Driven by the dual pressures of continuous global population growth and dwindling arable land, ensuring food security has become a paramount challenge for human society. However, soil salinization, a primary abiotic stress factor limiting agricultural production, is degrading vast tracts of arable land globally and causing drastic reductions in crop yields. Consequently, harnessing microorganisms to enhance crop adaptability to saline-alkaline environments has become a critical focus in the reclamation and utilization of these degraded soils. In this study, a salt-tolerant plant growth-promoting bacterium, Cupriavidus metallidurans strain YX16, was isolated from the red soil of Yunnan Province in China. It is characterized by salt tolerance, nitrogen fixation, inorganic phosphorus solubilization, and indole-3-acetic acid (IAA) production (83.75 ± 1.14 µg/mL), but lacks the ability to solubilize potassium and organic phosphorus, and it does not produce siderophores or 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Under salt stress, compared to the control group, the YX16 suspension treatment elevated the primary root length, plant height, root dry weight, shoot fresh weight, and shoot dry weight by 23.95

Dimethyl trisulfide (DMTS) exhibits potent antifungal activity against Alternaria alternata, yet its molecular mode of action has not been fully elucidated. In this study, we analyzed the key gene expression and phenotypic alterations in A. alternata after DMTS treatment to clarify its potential antifungal mechanism, and to provide insight into possible fungicidal targets. Given the pronounced antifungal activity of DMTS, transcriptomic analysis was performed to profile global gene expression changes in A. alternate following DMTS exposure, complemented by bioinformatics analysis and real-time fluorescent quantitative PCR (RT-qPCR) validation. A total of 2,321 differentially expressed genes (DEGs) were identified, including 934 up-regulated and 1,387 down-regulated genes. RT-qPCR validation confirmed that the gene expression trends were consistent with the transcriptomic data, supporting the reliability of the sequencing results. GO functional annotation and KEGG enrichment analysis revealed that the DEGs were associated with peroxisome formation, fatty acid β-oxidation, cellular ROS homeostasis, and energy metabolism pathways such as the tricarboxylic acid (TCA) cycle. In line with these transcriptional changes, DMTS exposure caused substantial intracellular ROS accumulation, impaired mitochondrial activity, reduced ATP production and DNA fragmentation, reflecting significant bioenergetic impairment and redox imbalance. Collectively, these findings suggest that DMTS inhibits fungal growth by disrupting peroxisome formation, mitochondrial function, and triggering excessive ROS-mediated oxidative damage. Simultaneously, DMTS impedes fatty acid β-oxidation and the TCA cycle, resulting in significant cellular ATP depletion. These combined effects ultimately inhibited the growth of A. alternata.

Enhancing the saline alkali tolerance of crops via microorganisms has become a focal point in the reclamation and utilization of saline-alkali lands. In this study, a salt-tolerant plant growth-promoting bacterium, Cupriavidus metallidurans strain YX16, was isolated fromt the red soil of Yunnan Province in China. It is characterized by salt tolerance, nitrogen fixation, inorganic phosphorus solubilization, and indole-3-acetic acid (IAA) production (83.75 ± 1.14 µg/mL), but lacks the ability to solubilize potassium and organic phosphorus, and it does not produce siderophores or 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Under salt stress, inoculation (YX16 suspension) increased the germination rate, radicle length, and index of maize seeds by 23.08%, 33.33%, and 32.62%, respectively. Furthermore, the primary root length, plant height, root dry weight, shoot fresh weight, and shoot dry weight elevated by 23.95%, 52.45%, 28.38%, 51.46%, and 107.69%, respectively, whereas the total root length and root surface area increased by 44.08% and 32.48%, respectively. Inoculation (YX16 suspension) increased the root soluble protein and proline contents by 29.24% and 19.09%, respectively, and the leaf soluble sugar, soluble protein, and proline contents by 16.16%, 18.70%, and 18.71%, respectively, thereby activating the antioxidant system. Specifically, the root superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities elevated by 22.60%, 75.67%, and 15.50%, respectively, while the leaf SOD and POD activities enhanced by 14.11% and 40.27%, respectively; however, the leaf CAT activity and chlorophyll content decreased by 25.80% and 20.81%, respectively. Moreover, the malondialdehyde (MDA) in both the roots and leaves decreased by 27.50% and 49.57%, respectively. Compared with the uninoculated control, the bacterial treatment decreased the root soluble sugar content by 20.64% and the leaf CAT activity by 13.08%, but elevated the root proline content by 29.16%, the root dry weight by 18.75%, and the leaf chlorophyll content by 12.74%; however, other antioxidant enzyme (SOD, POD) activities and root dehydrogenase activity (DHA) were not significantly affected. These findings indicate that Cupriavidus metallidurans YX16 is a salt-tolerant plant growth-promoting rhizobacterium(PGPR) that effectively alleviates salt-induced damage and promotes maize growth, providing a basis for the development of microbial agents for the amelioration of saline-alkali soils.

Soil salinization poses a significant constraint to agricultural productivity. However, certain plant growth-promoting bacteria (PGPB) can mitigate salinity stress and enhance crop performance. In this study, a bacterial isolate, R-18, isolated from saline-alkali soil in Ningxia, China, was identified as Enterobacter bugandensis based on 16S rRNA gene sequencing. The isolate was characterized for its morphological, biochemical, and plant growth-promoting traits and was evaluated for its potential to alleviate NaCl-induced stress in maize (Zea mays L.) under hydroponic conditions. Isolate R-18 exhibited halotolerance, surviving at NaCl concentrations ranging from 2.0% to 10.0%, and alkaliphilic adaptation, growing at pH 8.0–11.0. Biochemical assays confirmed it as a Gram-negative bacterium, displaying positive reactions in the Voges–Proskauer (V–P) tests, catalase activity, citrate utilization, fluorescent pigment production, starch hydrolysis, gelatin liquefaction, and ammonia production, while testing negative for the methyl red and cellulose hydrolysis. Notably, isolate R-18 demonstrated multiple plant growth-promoting attributes, including nitrogen fixation, phosphate and potassium solubilization, ACC deaminase activity, and indole-3-acetic acid (IAA) biosynthesis. Under 100 mM NaCl stress, inoculation with isolate R-18 significantly enhanced maize growth, increasing plant height, stem dry weight, root fresh weight, and root dry weight by 20.64%, 47.06%, 34.52%, and 31.25%, respectively. Furthermore, isolate R-18 improved ion homeostasis by elevating the K+/Na+ ratio in maize tissues. Physiological analyses revealed increased chlorophyll and proline content, alongside reduced malondialdehyde (MDA) levels, indicating mitigated oxidative damage. Antioxidant enzyme activity was modulated, with decreased superoxide dismutase (SOD) and peroxidase (POD) activities but increased catalase (CAT) activity. These findings demonstrated that Enterobacter bugandensis R-18 effectively alleviated NaCl-induced growth inhibition in maize by enhancing osmotic adjustment, reducing oxidative stress, and improving ion balance.

BACKGROUND:Using microbes and their metabolites as material to develop new biological fungicides is still vital for pesticide development. Our preliminary study found that the endophytic fungi Arthrinium sp. 2-65 of Thymus mongolicus (Ronniger) Ronniger showed a certain inhibitory effect on pathogenic fungi. RESULTS:In this study, the antifungal activity of Arthrinium sp. 2-65 was evaluated. The ethyl acetate extract of Arthrinium sp. 2-65 exhibited significant inhibitory activity against pathogenic fungi, especially Botrytis cinerea. The main compounds of Arthrinium sp. 2-65 metabolites were isolated and purified, and the two compounds were identified by infrared spectroscopy (IR), high-performance liquid chromatography (HPLC), 1H nuclear magnetic resonance (NMR), 13C NMR, and high-resolution mass spectrometry (HRMS) as 2-hexyl-3-methylmaleic anhydride (A) and 2-carboxymethyl-3-n-hexylmaleic acid anhydride (B). CONCLUSIONS:The main compounds (A and B) isolated and characterised from the fermentation broth of Arthrinium sp. 2-65 showed satisfactory inhibitory effects against pathogenic fungi, especially B. cinerea. These compounds could be used as potential molecules for the development of novel pesticides to control grey mould.

Alternaria alternata, as a main decay fungus of goji berry, can produce mycotoxins such as alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA). Carvacrol (CVR) has exhibited a broad-spectrum antifungal activity in vitro. We assumed that CVR can also be applied to control Alternaria rot on goji berries and mycotoxins produced by the pathogens. To investigate whether CVR impacts the accumulation of mycotoxins and cell membrane damage of A. alternata, the antifungal activity of CVR on the fungal growth and mycotoxin production was evaluated in this study. The results showed that the minimum inhibitory concentration (MIC) of CVR against A. alternata was 0.12 µL/mL. Meanwhile, the destruction of plasma membrane integrity, cytoplasmic leakage, intracellular oxidative damage, and inhibitory effect in vivo were also observed in A. alternata treated with CVR. Moreover, CVR significantly reduced the accumulation of AOH, AME, and TeA. Transcriptomic profiling was performed by means of comparative RNA-Seq analysis to research the gene expression level of A. alternata, which attested to significant changes in nitrogen metabolism, carbon utilization, fatty acid oxidation, and antioxidant enzymes in CVR-treated A. alternata. This study suggests a new understanding of the molecular mechanism of response to CVR treatment in A. alternata, indicating that CVR is a novel antifungal agent with the potential to be applied to various fungi.

Lycium barbarum, is a medicine-food homology plant, so sustainable control of the postharvest Goji berry black mold caused by Alternaria alternata is particularly critical. In this paper, the impact of dimethyl trisulfide (DMTS) on A. alternata was studied, as well as the effects of DMTS on hypha ultrastructure, membrane permeability, reactive oxygen production, and essential enzymes of the cellular defense system. DMTS was shown to significantly inhibit the spore germination and hyphal growth of A. alternata in a concentration-dependent manner. The results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that A. alternata cells were separated between cytoplasm and cell wall, organelles such as mitochondria were vacuolate or even disappeared, and the cytoplasm was fused. PI staining, conductivity measurements, and intracellular nucleic acid and protein content measurements showed that the permeability of the cell membrane changed after DTMS treatment, leading to the leakage of intracellular nucleic acid and protein. DMTS could also cause the accumulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA), thus causing membrane oxidative damage. Through directly destroying the fungal cell and indirectly inducing membrane damage, DMTS can control the postharvest Goji berry black mold, and is a potential application prospect in the control of postharvest diseases.

植物病原真菌是导致作物产量损失和品质下降的重要因素之一,因此,开发低毒高效的抑菌剂一直是研究的热点.本研究从百里香植株茎中分离得到1株内生真菌2-63菌株,通过形态学结合分子生物学鉴定其为塞缪尔斯木霉Trichoderma samuelsii.平板拮抗活性表明:T.samuelsii 2-63菌株对8种植物病原真菌的拮抗活性均达70.0％以上,其中对枸杞黑霉病菌Alternaia alternata拮抗活性最高可达87.1％;平板共培养试验表明:T.samuelsii 2-63菌株挥发性有机化合物(VOCs)也表现出对病原菌不同程度的抑制活性,抑制率在31.0％～68.5％;但T.samuelsii 2-63菌株液体发酵液和粗提物的抑菌活性较低.抑菌活性结果结合气相色谱-质谱联用(GC-MS)分析试验结果表明:T.samuelsii2-63菌株抑菌活性的关键成分为VOCs,其主要组分为6-戊基-2H-吡喃-2-酮(6-PP).探索性试验表明:固体发酵条件下,大米培养基比大麦培养基更利于6-PP的产生,最大产量为38.6 mg/mL;浅层液体培养条件下,6-PP随着培养时间的增加出现先上升后下降的趋势,在培养第15天时产量最大,为0.1 mg/mL.该研究结果为基于木霉菌的微生物菌剂和农药的开发提供了 一定的理论依据和试验基础.

提高大学生实践能力和创新能力是深化实践教学改革的重要内容.综合研究性实验对培养学生综合实践能力具有重要的促进作用,已成为高校实践教学中的重要组成部分.以"微生物学综合研究性实验"课程为研究对象,建立以课前动员、方案制定与论证、过程管理、实验总结与分析、撰写报告等为关键环节,探索构建综合研究性实验课程教学模式.在教学过程中,充分融入教师科研项目内容,以问题为驱动,注重过程考核,加强交流与协作,提倡团队精神,营造良好的学习氛围.通过该教学模式,能够培养学生的科研创新能力,提升学生的团队意识和协作意识,具有一定的推广价值和示范作用.

Taking plant metabolites as material to develop new biological fungicides is still an important mission for pesticide development, and the preliminary study confirmed that Allium mongolicum showed a certain inhibitory effect on plant pathogens. In this study, the antifungal activity of extracts of A. mongolicum was studied and the compounds were isolated, purified, and identified by HPLC, NMR, and ESI-MS. The methanol extract of A. mongolicum exhibited certain inhibitory activity against almost all nine tested pathogens at concentration of 0.5 mg/ml. Sixteen compounds were isolated and purified from the extract, which were identified as nine flavonoids, six phenolic acids, and an amino acid. Among them, cinnamic acid derivatives 1, 2, and 3 and flavonoids 7, 8, 9, and 13 were separated in A. mongolicum for the first time.

[目的]寻找较高抑菌活性的酚类化合物.[方法]采用菌丝生长速率法测试了丹皮酚和百里酚磺酸酯类衍生物的抑菌活性.[结果]在50 mg/L时,丹皮酚(1)衍生物4a～4n对供试病原菌表现出较好的抑制活性,部分表现出比阳性对照百菌清更高的抑制活性.而百里酚(2)衍生物5a～5n抑菌活性较低,酚羟基对于百里酚维持其高的抑菌活性十分关键.[结论]同属于酚类化合物,但酚羟基对于丹皮酚和百里酚抑菌活性的影响却大不相同,该研究为开发高效、低毒的新型杀菌剂提供理论参考.

为了探究盐酸小檗碱在植物病原真菌方面的抑制作用,以黄连根粉为材料,采用酸水法提取和乙醇重结晶获得盐酸小檗碱纯品,采用生长速率法研究了盐酸小檗碱对常见植物病原菌的抑制活性.结果 表明,盐酸小檗碱的提取率为3.3％,经高效液相色谱法测得其含量为93.56％;抑菌活性试验表明,盐酸小檗碱在100μg/mL时对玉米大斑病菌的抑制率达99.9％,EC50为8.20μg/mL,表现出比药剂对照噁霉灵和百菌清更高的抑制活性;进一步的试验表明,与噁霉灵及百菌清相比,盐酸小檗碱对玉米大斑病菌的抑制作用具有持效期长的特点.

为有效防控构杞木虱,提高宁夏枸杞产品品质,以当地常用药剂吡虫啉为对照药剂,另选4种药剂开展田间枸杞木虱防治试验,比较各药剂处理的田间防效.结果 表明,供试药剂中,以22.4％螺虫乙酯悬浮剂1 000倍液、1.8％阿维菌素乳油1 500倍液处理的速效性较好,药后3d的防效分别为72.07％、74.09％;持效性方面,22.4％螺虫乙酯悬浮剂1 000倍液处理表现最好,药后10、14 d的防效分别为85.94％、75.41％,30％唑虫酰胺悬浮剂7 500倍液次之,药后10、14 d的防效分别为69.12％、66.81％,1.8％阿维菌素乳油1 500倍液在药后10 d的防效保持在70％以上,但药后14 d防效下降幅度较大.

学习兴趣在"90后"大学生的教育中占有重要地位,激发与培养学习兴趣的途径众多.问题引导式教学方法是提高学生课堂参与度、提高教师教学效果的重要手段.本文从改革课程评价方法、优化教学模块、精心设计课堂教学流程、合理安排实验模块难易程度和教学制度保障五个方面,将问题引导式教学方法应用于高校生物化学实验课,旨在达到激发与培养学生的学习兴趣、提高课堂教学质量的目的.

以吡虫啉为代表的新烟碱类杀虫剂具有农业用量大、环境残留高和对非靶标生物毒性效应显著的特征,引发的生态环境问题日益凸显.光解是环境中有机农药的主要降解方式之一.根据近年来的文献报道,简述新烟碱类杀虫剂在环境中残留的潜在生态毒性风险和光降解转化行为,以期为正确评估该类化合物在环境介质中残留的环境健康风险提供科学依据.

[目的]从宁夏中卫硒砂瓜种植区多年连作土壤中分离获得1株高效降解酚酸类物质的菌株,对其进行分类鉴定,并全面评估其对11种酚酸类物质的降解效能,以期为该菌在酚酸类自毒物质降解领域中的应用提供理论依据.[方法]通过形态特征和16S rRNA基因序列分析进行菌株鉴定;采用液相色谱串联二极管阵列检测器研究菌株对多种酚酸物质的降解特性.[结果]经生理生化及分子生物学鉴定,该菌株为不动杆菌属(Acinetobacter sp.),命名为K7.该菌株对4-羟基苯甲酸、香豆酸、香草酸、苯甲酸、阿魏酸和咖啡酸具有良好的降解效果,对丁香酸、香草醛、肉桂酸和没食子酸的降解效能较弱,不能降解水杨酸.以咖啡酸为代表,研究不同条件对菌株K7降解效能的影响,发现在中性偏碱(pH7～8)、较高温度(30～40℃)、咖啡酸初始浓度小于100 mg·L-1时,菌株K7对咖啡酸具有高效降解能力.[结论]不动杆菌K7对多种酚酸类化合物表现出良好的降解效能.

蚜虫是枸杞最主要的害虫之一,不仅造成枸杞植株营养成分的流失,而且传播多种植物病毒,严重影响枸杞的品质和产量.蚜虫具有个体小、繁殖快、适应能力强的特点,由于西北地区高温干旱的环境以及长期单一地使用化学药剂防治使其抗药性增强等原因,导致宁夏蚜虫防治难度大,危害逐年加重.为做好蚜虫的防治工作,促进枸杞产业的可持续发展.本文归纳和总结了近年来国内利用生物农药防治枸杞蚜虫的研究进展,旨在为宁夏枸杞蚜虫的防治提供参考.

[Aims] The aims were to search for paeonol-azo derivatives with high antifungal activities.[Methods] A series of novel paeonol-azo derivatives were synthesized by combining the azo moiety to the structure ofpaeonol,their antifungal activities against phytopathogenic fungi were investigated by using the mycelial growth rate method.[Results] All the synthesized compounds have been reported for the first time except 4a,and the structures were confirmed by 1H NMR and ESI-MS.The results of biological assay indicated that 4b-4h exhibited excellent antifungal activities against Botrytis cinerea,Exserohilum turcicum and Alternaria solani at the concentration of 50 mg/L with the inhibition rates of more than 70％,which were better than that ofpaeonol and chlorothalonil.[Conclusions] Paeonol-azo derivatives might be considered as new promising lead candidates for further design and synthesis of agricultural fungicides with high efficacy and low toxicity as well as safety to non-target organisms.

微视频是信息化教育的重要组成部分,本文通过探究微视频在生物化学实验教学中的应用,阐明了利用微视频教学方法有利于引导学生自主探究性学习,培养学生创新能力,提高课堂教学效率,实现教学方法的改革与创新.借助网络和多媒体技术,微视频资源的共享与交流还将进一步加强,有助于凝结和打造优秀的教学团队,为高校生物化学实验信息化教学提供借鉴.

[目的]寻找具有较高抑菌活性的百里酚偶氮类化合物.[方法]以百里酚为母体,采用组合优化原理合成系列百里酚偶氮类衍生物,并采用菌丝生长速率法对其抑菌活性进行了初步筛选,对抑菌活性较好的化合物测定EC50值.[结果]目标化合物结构经1H NMR和HR-MS确证,化合物3a、3b、3c、3h、3i和3j为已知化合物,其余化合物3d、3e、3f、3g、3k为首次报道.目标产物3a和3d在100 mg/L对除番茄灰霉病菌外的所有供试病菌均表现出比阳性对照(口恶)霉灵更高的抑菌活性.化合物3a对玉米大斑病菌和苹果腐烂病菌的EC50值远低于(口恶)霉灵对2种病菌的Ec50值,表现出较好的抑菌活性.[结论]百里酚偶氮类化合物表现出较好的抑菌活性,可在其结构基础上,进行多位点和基团的修饰,有望发现抑菌活性更高的广谱型抑菌化合物,为开发高效、低毒和对非靶标生物安全的新型杀菌剂提供理论参考.