浅析植物根分泌物与根际微生物的相互作用关系

综述了根分泌物与根际微生物、病原微生物的相互影响以及根际微生物作用几方面内容。根分泌物作用于周围环境产生根际效应,影响根际微生物的生态分布、种群组成,不同抗性品种根分泌物对病原微生物表现出促进或抑制的作用;而根际微生物又会对根分泌物起到修饰限制作用,通过各种途径改变根分泌物的数量、组成。根分泌物与根际微生物间的作用是相互的。此外,根际微生物在植物养分转化与吸收、病虫草害控制、物质循环等方面发挥着不可替代的作用。     

根际微生物研究进展

根际是土壤-植物生态系统物质交换的活跃界面。植物作为第一生产者同化大气CO2,将部分光合产物转运至地下,激发土壤微生物的生长和新陈代谢;土壤微生物则将有机态养分转化成无机形态,利于植物吸收利用。这个植物-微生物的互作关系维系和主宰着陆地生态系统的功能。自从100年前德国科学家LorenzHiltner提出根际概念以来,根际研究方兴未艾,研究内容不断得以丰富和发展。近年来,随着分子生物技术在土壤环境领域的应用,根际微生物研究出现快速发展的趋势。本文根据2004年在慕尼黑召开的第一届国际根际大会交流内容、结合近年来国际上报道的研究动向,对根际微生物研究方法、根际微生物生物多样性和生态功能、转基因生物的环境安全和根际微生物生物修复技术等内容作一综述。期望我国的根际微生物研究能在基础和应用领域得到快速发展。     

根际微生物对植物与土壤交互调控的研究进展

土壤中拥有非常丰富的微生物群落,这些微生物对植物与土壤之间的交互作用起到了非常重要的调节作用,尤其是根际微生物,其中一些重要的功能微生物作为主要的共生功能体参与到植物根系养分转化中。对根际与根际土壤微生物的形成及其与土壤环境、植物根系之间互作关系的最新研究进展进行了综述,这些研究成果均肯定了根际微生物群落和多样性是积极促进植物个体和维持生态系统功能的活跃因子,并展望了今后土壤微生物在多组学、植物功能性状和全球变化方面的研究前景。     

植物根系分泌物与根际微生物交互作用机制研究进展

根际是受植物根系影响最为强烈的微域环境,是植物和土壤交流的桥梁。根系能通过调控根系分泌物的种类和数量影响根际微生物的种群结构和多样性,根际微生物通过改变根际土壤特性影响根系的分泌作用,进而影响植物的生长发育过程。因此,很有必要对这些研究进展进行梳理,提出未来该领域的研究重点。本文以1999～2022年中国知网（CNKI）和Web of Science核心数据库为文献来源,对根系分泌物与根际微生物互作相关的64篇论文进行分析。总结了近年来根系分泌物和根际微生物互作的最新研究成果,重点介绍了根系分泌物对根际微生物种类、数量和分布的影响,环境胁迫对根系分泌物和根际微生物的影响,以及根际微生物对植物生长的影响。基于此,我们对该领域未来的研究方向进行了展望。深入理解根系分泌物和根际微生物之间复杂的互作关系及其机理,对揭示根际微生态调控过程、土壤微生物组功能、促进农作物增产等方面具有重要的意义。     

酸性黄壤铅污染下植物根际微生物和酶活性研究

采用盆栽试验研究了酸性黄壤铅污染下4种草本植物根际土壤微生物数量和酶活性的变化。结果表明：植物根际土壤中细菌、真菌和放线菌对铅污染的响应因植物根系环境的不同而有所区别：4种植物根际土壤中细菌和真菌数量增加,但增幅不一致。黑麦草和早熟禾根际土壤放线菌数量降低,翦股颖根际土壤放线菌数量呈现波动起伏。4种植物根际土壤中过氧化氢酶活性、淀粉酶活性和中性磷酸酶活性与土壤铅含量都表现出负相关性,与淀粉酶活性负相关达到极显著,铅对黑麦草和狗牙根根际土壤脲酶活性表现出低浓度下激活高浓度下抑制,早熟禾和翦股颖根际土壤脲酶活性与土壤铅含量表现出正相关性。     

植物根系和根际微生物对氮的竞争

植物根系可促进土壤中有机碳和氮的矿化^[1-3]。     

植物根际微生物组的研究进展

根际微生物组(rhizosphere microbiome),是植物从其种子库土壤微生物组中有选择性地招募在根际聚集的动态微生物集群.随着近年来高通量测序技术、宏基因组学等的飞速发展,根际微生物组与植物宿主及土壤微生物组间的紧密联系引起了全球关注和研究热潮.根际微生物组被视作植物第二基因组,其与植物间的互作极为复杂,有...     

柑桔根际土壤微生物种群动态及根际效应的研究

在柑桔根际土壤微生物的种群结构中，细菌占优势，最高达76871×10⁷个每克干土；真菌次之，达17549个每克干土；放线菌最少，达12462个每克干土。三种菌的根际效应非常显著，根际细菌最高约为对照的67.6倍，真菌约为12.4倍，放线菌约为26.9倍，柑桔中，温州密柑根际土壤细菌最多，年平均为6490×10⁷个每克干土；红桔的放线菌及真菌最多，年均分别为1326个每克干土及1728个每克干土。柑桔根际土壤微生物区系的种群结构和数量变动，受土壤理化性质的影响，并随树种、树龄、砧木及季节而变化。柑桔根部及根颈部对脚腐病、根腐病及线虫病的感病性和耐病性同柑桔同柑桔根际土壤微生物区系中，有益微生物与有害微生物的种类、数量及分布有密切的关系。柑桔根际土壤有益微生物有促进生长发育和保护的作用。     

南亚热带不同植被根际微生物数量与根际土壤养分状况

研究了包括尾叶桉、广东凤丫蕨、柳叶竹、大叶相思、青皮、木荷、湿地松在内的7种南亚热带不同植物植被下土壤根际微生物与根际养分状况及其相关关系。结果表明，根际环境对细菌有明显的正效应，对放线菌和真菌有正、负两方面的影响，但对根际微生物总量具有根际效应明显;在南亚热带森林生态系统中，在植物的某些生长季节，微生物的根际效应与土壤养分的根际效应一致。     

酸性黄壤铅污染下植物根际微生物和酶活性研究

采用盆栽试验研究了酸性黄壤铅污染下4种草本植物根际土壤微生物数量和酶活性的变化。结果表明:植物根际土壤中细菌、真菌和放线菌对铅污染的响应因植物根系环境的不同而有所区别:4种植物根际土壤中细菌和真菌数量增加,但增幅不一致。黑麦草和早熟禾根际土壤放线菌数量降低,翦股颖根际土壤放线菌数量呈现波动起伏。4种植物根际土壤中过氧化氢酶活性、淀粉酶活性和中性磷酸酶活性与土壤铅含量都表现出负相关性,与淀粉酶活性负相关达到极显著,铅对黑麦草和狗牙根根际土壤脲酶活性表现出低浓度下激活高浓度下抑制,早熟禾和翦股颖根际土壤脲酶活性与土壤铅含量表现出正相关性。     

Importance of rhizodeposition in the coupling of plant and microbial productivity

Plant roots influence the biological, chemical and physical properties of rhizosphere soil. These effects are a consequence of their growth, their activity and the exudation of organic compounds from them. In natural ecosystems, the linkages between inputs of carbon from plants and microbial activity driven by these inputs are central to our understanding of nutrient cycling in soil and the productivity of these systems. This coupling of plant and microbial productivity is also of increasing importance in agriculture, where the shift towards low‐input systems increases the dependence of plant production on nutrient cycling, as opposed to fertilizers. This review considers the processes by which plants can influence the cycling of nutrients in soil, and in particular the importance of organic inputs from roots in driving microbially mediated transformations of N. This coupling of plant inputs to the functioning of the microbial community is beneficial for acquisition of N by plants, particularly in low‐input systems. This occurs through stimulation of microbes that produce exoenzymes that degrade organic matter, and by promoting cycling of N immobilized in the microbial biomass via predation by protozoa. Also, plants increase the cycling of N by changes in exudation in response to nitrogen supply around roots, and in response to browsing by herbivores. Plants can release compounds in exudates that directly affect the expression of genes in microbes, and this may be an important way of controlling their function to the benefit of the plant.     

参与土壤氮素循环的微生物功能基因多样性研究进展

土壤氮素循环是生物地球化学循环的重要组成部分, 不但影响着土壤生产力和可持续发展, 还影响着全球环境变化.土壤微生物在土壤氮循环中发挥着不可替代的作用, 参与了包括固氮作用、氨化作用、硝化作用和反硝化作用等重要生态过程.近十年中, 分子生物学技术的发展为从功能基因角度研究与土壤氮循环密切相关的微生物功能群结构、组成和丰度的变化提供了新的契机.本文综述了参与土壤氮循环的微生物功能基因多样性研究进展, 并展望了未来发展方向.     

氯化钾抑制玉米茎腐病发生与土壤微生物关系初探

十二年的钾肥长期定位试验表明,氯化钾能够显著降低玉米茎腐病的发生率。为了探讨其机理,通过室内培养试验,研究了PDA培养基中添加氯化钾和土壤浸提液对禾谷镰刀菌(Fusarium.graminearum)生长速度的影响,分析了长期施用氯化钾条件下玉米各生育期根际真菌、细菌和放线菌数目的变化。结果发现,一定浓度的氯化钾不能直接抑制禾谷镰刀菌的生长;与不施氯化钾处理相比,施氯化钾处理的土壤浸提液对禾谷镰刀菌生长具有明显的抑制效果,表明土壤浸提液在病原菌与玉米互作中发挥一定作用。长期施氯化钾显著影响玉米生育前期根际土壤真菌和放线菌数目,对根际土壤细菌数目影响不明显,而且真菌数目与茎腐病的发生率呈显著负相关。各处理根际土壤真菌与放线菌数目差异显著时期正处于病原菌的主要浸染时期,因此,施氯化钾引起的玉米根际土壤微生物区系(尤其是真菌数目)的变化是抑制玉米茎腐病发生的机制之一。     

Impact of plant species and atmospheric CO2 concentration on rhizodeposition and soil microbial activity and community composition

Both plant species and CO₂ concentration can potentially affect rhizodeposition and consequently soil microbial activity and community composition. However, the effect differs based on plant developmental stage. We focused on the effect of three plant species (forbs, grasses, and N₂‐fixers) at an early stage of development on root C deposition and fate, soil organic matter (SOM) mineralization and soil microbial community composition at ambient (aCO₂) and elevated (eCO₂) CO₂ levels. Plants were grown from seed, under continuous ¹³C‐labelling atmospheres (400 and 800 µmol mol^?1 CO₂), in grassland soil for three weeks. At the end of the growth period, soil respiration, dissolved organic C (DOC) and phospholipid fatty acid (PLFA) profiles were quantified and isotopically partitioned into root‐ and soil‐derived components. Root‐derived DOC (0.53 ± 0.34 and 0.26 ± 0.29 µg mL soil solution^?1) and soil‐derived CO₂ (6.14 ± 0.55 and 5.04 ± 0.44 µg CO₂‐C h^?1) were on average two times and 22% higher at eCO₂ than at aCO₂, respectively. Plant species differed in exudate production at aCO₂ (0.11 ± 0.11, 0.10 ± 0.18, and 0.58 ± 0.58 µg mL soil solution^?1 for Plantago, Festuca, and Lotus, respectively) but not at eCO₂ (0.20 ± 0.28, 0.66 ± 0.32, and 0.75 ± 0.15 µg mL soil solution^?1 for Plantago, Festuca, and Lotus, respectively). However, no differences among plant species or CO₂ levels were apparent when DOC was expressed per gram of roots. Relative abundance of PLFAs did not differ between the two CO₂ levels. A higher abundance of actinobacteria and G‐positive bacteria occurred in unplanted (8.07 ± 0.48 and 24.36 ± 1.18 mol%) and Festuca‐affected (7.63 ± 0.31 and 23.62 ± 0.69 mol%) soil than in Plantago‐ (7.04 ± 0.36 and 23.41 ± 1.13 mol%) and Lotus‐affected (7.24 ± 0.17 and 23.13 ± 0.52 mol%) soil. In conclusion, the differences in root exudate production and soil respiration are mainly caused by differences in root biomass at an early stage of development. However, plant species evidently produce root exudates of varying quality affecting associated microbial community composition.     

土壤和植物中元素含量的Zipf法则描述

土壤中含有人类已经发现的大多数化学元素,构成了植物矿质营养的主要来源.植物体内元素的种类也高达70余种,其含量从10-16到10-1,差异巨大.如果把土壤的化学组成和植物体内必须营养元素组成加以比较,可以看出两者之间存在相当大的差别.其中一些元素在土壤中的含量很高,但植物的需求量很低,如Si、Al、Fe等;而另一些元素在土壤中含量很低,但却是植物需求量较多的元素,如N、P、S;正是这些差异构成了土壤化学组成和植物营养之间关系的基础[1].元素的原子序数即核电荷数决定了元素的内在性质,一般的土壤和植物分析结果也表现出原子序数越大的重金属元素,其在土壤和植物中的含量也越低.Zipf法则由于具有普适性的特点,已被广泛地应用于离散型分布的研究[2],为了解土壤与植物中元素含量与元素原子序数之间存在的关系,利用Zipf法则对土壤与植物体内元素含量与原子序数之间的关系进行了研究.     

土壤母质与茶叶质量的关系初探

Six tea plantations with different soil-forming parent naterials,the same tea variety and tea age and similar landforms and management were selected to conduct a systematic study on the realtionship between soil properties and tea quality.The results showed that the quality of tea grown on the soil derived from dolomites,Quaternary red clays,were inferior.Further study showed that sandy soils were beneficial to improving amino acid content of tea ,and clayey soils made it decrease;high content of bases might decrease the contents of tea polypenols,caffeine,water extracts,but promote the content of amino acds;available phosphorous was significantly positively correlated with water extracts ,but significantly negatively correlated with caffeine;slowly avaiable potassium was positively correlated with amino acid content .Soil parent materials should be regarded as an important factor in eveluating the adatability of tea to soils.     

土壤基质吸力与土壤微生物活性关系的研究

研究了土壤微生物活性与土壤基膜吸力的关系，将土壤发泡点，即土壤导气率由0突变为非0时的基质吸力，与微生物的最高呼吸活性相联系，试图证明土壤微生物的最高活性发生于略高于土壤发泡点的基模吸力。对粗沙土、细沙土和砂壤土三种轻质地土壤的测定表明，土壤微生物的最高呼吸活性发生在略高于土壤发泡吸力的基质吸力。土壤基模吸力较小时微生物活性到达最高值的速度较慢，土壤基模吸力在发泡点附近时，微生物活性到达最高值的速度较快。     

Phosphate fertilizer compounds in soils: Their influence on the relationship between plant yield and soil test value

Abstract

A pot experiment with a lateritic soil measured the relative effectiveness of monocalcium phosphate (MCP) fertilizers and six phosphate (P) compounds which were used to represent fertilizer compounds that may be present in soils. The P compounds were added at various rates, wheat was grown, and the treated soils were extracted with eight standard soil P‐test reagents. The relative effectiveness (RE) values for the fertilizer compounds based on plant yield were 1.00, 0.33, 0.32, 0.20, 0.16, 0.15, and 0.09 for MCP, P sorbed on gibbsite (Gi‐P), P sorbed on goethite (Go‐P), P sorbed on calcite (Ca‐P), AlPO₄ (Al‐P), Apatite (Ap‐P) and FePO₄ (Fe‐P), respectively. For soil treated with Ap‐P, Gi‐P, Go‐P, Ca‐P, and MCP, soil test values were significantly related to the yield of wheat. Only Bray 1, Bray 2, ammonium oxalate, and Colwell soil tests adequately predicted yield for Al‐P treated soil, and no soil test was suitable for soil treated with Fe‐P. Where soil tests were predictive of yield, separate calibrations were required for the different P compounds. For example, in order to obtain 100 mg of wheat per pot from soil that was treated with Al‐P, Fe‐P, Ap‐P, Gi‐P, Go‐P, Ca‐P, and Bray 2 soil test values of 122, 8, 387, 112, 9, 202, and 50 ug/g, respectively, were required.     

微生物制浆漂白研究进展

简述了用于制浆的降解木素微生物种类、降解过程与机理，分析了用于漂白的微生物所产木聚糖酶和漆酶的产酶条件、助漂过程和助漂机理。     

Comparative analysis of the relationship between Cs and K in soil and plant parts toward control of Cs accumulation in rice

The effect of soil exchangeable potassium (K) and cesium (Cs) levels on Cs uptake and accumulation in different parts of rice (Oryza sativa L.) plants were examined using paddy soils with diverse exchangeable K and Cs in pot experiments. Aboveground Cs uptake decreased with higher exchangeable K and was linearly correlated with exchangeable Cs/K ratios, indicating competitive absorption of these elements by roots. Variation in Cs concentration in brown rice among soils was also related to the exchangeable Cs/K ratio. The exchangeable Cs/K ratio was positively reflected in the Cs/K concentration ratio in each plant part, with a specific slope, suggesting that Cs transport was coordinated with K transport and that there were regulated discriminations of Cs against K in the translocation process among parts. The Cs/K ratio was higher in brown rice and dead leaves than in active leaves, stems and husks. The distribution of Cs accumulation in brown rice was 14.5% on average, but it was variable and negatively related to K concentration in the stem. The Cs distribution in aboveground plant parts also decreased with higher K concentration in the root. These results imply the importance of the competitiveness with K in the root absorption and translocation of Cs within the plant. Based on the observed relationship between Cs and K, effective K management and other measures to control Cs accumulation in plant parts are discussed.