Microbial community response to drought depends on crop

Legacy effects after the removal of invasive plants present significant challenges to restoration. The pivotal role of soil microbial communities in shaping these legacy effects is increasingly recognized, yet there is a lack of effective methods to mitigate altered microbial communities. In Point Reyes National Seashore (California), although the invaded European beachgrass (Ammophila arenaria [L.] Link) was successfully controlled by herbicide treatment, beachgrass litter remained undecomposed for over 5 years, leaving pronounced legacy effects on soil organic matter and microbial community composition. We hypothesized that soil inoculation from uninvaded dune scrub can accelerate the decomposition of beachgrass litter in herbicide‐treated sites by restoring the soil microbial communities and the abundance of microbial decomposers. Three litterbags containing European beachgrass litter or litter from two common shrubs at dune scrub were deployed into each plot to assess the impact of soil inoculation on litter decomposition rates. Our results revealed that soil inoculation, regardless of the inoculation level, did not accelerate the decomposition of European beachgrass. Only the decomposition of bush lupine litter, which had the highest litter quality among three types of litter, was accelerated at the highest inoculation level (approximately 11,880 g/m2). Additionally, soil inoculation increased the richness and compositional homogeneity of soil microbial communities, along with the relative abundances of wood saprotrophic fungi, soil saprotrophic fungi, and lichenized fungi. Although these findings demonstrate the potential of soil inoculation, the cost‐effectiveness of soil inoculation limits its feasibility in accelerating the delayed decomposition of European beachgrass litter in Point Reyes.

Tomato plant growth promotion and drought tolerance conferred by three arbuscular mycorrhizal fungi is mediated by lipid metabolism

PDF HTML阅读 XML下载 导出引用 引用提醒 丛枝菌根真菌与植物共生对植物水分关系的影响及机理 DOI: 10.5846/stxb201306091556 作者: 作者单位: 兰州大学草地农业生态系统国家重点实验室,兰州大学草地农业生态系统国家重点实验室,兰州大学草地农业生态系统国家重点实验室,兰州大学草地农业生态系统国家重点实验室,兰州大学信息科学与工程学院,兰州大学草地农业生态系统国家重点实验室,兰州大学草地农业生态系统国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(31070372);国家科技支撑计划(2012BAD14B10);科技部国际合作项目(2013DFA30950);国家星火计划项目(2012GA860003);国家自然科学基金青年科学基金(61201421);甘肃省青年科技基金计(1208RJYA058);甘肃省科学院开发与应用基金项目(2012JK-03);国家公益性行业(气象)科研专项(GYHY201106029-2);高等学校博士学科点专项科研基金(20110211110022) Effects of arbuscular mycorrhizal fungi and plant symbiosis on plant water relation and its mechanism Author: Affiliation: State Key Laboratory of Glassland and Agro-Ecosystems,Institute of Arid Agroecology,School of Life Sciences,Lanzhou University,State Key Laboratory of Glassland and Agro-Ecosystems,Institute of Arid Agroecology,School of Life Sciences,Lanzhou University,State Key Laboratory of Glassland and Agro-Ecosystems,Institute of Arid Agroecology,School of Life Sciences,Lanzhou University,State Key Laboratory of Glassland and Agro-Ecosystems,Institute of Arid Agroecology,School of Life Sciences,Lanzhou University,School of Information Science and Engineering,Lanzhou University,State Key Laboratory of Glassland and Agro-Ecosystems,Institute of Arid Agroecology,School of Life Sciences,Lanzhou University,State Key Laboratory of Glassland and Agro-Ecosystems,Institute of Arid Agroecology,School of Life Sciences,Lanzhou University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:自1885年Frank首次提到菌根(mykorhiza)概念以来,大量的试验证实了丛枝菌根真菌(AMF)与植物根系之间形成具有一定结构和功能的共生体,促进植物生长并提高干旱耐受能力,在干旱生态系统中发挥重要的作用。该研究多集中在对宿主植物生理生态的影响及其机制方面,然而菌根共生对宿主植物水分吸收和信号产生、传递的影响研究少而分散,缺少系统总结。综述了最近四十多年丛枝菌根真菌与植物共生体对宿主植物干旱适应性影响研究进展,讨论了菌根共生对植物根冠通讯的影响及机理。干旱胁迫下AMF与植物共生,通过影响宿主植物一系列生理生态过程,提高宿主植物横向根压和纵向蒸腾拉力。经典的Ohm吸水模型是该方向最有代表性的研究成果,该模型揭示了菌根共生的根外菌丝具有不同于根细胞的细胞结构和水分运输性能,这为宿主植物提供一种特殊的快速吸水方式,可提高植物对土壤水分的吸收和运输能力。研究表明,AMF会影响宿主植物根冠通讯过程,如诱发信号级联反应,诱导根系尽早感知水分胁迫并产生非水力根源信号,提高宿主对干旱的耐受性。讨论了AMF在根冠通讯分子机制研究方面存在的问题及可能的解决途径,展望了AMF在干旱农业生产中的应用潜力。 Abstract:Since Frank proposed "mykorhiza" for the first time in 1885, extensive studies have demonstrated the formation of mycorrhizae between arbuscular mycorrhizal fungi (AMF) and plant roots, and the functioning of mycorrhizae in improving plant gowth and drought adaptability under drought stress particularly in semiarid and arid ecosystems. However, information is limited on the mechanisms how AMF could affect the host plant water uptake, root signal generation and transfer, while most studies have focused on effects of AMF on their physiological and ecological changes in host plants. In this review, progresses in how AMF could balance water relations and affect root to shoot communications are summarized from studies in the last four decades, and possibly related mechanisms are also concluded. These mechanisms include enhanced water uptake, root hydraulic conductance, antioxidant activity, altered hormone relations, osmotic adjustment, aquaporin expression and nutrition absorption. Studies have showed that AMF associated symbioses have usually altered eco-physiological characteristics, e.g. stomatal conductance, plant size and abscisic acid (ABA) content, and thus enhancing the lateral root pressure and vertical transpiration to benefit for host plant's water absorption. The Ohm's law model, which is the most representatively traditional progress in water uptake mechanisms, could further reveal how AMF is able to improve soil water absorption and transport. This mode reveals that mycorrhizal hyphae, which are different from plant root cells, having aseptate or coenocytic and elastic hyphal wall at the tip, and only infrequent, adventitious septa, can contribute to transport water rapidly in host plants under drought stress. Thus, AMF in plant root may be able to feel drier soil more quickly and produce non-hydraulic root-sourced signals earlier. AMF can also affect root to shoot communications, such as inducing signaling cascades for root-sourced signal generation and the improvement of drought tolerance from cellular to whole plant level. Nevertheless, the composition of root exudates are complex, and the mechanisms of root to shoot communications still need to be solved: 1) how AMF help root cells to perceive root water stress; 2) relationships between early drought-gene expression and non-hydraulic root-sourced signal (nHRS); and 3) relationships between late drought-gene expression and hydraulic root-sourced signal (HRS). Possible pathways may further reveal the unknown mechanisms in root to shoot communications that are affected by AMF: 1) the differences in their composition among root exudates and root ingredient under moisture gradients, which may have potential in indicating the perception of water stress signal component; 2) the ABA-binding factor (ABF), which may be as one of the important transcripts to respond to the early drought stress, and Ca2+ as a second messenger collaborating ABA to regulates the open and close of guard cells. Therefore, studies on their distribution of ABA and Ca2+ in root, stem and leaf under moisture gradients may provide insight into relationships between early drought-gene expression and nHRS; and 3) relationships between the whole plant drought tolerance (e.g. plant type and biomass allocation) and the cell drought tolerance (e.g. antioxidant enzymes and penetration substances), which may address mechanisms involving in the late drought-gene expression and HRS. With the further progresses are made on the contribution of AMF symbiosis to plant water uptake and drought tolerance, we believe that AMF will have potential application in semi-arid and arid agricultural production. 参考文献 相似文献 引证文献

Elevation explains variation in soil microbial diversity and community composition under experimental warming and fertilization treatments in mountain meadows

Microbial communities and their functionality are affected by climate change, which consequently impacts the functionality of soil biogeochemical cycles and in turn the persistence of individual tree species. Despite their importance for forest ecosystems, few studies have investigated the impacts of multiple, concurrent elements of climate change on microbial communities under tree species with contrasting drought tolerance and different biogeographic origins.In our study, we investigated how soil microbial communities of different native and non-native tree species responded to warming and warming associated with drought. The experiment was located in Switzerland and included three forest sites with different climatic and environmental characteristics where temperature and precipitation have been manipulated since 2022. Soil microbial communities were assessed using DNA metabarcoding, and extracellular enzyme activities were assessed alongside environmental variables and soil nutrient availability.Preliminary results showed that strong differences across sites shape microbial community composition and modulate their responses to the experimental climate treatments. The strongest effects of climate manipulations were found at the warmest and driest site. Soil microbial community composition responses to the different climate change treatments further among the tree species. In addition to microbial community composition, microbial functioning, as assessed via enzymatic activities, also differed across sites and generally decreased with the climate treatments, suggesting that biogeochemical cycles are likely to change in the future.Our research aimed to clarify the possible consequences of warming and drought on forest microbiomes and consequently soil biogeochemical cycles under global change. This will support the development of climate change mitigation strategies to maintain forest ecosystem functionality and to choose future tree species able to resist climatic stresses.

Re-establishment of suppressiveness to soil- and air-borne diseases by re-inoculation of soil microbial communities

Wildfires are unpredictable disturbances with profound effects on soil properties and microbial communities within forest ecosystems. However, knowledge of post-fire microbial communities in karst forests remains limited. In this study, microbial amplicon sequencing techniques were employed to investigate the impact of wildfires on the composition, diversity, function, and co-occurrence network of soil microbial communities in karst forest landscapes and to identify the key soil physicochemical factors affecting the post-fire microbial communities. The wildfire affected the fungal community to a greater extent than the bacterial community, with the former shifting from a dominance of Basidiomycota to Ascomycota at the phylum level, while the relative abundance of Actinobacteria increased significantly in the bacterial community. Moreover, the wildfire increased the α-diversity of the microbial community and changed the β-diversity. Network analysis indicated significant reductions in the complexity of microbial community networks and the hub microbiome in burned soils compared to those of unburned soils. Functional predictions indicated an increase in the highly abundant functional taxa of chemoheterotrophic and aerobic chemoheterotrophic bacteria, along with a significant rise in saprotrophic functional fungal taxa following the fire. In addition, soil organic matter, total nitrogen, total phosphorus, and soil water content emerged as key soil physicochemical factors affecting post-fire soil microbial communities in the karst forest. Overall, this study revealed the structural and functional characteristics of soil microbial communities and their key influencing factors after a fire in a karst forest, which will provide a valuable theoretical basis for ecosystem restoration after a wildfire.IMPORTANCEDespite the significant impacts of wildfires on forest ecosystems, most existing studies have largely focused on boreal and Mediterranean coniferous forest types, with limited research on the impacts of coniferous and broadleaf forest types in subtropical karst regions. This study reveals the effects of wildfires on soil microbial communities of coniferous and broadleaf forest types in a karst forest. The results of this study not only improve the understanding of the effects of wildfires on the composition, diversity, function, and network of soil microbial communities but also provide a meaningful theoretical basis for post-fire ecosystem restoration in the karst forest.

Salt effects on the soil microbial decomposer community and their role in organic carbon cycling: A review

Currently, characterization of soil microbial communities relies heavily on the use of molecular approaches. Independently of the approach used, soil DNA extraction is a crucial step, and success of downstream procedures will depend on how well DNA extraction was performed. Often, studies describing and comparing soil microbial communities are based on a single DNA extraction, which may not lead to a representative recovery of DNA from all organisms present in the soil. The use of successive DNA extractions might improve soil microbial characterization, but the benefit of this approach has only been limitedly studied. To determine whether successive DNA extractions of the same soil sample would lead to different observations in terms of microbial abundance and community composition, we performed three successive extractions, with two widely used commercial kits, on a range of clay and sandy soils. Successive extractions increased DNA yield considerably (1–374%), as well as total bacterial and fungal abundances in most of the soil samples. Analysis of the 16S and 18S ribosomal RNA genes using 454-pyrosequencing, revealed that microbial community composition (taxonomic groups) observed in the successive DNA extractions were similar. However, successive DNA extractions did reveal several additional microbial groups. For some soil samples, shifts in microbial community composition were observed, mainly due to shifts in relative abundance of a number of microbial groups. Our results highlight that performing successive DNA extractions optimize DNA yield, and can lead to a better picture of overall community composition.

Interactions of soil particulate organic matter chemistry and microbial community composition mediating carbon mineralization in karst soils

Biochar (BC) application is widely recognized as a promising strategy for enhancing soil fertility; however, its lasting effects on microbial communities in aeolian sandy soils of semi-arid regions remain poorly understood. To fill this knowledge gap, we conducted a field experiment to evaluate long-term changes in soil properties and microbial community structure in a buckwheat cropping system, 4 years after a single application of biochar (BC) at rates of 0 (BC0), 20 (BC1), 40 (BC2), and 60 (BC3) Mg ha-1 in aeolian sandy soils of Inner Mongolia, China. Results revealed significant improvements in soil pH, moisture content, organic carbon (SOC), and available nutrients, as well as microbial biomass and enzyme activity, particularly at higher BC application rates (BC2 and BC3). SOC increased by 9.42% (BC2) and 14.13% (BC3). BC application altered microbial community composition, with minimal effects on bacterial diversity but reduced fungal diversity. Enhanced soil C and N cycling was linked to shifts in key microbial genera, while relative abundances of potential pathogens such as Fusarium and Nothophoma declined by up to 58 and 77%, respectively. Mantel tests confirmed significant correlations between shifts in microbial diversity and community composition and changes in soil properties, with particularly strong associations for fungal diversity related to SOC (r = 0.50, p < 0.001) and microbial biomass carbon (SMC; r = 0.43, p < 0.001). Redundancy analysis further revealed that bacterial communities were significantly associated (p < 0.05) with pH, microbial biomass nitrogen (SMN), and invertase activity, while fungal communities were linked to pH, microbial biomass phosphorus (SMP), and urease activity. This study underscores the potential of biochar to enhance soil health by improving soil fertility, reshaping microbial community composition, and suppressing soil-borne pathogens, particularly at higher application rates. These findings provide valuable insights for the reclamation of degraded sandy soils in semi-arid regions on a global scale.

DNA fingerprinting reveals links among agricultural crops, soil properties, and the composition of soil microbial communities

Drought-tolerant coffee plants display increased tolerance to waterlogging and post-waterlogging reoxygenation

Chapter Five - Impacts of Climate Change on Soil Microbial Communities and Their Functioning

The response of soil microbial communities to management practices is composite, as it depends on the various environmental factors which contribute to a shift in the microbial communities. In this study we explored the impact of combinations of soil management practices on microbial diversity and community composition in a dryland soybean production system. Soil samples were collected from the experimental field maintained under no till, cover crops, and fertility treatments, at Pontotoc Ridge-Flatwoods Branch Experiment Station, MS, USA. Targeted amplicon sequencing of 16S rRNA and ITS2 genes was used to study the bacterial and fungal community composition. Poultry litter amendment and cover crops significantly influenced soil bacterial diversity. Fertilizer sources had significantly different bacterial communities, as specific microbial taxa were strongly influenced by the changes in the nutrient availability, while cover crops influenced the soil fungal community differences. Differential enrichment of advantageous bacterial (Proteobacteria, Actinobacteria and Acidobacteria) and fungal (Mortierellomycota) phyla was observed across the treatments. Soil pH and easily extractable glomalin-related soil proteins (EE-GRSP) were correlated with bacterial communities and aggregate stability (WSA) was influenced by the poultry litter amendment, thus driving the differences in bacterial and fungal communities. These findings suggest that a long-term study would provide more inferences on soil microbial community response to management changes in these dryland soybean production systems.