Application of atmospheric cold plasma for zearalenone detoxification in cereals: Kinetics, mechanisms, and cytotoxicity analysis.

INTRODUCTION: Zearalenone (ZEN) is one of the most widely contaminated mycotoxins in world, posing a severe threat to human and animal health. Atmospheric cold plasma (ACP) holds great penitential in mycotoxin degradation. OBJECTIVES: This study aimed to investigate the degradation efficiency and mechanisms of ACP on ZEN as well as the cytotoxicity of ZEN degradation products by ACP. Additionally, this study also investigated the degradation efficiency of ACP on ZEN in cereals and its effect on cereal quality. METHODS: The degradation efficiency and products of ZEN by ACP was analyzed by HPLC and LC-MS/MS. The human normal liver cells and mice were employed to assess the cytotoxicity of ZEN degradation products. The ZEN artificially contaminated cereals were used to evaluate the feasibility of ACP detoxification in cereals. RESULTS: The results showed that the degradation rate of ZEN was 96.18 % after 30-W ACP treatment for 180 s. The degradation rate was dependent on the discharge power, and treatment time and distance. Four major ZEN degradation products were produced after ACP treatment due to the oxidative destruction of CC double bond, namely C18H22O7 (m/z = 351.19), C18H22O8 (m/z = 367.14), C18H22O6 (m/z = 335.14), and C17H20O6 (m/z = 321.19). L02 cell viability was increased from 52.4 % to 99.76 % with ACP treatment time ranging from 0 to 180 s. Mice results showed significant recovery of body weight and depth of colonic crypts as well as mitigation of glomerular and liver damage. Additionally, ACP removed up to 50.55 % and 58.07 % of ZEN from wheat and corn. CONCLUSIONS: This study demonstrates that ACP could efficiently degrade ZEN in cereals and its cytotoxicity was significantly reduced. Therefore, ACP is a promising effective method for ZEN detoxification in cereals to ensure human and animal health. Future study needs to develop large-scale ACP device with high degradation efficiency.

Genome-Wide Identification, Characterization, and Expression Analysis of Four Subgroup Members of the GH13 Family in Wheat (Triticum aestivum L.).

The glycoside hydrolase 13 (GH13) family is crucial for catalyzing α-glucoside linkages, and plays a key role in plant growth, development, and stress responses. Despite its significance, its role in plants remains understudied. This study targeted four GH13 subgroups in wheat, identifying 66 GH13 members from the latest wheat database (IWGSC RefSeq v2.1), including 36 α-amylase (AMY) members, 18 1,4-α-glucan-branching enzyme (SBE) members, 9 isoamylase (ISA) members, and 3 pullulanase (PU) members. Chromosomal distribution reveals a concentration of wheat group 7 chromosomes. Phylogenetic analysis underscores significant evolutionary distance variations among the subgroups, with distinct molecular structures. Replication events shaped subgroup evolution, particularly in regard to AMY members. Subcellular localization indicates AMY member predominance in extracellular and chloroplast regions, while others localize solely in chloroplasts, confirmed by the heterologous expression of TaSEB16 and TaAMY1 in tobacco. Moreover, 3D structural analysis shows the consistency of GH13 across species. Promoter cis-acting elements are suggested to be involved in growth, stress tolerance, and starch metabolism signaling. The RNA-seq data revealed TaGH13 expression changes under drought and submergence stress, and significant expression variation was observed between strong and weak gluten varieties during seed germination using quantitative real-time PCR (qRT-PCR), correlating with seed starch content. These findings demonstrate the pivotal role of GH13 family gene expression in wheat germination, concerning variety preference and environmental stress. Overall, this study advances the understanding of wheat GH13 subgroups, laying the groundwork for further functional studies.

Inhibition of Fungal Growth and Aflatoxin B1 Synthesis in Aspergillus flavus by Plasma-Activated Water.

The gaseous reactive oxygen/nitrogen species (RONS) generated by cold atmospheric plasma (CAP) can effectively inactivate Aspergillus flavus (A. flavus) and prolong the shelf-life of food. Plasma-activated water (PAW) is the extension of cold plasma sterilization technology. Without the limitation of a plasma device, PAW can be applied to more scenarios of food decontamination. However, the efficacy of PAW as a carrier of RONS for eradicating A. flavus or inhibiting its growth remains unclear. In this study, the immediate fungicidal effect and long-term inhibitory effect of PAW on A. flavus were investigated. The results demonstrated that 60-min instant-prepared PAW could achieve a 3.22 log reduction CFU/mL of A. flavus and the fungicidal efficacy of PAW gradually declined with the extension of storage time. Peroxynitrite (ONOO-/ONOOH) played a crucial role in this inactivation process, which could damage the cell wall and membrane structure, disrupt intracellular redox homeostasis, and impair mitochondrial function, ultimately leading to fungal inactivation. In addition to the fungicidal effect, PAW also exhibited fungistatic properties and inhibited the synthesis of aflatoxin B1 (AFB1) in A. flavus. By analyzing the cellular antioxidant capacity, energy metabolism, and key gene expression in the AFB1 synthesis pathway, it was discovered that PAW can significantly reduce ATP levels, while increasing SOD and CAT activity during 5-d cultivation. Meanwhile, PAW effectively suppressed the expression of genes related to AFB1 synthesis.

The Role of Reactive Oxygen Species in Plant Response to Radiation.

Radiation is widespread in nature, including ultraviolet radiation from the sun, cosmic radiation and radiation emitted by natural radionuclides. Over the years, the increasing industrialization of human beings has brought about more radiation, such as enhanced UV-B radiation due to ground ozone decay, and the emission and contamination of nuclear waste due to the increasing nuclear power plants and radioactive material industry. With additional radiation reaching plants, both negative effects including damage to cell membranes, reduction of photosynthetic rate and premature aging and benefits such as growth promotion and stress resistance enhancement have been observed. ROS (Reactive oxygen species) are reactive oxidants in plant cells, including hydrogen peroxide (H2O2), superoxide anions (O2•-) and hydroxide anion radicals (·OH), which may stimulate the antioxidant system of plants and act as signaling molecules to regulate downstream reactions. A number of studies have observed the change of ROS in plant cells under radiation, and new technology such as RNA-seq has molecularly revealed the regulation of radiative biological effects by ROS. This review summarized recent progress on the role of ROS in plant response to radiations including UV, ion beam and plasma, and may help to reveal the mechanisms of plant responses to radiation.

Reactive oxygen species may be involved in the distinctive biological effects of different doses of 12C6+ ion beams on Arabidopsis.

Introduction: Heavy ion beam is a novel approach for crop mutagenesis with the advantage of high energy transfer line density and low repair effect after injury, however, little investigation on the biological effect on plant was performed. 50 Gy irradiation significantly stimulated the growth of Arabidopsis seedlings, as indicated by an increase in root and biomass, while 200 Gy irradiation significantly inhibited the growth of seedlings, causing a visible decrease in plant growth. Methods: The Arabidopsis seeds were irradiated by 12C6+. Monte Carlo simulations were used to calculate the damage to seeds and particle trajectories by ion implantation. The seed epidermis received SEM detection and changes in its organic composition were detected using FTIR. Evidence of ROS and antioxidant systems were analyzed. RNA-seq and qPCR were used to detect changes in seedling transcript levels. Results and discussion: Monte Carlo simulations revealed that high-dose irradiation causes various damage. Evidence of ROS and antioxidant systems implies that the emergence of phenotypes in plant cells may be associated with oxidative stress. Transcriptomic analysis of the seedlings demonstrated that 170 DEGs were present in the 50 Gy and 200 Gy groups and GO enrichment indicated that they were mainly associated with stress resistance and cell wall homeostasis. Further GO enrichment of DEGs unique to 50 Gy and 200 Gy revealed 58 50Gy-exclusive DEGs were enriched in response to oxidative stress and jasmonic acid entries, while 435 200 Gy-exclusive DEGs were enriched in relation to oxidative stress, organic cyclic compounds, and salicylic acid. This investigation advances our insight into the biological effects of heavy ion irradiation and the underlying mechanisms.

Regulation of cellular redox homeostasis in Arabidopsis thaliana seedling by atmospheric pressure cold plasma-generated reactive oxygen/nitrogen species.

Atmospheric pressure cold plasma (APCP) holds great potential as an efficient, economical and eco-friendly approach for improving crop production. Although APCP-induced plant growth promotion is undisputedly attributed to the reactive oxygen and nitrogen species (RONS), how these RONS regulate the intracellular redox state and plant growth is still largely unknown. This study systematically investigates the regulation mechanism of APCP-generated RONS on intracellular redox homeostasis in Arabidopsis thaliana seedling by measuring the RONS compositions in APCP-treated solutions and intracellular RONS and antioxidants in Arabidopsis seedlings. The results show that APCP exhibited a dual effect (stimulation or inhibition) on Arabidopsis seedling growth dependent on the treatment time. APCP-generated RONS in liquids increased in a time-dependent manner, leading to an increase of conductivity and oxidation reduction potential (ORP) and decrease of pH. APCP caused an enrichment of intracellular RONS and most of them increased with APCP treatment time. Meanwhile, APCP treatment accelerated malondialdehyde (MDA) generation, and the level of intracellular antioxidants were enhanced by low-dose APCP treatment while decreased at high doses. The results of correlation analysis showed that the extracellular RONS produced by APCP were positively correlated with the intracellular RONS and negatively correlated with the antioxidants. These results demonstrate that the improved antioxidant capacity induced by moderate APCP-generated RONS plays an important role in the growth promotion of Arabidopsis seedlings, which may be a promising alternative for fertilizers in agricultural production.

Effective control of microbial spoilage in soybeans by water-soluble ZnO nanoparticles.

The microbial spoilage of soybeans during soaking process severely deteriorates the quality of soybean products and threatens human health. Herein, water-soluble aminated zinc oxide nanoparticles (ZnO NPs) were developed to effectively control the microbial spoilage in soybeans during soaking. ZnO NPs achieved significant inactivation of three dominant spoilage bacteria (bacillus cereus, bacillus megaterium and enterococcus faecium) isolated from the deteriorated soybeans, which could adhere to the bacterial surface and damage the cell wall/membrane, but also generate large amounts of reactive oxygen species (ROS). Compared to two commercial ZnO, water-soluble ZnO exhibited superior antibacterial properties due to producing more ROS and bacteria-adhered ability. After ZnO NPs treatment, the content of the residual Zn (51.1 mg/kg) in soybeans was the safety standards of Zn element in soybeans products for human). Therefore, the water-soluble ZnO NPs showed great potentials as efficient and safe antimicrobial agents for soybeans preservation during soaking process.

Research on the Physio-Biochemical Mechanism of Non-Thermal Plasma-Regulated Seed Germination and Early Seedling Development in Arabidopsis.

Non-thermal plasma holds great potentials as an efficient, economical, and eco-friendly seed pretreatment method for improving the seed germination and seedling growth, but the mechanisms are still unclear. Therefore, a plant model organism Arabidopsis thaliana was used to investigate the physio-biochemical responses of seeds to non-thermal plasma at different treatment times by measuring the plant growth parameters, redox-related parameters, calcium (Ca2+) level and physicochemical modification of seed surface. The results showed that short-time plasma treatment (0.5, 1, and 3 min) promoted seed germination and seedling growth, whereas long-time plasma treatment (5 and 10 min) exhibited inhibitory effects. The level of superoxide anion (O2 •-) and nitric oxide (NO) and the intensity of infrared absorption of the hydroxyl group were significantly higher in short-time plasma treated Arabidopsis seeds, and the level of hydrogen peroxide (H2O2) was remarkably increased in long-time plasma treated seeds, indicating that O2 •-, ·OH, and NO induced by plasma may contribute to breaking seed dormancy and advancing seed germination in Arabidopsis, while plasma-induced H2O2 may inhibit the seed germination. The intensity of hydroxyl group and the contents of H2O2, malondialdehyde, and Ca2+ in Arabidopsis seedlings were obviously increased with the plasma treatment time. Catalase, superoxide dismutase, and peroxidase activities as well as proline level in short-time treated seedlings were apparently higher than in control. The etching effects of plasma on seed surface were dose-dependent, spanning from slight shrinkages to detached epidermis, which also significantly increased the oxidation degree of seed surface. Therefore, the improved activities of antioxidant systems, moderate ·OH, H2O2, and Ca2+ accumulation and seed surface modification induced by plasma all contribute to the enhanced seedling growth of Arabidopsis after short-time plasma treatment.

Physio-biochemical and molecular mechanism underlying the enhanced heavy metal tolerance in highland barley seedlings pre-treated with low-dose gamma irradiation.

Heavy metal pollution, as a consequence of rapid industrialization and urbanization, poses a threat to highland barley grown in Tibet. This study investigates the effect of different doses of gamma irradiation (50-300 Gy) on the physio-biochemical and molecular mechanism of highland barley under heavy metal stress. Growth data showed that 50-Gy gamma irradiation had the maximal beneficial effects on the highland barley seedlings under lead/cadmium stress. The results of oxidative parameters demonstrated that 50-Gy gamma-irradiated seedlings had lower hydrogen peroxide and malondialdehyde contents under lead/cadmium stress compared to non-irradiated seedlings. Moreover, the activities of antioxidant enzyme and proline levels in 50-Gy gamma-irradiated seedlings were drastically higher than those in non-irradiated seedlings under lead/cadmium stress. Additionally, transmission electron microscopy results revealed that the 50-Gy gamma-irradiated seedlings exhibited improved chloroplasts ultrastructure compared with non-irradiated seedlings exposed to lead/cadmium stress. Notably, transcriptional expression analysis showed that 50-Gy gamma irradiation could significantly affect the expression of genes related to heavy metal transport and abscisic acid metabolism under lead/cadmium stress. Collectively, these results provide insights into the physio-biochemical and molecular mechanisms of low-dose-gamma-irradiation-enhanced heavy metal tolerance in highland barley seedlings, thus proposing gamma irradiation as a potential technology to mitigate heavy metal toxicity in crops.