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Drought stress induces a range of physiological changes in plants, including oxidative damage. Ascorbic acid (AsA), commonly known as vitamin C, is a vital non-enzymatic antioxidant capable of scavenging reactive oxygen species and modulating key physiological processes in crops under abiotic stresses like drought. Chickpea ( Cicer arietinum L.), predominantly cultivated in drought-prone regions, offers an ideal model for studying drought tolerance. We explored the potential of AsA phenotyping to enhance drought tolerance in chickpea. Using an automated phenomics facility to monitor daily soil moisture levels, we developed a protocol to screen chickpea genotypes for endogenous AsA content. The results showed that AsA accumulation peaked at 30% field capacity (FC)—when measured between 11:30 am and 12:00 noon—coinciding with the maximum solar radiation (32 °C). Using this protocol, we screened 104 diverse chickpea genotypes and two control varieties for genetic variability in AsA accumulation under soil moisture depletion, identifying two groups of genotypes with differing AsA levels. Field trials over two consecutive years revealed that genotypes with higher AsA content, such as BDNG-2018-15 and PG-1201-20, exhibited enhanced drought tolerance and minimal reductions in yield compared to standard cultivars. These AsA-rich genotypes hold promise as valuable genetic resources for breeding programs aimed at improving drought tolerance in chickpea.

Vitamin C deficiency is found in patients with cancer and might complicate various therapy paradigms. Here we show how this deficiency may influence the use of DNA methyltransferase inhibitors (DNMTis) for treatment of hematological neoplasias. In vitro, when vitamin C is added at physiological levels to low doses of the DNMTi 5-aza-2′-deoxycytidine (5-aza-CdR), there is a synergistic inhibition of cancer-cell proliferation and increased apoptosis. These effects are associated with enhanced immune signals including increased expression of bidirectionally transcribed endogenous retrovirus (ERV) transcripts, increased cytosolic dsRNA, and activation of an IFN-inducing cellular response. This synergistic effect is likely the result of both passive DNA demethylation by DNMTi and active conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) by ten–eleven translocation (TET) enzymes at LTR regions of ERVs, because vitamin C acts as a cofactor for TET proteins. In addition, TET2 knockout reduces the synergy between the two compounds. Furthermore, we show that many patients with hematological neoplasia are markedly vitamin C deficient. Thus, our data suggest that correction of vitamin C deficiency in patients with hematological and other cancers may improve responses to epigenetic therapy with DNMTis.

Pediatric T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy resulting from overproduction of immature T-cells in the thymus and is typified by widespread alterations in DNA methylation. As survival rates for relapsed T-ALL remain dismal (10 to 25%), development of targeted therapies to prevent relapse is key to improving prognosis. Whereas mutations in the DNA demethylating enzyme TET2 are frequent in adult T-cell malignancies, TET2 mutations in T-ALL are rare. Here, we analyzed RNA-sequencing data of 321 primary T-ALLs, 20 T-ALL cell lines, and 25 normal human tissues, revealing that TET2 is transcriptionally repressed or silenced in 71% and 17% of T-ALL, respectively. Furthermore, we show that TET2 silencing is often associated with hypermethylation of the TET2 promoter in primary T-ALL. Importantly, treatment with the DNA demethylating agent, 5-azacytidine (5-aza), was significantly more toxic to TET2-silenced T-ALL cells and resulted in stable re-expression of the TET2 gene. Additionally, 5-aza led to up-regulation of methylated genes and human endogenous retroviruses (HERVs), which was further enhanced by the addition of physiological levels of vitamin C, a potent enhancer of TET activity. Together, our results clearly identify 5-aza as a potential targeted therapy for TET2-silenced T-ALL.

Using a philosophical approach or deductive reasoning, we challenge the dominant clinico-radiological worldview that defines multiple sclerosis (MS) as a focal inflammatory disease of the central nervous system (CNS). We provide a range of evidence to argue that the ‘real MS’ is in fact driven primarily by a smouldering pathological disease process. In natural history studies and clinical trials, relapses and focal activity revealed by magnetic resonance imaging (MRI) in MS patients on placebo or on disease-modifying therapies (DMTs) were found to be poor predictors of long-term disease evolution and were dissociated from disability outcomes. In addition, the progressive accumulation of disability in MS can occur independently of relapse activity from early in the disease course. This scenario is underpinned by a more diffuse smouldering pathological process that may affect the entire CNS. Many putative pathological drivers of smouldering MS can be potentially modified by specific therapeutic strategies, an approach that may have major implications for the management of MS patients. We hypothesise that therapeutically targeting a state of ‘no evident inflammatory disease activity’ (NEIDA) cannot sufficiently prevent disability accumulation in MS, meaning that treatment should also focus on other brain and spinal cord pathological processes contributing to the slow loss of neurological function. This should also be complemented with a holistic approach to the management of other systemic disease processes that have been shown to worsen MS outcomes.

Melatonin is an ancient hormone whose physiological effects have been extensively studied in animals and human. We now know that it also plays a prominent role in the growth and development of plants. In our present experiment, the relationship between endogenous melatonin and the antioxidant system was investigated in potato plant grown in vitro . Changes in redox homeostasis under ultrasound stress were examined. The concentration of small molecule antioxidants and enzymes of the three-level antioxidant pathway was measured. ELISA method was used to determine the melatonin levels in plant tissues at each growth stage (0 h, 24 h, 48 h, 1 week, and 4 weeks after subculturing the explants) both in control and ultrasound-treated plants. Ultrasound stress activated the three-level defense system and decreased the endogenous melatonin levels. Melatonin was able to provide protection against membrane damage caused by drastic ultrasound treatment. Melatonin at the heart of the redox network is a key component regulating various biochemical, cellular, and physiological responses. It has a dual role, as it is able to act both as a growth regulator and an antioxidant. A close relationship was evidenced between the plant hormone indole-3-acetic acid and melatonin and ascorbic acid.

The growth and development of cold-season plants are susceptible to high temperature. Melatonin is a plant growth regulator with potential to improve plant tolerance to biological and abiotic stresses. In our study, cherry radish (Raphanus sativus L. var. radculus pers) was cultured at a high temperature (35 °C/30 °C day/night) and different concentrations (0, 11.6, 17.4, 29.0, 34.8 and 67.0 mg L−1) of melatonin were applied to these high-temperature stressed plants to its effects on biomass, quality, antioxidant enzyme activity, chlorophyll and endogenous hormone contents. The plants were grown under normal temperature (25 °C/20 °C) as control and high-temperature condition as HT-stress treatment. The results revealed that under high temperature with 29.0 mg L−1 melatonin treatment, cherry radish biomass was significantly increased by 12.9%, and the soluble protein and soluble solid were increased by 18.7 and 9.2%, respectively. The activity of antioxidant enzyme, ascorbate peroxidase and peroxidase were increased by 43.7 and 45.5%, respectively. The chlorophyll a and carotenoid contents were increased by 7.4 and 20.0% compared with the control at 27 days. The auxin and abscisic acid contents were significantly increased by 28.5 and 6.7% compared with HT at 9 days. Thus, application of optimal rate of melatonin had a positive effect on cherry radish growth under high-temperature stress.

Light conversion films are crucial for optimizing vegetable crop production in greenhouses, particularly during winter and spring seasons. This study investigated the effects of a europium-based light conversion film (RPO) compared to traditional polyolefin film (PO film, control) on cucumber ( Cucumis sativus L.) cultivation, focusing on handle length, yield, and fruit quality in a randomized complete block design with three replications. Results demonstrated that RPO film significantly enhanced multiple light parameters: overall transmittance (8.5% increase), far-red radiation (710–760 nm, 17% increase), red-orange radiation (610–709 nm, 9.8% increase), and blue radiation (440–509 nm, 9.6% increase). The film also increased average light intensity (400–700 nm) by 13% and maximum temperature by 13%. Conversely, it reduced ultraviolet radiation (300–399 nm) by 38%, violet radiation (400–439 nm) by 3.3%, and green radiation (510–609 nm) by 5.7%. The modified light environment substantially improved cucumber production metrics. Handle length ratio decreased by 24% due to reduced cell numbers, while yield increased by 30%. Fruit quality parameters showed significant improvements: soluble protein (25% increase), vitamin C (27% increase), free amino acids (28% increase), and soluble solids (9% increase), with a 35% reduction in organic acid content. Notably, both auxin synthesis gene expression and auxin content in cucumber handles decreased by 87% and 24%, respectively.

The effects of foliar application of spermidine (Spd) on the physiological aspects of salt-stressed oat seedlings were studied under greenhouse conditions. At the seedling stage, the salt-sensitive variety, namely, Caoyou 1 and the salt-tolerant variety, namely, Baiyan 2 were treated with 70 and 100 mM of salt, followed by the foliar application of 0.75 mM Spd or distilled water. Results showed that Spd application increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and reduced the rate of O 2 ⋅– production and the accumulation of H 2 O 2 and malondialdehyde (MDA). In addition, it increased the level of zeatin riboside (ZR) and the content of endogenous polyamines. The application of Spd increased the contents of soluble sugar, soluble protein, and free proline and helped maintain the osmotic balance of oat leaves. At the same time, foliar Spd treatment helped in maintaining the ion nutrition balance. Specifically, it reduced the content of Na + and thereby stabilized the ratio of Na + /K + , Na + /Ca 2+ , and Na + /Mg 2+ . The effects of Spd application were more obvious for the salt-sensitive cultivar Caoyou 1 and under the lighter 70 mM salt stress.

Compared with single stem ginseng (G1), there is a significant gap in the research on the morphology and quality formation of multi stem ginseng (MG). This study measured the ginsenoside content in the roots, stems, and leaves of 3-year-old single stem ginseng, double stem ginseng (G2), and triple stem ginseng (G3), as well as the endogenous hormone content in the rhizomes. At the same time, the physicochemical properties and enzyme activity of the rhizosphere and non-rhizosphere soil were measured, and the differences and connections between each indicator were analyzed. ResultsThe content of ginsenosides in the roots of MG was significantly higher than that in G1, with the total ginsenoside content in G2 and G3 being 1.30 and 1.24 times higher than that in G1. There was a significant difference in the content of salicylic acid and brassinolide between G1 and MG. Differential analysis showed that aluminum bound phosphorus, aggregates with a particle size of 2-3 mm, and praseodymium were characteristic abiotic factors that contributed to differences in soil properties, fluorescein diacetate, peroxidase and invertase were characteristic enzymes that differed in different soils. A regulatory network of \"soil abiotic factor-ginsenosides-soil enzymes\" was constructed based on the results of correlation analysis. ConclusionsThe interaction between soil enzymes (fluorescein diacetate, peroxidase, ascorbate peroxidase) and abiotic factors (praseodymium, neodymium, yttrium) were the main influencing factors of ginsenoside accumulation in MG. The results had improved our understanding and helped to better guide the planting of MG.

Antioxidant requirements have neither been defined for endurance nor been defined for ultra-endurance athletes. To verify whether an acute bout of ultra-endurance exercise modifies the need for nutritive antioxidants, we aimed (1) to investigate the changes of endogenous and exogenous antioxidants in response to an Ironman triathlon; (2) to particularise the relevance of antioxidant responses to the indices of oxidatively damaged blood lipids, blood cell compounds and lymphocyte DNA and (3) to examine whether potential time-points of increased susceptibility to oxidative damage are associated with alterations in the antioxidant status. Blood that was collected from forty-two well-trained male athletes 2 d pre-race, immediately post-race, and 1, 5 and 19 d later was sampled. The key findings of the present study are as follows: (1) Immediately post-race, vitamin C, α-tocopherol, and levels of the Trolox equivalent antioxidant capacity, the ferric reducing ability of plasma and the oxygen radical absorbance capacity (ORAC) assays increased significantly. Exercise-induced changes in the plasma antioxidant capacity were associated with changes in uric acid, bilirubin and vitamin C. (2) Significant inverse correlations between ORAC levels and indices of oxidatively damaged DNA immediately and 1 d post-race suggest a protective role of the acute antioxidant responses in DNA stability. (3) Significant decreases in carotenoids and γ-tocopherol 1 d post-race indicate that the antioxidant intake during the first 24 h of recovery following an acute ultra-endurance exercise requires specific attention. Furthermore, the present study illustrates the importance of a diversified and well-balanced diet to maintain a physiological antioxidant status in ultra-endurance athletes in reference to recommendations.