Microplastics (MPs) and arbuscular mycorrhizal fungi (AMF) are ubiquitous in soil, yet the comprehensive impact of their coexistence on soil microecology and greenhouse gas (GHG) emissions remains elusive. This study used 2 % (w/w) nitrile butadiene rubber (particle size <= 150 mu m), Glomus versiforme, field soil, and soybeans as research materials. The objectives of this research were to systematically evaluate the impacts of AMF on soil physicochemical properties, microecological characteristics, and GHG fluxes under the stress of MPs via controlled experimental design. Our results reveal that exposure to MPs reduced soil porosity, enzyme activity, and carbon (C) and nitrogen (N) content, as well as disrupted soil microbial interactions, ultimately resulting in a significant increase in CO2, CH4 and N2O fluxes. MPs also inhibited soybean plant height and dry matter accumulation, and reduced leaf chlorophyll content. However, the coexistence of AMF and MPs reversed this trend. AMF significantly enhanced soil enzyme activity, C and N content, maintained healthy microbial interactions, and reduced CO2, CH4, and N2O emissions approximately by 5.49 %, 38.66 %, and 15.32 % in MPspolluted soil. Further in-depth analysis reveals that AMF induced changes in plant root exudates such as succinic acid, phlorizin, and indoleacrylic acid which in turn mediated alterations in soil microbial communities, including the abundance and activity of bacteria belonging to taxa like Saprospiraceae, Arthrobacter, and Sphingomonas. This mechanism underlies the antagonistic effect of AMF on GHG emissions when coexisting with MPs. Our findings provide novel insights into the research of coexistence in AMF and MPs then offer valuable strategies for mitigating the challenges posed by emerging pollutants to plants.

The agronomic characters and physio-chemical indexes of plants under heavy metal pollution will be affected in varying degrees. Arbuscular mycorrhizal fungi (AMF) play an important role in plant response to abiotic stress due to their unique properties. In order to understand the tolerance effect of maize to Pb after symbiosis with arbuscular mycorrhizalfungi (AMF), the environment led by Pb pollution in the maize farmland was simulated using exogenous Pb(NO3)2 aging soil for 15 days. The effects of AMF inoculation ( Funneliformis mosseae, Fm; Claroideoglomus etunicatum, Ce; Glomus versiforme, Gv) and no AMF inoculation (NM) on the growth of maize at different Pb concentrations (0, 170, 570, 970 mg·kg-1) were investigated in pot experiment, and the changes of agronomic traits, antioxidant capacity and Pb content of maize inoculated with AMF were analyzed. The results show that the colonization rate of mycorrhizal under Pb contamination was 15.0%-36.0% higher than that without Pb contamination. The height and chlorophyll content of colonized maize were increased by 11.8%-26.8% and 3.9%-7.5%, respectively, and the fresh weight increased by 50%. The translocation factor decreased, meanwhile the Pb content in stem and leaf of maize decreased significantly, but for root it increased significantly ( P < 0.05). Resistance analysis indicate that the formation of mycorrhiza inhibited the activity of SOD in maize leaves, but significantly increased the activity of SOD in maize roots, while the activity of POD in the leaves and roots increased. When the concentration of Pb was high, the activity of CAT in roots increased significantly ( P < 0.05). The formation of mycorrhiza resulted in the decrease of proline content in maize roots and the increase of soluble protein content in maize leaves and roots ( P < 0.05). Under the condition of Pb pollution, AMF inoculation increased the antioxidant capacity of maize, increased the content of soluble protein in maize leaves and roots, and improved the water retention capacity, so as to enhance the resistance of maize to Pb pollution and ensure the normal growth of maize in Pb-contaminated soil. This study provides a theoretical basis for the remediation of heavy metal contaminated soil in farmland and the safe production of crops.

Drought, water, and nitrogen (N) losses have always been great challenges for agricultural production in subtropical regions of China. To study appropriate irrigation regimes and reasonable N applications, a field experiment was conducted for summer maize (Zea mays L.) from 2018 to 2019. Two irrigation treatments, namely, rain-fed irrigation and supplementary irrigation, were designed, and five levels of N fertilizer were applied. The differences in the growth periods of biomass, leaf area index, agronomic traits, carbon accumulation, and carbon metabolism enzyme activity were measured. Findings revealed that the interaction of water and N has a significant impact on maize growth. Compared to other N treatments, N250 produced significantly higher biomass, leaf area index, agronomic traits, carbon accumulation, and carbon metabolism enzyme activity. In 2018, the agronomic traits and leaf area index were significantly higher than in 2019. Meanwhile, additional irrigation could help improve agronomic traits and the leaf area index. Further correlation analysis revealed that carbon accumulation was positively correlated with carbon metabolism enzyme activity, although lower at maturity than in the flowering period. Overall, the findings suggest that supplementary irrigation in conjunction with N250 treatment is a worthwhile measure for sustainable maize production in subtropical regions of China.

Drought and flooding are the two most important environmental factors limiting maize (Zea mays L.) production globally. This study aimed to investigate the physiological mechanisms and accurate evaluation indicators and methods of maize germplasm involved in drought and flooding stresses. The twice replicated pot experiments with 60 varieties, combined with the field validation experiment with 3 varieties, were conducted under well-watered, drought, and flooding conditions. Most varieties exhibited stronger tolerance to drought than flooding due to higher antioxidant enzyme activities, osmotic adjustment substances, and lower reactive oxygen species. In contrast, flooding stress resulted in higher levels of reactive oxygen species (particularly O2-), ascorbate peroxidase, catalase, peroxidase, and soluble sugars but lower levels of superoxide dismutase, proline, and soluble protein compared with well-watered conditions. Superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, proline, soluble sugars, and protein contents, in addition to plant height, leaf area/plant, and stem diameter, were accurate and representative indicators for evaluating maize tolerance to drought and flooding stresses and could determine a relatively high mean forecast accuracy of 100.0% for the comprehensive evaluation value. A total of 4 principal components were extracted, in which different principal components played a vital role in resisting different water stresses. Finally, the accuracy of the 3 varieties screened by multivariate analysis was verified in the field. This study provides insights into the different physiological mechanisms and accurate evaluation methods of maize germplasm involved in drought and flooding stresses, which could be valuable for further research and breeding.

深部工程岩爆灾害孕育过程中硬岩破裂模式的合理识别对岩爆预警具有重要意义.针对传统方法的局限性,本文在硬岩微震试验的基础上提出了一种基于微震信号的硬岩破裂模式识别方法.首先,通过巴西圆盘与直剪试验分别采集花岗岩张拉破裂及剪切破裂的微震信号;然后,利用小波分析方法对两类信号进行分解重构,将样本熵与微震信号幅度作为特征指标并构建训练样本;最后,采用训练样本训练支持向量机,建立硬岩拉剪破裂模式与特征指标的非线性映射关系.研究表明,该方法适用于硬岩拉剪破裂演化过程识别,可为岩爆灾害的合理预警提供有效手段.

Excessively high concentrations of selenium (Se) in soil are toxic to crop plants, and inoculation with arbuscular mycorrhizal fungi (AMF) can reverse Se stress in maize (Zea mays L.). To investigate the underlying mechanisms, maize seedlings were treated with sodium selenate (5 mg Se[VI] kg-1) and/or AMF (Funneliformis mosseae and Claroideoglomus etunicatum). Dual RNA sequencing in mycorrhiza and 16 S ribosomal DNA sequencing in soil were performed. The results showed that Se(VI) application alone decreased plant dry weight, but increased plant Se concentration, total Se content (mainly selenocysteine), and root superoxide content. Inoculation with either F. mosseae or C. etunicatum increased plant dry weight, decreased Se accumulation and selenocysteine proportion, enhanced root peroxidase activity, and alleviated oxidative stress in Se(VI)-treated plants. Inoculation also downregulated the expression of genes encoding Se transporters, assimilation enzymes, and cysteine-rich receptor-like kinases in Se(VI)-stressed plants, similar to plant-pathogen interaction and glutathione metabolism related genes. Conversely, genes encoding selenium-binding proteins and those related to phenylpropanoid biosynthesis were upregulated in inoculated plants under Se(VI) stress. Compared with Se(VI)-free plants, Se tolerance index, symbiotic feedback percentage on plant dry weight, and root colonization rate were all increased in inoculated plants under Se(VI) stress, corresponding to upregulated expression of 'key genes' in symbiosis. AMF inoculation increased bacterial diversity, decreased the relative abundances of selenobacteria related to plant Se absorption (e.g., Proteobacteria and Firmicutes), and improved bacterial network complexity in Se(VI)-stressed soils. We suggest that stress-mediated enhancement of mycorrhizal symbiosis contributed to plant Se(VI) tolerance, whereas AMF-mediated reshaping of soil bacterial community structure prevented excessive Se accumulation in maize.

为了研究施加不同浓度的生物炭对丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)共生体系下玉米根系及生长的影响,选用玉米正大619以盆栽方式进行试验,设置0％(CK)、0.75％(C1)、1.50％(C2)、2.25％(C3)、3.00％(C4)5个不同的生物炭施用量和3个取样期(玉米出苗30、50、70 d).结果表明,施加生物炭显著降低30、50 d时玉米根系的侵染率(P<0.05)、降低30 d时的接种势和基质孢子数;提高玉米叶片叶绿素含量(50 d时的C1、C2处理除外);施加生物炭处理在30、50 d时玉米根系指标相比同时期的对照主要表现为下降,而在50 d时C2、C3处理的根系指标则高于对照;施加生物炭提高了30、70 d时的根系活力(30 d时的C3处理除外),而50 d时由于侵染率较低且根系生长相比其他2个时期较弱,因此根系活力较低;30、50 d时,施加生物炭显著提高玉米地上部和地下部干质量(30 d时的C3、C4处理及50 d时的C4处理除外),而70 d时玉米处于开花期,对养分需求量较大,C1、C2、C3处理因菌根侵染率较低,根系生长状况不及CK,因此干物质积累较少,而C4处理在高浓度的生物炭作用下保障了养分供给,使玉米干质量高于CK(P<0.05).生物炭的施加会抑制菌根和玉米根系的生长,但生物炭改善土壤理化性质和养分含量,保证养分供给,因此提高了玉米的叶绿素含量和干质量.

Background Melatonin played an essential role in numerous vital life processes of animals and captured the interests of plant biologists because of its potent role in plants as well. As far as its possible contribution to photoperiodic processes, melatonin is believed to act as a growth regulator and a direct free radical scavenger/indirect antioxidant. The objective of this study to identify a precise melatonin concentration for a particular application method to improve plant growth requires identification and clarification. Methods This work establishes unique findings by optimizing melatonin concentration in alleviating the detrimental effects of drought stress in maize. Maize plants were subjected to drought stress (40–45% FC) after treatments of melatonin soil drenching at different concentrations (50, 100, and 150 µM) to consider the changes of growth attribute, chlorophyll contents, photosynthetic rate, relative water content (RWC), chloroplast ultrastructure, endogenous hormonal mechanism, and grain yield. Results Our results showed that the application of melatonin treatments remarkably improved the plant growth attributes, chlorophyll contents, photosynthetic rate, RWC, hormonal mechanism, and grain yield plant −1 under drought conditions at a variable rate. Conclusion Our current findings hereby confirmed the mitigating potential of melatonin application 100 µM for drought stress by maintaining plant growth, hormone content, and grain yield of maize. We conclude that the application of melatonin to maize is effective in reducing drought stress tolerance. Graphical Abstract

为探究酸性土壤下丛枝菌根真菌(AMF)对玉米生长特性及铝吸收情况的影响,采取盆栽试验法,在酸性土壤(pH值为4.4)中分别将4种AMF(摩西管柄囊霉、幼套近明球囊霉、聚丛根孢囊霉、变形球囊霉)接种到耐铝型玉米桂单0810和铝敏感型玉米郑单958上,研究酸性土壤中AMF共生对玉米的影响.结果表明,在酸性土壤条件下,AMF与2种玉米均建立了良好的共生关系(菌根侵染率均大于45％),显著促进了玉米生长.AMF共生显著提高玉米根际土壤pH值,减少了活性铝溶出,抑制了玉米对铝(Al)的吸收和积累.同时,AMF还提高了土壤有机质和土壤球囊霉素的含量.但不同AMF对玉米促生效果不同,与桂单0810共生的AMF中,幼套近明球囊霉的促生效应最佳,菌根侵染率达到了59.3％,玉米干物质质量较CK处理增加了100.00％,而其根部、茎秆、叶片的Al浓度较CK处理减少了33.30％、58.19％、52.60％;土壤pH值较CK增加了18.96％,土壤活性铝总量较CK减少了30.73％.与郑单958共生的AMF中,摩西管柄囊霉的效果最好,菌根侵染率达到了53.60％,玉米干物质质量较CK处理增加了71.70％,根部、茎秆、叶片的Al浓度则较CK处理分别减少了39.55％、61.98％、57.58％;土壤pH值较CK处理增加了23.90％,土壤活性铝总量较CK处理减少了26.11％.本研究表明,AMF可以有效改善玉米根际土壤微生态环境,促进玉米在酸性土壤中生长,增强玉米耐铝性.本试验筛选出了摩西管柄囊霉、幼套近明球囊霉这2种与耐铝型玉米和铝敏感型玉米共生效果最好的AMF.

丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)在土壤生态系统中发挥着巨大作用,但目前AMF还不能纯培养,只能通过与宿主植物共生的方式扩繁.为研究不同宿主植物对AMF的扩繁效应,本研究选择玉米(Zea mays)、高粱(Sorghum bicolor)、黑麦草(Lolium perenne)、三叶草(Trifolium pratense)作为宿主,分别对聚丛根孢囊霉(Rhizophagus aggregatus)和幼套近明球囊霉(Claroideoglomus etunicatum)进行扩繁.在种植后的第30、60、90和120天分别对接种AMF后宿主植物根系的AMF侵染率、基质中的AMF孢子密度以及AMF的接种势进行测定分析.结果 显示,不同宿主对AMF的扩繁效应不同,扩繁结束后聚丛根孢囊霉及幼套近明球囊霉对宿主植物的侵染率由高到低依次为玉米＞高粱＞三叶草＞黑麦草,聚丛根孢囊霉的孢子密度由高到低依次为玉米＞高粱＞黑麦草＞三叶草,幼套近明球囊霉的孢子密度影响由高到低依次为高粱＞玉米＞三叶草＞黑麦草.同一宿主对不同AMF的扩繁效应也不同,玉米和黑麦草对聚丛根孢囊霉的扩繁效应高于幼套近明球囊霉,三叶草和高粱对幼套近明球囊霉的扩繁效应高于聚丛根孢囊霉.试验还发现,AMF的孢子密度与其对植物的侵染率有关,并且存在极显著正相关的关系.本研究表明,玉米是聚丛根孢囊霉扩繁的最佳宿主植物,高粱是幼套近明球囊霉扩繁的最佳宿主植物.

Arbuscular mycorrhizal fungi (AMF) widely exist in the soil ecosystem. It has been confirmed that AMF can affect the root exudates of the host, but the chain reaction effect of changes in the root exudates has not been reported much. The change of soil microorganisms and soil enzyme vigor is a direct response to the change in the soil environment. Root exudates are an important carbon source for soil microorganisms. AMF colonization affects root exudates, which is bound to have a certain impact on soil microorganisms. This manuscript measured and analyzed the changes in root exudates and allelopathic effects of root exudates of maize after AMF colonization, as well as the enzymatic vigor and bacterial diversity of maize rhizosphere soil. The results showed that after AMF colonization, the contents of 35 compounds in maize root exudates were significantly different. The root exudates of maize can inhibit the seed germination and seedling growth of recipient plants, and AMF colonization can alleviate this situation. After AMF colonization, the comprehensive allelopathy indexes of maize root exudates on the growth of radish, cucumber, lettuce, pepper, and ryegrass seedlings decreased by 60.99%, 70.19%, 80.83%, 36.26% and 57.15% respectively. The root exudates of maize inhibited the growth of the mycelia of the pathogens of soil-borne diseases, and AMF colonization can strengthen this situation. After AMF colonization, the activities of dehydrogenase, sucrase, cellulase, polyphenol oxidase and neutral protein in maize rhizosphere soil increased significantly, while the bacterial diversity decreased but the bacterial abundance increased. This research can provide a theoretical basis for AMF to improve the stubble of maize and the intercropping mode between maize and other plants, and can also provide a reference for AMF to prevent soil-borne diseases in maize.

针对那板水库引水隧洞开挖过程中存在发生塌方地质灾害的安全隐患问题,采用微震技术追踪引水隧洞开挖过程中的围岩破裂过程,论述了塌方微震监测与预警的技术要点.工程实践表明,微震监测与预警技术是可行的,是浅埋隧洞Ⅳ、Ⅴ类围岩塌方灾害监测与预警的有效手段.

农业农村现代化是实施乡村振兴战略的总目标.近年来,广西大力开展现代特色农业示范区建设,现代特色农业示范区建设已成为推进农业现代化发展的重要抓手,但在建设中存在用地保障不足、资金投入不足、科技支撑不足、产业融合不足等问题,需着力化解示范区建设用地困难、拓展融资渠道、加强科技服务、打造农业全产业链,推动南宁市现代特色农业示范区在"十四五"期间高质量发展.

We explored the influence of symbiosis with arbuscular mycorrhizal fungi (AMF) on rhizosphere-soil microecology and its relationship with the artemisinin content in Artemisia annua (Artemisia annua L.). Three treatment groups were established: A. annua in symbiosis with Funneliformis mosseae, A. annua in symbiosis with Glomus versiforme, and A. annua without AMF symbiosis as a blank control. The nutrient content, pH, microbial density, activity, diversity, and evenness as well as the urease, acid phosphatase, and sucrase activities of A. annua rhizosphere soil and the relative artemisinin content in A. annua in the absence and presence of AMF symbiosis were measured and analyzed at four stages: T1 (rosette stage, 30 d after transplanting), T2 (growth stage, 70 d after transplanting), T3 (mature stage, 90 d after transplanting), and T4 (harvest stage, 120 d after transplanting). The results showed that AMF symbiosis increased the activities of urease, acid phosphatase, and sucrase in the rhizosphere soil of A. annua; promoted the absorption and utilization of N and P; increased the relative content of artemisinin in the aboveground parts of A. annua; and improved the utilization of various carbon sources by rhizosphere microorganisms to some extent. In addition, AMF also improved the density, quantity. and diversity of microorganisms in the A. annua rhizosphere. Different AMF had different effects on A. annua. The results showed that AMF symbiosis improved the absorption and utilization of soil nutrients by A. annua and increased its relative artemisinin content. These results may provide a theoretical basis for the production of A. annua.

Selenium (Se) is a beneficial trace element for certain animals including humans, while remaining controversial for plants. High Se concentration in soil is toxic to plants especially at seedling stage of the plants. Although, arbuscular mycorrhizal fungi (AMF) are important for plant stress resistance; but the mechanisms by which AMF alleviate Se stress in crop seedlings are unclear. Therefore, we investigated the potential strategies of AMF symbiosis to alleviate Se stress in maize (Zea mays) from plants and soil perspectives. Results showed that Se stress (Se application level > 5 mg kg-1) significantly inhibited leaf area, shoot dry weight, and root dry weight of maize (P < 0.05). In contrast, AM symbiosis significantly improved root morphology, increased nitrogen and phosphorus nutrition, promoted shoot growth, inhibited the transport of Se from soil/roots to shoots, and then diluted the concentration of Se in shoots (32.65-52.80%). In general, the response of maize growth to AMF was mainly observed in shoots rather than roots. In addition, AMF inoculation significantly increased the easily extractable glomalin-related soil protein and organic matter contents and decreased the availability of soil Se to the plant. Principal component analysis showed that AMF promoted growth and nutrition uptake of maize was the most dominant effect of Se stress alleviation, followed by the decrease of soil Se availability, limiting Se transport from soil/roots to shoots. Moreover, the expression of Se uptake-related ion transporter genes (ZmPht2, ZmNIP2;1, and ZmSultr1;3) in maize roots were down-regulated upon AM symbiosis which resultantly inhibited the uptake and transport of Se from soil to maize roots. Thus, AMF could impede Se stress in maize seedlings by improving plant and soil characteristics.

以发根农杆菌(Agrobacterium rhizogenes)K599诱导胡萝卜产生毛状根,接种丛枝菌根(AM)真菌摩西斗管囊霉(Funneliformis mosseae)建立双重培养体系,研究不同消毒方法、超声波、低温预处理和培养基pH对摩西斗管囊霉孢子萌发的影响及其与胡萝卜毛状根建立双重培养体系的最佳条件.研究结果表明:消毒方法3孢子萌发率最高,孢子污染率最低,15 d孢子萌发率达48.88％,而污染率仅为9.98％;超声波处理能降低孢子污染率11.17％～14.53％;低温预处理可有效提高孢子的萌发率,4℃低温处理10 d和15 d效果较好,其萌发率分别为70％和65％;AM真菌孢子在水琼脂培养基萌发最佳pH为6.5,萌发率达到48.50％,pH<5.5或pH>8.0均抑制孢子萌发,pH 5.5和pH 8.0的萌发率分别为15.43％和16.06％.消毒孢子先于水琼脂萌发后,再挑取萌发管多,菌丝较长的孢子并将菌丝生长方向正对毛状根方向进行转接,可以提高双重培养的成功率.MSR培养基为双重培养的最优培养基.胡萝卜毛状根与AM真菌双重培养可为菌根真菌繁殖及相关分子机理研究提供可行有效的途径.

研究盆栽条件下,接种与未接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)摩西球囊霉(Glomus mosseae)对黄花蒿(Artemisia annua L.)生长和根系分泌物化学组成的影响.结果 表明,接种AMF黄花蒿的株高、苗干重和根干重均显著增加,增幅均达到20％以上;接种AMF也改善了黄花蒿的根系形态,除了根系半径以外,根长增加了87.0％、根表面积增加了97.0％、根体积增加了10.7％、根尖数增加了38.4％、根分叉数增加了75.6％、根系活力提高了19.6％,差异均达到极显著水平;与未接种AMF的黄花蒿基质中的根系分泌物(NM-S)相比,接种AMF下黄花蒿基质中的根系分泌物(AM-S)可溶性蛋白含量增加了74.38％,可溶性糖含量增加了16.13％,游离氨基酸含量增加了203％,有机酸的种类增多且含量显著提高;但接种AMF对黄花蒿水培液中根系分泌物含量的影响却呈现出了相反的作用.说明接种AMF有助于改善黄花蒿的根系形态,提高根系活力,在基质中促进根系分泌物的分泌,从而使黄花蒿汲取更多养分、提高生物量.

[目的]中药材广藿香〔Pogostemon cablin(Blanco)Benth.〕面临着种质资源衰竭、产品质量下降等问题,不利于入药的安全性、稳定性、有效性.选择丛枝菌根真菌对广藿香进行接种,以了解其对广藿香生长和药用有效成分的影响,以期达到提高质量、增加产量,满足用药需要的目的.[方法]采用盆栽试验,设置单接种幼套近明球囊霉(Claroideoglomus etunicatum,CE)、单接种摩西管柄囊霉(Funneliformis mosseae,FM)和不接种对照3种处理对广藿香进行侵染,比较广藿香生长期内和收获后各项指标的差异.[结果]FM处理广藿香株高比对照高9.0％,基部茎径比对照高9.8％,干物质量比对照高21.4％,挥发油得率比对照高0.59个百分点;CE处理广藿香株高比对照高18.6％,基部茎径比对照高14.4％,干物质量比对照高51.4％,挥发油得率比对照高1.40个百分点.[结论]不同丛枝菌根真菌对广藿香侵染能力不同,FM与CE处理均对广藿香生长有显著的促进作用,还能提高吲哚乙酸含量、抑制脱落酸产生,但幼套近明球囊霉对广藿香的整体增益效果更好,且对于广藿香产量中最重要的挥发油含量积累的促进效果更佳.

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