Lead (Pb) contamination in aquatic ecosystems poses a persistent threat to environmental quality and human health. Duckweed-mediated phytoremediation serves as a valuable model for exploring the short-term physiological endurance of aquatic macrophytes under extreme Pb stress in highly contaminated aqueous environments. However, the integrated mechanisms underlying Pb hyperaccumulation in this system remain insufficiently understood. In this study, we employed a combined physiological, microbiomic, and transcriptomic approach to investigate the acute stress responses of the hyperaccumulating duckweed Landoltia punctata. Non-invasive micro-test technology (NMT) demonstrated that this hyperaccumulation was driven by enhanced, root-specific Pb²⁺ uptake, with the Pb-hyperaccumulating genotype exhibiting a 36.08% higher net influx than the non-hyperaccumulating genotype. Meanwhile, Pb exposure induced pronounced kingdom-specific restructuring in the root-associated microbiome, characterized by bacterial specialization for potential detoxification and fungal transitions toward opportunistic saprotrophy. Transcriptomic profiling further revealed a transcriptional shift favoring defense pathways in the host, marked by the upregulation of core stress signaling and the repression of energy-intensive lipid metabolism to sustain essential structural barriers. Collectively, our findings indicate that this short-term physiological endurance involves a complex host-microbiome response, with causal relationships requiring further functional validation. These results provide mechanistic insights and a theoretical framework for future optimization of phytoremediation systems.

Industrialization and urbanization have intensified cadmium (Cd) pollution threats to ecosystems and agricultural safety, positioning phytoremediation as a prominent research frontier. This review systematically reviews recent advances in multidimensional molecular mechanisms underlying plant responses to Cd stress and the synergistic enhancement effects of endophytes. First, we comprehensively dissect the physiological and molecular regulatory networks in plants under Cd stress, encompassing core mechanisms including absorption and transport, cell wall and vacuolar compartmentalization, dynamic antioxidant system homeostasis, and hormone signaling coupled with transcription factor regulation. Second, focusing on plant-endophyte synergy, we elucidate direct mechanisms such as Cd adsorption, nutrient provision, and phytohormone synthesis/nutrient solubilization alongside indirect mechanisms including antioxidant system activation, gene expression modulation, and rhizosphere microenvironment remodeling, demonstrating how functional microbial strain diversity amplifies plant Cd tolerance and remediation efficacy. This review emphasizes systematic interpretation of molecular regulatory mechanisms in plant-endophyte interactions, with particular focus on revealing synergistic networks involving microRNAs and transcription factors. It provides a quantitative evaluation of multi-strain remediation efficiency to holistically validate the role of microbial diversity in enhancing plant Cd tolerance and pollution mitigation. Core insights highlight plant-microbe synergy in optimizing Cd distribution, elevating detoxification efficiency, and fortifying remediation stability. Finally, this review discusses current limitations and future development. This review provides critical theoretical foundations for developing efficient, sustainable plant-microbe combined remediation technologies against Cd pollution, offering a scientific reference for supporting farmland ecological security and sustainable food production under clearly defined biosafety and field-feasibility prerequisites.

Chimonobambusa utilis is an advantageous bamboo species known for its edible shoots, which are celebrated as “the crown of bamboo shoots”. The coloration of bamboo sheaths is related to the color, flavor and nutritional components of bamboo shoots. However, the process of bamboo sheath coloration remains unexplored in scientific literature. Therefore, the pigment content and color difference values of the bamboo sheaths of five distinct cultivars of Chimonobambusa utilis (Keng) Keng f. -1, Chimonobambusa utilis (Keng) Keng f. -2, Chimonobambusa utilis (Keng) Keng f. -3, Chimonobambusa utilis (Keng) Keng f. -4, and Chimonobambusa utilis (Keng) Keng f. -5 (C1, C2, C3, C4, and C5) were measured in this study. According to the color difference values, C1 exhibits a color index of red leaf < 2, while the remaining four cultivars fall within 2 < color index of red leaf < 4. Regarding pigment content, C1 demonstrated the highest chlorophyll levels, C4 contained the most anthocyanins, and C5 had significantly higher carotenoid content compared to the other four cultivars. A targeted metabolome assay revealed a total of 28 flavonoids in the bamboo sheaths, with 25, 27, 26, 25, and 25 flavonoids identified in the five C. utilis, respectively. Analysis of these flavonoids indicated substantial variations among the five cultivars’ bamboo sheaths. This study offers a reference point for the selection and breeding of distinctive bamboo shoots, as well as for understanding the coloration mechanism of the bamboo sheaths of C. utilis.

The enhancement of heavy metal remediation efficiency by endophytes in hyperaccumulators has been widely demonstrated. However, research on the influence of endophytes on cadmium (Cd) remediation efficiency of hyperaccumulating duckweed remains limited. In this study, a Cd-resistant endophyte, Agrobacterium fabrum GY8 (GY8), was identified, which increased Cd removal rate of duckweed to 93%. And, colonization of GY8 enhanced duckweed growth rates (up to 117.78%) and alleviated Cd-induced oxidative damage by activating key antioxidant enzymatic pathways. Further investigation revealed that GY8 facilitated phytoremediation through reducing Cd accumulation within duckweed organelles and transforming bioavailable NaCl-extractable Cd into stable HCl-extractable complexes. Whole-genome sequencing identified genes of GY8 associated with Cd resistance and plant growth promotion, including those involved in glutathione metabolism, sulfur cycling, ABC transporter systems, and phenylpropanoid biosynthesis pathways. Microbial diversity analyses confirmed the successful colonization and predominance of GY8 within duckweed. The results provide innovative insights into the mechanisms of endophytes enhancing the Cd removal rate of duckweed, offering theoretical basis for the development of plant-microbe remediation strategies for heavy metal contamination.

Nutrient starvation and ABA promote starch accumulation in duckweed fronds and turions, enhancing ADP-glucose pyrophosphorylase activity and starch grain size. Duckweed has excellent development potential due to its fast growth, high starch content, and low cellulose content. Nutrient starvation or abscisic acid (ABA) are known to affect growth and starch accumulation in duckweed. However, the joint effects of nutrient starvation and ABA on growth and starch accumulation in duckweed remain unknown. This study analyzed the response of duckweed (Spirodela polyrhiza) to nutrient starvation and ABA and the synergistic treatment of the two to examine the growth and starch accumulation of duckweed. Nutrient starvation and ABA can promote starch accumulation in both the frond and turion of duckweed as a result of the key enzyme ADP-glucose pyrophosphorylase activity that was significantly increased in the starch synthesis pathway of duckweed. Nutrient starvation and ABA can induce the formation of turions with high starch content, which reached up to 38.3 ± 1.9

Heavy metal (HM) pollution remains one of the significant environmental challenges. The plant-endophyte combined remediation technology, by integrating the dual advantages of plants and microorganisms, overcomes the limitations of individual systems in responding to HM stress, demonstrating broad application prospects. However, the mechanisms underlying this combined system, particularly how endophytes enhance plant accumulation of heavy metals, still require in-depth investigation. Recent research highlights endophytes as key facilitators to plant growth in metal-contaminated environments through nitrogen fixation, phosphorus and potassium solubilization, siderophore formation, as well as phytohormone production. Simultaneously, endophytes enhance plant HM resistance by activating antioxidant systems and inducing the synthesis of secondary metabolites. Notably, multiple mechanisms by which endophytes reduce HM toxicity have been gradually elucidated, including enhanced biosorption and bioaccumulation, reductions in bioavailability, promotion of metal transport, and enhancement of plant metal tolerance. This article systematically reviews the latest advancements in inoculation and detection methods for endophytes, and introduces the development and application of multi-omics technologies in this field, providing a solid theoretical foundation for a deeper understanding of plant-endophyte interaction mechanisms and facilitating the remediation of HM contamination.

As cadmium (Cd) pollution increases, ecological security becomes increasingly endangered, highlighting the significance of exploring and optimizing sustainable remediation technologies. Phytoremediation, recognized as a promising strategy for environmental restoration, is enhanced when combined with microorganisms, particularly endophytes. Duckweed, known for its high Cd accumulation capacity, holds great potential for remediating Cd pollution. However, the impact of endophytic microorganisms on duckweed's remediation of Cd pollution remains unclear. This study focuses on the endophytic bacterium Paenibacillus illinoisensis Y11 to investigate its effects on duckweed (Lemna minor) growth and duckweed's capacity to remediate Cd pollution. The results indicate that strain Y11 can successfully colonize duckweed under Cd stress, and the colonization by strain Y11 can significantly promote duckweed growth and increase its Cd removal rate. Strain Y11 was evaluated in vitro for plant growth-promoting properties, revealing the capacity to synthesize indole-3-acetic acid and siderophores, solubilize phosphate, and produce 1-aminocyclopropane-1-carboxylate deaminase, all of which contribute to plant growth. This study not only provides valuable microbial resources to enhance the Cd pollution remediation capacity of duckweed, but also establishes a theoretical foundation for the widespread application of endophytic microorganisms in plant-microbe combined remediation techniques.

Cadmium (Cd) contamination threatens aquatic ecosystems and human health. Duckweeds are ideal for toxicological studies due to their rapid growth and high metal uptake. While interactions between single duckweed species and Cd has been extensively studied, the impact of duckweed diversity on Cd tolerance remains unknown. This study examines three duckweed species (Lemna minor, Landoltia punctata, and Spirodela polyrhiza) under Cd stress, assessing growth, chlorophyll content, Cd accumulation, removal efficiency, and metabolic adaptations in monoculture and mixed-culture systems. The results showed that the growth of duckweeds was inhibited across all cultivation modes under 10 mg L⁻1 Cd stress, with growth rates remaining below 0.1 g d⁻1 and experiencing more than 80

Lead (Pb) is one of the most harmful, toxic pollutants to the ecological environment and humans. Duckweed, a fast-growing aquatic plant, is excellent for remediation of Pb pollution. Low molecular weight organic acids (LMWOAs) are more efficient, environmentally friendly and biodegradable than inorganic chelating agents, but the effects of LMWOAs on the tolerance and Pb enrichment of duckweed are still unclear and which LMWOAs has the best enhancing effect remains to be further studied. In this study, we screened out the optimal Pb-enriched duckweed (Landoltia punctata 0021) from 60 duckweed samples. We then investigated the effects of LMWOAs, including citric acid (CA), malic acid (MA), tartaric acid (TA), and oxalic acid (OA), on the Pb enrichment abilities of this duckweed. The results showed that the addition of CA significantly increased the biomass, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), reduced malondialdehyde (MDA) content and mitigated oxidative damage of duckweed compared to CK. The enhancement effects of the four LMWOAs on duckweed Pb enrichment were CA>MA> TA>OA. The effect of different concentrations of CA was further investigated, and it suggested that the Pb enrichment and BCF of duckweed were highest at 500 mu M. These results indicate that CA and 500 mu M are considered the best LMWOAs and CA treatment concentration for Pb-contaminated water remediation with duckweed. The study may provide a new idea for the remediation of Pb-polluted water by duckweed combined with LMWOAs.

Heavy metal contamination in the soil has become more serious due to the rapid development of the economy. Phytoremediation has evoked widespread curiosity in recent years due to its advantages in terms of being environmentally friendly and sustainable. However, there are few reports on the application of bamboo species in the field of phytoremediation, and a comprehensive overview of their potential for restoring contaminated soil by removing heavy metals is lacking. This paper incorporates existing research on bamboo species for the remediation of heavy metal-contaminated soils. It meticulously debates the physiological responses exhibited by bamboo species to heavy metal stress, encompassing growth and development responses, photosynthetic responses, and antioxidant system responses, among others. Furthermore, it elaborates on the capacity of bamboo for heavy metal accumulation and translocation, as well as their remarkable tolerance and detoxification mechanisms. This comprehensive analysis sheds light on the intricate interactions between bamboo and contaminated soil environments. Additionally, the paper summarizes various strategies for the remediation of heavy metal contamination using bamboo species. This review facilitates a more thorough exploration of the potential applications of bamboo species in the remediation of heavy metal-contaminated soils, offering a novel approach for soil environmental restoration.

Glutathione S-transferase (GST) has been established to play an important role in regulating the responses of plants to stress, although its function and mechanisms of action in the cadmium (Cd)-tolerant Lemna minor remain unclear. In this study, we sought to identify a Cd-responsive GST gene from Lemna minor for functional analysis and mechanistic characterization. We accordingly identified a member of the GST gene family, LmGSTF3, which plays a positive role in adaptation of Lemna minor to Cd. Having successfully obtained overexpressing (OE) strains via genetic transformation, we established that these strains were characterized by elevated Cd tolerance compared with the wild-type strain, as evidenced by significant increases in growth rate, chlorophyll content, antioxidant enzyme activities, and Cd removal rate. At the transcriptome level, the OE strains were found to have a stronger regulatory ability in response to Cd, particularly with respect to photoprotection, antioxidant defense, and glycolytic metabolism, which may be key factors contributing to the Cd tolerance of Lemna minor. Our findings provide a basis for further elucidating the biochemical and molecular mechanisms underlying the Cd tolerance conferred by GST genes in Lemna minor and will potentially contribute to the utilization of Lemna minor in remediating aquatic pollution.

IntroductionThe pharmacokinetic profile and residue depletion of eugenol in carp (Cyprinus carpio) tissues and plasma were performed by a convenient and reliable high-performance liquid chromatography (HPLC) method.MethodsThe eugenol in carp tissues and plasma was extracted with a mixed solution of acetonitrile and methanol. N-hexane was used to remove lipid impurities. The method was successfully applied to the pharmacokinetic and residue elimination of eugenol in carp after the carp was administered a medicated bath.ResultsThe average recoveries of eugenol in tissues and plasma fortified with four concentration levels were 69.0–106.6% and 80.0–86.7%, respectively. The relative standard deviations were < 8.9%. The limit of detection (LOD) was 0.01 μg/g in tissue and 0.008 μg/ml in plasma, respectively. The pharmacokinetic parameter of Cmax for eugenol in plasma at the concentrations of 20, 35, and 75 mg/L were 10.86, 17.21, and 37.32 mg/L, respectively. The t1/2 values were 3.68, 4.22, and 9.31 h. After the investigation of the anesthetic effect, 35 mg/L of eugenol was the optimal concentration for anesthesia. The highest accumulation concentration of eugenol in carp is in the liver and the lowest is in the muscle. In addition, the eugenol in tissue was eliminated rapidly and at a lower level than the LOD at 48 h. According to the residue elimination, the withdrawal time of eugenol was suggested at 5.2 days.DiscussionThese results indicate that the developed method had good linearity and accuracy, and is sensitive enough for the monitoring of eugenol residue in carp. The half-life of eugenol decreased with the increase in drug concentration and the eugenol was eliminated rapidly in carp tissues. 35 mg/L eugenol was recommended as an anesthetic in carp due to its favorable anesthetic effect and no mortality. This study will contribute to the establishment of MRL regulation and setting a withdrawal period.

Cadmium (Cd) is one of the most toxic metals in the environment and exerts deleterious effects on plant growth and production. Duckweed has been reported as a promising candidate for Cd phytoremediation. In this study, the growth, Cd enrichment, and antioxidant enzyme activity of duckweed were investigated. We found that both high-Cd-tolerance duckweed (HCD) and low-Cd-tolerance duckweed (LCD) strains exposed to Cd were hyper-enriched with Cd. To further explore the underlying molecular mechanisms, a genome-wide transcriptome analysis was performed. The results showed that the growth rate, chlorophyll content, and antioxidant enzyme activities of duckweed were significantly affected by Cd stress and differed between the two strains. In the genome-wide transcriptome analysis, the RNA-seq library generated 544,347,670 clean reads, and 1608 and 2045 differentially expressed genes were identified between HCD and LCD, respectively. The antioxidant system was significantly expressed during ribosomal biosynthesis in HCD but not in LCD. Fatty acid metabolism and ethanol production were significantly increased in LCD. Alpha-linolenic acid metabolism likely plays an important role in Cd detoxification in duckweed. These findings contribute to the understanding of Cd tolerance mechanisms in hyperaccumulator plants and lay the foundation for future phytoremediation studies.

生物化学是生命科学相关专业的核心课程,是一门重要的必修课程.然而,在教学过程中,因为生物化学的专业性强,涉及生物与化学的知识点繁杂且众多,在传统的PPT教学过程中学生兴趣不高,影响教学质量.OBE(Outcome based education)教育理念,是一种以成果为导向,采用逆向思维设计课程体系的先进理念,重点突出学生的主体地位.该文基于目前生物化学课程的教学现状、学生特点以及预期目标,构建OBE理念下的生物化学课程教学模式并实践,达到一定的预期效果,为生物化学的教学提供支撑.

Cadmium (Cd) and polyethylene (PE) seriously contaminate the aquatic environment and threaten human health. Many studies have reported the toxic effects of Cd and PE on plants, whereas few have reported the combined contamination of these two pollutants. In this study, duckweed (Lemma minor) was used as an indicator to explore the effect of PE microplastics (PE-MPs) at concentrations of 10, 50, 100, 200, and 500 mg/L on tolerance to 1 mg/L Cd. The results showed that different concentrations of PE-MPs inhibited the growth rate and chlorophyll content of duckweed to different degrees, both of which were minimal at 50 mg/L PE-MPs, 0.11 g/d, and 0.32 mg/g, respectively. The highest Cd enrichment (7.77 mg/kg) and bioaccumulation factors (94.22) of duckweed were detected when Cd was co-exposed with 50 mg/L of PE-MPs. Catalase and peroxidase activity first decreased and then increased with increasing PE-MPs concentrations, showing “hormesis effects”, with minimum values of 11.47 U/g and 196.00 U/g, respectively. With increasing concentrations of PE-MPs, the effect on superoxide dismutase activity increased and then declined, peaking at 162.05 U/g, and displaying an "inverted V" trend. The amount of malondialdehyde rose with different PE-MPs concentrations. This research lay a foundation for using duckweed to purify water contaminated with MPs and heavy metals.

Duckweed is a cadmium (Cd) hyperaccumulator. However, its enrichment characteristics and physiological responses to Cd have not been systematically studied. The physiological responses, enrichment characteristics, diversity of endophytic bacterial communities, and isolation of Cd-resistant endophytes in duckweed (Lemna minor 0014) were studied for different durations and Cd concentrations. The results indicated that peroxidase (POD) and catalase (CAT) activities decreased while superoxide dismutase activity first increased and then decreased with increasing Cd stress duration. POD activities, CAT activities, and O2− increased as Cd concentrations increased. Malondialdehyde content and Cd accumulation in duckweed increased with increasing concentrations and time. This endophytic diversity study identified 488 operational taxonomic units, with the dominant groups being Proteobacteria, Firmicutes, and Actinobacteria. Paenibacillus sp. Y11, a strain tolerant to high concentrations of Cd and capable of significantly promoting duckweed growth, was isolated from the plant. Our study revealed the effects of heavy metals on aquatic plants, providing a theoretical basis for the application of duckweed in water pollution.

IntroductionTrifolium pratense L. has anti-inflammatory, antioxidant, cardiovascular disease prevention, and estrogen-like effects. The existing method for the assay of effective components is commonly based on a spectrophotometer, which could not meet the requirement of quality control. Furthermore, although there have been many studies on the anti-inflammation effect of red clover, a few have been reported on the regulatory effect of red clover isoflavones (RCI) on lipopolysaccharide (LPS)-induced inflammatory response in porcine alveolar macrophages (3D4/2 cells), and its mechanism of action is still unclear.MethodsThe main components of RCI including daidzein, genistein, and biochanin A were accurately quantified by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) after optimizing the extraction process through response surface methodology. The anti-inflammatory potential of RCI was carried out by detecting the level of inflammatory cytokines and mRNA expression of related genes. Furthermore, its anti-inflammatory mechanism was explored by investigating two signaling pathways (NF-κB and MAPK).ResultsThe optimal extraction conditions of RCI were as follows: the concentration of ethanol is 86% and the solid–liquid ratio is 1:29, with the herb particle size of 40 mesh sieve. Under the optimal conditions, the total extraction of target components of RCI was 2,641.469 μg/g. The RCI could significantly suppress the production and expression of many pro-inflammatory cytokines. The results of the Western blot revealed that RCI dramatically reduced the expression of p65, p-p65, IκB-α, p38, and p-p38. These results are associated with the suppression of the signal pathway of p38 MAPK, and on the contrary, activating the NF-κB pathway. Collectively, our data demonstrated that RCI reversed the transcription of inflammatory factors and inhibited the expression of p65, p-p65, IκB-α, and p38, indicating that RCI had excellent anti-inflammatory properties through disturbing the activation of p38 MAPK and NF-κB pathways.ConclusionThe extraction conditions of RCI were optimized by HPLC-DAD combined with response surface methodology, which will contribute to the quality control of RCI. RCI had anti-inflammatory effects on the LPS-induced 3D4/2 cells. Its mechanism is to control the activation of NF-κB and p38 MAPK pathways, thereby reducing the expression of inflammatory-related genes and suppressing the release of cytokines.

应用葡聚糖凝胶层析法对烟草FI蛋白进行纯化,通过SDS-PAGE、PAGE电泳进行组分鉴定及质谱分析,并对FI蛋白进行小鼠限量试验.结果表明:(1)通过热沉法得到FI粗蛋白,经过凝胶层析法分离收集到3个组分.在凝胶电泳图中,明确组分1有两个亚基,分别为55、13.6 kD,经过与标准品对比确定组分1为FI蛋白.(2)质谱分析结果中FI蛋白含有20种氨基酸及人体8种必需氨基酸,且已达到FAO/WHO的优质蛋白评分标准.(3)限量试验表明FI蛋白对小鼠的临床行为学、体重、脏器系数均影响不显著(P＞0.05),说明FI蛋白对小鼠生长发育和健康没有抑制作用,属于基本无毒.本试验通过蛋白质谱对FI蛋白的氨基酸组成进行评估分析及小鼠限量试验,明确了 FI蛋白的营养价值及食用安全性,为烟草FI蛋白的多用途开发利用提供理论依据.

为揭示不同环境下鸡粪中氯苯胍的残留降解规律,模拟不同环境状态,研究氯苯胍在不同起始浓度、温度和pH下的降解特征.鸡粪中氯苯胍经乙腈提取,正己烷除脂,分散固相萃取法进行净化,以C18色谱柱进行分离,高效液相色谱二极管阵列检测器进行检测.结果表明,氯苯胍在0.1～30μg/g浓度间呈线性相关,相关系数R2为0.999 6,检测限为0.03 μg/g,定量限为0.10 μg/g;鸡粪中氯苯胍在0.10、0.50、1.00 μg/g 3个添加水平下,外标法定量,回收率在83.81％～94.61％之间,批内相对标准偏差为2.74％～8.93％,批间相对标准偏差为7.62％～9.72％;鸡粪中氯苯胍降解速率受起始浓度、温度和pH影响,药物起始浓度越高,鸡粪中氯苯胍降解速率越慢,当药物起始浓度为10、40、200 μg/g时,在30 d内,氯苯胍降解速率分别为100％、100％和77.10％,半衰期分别为2.36 d、8.61 d和15.43 d;鸡粪中氯苯胍降解速率随温度升高而加快,当温度为4 ℃时,氯苯胍在30 d后降解速率为43.30％,而在25 ℃和45 ℃时完全降解;酸化或碱化后氯苯胍降解速率较未处理组明显加快,在试验期内均降解完全.因此,在进行粪便无害化处理时,可通过提高堆肥温度、将堆体酸化或碱化以提高氯苯胍降解速率,进而降低环境污染风险.

Using single factor experiments and response surface methodology, the extraction conditions of N~6-（2-hydroxyethyl） adenosine（HEA） from Cordyceps chanhua were optimized. Based on the results of the single factor experiments, a Box-Behnken surface response design was used to optimize liquid-to-material ratio,water bath temperature, and water bath time. The optimized conditions were as follows: ultrapure water as the solvent, liquid-to-material ratio 118∶1, ultrasonic time 25 min, water bath at 24 ℃ for 3.8 h. Using the optimized conditions, the resultant HEA content in the extract was（0.836 ± 0.030） mg·g -1 . HEA was further purified by macroporous resin, acidic alumina chromatography, semi-preparative high performance liquid chromatography（SP-HPLC） and then confirmed to be HEA by electrospray ionization mass spectrometry（ESI-MS） and proton nuclear magnetic resonance spectroscopy（~1H NMR）. The purity of HEA was determined to be 99.32% by high performance liquid chromatography（HPLC）.