting plant growth and inhibiting heavy metal accumulation in vegetables, which highlights the application of PMB in sustainable agro-ecosystems. Full article

The phytotoxicity of aluminum (Al) to plants is well known. Auxin accumulation and reactive oxygen species (ROS) burst induced by Al toxicity are the key factors in root growth inhibition. Yucasin, an auxin synthesis inhibitor, effectively ameliorates Al phytotoxicity in tomato seedlings. However, the physiological mechanisms by which yucasin alleviates Al phytotoxicity in tomatoes remain elusive. Here, we examined the regulatory mechanisms of yucasin involved in tomato seedling growth under Al conditions through phenotypic, plant physiology analysis, and cellular experiments. Exogenous indole-3-acetic acid (IAA) application increased Al accumulation in tomato seedling roots, while yucasin decreased Al accumulation. Yucasin application reduced Al-induced ROS accumulation, lipid peroxidation, and cell death, enhanced root viability, and promoted tomato seedling root growth. Further, yucasin enhanced the antioxidant enzyme activities of superoxide dismutase, catalase, and peroxidase in plants under Al conditions. The results suggest that yucasin improves the scavenging capacity of ROS by maintaining the activities of antioxidative enzymes. This study elucidates the physiological mechanism by which yucasin alleviates Al phytotoxicity, highlighting its potential to enhance plant tolerance under acidic Al conditions. Full article

Heavy metal (HMs) toxicity has severely impacted wheat production and is considered an emerging threat to human health due to bioaccumulation. The application of organic and inorganic amendments has proven effective in mitigating HM’s phytotoxicity by limiting their mobility in soil and plants. A pot experiment was conducted to evaluate the efficiency of biochar (BC), bentonite (BN), and rock phosphate (RP), both individually and in combination, in alleviating lead (Pb) toxicity and enhancing wheat growth, and physiological attributes. The present investigation revealed that BC, BN, RP, and their combined mineral biochar amendments (MBAs) at 1.5% level significantly enhanced wheat growth along with reducing DTPA-extractable Pb in soil by 30.0–49.8% and Pb uptake in roots by 15.7–37.5% and in shoots by 34.5–48.5%. Antioxidant enzymatic activities were improved, and stress indicators were reduced in roots and shoots of wheat under Pb stress, including hydrogen peroxide (H₂O₂) by 50.7 and 81.0%, malondialdehyde (MDA) levels by 16.0 and 74.9%, and proline content by 34.5 and 64.0%, respectively. The effectiveness of the treatments is described in descending order viz. MBA-1 > MBA-3 > MBA-2 > BC > RP > BN under Pb stress. In conclusion, the integration of biochar, bentonite, and rock phosphate is a promising strategy for sustainable and cleaner cereal crop production under heavy metal stress conditions. Full article

Iron-based metal–organic frameworks (Fe-MOFs) are widely used for agricultural chemical delivery due to their high loading capacity, and they also have the potential to provide essential iron for plant growth. Therefore, they hold significant promise for agricultural applications. Evaluating the plant biotoxicity of Fe-MOFs is crucial for optimizing their use in agriculture. In this study, we used the natural biomacromolecule carboxymethyl cellulose (CMC) to encapsulate the Fe-MOF NH₂-MIL-101 (Fe) (MIL). Through hydroponic experiments, we investigated the biotoxic effects of Fe-MOFs on rice before and after CMC modification. The results show that the accumulation of iron in rice is dependent on the dose and the exposure concentration of Fe-MOFs. CMC modification (MIL@CMC) can reduce the release rate of Fe ions from Fe-MOFs in aqueous solutions with different pH values (5 and 7). Furthermore, MIL@CMC treatment significantly increases the absorption of iron by both the aboveground and root parts of rice. MIL@CMC significantly alleviated the growth inhibition of rice seedlings and increased the aboveground biomass of rice under medium- to high-exposure conditions. Specifically, in rice roots, MIL induced a more intense oxidative stress response, with significant increases in the activities of related antioxidant enzymes (CAT, POD, and SOD) and MDA content. Our results demonstrated that the encapsulation of NH₂-MIL-101(Fe) using CMC effectively alleviated oxidative damage and promoted the uptake and growth of iron in rice. These findings suggest that rational modification can have a positive effect on reducing the potential phytotoxicity of MOFs and improving their biosafety in agricultural applications. Full article

Arbuscular mycorrhizal fungi (AMF) affect cadmium (Cd) accumulation and tolerance in host plants. However, the effects of AMF on Cd accumulation and phytotoxicity and their underlying mechanism in apples remain uncharacterized. In this study, the comprehensive physiological and molecular responses of uninoculated and Rhizophagus intraradices-inoculated Malus hupehensis Rehd. rootstocks exposed to 0 or 300 μM Cd were investigated. AMF inoculation mitigated Cd-induced growth and photosynthesis inhibition and nutrient ion disorders. It also lowered the concentrations of Cd in all tissues and reduced Cd transport to the shoots. Compared to uninoculated apple plants, those inoculated with mycorrhizal fungi reduced the mobility and toxicity of Cd by altering its form and binding it to the cell walls of the roots and leaves. AMF inoculation ameliorated Cd stress by altering endogenous phytohormone levels and triggering enzymatic and non-enzymatic antioxidant systems. Transcriptome analysis revealed that the differentially expressed genes (DEGs) associated with AMF under Cd stress regulated carbohydrate and amino acid biosynthesis and metabolism, as well as phytohormone biosynthesis and signal transduction. Furthermore, AMF inoculation downregulated certain genes involved in Cd uptake and transport while upregulating other genes involved in detoxification. These results suggest that AMF alleviate Cd phytotoxicity by orchestrated physiological and transcriptomic regulation in M. hupehensis Rehd., providing valuable insights into the efficacy of AMF inoculation in improving the heavy metal resistance of fruit trees. Full article

Salt stress significantly reduces rice yield and deteriorates rice quality. The present study was conducted to explore the regulatory effects of sole and combined application of S-abscisic acid (S-ABA) and soil conditioner on rice under high salt stress. The experimental treatments comprised 0.1% S-ABA alone (T1), the application of soil conditioner (T2), the combined application of both S-ABA and halotolerant microorganism soil conditioner (T3), and a control without any regulatory substance (CK). The treatments were arranged in a randomized complete block design in triplicate. To simulate high salinity stress, a 0.6% saltwater solution (by mixing natural seawater with freshwater) was used for irrigation. The results showed that T3 alleviated the phytotoxic effects of high salt stress and substantially improved rice yield. Furthermore, the numbers of effective panicles, grains per panicle, and 1000-grain weight under T3 treatment were 13.3–14.5%, 8.9–14.1%, and 4.9–5.5% higher than CK owing to improvement in dry matter accumulation, SPAD values, leaf area index, antioxidant enzyme activity, and reduced malondialdehyde and sodium ion content in rice. Moreover, the T3 treatment increased the output, output rate, and conversion rate of stem sheath matter after the heading stage; improved the milling yield, starch paste viscosity, starch stickiness, and gelatinization enthalpy; and reduced rice chalkiness. In addition, the T3 treatment also increased the amylose contents and decreased the total protein contents, thereby improving the taste of the rice. Overall, the results indicated that the application of exogenous S-ABA and soil conditioner is an effective strategy to alleviate the severity of salt stress in rice. Full article

This research study investigated the production and properties of zinc oxide (ZnO) nanoparticles derived from corn husks and their priming effects on wheat plant proliferation and antioxidant mechanisms compared to the nutri-priming technique under regular irrigation and drought-stressed conditions. Transmission and scanning electron microscopy (TEM and SEM), energy-dispersive X-ray spectroscopy (EDAX), and X-ray diffraction confirmed the nanoparticles’ hexagonal morphology and typical dimensions of 51 nm. The size and stability of these nanoparticles were assessed through the size distribution and zeta potential analysis, indicating reasonable stability. Fourier-transform infrared spectroscopy (FTIR) detected the newly formed functional groups. This study emphasized the role of reactive oxygen species (ROS) and phenolic compounds in plant responses to nanoparticle treatment, particularly in detoxifying harmful radicals. The research also examined the activity of antioxidant enzymes, including peroxidase (POX), catalase (CAT), and glutathione reductase (GR), in alleviating stress caused by oxidation while subjected to various treatments, including micronutrient seed priming with DR GREEN fertilizer. Some biochemical compounds, such as total phenolics (TPCs), total flavonoids (TFCs), and total hydrolysable sugars, were estimated as well to show the effect of the different treatments on the wheat plants. The findings suggested that ZnO nanoparticles can enhance antioxidant enzyme activity under certain conditions while posing phytotoxic risks, underscoring the complexity of plant–nanoparticle interactions and the potential for improving crop resilience through targeted micronutrient applications. Full article

The escalating release of multi-walled carbon nanotubes (MWCNTs) into the environment has raised concerns due to their potential ecotoxicological impacts. However, their combined phytotoxicity with heavy metals such as copper (Cu) is still unclear. This study investigated the individual and combined toxic effects of MWCNTs (MWCNT, MWCNT-OH, and MWCNT-COOH) and Cu²⁺ on ryegrass (Lolium multiflorum), uniquely considering different addition orders. The results show that Cu severely inhibited the growth of ryegrass while MWCNTs exhibited a hormesis effect on ryegrass. When MWCNT and Cu were combined, the malondialdehyde (MDA) content in ryegrass showed a 32.39% increase at 20 mg/L MWCNT exposure, suggesting reduced oxidative stress. However, at the higher concentration of 1000 mg/L, it led to a significant 75.22% reduction in ryegrass biomass. MWCNT-COOH had the most pronounced effect, reducing the total chlorophyll content by 39.76% compared to unmodified MWCNT and by 10.67% compared to MWCNT-OH (500 mg/L). Additionally, pre-induced MWCNTs might alleviate the Cu in the plant by 23.08–35.38% through adsorption in the nutrient solution. Small molecule organic acids and amino acids primarily mediated the response to environmental stress in ryegrass. This research provides crucial insights into understanding the complex interactions of MWCNT and Cu²⁺ and their combined effects on plant ecosystems. Full article

Fenoxaprop-P-ethyl (FE) can effectively control weeds in rice fields, but it has been found to cause phytotoxicity in rice. In this study, the phytotoxicity of FE was mitigated by perilla leaf essential oil (PEO) in rice seedlings. The injury recovery rates (IRRs) for shoot length and fresh weight treated with 800 mg/L of PEO were 101.51% and 99.05%, respectively. Moreover, the damage of s-metolachlor and pretilachlor was also alleviated when co-applied with 800 mg/L PEO; the IRR of s-metolachlor phytotoxicity was 26.07% and 27.34%, respectively, and the IRR of pretilachlor phytotoxicity was 127.27% and 124.39%, respectively. However, PEO had no significant effect on the phytotoxicity of pinoxaden, mesotrione, penoxsulam, mesosulfuron-methyl, and nicosulfuron. The results of GC–MS analysis showed that a total of 23 components were detected in PEO, among which linalool (36.49%), linalyl formate (26.96%), α-terpineol (10.63%), 2-hexanoylfuran (5.81%), geranyl acetate (4.13%), and neryl acetate (2.30%) were the primary components. Among them, 2-hexanoylfuran was the most effective component to alleviate FE damage, for which the IRR of shoot length and fresh weight was 73.17% and 73.02%, respectively, followed by the geranyl acetate, for which the IRR was 72.32% and 60.56%, respectively, and neryl acetate, for which the IRR was 65.28% and 58.11%, respectively. Furthermore, the application of 50 mg/L of 2-hexanofuran significantly improved the tolerance of shoot length and fresh weight to FE stress by factors of 5.32 and 5.35, respectively. This research demonstrates that PEO and 2-hexanoylfuran have the potential to serve as natural safeners to reduce phytotoxicity. Full article

S-metolachlor is a selective pre-emergence herbicide used in dryland. However, it is challenging to employ in paddy fields due to its phytotoxic effects on rice. As a common phytohormone, Gibberellin-3 (GA₃) is inferred to have the ability to alleviate herbicide phytotoxicity. This study first quantitatively verified the phytotoxicity of s-metolachlor to rice and then demonstrated the mitigative effect of GA₃ on these adverse reactions. Furthermore, a transcriptome of rice seedlings subjected to different treatments was constructed to assemble the reference genes, followed by comparative metabolomics and proteomics analyses. Metabolomics revealed an enrichment of flavonoid metabolites in the group of adding GA₃, and these flavonoids can eliminate ROS in plants. Proteomics analysis indicated that differential proteins were enriched in the phenylpropanoid biosynthesis pathway responsible for the synthesis of flavonoids and that the functions of most differential proteins are associated with peroxidase. The proteome, combined with the transcriptome, revealed that the expressions of proteins and genes was related to the POD activity in the group of adding GA₃. It was speculated that the elimination of ROS is key to alleviating the stress of s-metolachlor on rice growth. It was inferred that the mechanism of GA₃ in alleviating the phytotoxicity of the substance s-metolachlor is by increasing the activity of the POD and influencing the growth of rice seedlings through the restoration of flavonoid synthesis. In this study, we screened GA₃ as a safener to alleviate the phytotoxicity of s-metolachlor on rice. On this basis, the mechanism of alleviating phytotoxicity was studied. The application range of s-metolachlor might be expanded, providing a new supplementary method for weed control and herbicide resistance management. Full article

Co-application of sewage sludge (SS) with biochar in landscape/forestry soil is a common strategy for enhancing soil fertility and reducing the bioavailability of potential toxic elements (PTEs) derived from SS, such as Cd, Pb, Cu, Zn, and Ni. However, due to variability of biochar quality and uncertainties in responses of different plant species, whether the co-application benefits the landscape/forestry plant system remains elusive. Here, we tested the effectiveness of three types of biochar (SS-derived biochar (SB), rice straw-derived biochar (RB), and litter-derived biochar (LB)), which were added to soil amended with SS at 50% (w/w) at rates of 1.5%, 3%, and 4.5% as growth media for the landscape plant Aglaonema modestum (A. modestum). We analyzed the substrate’s physicochemical properties and assessed the alleviation of phytotoxicity by biochar application. A significant increase in the fertility index of substrate was observed in all the treatments with biochar addition. The addition of biochar reduced the potential mobility of PTEs while increasing their residual fraction in media. Nonetheless, it has been found that the addition of biochar has ineffective or even negative effects on A. modestum growth (height, biomass, root length) and nutrient absorption. Importantly, the reduction in root biomass and the increased activity of root antioxidant enzymes (SOD, POD, CAT, and MDA) indicate contamination stress of biochar on the roots of A. modestum. Toxic elements of concern—namely Cu, Cd, and Pb—were not significantly higher in tissues of A. modestum saplings planted in biochar-SS-amended soil. However, elevated levels of other elements that may pose toxicity concerns, such as Ni and Zn, increased in tissues at high biochar dosages. Based on the Entropy–Weight TOPSIS method, it was further confirmed that compared to the treatment without biochar, all treatments except for 3.0% LB application resulted in poorer A. modestum comprehensive growth. Our results emphasize the need for detailed research on the response of specific plants to biochar in specific environments, including plant adaptability and the unexplored toxicity of biochar, to understand the large variations and mechanisms behind these ineffective or negative effects before the large-scale co-utilization of SS and biochar in landscape/forestry soils. Full article

Drought stress is the prime obstacle for worldwide agricultural production and necessitates innovative strategies for enhancing crop resilience. This study explores the efficacy of plant growth-promoting rhizobacteria (PGPR) and biochar (BC) as sustainable amendments for mitigating the effects of drought on wheat growth. Multiple experiments were carried out on isolated strains to assess their drought tolerance potential and multiple plant growth-promoting attributes. Experiments in the laboratory and natural environment were conducted to assess the impact of plant growth-promoting rhizobacteria, biochar, and their synergistic application on various growth parameters of wheat. The results revealed that the drought-tolerant PGPR strains (Bacillus subtilis and Bacillus tequilensis), alongside biochar (rice husk), alleviated the phytotoxic impact of drought by increasing the root length from 17.0% to 70.0% and shoot length from 30.0% to 82.0% as compared to un-inoculated stressed controls. The total chlorophyll and carotenoid contents of the plants were substantially increased to 477% and 423%, respectively, when biochar and PGPR were applied synergistically. Significant enhancements in membrane stability index, relative water content, proline, and sugar level were achieved by combining biochar and bacterial strains, resulting in increases of 19.5%, 37.9%, 219%, and 300%, respectively. The yield of wheat in terms of plant height, spike length, number of spikelets per spike, and number of grains per spike was enhanced from 26.7% to 44.6%, 23.5% to 62.7%, 91.5% to 154%, and 137% to 182%, respectively. It was concluded that the biochar-based application of PGPR induced drought tolerance in wheat under water deficit conditions, ultimately improving the production and yield of wheat. Full article

In today’s time, agricultural productivity is severely affected by climate change and increasing pollution. Hence, several biotechnological approaches, including genetic and non-genetic strategies, have been developed and adapted to increase agricultural productivity. One of them is nano-priming, i.e., seed priming with nanomaterials. Thus far, nano-priming methods have been successfully used to mount desired physiological responses and productivity attributes in crops. In this review, the literature about the utility of nano-priming methods for increasing seed vigor, germination, photosynthetic output, biomass, early growth, and crop yield has been summarized. Moreover, the available knowledge about the use of nano-priming methods in modulating plant antioxidant defenses and hormonal networks, inducing salinity tolerance and disease resistance, as well as alleviating heavy metal toxicity in plants, is reviewed. The significance of nano-priming methods in the context of phytotoxicity and environmental safety has also been discussed. For future perspectives, knowledge gaps in the present literature are highlighted, and the need for optimization and validation of nano-priming methods and their plant physiological outcomes, from lab to field, is emphasized. Full article