Antioxidant Enzyme System Research Articles

Biochemical features of tomato under the influence of gibberellin and its impact on life table and physiology of Tuta absoluta (Merick) (Gelechiidae, Lepidoptera) reared on tomato

The Tomato leaf miner Tuta absoluta is an important agricultural pest and exerts a considerable influence on tomato production across the world. In the present research tomato plants were sprayed with a gibberellin solution at a concentration of 50 µM. The gibberellin treatment resulted in a prolonged duration of T. absoluta preadult stage (33.67 days) compared to control group (27.38 days). The fecundity rate in treated females (82.33 eggs/female) was lowered compared to the controls (96.92 eggs/female). The intrinsic rate of increase (r) (0.080 day−1) was also reduced in treatments compared with the control (0.110 day−1). The finite rate of increase (λ) in treatment (1.084 day−1) decreased compared to the controls (1.116 day−1). The antioxidant system enzymes of T. absoluta, including catalase, peroxidase, and superoxide dismutase (SOD) were increased in treated insects. The gibberellin also increased the activity of detoxifying enzymes including Glutathione s-transferase with two substrates (DCNB and CDNB) and cytochrome P450 compared to the control group. While general esterase did not show significant differences in treatment and control. The secondary metabolites in treated plants including total sugar, total phenol content, anthocyanin, flavonoid and tannin showed an increasing trend. The results clearly show the negative impact of gibberellin on life table and physiology of the tomato leaf miner and can be considered favorable in integrated pest management programs of this pest.

Degradation of petroleum hydrocarbon contaminants by Rhodococcus erythropolis KB1 synergistic with alfalfa (Medicago sativa L.).

Petroleum hydrocarbons are a stubborn pollutant that is difficult to degrade globally, and plant-microbial degradation is the main way to solve this type of pollutant. In this study, the physiological and ecological responses of alfalfa to petroleum hydrocarbons in different concentrations of petroleum hydrocarbon-contaminated soil with KB1 (Rhodococcus erythropolis) were analyzed and determined by laboratory potting techniques. The growth of alfalfa (CK) and alfalfa with KB1 (JZ) in different concentrations of petroleum hydrocarbons contaminated soil was compared and analyzed. The results of the CK group showed that petroleum hydrocarbons could significantly affect the activity of alfalfa antioxidant enzyme system, inhibit the development of alfalfa roots and the normal growth of plants, especially in the high-concentration group. KB1 strain had the ability to produce IAA, form biofilm, fix nitrogen, produce betaine and ACC deaminase, and the addition of KB1 could improve the growth traits of alfalfa in the soil contaminated with different concentrations of petroleum hydrocarbons, the content of soluble sugars in roots, and the stress resistance and antioxidant enzyme activities of alfalfa. In addition, the degradation kinetics of the strain showed that the degradation rate of petroleum could reach 75.2% after soaking with KB1. Furthermore, KB1 can efficiently degrade petroleum hydrocarbons in advance and significantly alleviate the damage of high concentration of petroleum hydrocarbons to plant roots. The results showed that KB1 strains and alfalfa plants could effectively enhance the degradation of petroleum hydrocarbons, which provided new ideas for improving bioremediation strategies.

Chromosome-scale genome assembly clarifies the mechanism of flooding tolerance and evolutionary history of Myricaria laxiflora

Myricaria laxiflora, belonging to the Tamaricaceae family, is a valuable plant resource naturally occurring along the riverbanks of the Yangtze River Basin. In this study, we constructed a chromosome-level M. laxiflora genome which was 1.34 Gb in size, with 12 chromosomes and a contig N50 of 11.69 Mb. In total, 23,719 protein-coding genes were discovered across the M. laxiflora genome. Phylogenetic investigation indicated that Tamaricaceae and Polygonaceae diverged between 65 and 81 million years ago (Mya). M. laxiflora underwent one whole genome duplication (WGD) between 19.74 and 24.60 Mya, and experienced a long terminal repeat (LTR) insertion around 0.15 Mya. These genomic changes may be related to environmental upheavals (such as the uplift of the Qinghai-Tibet Plateau) experienced by M. laxiflora during its evolution, and also may have provided a foundation for its evolution and adaptation. To analyze the flooding adaption mechanism of M. laxiflora, we compared morphological, physiological, and transcriptomic changes under control and submerged conditions. Overall, M. laxiflora was found to adopt a "quiescence" strategy when completely submerged. Specifically, in response to submersion, photosynthesis weakens, growth stagnates, glycolysis is activated, and the antioxidant enzyme system is enhanced. The “ethylene response pathway” was ascertained as a likely regulator of this process, and a MlERF-VII gene (Mla11G026380) may be the key gene regulating this process. Our findings shed light on the underlying mechanisms behind the flooding resistance displayed by M. laxiflora, while also establishing a basis for the conservation of its genetic resources.

Exploring the molecular mechanisms of melatonin-induced tolerance to salt-alkali stress in Populus cathayana × canadansis 'Xinlin 1′

Melatonin is widely recognized as involved in a wide range of plant growth and development functions. Research has primarily focused on herbaceous plants, with few findings on the function of melatonin in supporting tree growth. In this study, it was demonstrated that melatonin, as an endogenous hormone, considerably contributed towards the increased tolerance of poplar to salt-alkali stress. Transcriptome and metabolome analysis revealed that melatonin may enhance the cellular protection and antioxidant mechanisms of poplar and improve salt-alkali tolerance by regulating genes and metabolites involved in photosynthesis, antioxidant enzyme systems, plant hormone signal transduction pathways, and in the flavonoid as well as the melatonin biosynthesis pathway. The results of this study not only aid our increased understanding of the potential roles of melatonin in salt-alkali stress but also shed light on the potential mechanisms of the economically important woody model plant, poplar, involved in resisting abiotic stress.

Utilizing transcriptomics and proteomics to unravel key genes and proteins of Oryza sativa seedlings mediated by selenium in response to cadmium stress

BackgroundCadmium (Cd) pollution has declined crop yields and quality. Selenium (Se) is a beneficial mineral element that protects plants from oxidative damage, thereby improving crop tolerance to heavy metals. The molecular mechanism of Se-induced Cd tolerance in rice (Oryza sativa) is not yet understood. This study aimed to elucidate the beneficial mechanism of Se (1 mg/kg) in alleviating Cd toxicity in rice seedlings.ResultsExogenous selenium addition significantly improved the toxic effect of cadmium stress on rice seedlings, increasing plant height and fresh weight by 20.53% and 34.48%, respectively, and increasing chlorophyll and carotenoid content by 16.68% and 15.26%, respectively. Moreover, the MDA, ·OH, and protein carbonyl levels induced by cadmium stress were reduced by 47.65%, 67.57%, and 56.43%, respectively. Cell wall metabolism, energy cycling, and enzymatic and non-enzymatic antioxidant systems in rice seedlings were significantly enhanced. Transcriptome analysis showed that the expressions of key functional genes psbQ, psbO, psaG, psaD, atpG, and PetH were significantly up-regulated under low-concentration Se treatment, which enhanced the energy metabolism process of photosystem I and photosystem II in rice seedlings. At the same time, the up-regulation of LHCA, LHCB family, and C4H1, PRX, and atp6 functional genes improved the ability of photon capture and heavy metal ion binding in plants. Combined with proteome analysis, the expression of functional proteins OsGSTF1, OsGSTU11, OsG6PDH4, OsDHAB1, CP29, and CabE was significantly up-regulated under Se, which enhanced photosynthesis and anti-oxidative stress mechanism in rice seedlings. At the same time, it regulates the plant hormone signal transduction pathway. It up-regulates the expression response process of IAA, ABA, and JAZ to activate the synergistic effect between each cell rapidly and jointly maintain the homeostasis balance.ConclusionOur results revealed the regulation process of Se-mediated critical metabolic pathways, functional genes, and proteins in rice under cadmium stress. They provided insights into the expression rules and dynamic response process of the Se-mediated plant resistance mechanism. This study provided the theoretical basis and technical support for crop safety in cropland ecosystems and cadmium-contaminated areas.

An Innovative Layer-by-Layer Edible Coating to Regulate Oxidative Stress and Ascorbate–Glutathione Cycle in Fresh-Cut Melon

Fresh-cut fruits, renowned for their convenience and nutritional value, are susceptible to rapid deterioration, compromising their quality and shelf life. In this study, a sustainable and environmentally friendly edible coating was developed based on sodium alginate (SA; 1% w/v), cedar mucilage (CM; 4% w/v), and calcium chloride (2% w/v), applied using a layer-by-layer technique to preserve the quality and prolong the shelf life of fresh-cut melon. Fruits were cut into cubes coated or uncoated by dipping and subsequently packaged in a polyethylene terephthalate container and stored for 15 days at 4 °C. Physicochemical traits and qualitative features such as polyphenol, flavonoid, carotenoid, ascorbic acid content, as well as antioxidant activity, were assessed. Furthermore, the enzymatic antioxidant system and the ascorbate–glutathione cycle were investigated. The coating reduced weight loss and enhanced polyphenol, flavonoid, and ascorbic acid content and antioxidant activity during cold storage. Edible coating (SA + CM) represents a valid tool to extend the postharvest life, improve the storability, and enhance the physicochemical and qualitative traits of fresh-cut melon. Further research is required to optimize coating formulations and application techniques to maximize their effectiveness and commercial viability in the food industry.

The Metabolism, Detrimental Effects, and Signal Transduction Mechanism of Reactive Oxygen Species in Plants under Abiotic Stress

Plants are a major source of bio based materials, and their productivity is significantly impacted by environmental adversities with the continuous deterioration of the environment. The disruption of reactive oxygen species (ROS) production and scavenging balance is a common consequence of various abiotic stresses in plants, resulting in the excessive accumulation of ROS. However, it is crucial to acknowledging the dual role of ROS, acting both as harmful substances and signaling molecules. ROS can interact with membrane proteins, initiating a chain reaction of membrane lipid peroxidation. This process leads to a decrease in membrane lipid unsaturation and fluidity, as well as an increase in membrane permeability. Inhibited enzyme activity even lead to loss of protein function, caused DNA damage and mutations, blocked DNA replication and transcription, eventually leading to cell death. This can result in significant reductions in crop yield and biomass in bio based agricultural production. ROS also played vital role in signal molecule transduction in the process of plant resistance to stress, and worked in concert with other signal molecules to induce the stress resistance genes’ expression and enhance plant resistance. Hereto, scavenging mechanism for ROS in plants is of the essence to regulate the concentration of ROS, thus determining which role ROS play. The thermal dissipation of excess light energy effectively avoids ROS production, and the enzymatic and non-enzymatic antioxidant defense systems in plants work cooperatively to clear excessive ROS. This review provides a comprehensive summary of the production pathway, detrimental effects, scavenging mechanism and signal transduction of ROS in plants under abiotic stress.

Serum SOD1 level predicts the severity and prognosis of community-acquired pneumonia patients

BackgroundSuperoxide dismutase 1 (SOD1) is one of the most important participants of antioxidant enzyme system in biological system. Previous studies have found that SOD1 is associated with many inflammatory diseases. The goal of this study was to assess the associations of serum SOD1 with the severity and prognosis in community-acquired pneumonia (CAP) patients by a prospective cohort study. MethodsCAP patients were enrolled from the Second Affiliated Hospital of Anhui Medical University. Peripheral blood samples were gathered. The level of serum SOD1 was detected through enzyme linked immunosorbent assay (ELISA). Clinical characteristics and demographic information were analyzed. ResultsThe level of serum SOD1 was gradually upregulated with elevated CAP severity scores. Spearman correlation coefficient or Pearson rank correlation analyses indicated that serum SOD1 was strongly connected with many clinical parameters among CAP patients. Further linear and logistic regression analyses found that the level of serum SOD1 was positively associated with CRB-65, CURB-65, SMART-COP, and CURXO scores among CAP patients. Moreover, serum higher SOD1 at admission substantially increased the risks of ICU admission, mechanical ventilation, vasoactive agent usage, death, and longer hospital stays during hospitalization. Serum SOD1 level combination with CAP severity scores elevated the predictive abilities for severity and death compared with alone serum SOD1 and CAP severity scores in CAP patients during hospitalization. ConclusionThe level of serum SOD1 is positively associated with the severity and poor prognosis in CAP patients, suggesting that SOD1 is implicated in the initiation and progression of CAP. Serum SOD1 may be regarded as a biomarker to appraise the severity and prognosis for CAP patients.

The Impact of Cr(III) and Cr(VI) on Lipid Accumulation in Chlorella pyrenoidosa

In this study, Chlorella pyrenoidosa was cultured with different concentrations of Cr(III) and Cr(VI), and the changes in biomass, lipid content, protein content and total sugar content of Chlorella pyrenoidosa under different culture conditions were detected. The effects of Cr(III) and Cr(VI) on the intracellular antioxidant system and related key enzymes of lipid synthesis were analyzed. The results showed that appropriate Cr(III) and Cr(VI) concentrations could make Chlorella pyrenoidosa regulate the contents of SOD, POD, ASA, CAT and GSH in cells, improve the enzyme activity of ACC and promote lipid synthesis. The aim was to investigate the mechanism of lipid synthesis by analyzing the distribution of Cr(III) and Cr(VI) in algal cells. The lipid content of Chlorella pyrenoidosa reached its highest level at 50.43 wt% and 38.00 wt% when both Cr(III) and Cr(VI) concentrations in the culture environment were 0.5 mg/L. These values were 1.37 and 1.03 times higher than the control group, respectively. The addition of appropriate Cr(III) and Cr(VI) concentrations can increase ME enzyme activity and decrease PEPC enzyme activity, shorten the biomass accumulation cycle and prolong the lipid synthesis cycle.

Responses to lead stress in Scrophularia striata: insights into antioxidative defence mechanisms and changes in flavonoids profile.

Lead (Pb) induces oxidative stress in plants, which results in different responses, including the production of antioxidants and changes in the profile of secondary metabolites. In this study, the responses of Scrophularia striata exposed to 250mgL-1 Pb (NO3 )2 in a hydroponic environment were determined. Growth parameters, oxidative and antioxidative responses, redox status, and the concentration of Pb were analysed in roots and shoots. Malondialdehyde and hydrogen peroxide (H2 O2 ) levels in the roots were significantly increased and reached their highest value at 72h after Pb treatment. Superoxide dismutase, catalase, and peroxidase, as an enzymatic antioxidant system, were responsible for reactive oxygen species scavenging, where their activities were increased in the shoot and root of Pb-treated plants. Enzymatic antioxidant activities were probably not enough to remove a significant H2 O2 content in response to Pb treatment. Therefore, other defence responses were activated. The results stated that the flavonoid components of S. striata progressed towards the increase of isoflavone, flavanol, and stilbenoid contents under Pb treatment. In general, S. striata stimulates the enzymatic defence system and activates the non-enzymatic system by modulating the profile of flavonoids toward the production of flavonoids with high antioxidant activity, such as quercetin and myricetin in response to Pb stress.

Role of Thioredoxin System in Regulating Cellular Redox Status in Alzheimer's Disease.

Alzheimer's disease (AD) is the most common form of dementia and a public health problem. It exhibits significant oxidative stress and redox alterations. The antioxidant enzyme systems defend the cellular environment from oxidative stress. One of the redox systems is the thioredoxin system (TS), which exerts decisive control over the cellular redox environment. We aimed to review the protective effects of TS, which include thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH. In the following, we discussed the physiological functioning and the role of the TS in maintaining the cellular redox-homeostasis in the AD-damaged brain. Trx protects the cellular environment from oxidative stress, while TrxR is crucial for the cellular detoxification of reactive oxygen species in the brain. However, TS dysregulation increases the susceptibility to cellular death. The changes in Trx and TrxR levels are significantly associated with AD progression. Though the data from human, animal, and cellular models support the neuroprotective role of TS in the brain of AD patients, the translational potential of these findings to clinical settings is not yet applied. This review summarizes the current knowledge on the emerging role of the TrxR-Trx system in AD.

The effects of cadmium on selected oxidative stress parameters and the content of photosynthetic pigments in cucumber Cucumis sativus L.

BackgroundEnvironmental pollution by cadmium (Cd) is currently a common problem in many countries, especially in highly industrialised areas. Cd present in the soil can be absorbed by plants through the root system. AimThe aim of the present study was to investigate the effects of cadmium on the metabolic activity of cucumber plants (Cucumis sativus L.) and the accumulation and distribution of Cd in the organs of the plants. MethodsCucumber seeds (3 g) were exposed to 0.76, 1.58 or 4.17 mg Cd/L (applied as CdCl2 solutions). The activity of selected antioxidant enzymes - glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), lipid peroxidation and the content of photosynthetic pigments were determined in 6-week-old cucumber plants. In addition, intake of Cd has been determined by flame atomic absorption spectrometry (F-AAS). ResultsThe results show that the applied cadmium concentrations affected the activity of antioxidant enzymes. An increase in CAT activity and a decrease in SOD activity were observed in all cucumber organs analysed. GSH-Px activity increased in the roots and stems. Surprisingly, GSH-Px activity decreased in the leaves. The level of lipid peroxidation was usually unchanged (the only one statistically significant change was a decrease in the concentration of malondialdehyde in the leaves which was observed after exposure to the highest Cd concentration). The applied Cd concentrations had no effect on the content of photosynthetic pigments. The highest cadmium content was found in the roots of cucumber plants. Cd tends to accumulate in the roots and a small amount was translocated to the stems and leaves, which was confirmed with the translocation factor (TF). ConclusionsThe results indicate that the range of cadmium concentrations used, corresponding to the level of environmental pollution recorded in Europe, effectively activates the antioxidant enzyme system, without intensifying lipid peroxidation or reducing the content of photosynthetic pigments.

Arbuscular mycorrhizal symbiosis modulates nitrogen uptake and assimilation to enhance drought tolerance of Populus cathayana

This study aims to investigate effects of arbuscular mycorrhizal fungi (AMF) inoculation on nitrogen (N) uptake and assimilation in Populus cathayana under drought stress (DS). Herein, we measured photosynthetic performance, antioxidant enzyme system, N level and N assimilation enzymes, proteins content and distribution, transcripts of genes associated with N uptake or transport in P. cathayana with AMF (AM) or without AMF (NM) under soil water limitation and adequate irrigation. Compared with NM-DS P. cathayana, the growth, gas exchange properties, antioxidant enzyme activities, total N content and the proportion of water-soluble and membrane-bound proteins in AM-DS P. cathayana were increased. Meanwhile, nitrate reductase (NR) activity, NO3− and NO2− concentrations in AM-DS P. cathayana were reduced, while NH4+ concentration, glutamine synthetase (GS) and glutamate synthetase (GOGAT) activities were elevated, indicating that AM symbiosis reduces NO3− assimilation while promoting NH4+ assimilation. Furthermore, the transcriptional levels of NH4+ transporter genes (PcAMT1-4 and PcAMT2-1) and NO3− transporter genes (PcNRT2-1 and PcNRT3-1) in AM-DS P. cathayana roots were significantly down-regulated, as well as NH4+ transporter genes (PcAMT1-6 and PcAMT4-3) in leaves. In AM P. cathayana roots, DS significantly up-regulated the transcriptional levels of RiCPSI and RiURE, the key N transport regulatory genes in AMF compared with adequate irrigation. These results indicated that AM N transport pathway play an essential role on N uptake and utilization in AM P. cathayana to cope with DS. Therefore, this research offers a novel perspective on how AM symbiosis enhances plant resilience to drought at aspect of N acquisition and assimilation.

Grape SnRK2.7 Positively Regulates Drought Tolerance in Transgenic Arabidopsis.

In this study, we obtained and cloned VvSnRK2.7 by screening transcriptomic data to investigate the function of the grape sucrose non-fermenting kinase 2 (SnRK2) gene under stress conditions. A yeast two-hybrid (Y2H) assay was used to further screen for interaction proteins of VvSnRK2.7. Ultimately, VvSnRK2.7 was heterologously expressed in Arabidopsis thaliana, and the relative conductivity, MDA content, antioxidant enzyme activity, and sugar content of the transgenic plants were determined under drought treatment. In addition, the expression levels of VvSnRK2.7 in Arabidopsis were analyzed. The results showed that the VvSnRK2.7-EGFP fusion protein was mainly located in the cell membrane and nucleus of tobacco leaves. In addition, the VvSnRK2.7 protein had an interactive relationship with the VvbZIP protein during the Y2H assay. The expression levels of VvSnRK2.7 and the antioxidant enzyme activities and sugar contents of the transgenic lines were higher than those of the wild type under drought treatment. Moreover, the relative conductivity and MDA content were lower than those of the wild type. The results indicate that VvSnRK2.7 may activate the enzyme activity of the antioxidant enzyme system, maintain normal cellular physiological metabolism, stabilize the berry sugar metabolism pathway under drought stress, and promote sugar accumulation to improve plant resistance.

Seeds treatment with salicylic acid increases gene expression and activity of antioxidant enzymes in wheat plants under zinc or copper deficiency

The effect of wheat seeds treatment with salicylic acid (SA) on the expression of the TaCu/ZnSOD, TaFeSOD and TaCAT2 genes and the activity of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) in leaves at the optimal content of zinc (2 µM) and copper (0.3 µM) in root environment or there deficiencies has been studied. It was shown for the first time that seeds treatment with SA leads to an increase of the number of genes transcripts compared to untreated plants, both under optimal conditions of mineral nutrition and under zinc or copper deficiency. The activity of enzymes, especially catalase, also increases. Judging by the MDA content, this allows one to avoid increasing the intensity of lipid peroxidation (LPO) and, accordingly, the development of oxidative stress. It is concluded that the discovered positive effect of seed treatment with SA on the activity of the main enzymes of antioxidant system may underlie the stimulating effect of this phytohormone on physiological processes in plants under microelements deficiency.

Arbuscular mycorrhizal fungi enhanced resistance to low-temperature weak-light stress in snapdragon (Antirrhinum majus L.) through physiological and transcriptomic responses.

Low temperature (LT) and weak light (WL) seriously affects the yield and quality of snapdragon in winter greenhouse. Arbuscular mycorrhizal fungi (AMF) exert positive role in regulating growth and enhancing abiotic stress tolerance in plants. Nevertheless, the molecular mechanisms by AMF improve the LT combined with WL (LTWL) tolerance in snapdragon remain mostly unknown. We compared the differences in root configuration, osmoregulatory substances, enzymatic and non-enzymatic antioxidant enzyme defense systems and transcriptome between AMF-inoculated and control groups under LT, WL, low light, and LTWL conditions. Our analysis showed that inoculation with AMF effectively alleviated the inhibition caused by LTWL stress on snapdragon root development, and significantly enhanced the contents of soluble sugars, soluble proteins, proline, thereby maintaining the osmotic adjustment of snapdragon. In addition, AMF alleviated reactive oxygen species damage by elevating the contents of AsA, and GSH, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR). RNA-seq analysis revealed that AMF regulated the expression of genes related to photosynthesis (photosystem I related proteins, photosystem II related proteins, chlorophyll a/b binding protein), active oxygen metabolism (POD, Fe-SOD, and iron/ascorbate family oxidoreductase), plant hormone synthesis (ARF5 and ARF16) and stress-related transcription factors gene (bHLH112, WRKY72, MYB86, WRKY53, WRKY6, and WRKY26) under LTWL stress. We concluded that mycorrhizal snapdragon promotes root development and LTWL tolerance by accumulation of osmoregulatory substances, activation of enzymatic and non-enzymatic antioxidant defense systems, and induction expression of transcription factor genes and auxin synthesis related genes. This study provides a theoretical basis for AMF in promoting the production of greenhouse plants in winter.

Enhanced resistance to heat and fungal infection in transgenic Trichoderma via over-expressing the HSP70 gene

Heat stress is one of the major abiotic stresses affecting the growth, sporulation, colonization and survival of Trichoderma viride. This study aimed to gain a better insight into the underlying mechanism governing the heat stress response of T. viride Tv-1511. We analysed the transcriptomic changes of Tv-1511 under normal and heat stress conditions using RNA sequencing. We observed that Tv-1511 regulates the biosynthesis of secondary metabolites through a complex network of signalling pathways. Additionally, it significantly activates the anti-oxidant defence system, heat shock proteins and stress-response-related transcription factors in response to heat stress. TvHSP70 was identified as a key gene, and transgenic Tv-1511 overexpressing TvHSP70 (TvHSP70-OE) was generated. We conducted an integrated morphological, physiological and molecular analyses of the TvHSP70-OE and wild-type strains. We observed that TvHSP70 over-expression significantly triggered the growth, anti-oxidant capacity, anti-fungal activity and growth-promoting ability of Tv-1511. Regarding anti-oxidant capacity, TvHSP70 primarily up-regulated genes involved in enzymatic and non-enzymatic anti-oxidant systems. In terms of anti-fungal activity, TvHSP70 primarily activated genes involved in the synthesis of enediyne, anti-fungal and aminoglycoside antibiotics. This study provides a comparative analysis of the functional significance and molecular mechanisms of HSP70 in Trichoderma. These findings provide a valuable foundation for further analyses.

Comparative Transcriptome Analysis of the Hepatopancreas from Macrobrachium rosenbergii Exposed to the Heavy Metal Copper.

The contamination of aquatic ecosystems by the heavy metal copper (Cu) is an important environmental issue and poses significant risks to the physiological functions of aquatic organisms. Macrobrachium rosenbergii is one of the most important freshwater-cultured prawns in the world. The hepatopancreas of crustaceans is a key organ for immune defense, heavy metal accumulation, and detoxification, playing a pivotal role in toxicological research. However, research on the molecular response of the hepatopancreas in M. rosenbergii to Cu exposure is still lacking. In this study, the transcriptomic response in the hepatopancreas of M. rosenbergii was studied after Cu exposure for 3 and 48 h. Compared with the control group, 11,164 (7288 up-regulated and 3876 down-regulated genes) and 10,937 (6630 up-regulated and 4307 down-regulated genes) differentially expressed genes (DEGs) were identified after 3 and 48 h exposure, respectively. Most of these DEGs were up-regulated, implying that gene expressions were largely induced by Cu. Functional enrichment analysis of these DEGs revealed that immunity, copper homeostasis, detoxification, DNA damage repair, and apoptosis were differentially regulated by Cu. Seven genes involved in immunity, detoxification, and metabolism were selected for validation by qRT-PCR, and the results confirmed the reliability of RNA-Seq. All these findings suggest that M. rosenbergii attempts to resist the toxicity of Cu by up-regulating the expression of genes related to immunity, metabolism, and detoxification. However, with the excessive accumulation of reactive oxygen species (ROS), the antioxidant enzyme system was destroyed. As a result, DNA damage repair and the cellular stress response were inhibited, thereby exacerbating cell damage. In order to maintain the normal function of the hepatopancreas, M. rosenbergii removes damaged cells by activating the apoptosis mechanism. Our study not only facilitates an understanding of the molecular response mechanisms of M. rosenbergii underlying Cu toxicity effects but also helps us to identify potential biomarkers associated with the stress response in other crustaceans.

Effects of supplementation with different zinc-based products on the growth and health of Nile tilapia

Zinc is one of the essential microelements for the metabolism of animals. Zinc nanoparticles may have higher bioavailability due to their low specific surface area, facilitating absorption by fish. The present study aimed to evaluate the effects of supplementation with different zinc-based products on the growth and health of Nile tilapia Oreochromis niloticus. Zinc, in different sizes (nanoparticles or bulk) and forms (inorganic or organic), were used as a supplement in the tilapia diet at a dose of 15 mg kg feed−1 for 60 days. At the end of the feeding trial, production performance, hemato-immunological parameters, activity of antioxidant system enzymes, exposure to Streptococcus agalactiae and zinc concentration in the muscle were examined. After the bacterial challenge, the mean corpuscular hemoglobin concentration (MCHC) significantly increased in the fish treated with organic zinc, inorganic nano zinc, and organic nano zinc, while in the control group (inorganic zinc), MCHC remained unchanged. Regarding defense cells, dietary inorganic nano zinc increased the number of basophils (1.50 ± 1.10) compared to organic zinc (0.80 ± 0.90). Lymphocyte count increased after the challenge only in the organic zinc treatments (bulk and nanoparticles). Neutrophils decreased in the control (inorganic zinc) (2.20 ± 1.70) and inorganic nano zinc (2.60 ± 2.70) treatments after the challenge. When compared before and after the bacterial challenge, the plasma antimicrobial titer significantly increased after the bacterial challenge in all treatments. No significant differences were observed for total proteins, enzymes (SOD and CAT), cumulative survival and zinc deposition on fillet. In conclusion, organic zinc in nanoparticles or bulk size increased Nile tilapia innate defense during bacterial infection. However, the other parameters evaluated were not affected by zinc particle size or form (organic or inorganic), indicating that further evaluations should be conducted with organic zinc in nanoparticles or bulk size in the tilapia diet.

Salicylic Acid and Gemma-Aminobutyric Acid Mediated Regulation of Growth, Metabolites, Antioxidant Defense System and Nutrient Uptake in Sunflower (Helianthus annuus L.) Under Arsenic Stress.

Arsenic (As) is a highly toxic and carcinogenic pollutant commonly found in soil and water, posing significant risks to human health and plant growth. The objectives of this study to evaluate morphological, biochemical, and physiological markers, as well as ion homeostasis, to alleviate the toxic effects of As in sunflowers through the exogenous application of salicylic acid (SA), γ-aminobutyric acid (GABA), and their combination. A pot experiment was conducted using two sunflower genotypes, FH-779 and FH-773, subjected to As stress (60mg kg-1) to evaluate the effects of SA at 100mg L-1, GABA at 200mg L-1, and their combination on growth and related physiological and biochemical attributes under As stress. The study revealed that As toxicity had a detrimental effect on various growth parameters, chlorophyll pigments, relative water content, total proteins, and nutrient uptake in sunflower plants. It also led to increased oxidative stress, as indicated by higher levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2), along with As accumulation in the roots and leaves. However, the application of SA and GABA protected against As-induced damage by enhancing the enzymatic antioxidant defense system. This was achieved through the activation of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities, as well as an increase in osmolytes. They also improved nutrient acquisition and plant growth under As toxicity. We investigated the regulatory roles of SA and GABA in mitigating arsenic-induced phytotoxic effects on sunflower. Our results revealed a significant interaction between SA and GABA in regulating growth, photosynthesis, metabolites, antioxidant defense systems, and nutrient uptake in sunflower under As stress. These findings provide valuable insights into plant defense mechanisms and strategies to enhance stress tolerance in contaminated environments. In the future, SA and GABA could be valuable tools for managing stress in other important crops facing abiotic stress conditions.