Excessive fluorine accumulation poses a significant threat to soil ecology and even human health, yet its impact on soil fauna, especially earthworms, remains poorly understood. This study employed multi-omics and biomarkers to investigate high fluorine-induced biochemical changes that cause tissue damages in Eisenia fetida. The results demonstrated that earthworms exhibited obvious damage with fluorine addition exceeding 200 mg kg(-1), with stress levels escalating as fluorine contents increased. Further analysis of the underlying mechanisms revealed that fluorine could upregulate genes encoding mitochondrial respiratory chain complexes I-III and downregulate those for IV-V, leading to reactive oxygen species (ROS) accumulation despite antioxidant system activation. The resulting ROS interfered with deoxyribonucleoside triphosphate synthesis, prompting homologous recombination as the main DNA repair mechanism. Additionally, fluorine-induced ROS also attacked and disrupted protein and lipid related metabolisms ultimately causing oxidative damages. These cumulative oxidative damages from high fluorine contents subsequently triggered autophagy or apoptosis, resulting in tissue ulceration and epithelial exfoliation. Therefore, high fluorine could threaten earthworms by inducing ROS accumulation and subsequent biomolecule damages.

Drought stress negatively affects cotton pollen fertility, which in turn leads to a decrease in seed number per boll and boll weight. Exogenous melatonin application significantly enhances pollen fertility under drought conditions, while the specific underlying mechanisms remain unclear. A pot experiment was conducted using a cultivar Yuzaomian 9110 under two moisture treatments (soil relative water content at 75 +/- 5 % and 45 +/- 5 %) with two melatonin concentration (0 and 200 mu M) to investigate the effects of exogenous melatonin on the structural traits and physiological metabolism of cotton anthers and its' relationships with pollen fertility. Results demonstrated the significant impact of drought on anthers development and metabolism, with damage to the anther tapetum and decreased starch and adenosine triphosphate (ATP) contents, subsequently resulting in reduced pollen germination rate, seed number per boll and boll weight. Melatonin application in water-deficit anthers up-regulated the expression of sucrose transporter protein (GhSWEET55) and phosphate sucrose synthetase, promoting sucrose import and synthesis, respectively. However, it also increased sucrose synthase and acid convertase, accelerating sucrose decomposition and reducing its content. Additionally, melatonin application promoted starch accumulation in water-deficit anthers by enhancing activities of adenosine diphosphate glucose pyrophosphorylase and soluble starch synthase, meaning that potential energy storage was increased, which facilitated the formation of pollen fertility. Although melatonin application reduced the expression of pyruvate kinase (GhPK) and glucose 6-phosphogluconate dehydrogenase (GhG6PD) genes in water-deficit anthers, it upregulated hexokinase (GhHXK) and citrate synthase (GhCIT) expression, enhancing ATP content, and ultimately pollen fertility, seed number and boll weight under drought. In summary, exogenous melatonin preserved cotton pollen fertility under drought stress by regulating carbohydrate and energy metabolism, especially enhancing starch and ATP accumulation in anthers.

The central carbon (C) metabolic network is responsible for most of the production of energy and biosynthesis in microorganisms and is therefore key to a mechanistic understanding of microbial life in soil communities. Many upland soil communities have shown a relatively high C flux through the pentose phosphate (PP) or the Entner-Doudoroff (ED) pathway, thought to be related to oxidative damage control. We tested the hypothesis that the metabolic organization of the central C metabolic network differed between two ecosystems, an anoxic marsh soil and oxic upland soil, and would be affected by altering oxygen concentrations. We expected there to be high PP/ED pathway activity under high oxygen concentrations and in oxic soils and low PP/ED activity in reduced oxygen concentrations and in marsh soil. Although we found high PP/ED activity in the upland soil and low activity in the marsh soil, lowering the oxygen concentration for the upland soil did not reduce the relative PP/ED pathway activity as hypothesized, nor did increasing the oxygen concentration in the marsh soil increase the PP/ED pathway activity. We speculate that the high PP/ED activity in the upland soil, even when exposed to low oxygen concentrations, was related to a high demand for NADPH for biosynthesis, thus reflecting higher microbial growth rates in C-rich soils than in C-poor sediments. Further studies are needed to explain the observed metabolic diversity among soil ecosystems and determine whether it is related to microbial growth rates. IMPORTANCE We observed that the organization of the central carbon (C) metabolic processes differed between oxic and anoxic soil. However, we also found that the pentose phosphate pathway/Entner-Doudoroff (PP/ED) pathway activity remained high after reducing the oxygen concentration for the upland soil and did not increase in response to an increase in oxygen concentration in the marsh soil. These observations contradicted the hypothesis that oxidative stress is a main driver for high PP/ED activity in soil communities. We suggest that the high PP/ED activity and NADPH production reflect higher anabolic activities and growth rates in the upland soil compared to the anaerobic marsh soil. A greater understanding of the molecular and biochemical processes in soil communities is needed to develop a mechanistic perspective on microbial activities and their relationship to soil C and nutrient cycling. Such an increased mechanistic perspective is ecologically relevant, given that the central carbon metabolic network is intimately tied to the energy metabolism of microbes, the efficiency of new microbial biomass production, and soil organic matter formation. We observed that the organization of the central carbon (C) metabolic processes differed between oxic and anoxic soil. However, we also found that the pentose phosphate pathway/Entner-Doudoroff (PP/ED) pathway activity remained high after reducing the oxygen concentration for the upland soil and did not increase in response to an increase in oxygen concentration in the marsh soil. These observations contradicted the hypothesis that oxidative stress is a main driver for high PP/ED activity in soil communities. We suggest that the high PP/ED activity and NADPH production reflect higher anabolic activities and growth rates in the upland soil compared to the anaerobic marsh soil. A greater understanding of the molecular and biochemical processes in soil communities is needed to develop a mechanistic perspective on microbial activities and their relationship to soil C and nutrient cycling. Such an increased mechanistic perspective is ecologically relevant, given that the central carbon metabolic network is intimately tied to the energy metabolism of microbes, the efficiency of new microbial biomass production, and soil organic matter formation.

Cadmium contamination can lead to a decrease in crop yield and quality. However, Cd-tolerant rice can improve rice resistance genes, improve crop tolerance to heavy metals, and protect plants from oxidative damage. In this study, Japonica rice: Chunyou 987 and Indica rice: Chuanzhong you 3607 were used to reveal the molecular response mechanism of Cd-tolerant rice under cadmium concentration of 3 mg/kg through comparative experiments combined with physiology and proteomics. The results showed that compared with indica rice, japonica rice showed more robust resistance to Cd stress and effectively retained many Cd ions in roots. Moreover, it enhanced its enzymatic and non -enzymatic anti -oxidative stress mechanism, which increased the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) by 47.37%, 21.75%, and 55.42%, respectively. The contents of non -enzymatic antioxidant substances ascorbic acid (AsA), glutathione (GSH), cysteine (Cys), proline (PRO), anthocyanins (OPC), and flavonoids were increased by 25.32%, 42.67%, 21.43%, 50.81%, 33.23%, and 72.16%, respectively. Through proteomics analysis, it was found that in response to the damage caused by cadmium stress, Japonica rice makes Photosynthesis functional proteins (psbO and PetH), Photosynthesis antenna proteins (LHCA and ASCAB9), Carbon fixation functional proteins (PEPC and OsAld), Porphyrin metabolism functional proteins (OsRCCR1 and SE5), Glyoxylate and dicarboxylate The expression of metabolism functional proteins (CATC and GLO4.) and Glutathione metabolism functional proteins (APX8 and OsGSTU13) were significantly up -regulated, which stimulated the antioxidant stress mechanism and photosynthetic system, and constructed a robust energy supply system to ensure the normal metabolic activities of life. Strengthening the mechanisms of plant homeostasis. In summary, this study revealed the molecular mechanism of tolerance to Cd stress in japonica rice, and the results of this study will provide a possible way to improve Cd-resistant rice seedlings.

Cadmium pollution affects the global ecosystem because cadmium can be transferred up the food chain. The bumblebee, Bombus terrestris, is an important insect pollinator. Their foraging activity on flowers exposes them to harmful heavy metals, which damages their health and leads to massive population declines. However, the effects of chronic exposure to heavy metals on the flight performance of bumblebees have not yet been characterized. Here, we studied variation in the flight capacity of bumblebees induced by chronic cadmium exposure at field -realistic concentrations using behavioral, physiological, and molecular approaches. Chronic cadmium exposure caused a significant reduction in the duration, distance, and mean velocity of bumblebee flight. Transcriptome analysis showed that the impairment of carbon metabolism and mitochondrial dysfunction in the flight muscle were the primary causes. Physiological, biochemical, and metabolomic analyses validated disruptions in energy metabolism, and impairments in mitochondrial respiratory chain complexes activities. Histological analysis revealed muscle fiber damage and mitochondrial loss. Exogenous decanoic acid or citric acid partially restored sustained flight ability of bumblebees by mitigating muscle fiber damage and increasing energy generation. These findings provide insights into how long-term cadmium stress affects the flight ability of insects and will aid human muscle or exercise -related disease research.