Effects Of Ectomycorrhizal Fungi Research Articles

Ectomycorrhizal fungi enhance salt tolerance of Quercus mongolica by regulating ion balance

We explored the effects of salt stress on the growth of Quercus mongolica and the effects of ectomycorrhizal fungi (ECMF) on the ion balance of Q. mongolica. After inoculating four kinds of ECMFs (Gomphidius visci-dus, Suillus leteus, Suillus grevillea, Boletus edulis) on Q. mongolica seedlings, we treated the annual non-mycorrhizated and mycorrhizated seedlings with NaCl stress (0, 100, 200, 300 mmol·L-1) for 36 days, and then analyzed the mycorrhizal characteristics, growth, leaf injury symptoms, leaf electrolyte permeability, water content, and ion contents in roots, stems, and leaves. The results showed that the four ECMFs could establish a symbiotic system with Q. mongolica, and that root system of mycorrhizal seedlings was stronger than that of non-mycorrhizal seedlings. Under salt stress, the growth of Q. mongolica seedlings was inhibited, with the symptoms of scorched leaves. The damage to leaf plasma membrane and the degree of water loss were aggravated with the increases of salt stress. Under low salt stress (100 mmol·L-1), Q. mongolica preferentially accumulated Na+ in roots and stems. Under medium-high salt stress (200-300 mmol·L-1), roots became the primary organ for accumulating Na+. ECMF regulated ion balance in plant by increasing the Na+ level in roots and reducing the Na+ accumulation in stems and leaves, enhancing the absorption of K+ and Ca2+ to increase the K+/Na+ and Ca2+/Na+. The four ECMFs had different mitigation effects on salt poisoning of Q. mongolica. G. viscidus had the strongest effect, followed by S. leteus, while S. grevillei and B. edulis had relatively little effect.

Effects of Ectomycorrhizal Fungi and Heavy Metals (Pb, Zn, and Cd) on Growth and Mineral Nutrition of Pinus halepensis Seedlings in North Africa.

The pollution of soils by heavy metals resulting from mining activities is one of the major environmental problems in North Africa. Mycorrhizoremediation using mycorrhizal fungi and adapted plant species is emerging as one of the most innovative methods to remediate heavy metal pollution. This study aims to assess the growth and the nutritional status of ectomycorrhizal Pinus halepensis seedlings subjected to high concentrations of Pb, Zn, and Cd for possible integration in the restoration of heavy metals contaminated sites. Ectomycorrhizal and non-ectomycorrhizal P. halepensis seedlings were grown in uncontaminated (control) and contaminated soils for 12 months. Growth, mineral nutrition, and heavy metal content were assessed. Results showed that ectomycorrhizae significantly improved shoot and roots dry masses of P. halepensis seedlings, as well as nitrogen shoot content. The absorption of Pb, Zn, and Cd was much higher in the roots than in the shoots, and significantly more pronounced in ectomycorrhizal seedlings—especially for Zn and Cd. The presence of ectomycorrhizae significantly reduced the translocation factor of Zn and Cd and bioaccumulation factor of Pb and Cd, which enhanced the phytostabilizing potential of P. halepensis seedlings. These results support the use of ectomycorrhizal P. halepensis in the remediation of heavy metal contaminated sites.

Local Responses and Systemic Induced Resistance Mediated by Ectomycorrhizal Fungi.

Ectomycorrhizal fungi (EMF) grow as saprotrophs in soil and interact with plants, forming mutualistic associations with roots of many economically and ecologically important forest tree genera. EMF ensheath the root tips and produce an extensive extramatrical mycelium for nutrient uptake from the soil. In contrast to other mycorrhizal fungal symbioses, EMF do not invade plant cells but form an interface for nutrient exchange adjacent to the cortex cells. The interaction of roots and EMF affects host stress resistance but uncovering the underlying molecular mechanisms is an emerging topic. Here, we focused on local and systemic effects of EMF modulating defenses against insects or pathogens in aboveground tissues in comparison with arbuscular mycorrhizal induced systemic resistance. Molecular studies indicate a role of chitin in defense activation by EMF in local tissues and an immune response that is induced by yet unknown signals in aboveground tissues. Volatile organic compounds may be involved in long-distance communication between below- and aboveground tissues, in addition to metabolite signals in the xylem or phloem. In leaves of EMF-colonized plants, jasmonate signaling is involved in transcriptional re-wiring, leading to metabolic shifts in the secondary and nitrogen-based defense metabolism but cross talk with salicylate-related signaling is likely. Ectomycorrhizal-induced plant immunity shares commonalities with systemic acquired resistance and induced systemic resistance. We highlight novel developments and provide a guide to future research directions in EMF-induced resistance.

The effects of ectomycorrhizal fungi on heavy metals’ transport in Pinus massoniana and bacteria community in rhizosphere soil in mine tailing area

Pinus massoniana is one of the potential tree species of afforestation in barren mine tailing area, and ectomycorrhizal fungi contributes remarkably to its survival. However, how ectomycorrhizal fungi interacts with Pinus massoniana under heavy metals’ stress is unknown. Two systems (Pinus massoniana inoculated with and without ectomycorrhizal fungi) were designed, and each system contained rhizosphere and non-rhizosphere, while bulk soil was sampled as control. The results showed that treatment of ectomycorrhizal fungi inoculation could obviously improved the absorption of soil moisture, total carbon/total nitrogen and nutrients, while reduced the bulk density and heavy metals of soil when compared with control (p＜0.05). The heavy metals accumulating in plants’ roots with ectomycorrhizal fungi were greater than that without ectomycorrhizal fungi. Conversely, they were lower in shoots with ectomycorrhizal fungi. The bacterial community were affiliated with 23 bacterial phyla, 70 classes, 115 orders, 201 families, and 363 genera. Constrained Principal Coordinate Analysis and redundancy analysis demonstrated that bacterial communities structure in the soil inoculated with or without ectomycorrhizal fungi and bulk soil were distinguishable, but no difference between rhizosphere and non-rhizosphere. The LEfSe analysis showed Acidobacteria, Actinobacteria, and Proteobacteria were the dominant phyla that contributed to the difference among treatments.

Ectomycorrhizal Fungal Communities and Their Functional Traits Mediate Plant-Soil Interactions in Trace Element Contaminated Soils.

There is an increasing consensus that microbial communities have an important role in mediating ecosystem processes. Trait-based ecology predicts that the impact of the microbial communities on ecosystem functions will be mediated by the expression of their traits at community level. The link between the response of microbial community traits to environmental conditions and its effect on plant functioning is a gap in most current microbial ecology studies. In this study, we analyzed functional traits of ectomycorrhizal fungal species in order to understand the importance of their community assembly for the soil–plant relationships in holm oak trees (Quercus ilex subsp. ballota) growing in a gradient of exposure to anthropogenic trace element (TE) contamination after a metalliferous tailings spill. Particularly, we addressed how the ectomycorrhizal composition and morphological traits at community level mediate plant response to TE contamination and its capacity for phytoremediation. Ectomycorrhizal fungal taxonomy and functional diversity explained a high proportion of variance of tree functional traits, both in roots and leaves. Trees where ectomycorrhizal fungal communities were dominated by the abundant taxa Hebeloma cavipes and Thelephora terrestris showed a conservative root economics spectrum, while trees colonized by rare taxa presented a resource acquisition strategy. Conservative roots presented ectomycorrhizal functional traits characterized by high rhizomorphs formation and low melanization which may be driven by resource limitation. Soil-to-root transfer of TEs was explained substantially by the ectomycorrhizal fungal species composition, with the highest transfer found in trees whose roots were colonized by Hebeloma cavipes. Leaf phosphorus was related to ectomycorrhizal species composition, specifically higher leaf phosphorus was related to the root colonization by Thelephora terrestris. These findings support that ectomycorrhizal fungal community composition and their functional traits mediate plant performance in metal-contaminated soils, and have a high influence on plant capacity for phytoremediation of contaminants. The study also corroborates the overall effects of ectomycorrhizal fungi on ecosystem functioning through their mediation over the plant economics spectrum.

Growth of ectomycorrhizal fungal mycelium along a Norway spruce forest nitrogen deposition gradient and its effect on nitrogen leakage

Almost all boreal and temperate forest tree species live in symbiosis with ectomycorrhizal fungi (EMF); the trees transfer carbon (C) to the fungi in exchange for nutrients and water. Several studies have shown that experimental application of inorganic nitrogen (N) represses production of EMF extramatrical mycelia (EMM), but studies along N deposition gradients are underrepresented. Other environmental variables than N may influence EMM production and in this study we included 29 thoroughly monitored Norway spruce stands from a large geographical region in Sweden in order to evaluate the importance of N deposition on EMM growth and N leaching in a broader context. It was concluded that N deposition was the most important factor controlling EMM production and that the amounts typically deposited in boreal and boreo-nemoral regions can be sufficient to reduce EMM growth. Other factors, such as phosphorus status and pH, were also correlated with EMM production and should be considered when predicting EMM growth and N leaching. We also showed that EMM production substantially contributed to the C sequestration (320 kg ha−1 yr−1), suggesting that it should be included in C cycle modelling. Furthermore, EMF are probably important for the N retention capacity since high N leaching coincided with low EMM growth. However, it was not possible to differentiate between the effects of EMF and the direct effect of N deposition on N leaching in the present study.

接种彩色豆马勃对模拟酸沉降下马尾松幼苗生物量的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 接种彩色豆马勃对模拟酸沉降下马尾松幼苗生物量的影响 DOI: 10.5846/stxb201301040018 作者: 作者单位: 中国林业科学研究院森林生态与环境保护研究所,中国林业科学研究院森林生态与环境保护研究所,河南大学环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 中央级公益性科研院所基本科研业务费专项资金(CAFRIFEEP2008004);国家自然科学基金项目(30901149)资助 Effects of ectomycorrhizal fungi (tinctorius (Pers.) Coker & Couch)on the biomass of masson pine (Pinus massoniana) seedlings under simulated acid rain Author: Affiliation: Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry,, 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:外生菌根能够提高宿主植物对外界环境胁迫的抵抗力,促进植物的生长,试图揭示外生菌根对酸雨胁迫下马尾松生长的保护作用。采用盆栽试验,共设置4个处理:酸雨对照处理((CK), 约pH值5.6)不接种,酸雨对照处理接种,酸雨pH值3.5处理不接种,酸雨pH值3.5处理接种。pH值3.5的酸雨处理降低马尾松的生物量,在试验前期降低根冠比,试验中后期则提高根冠比,在试验初期增加了叶面积,但中后期显著降低了叶面积。接种外生菌根菌有利于马尾松幼苗的生长,pH值3.5处理下接种外生菌根菌能提高马尾松幼苗的生物量,外生菌根菌对生物量分配和叶面积的影响与酸雨胁迫的影响是相反的,即外生菌根菌抵消了酸雨胁迫对马尾松的影响。 Abstract:Tree growth is a result of multiple, interacting, physiological processes influenced by an inherited genetic constitution and the ambient environment. The growth of coniferous trees is closely connected with the amount of nitrogen and other nutrients available. Air pollutants that limit carbon gain or nutrient availability may suppress growth rate and total biomass production, and thus affect the nutrient allocation pattern. An increase in the acidity of precipitation predisposes tree seedlings to a number of environmental stresses; these are reflected in seedling germination, growth, and survival. Decreased growth has been seen in response to sulfate-containing precipitation. However, considerable differences have been reported in the responses of conifer species to acid rain. Many tree species in forest ecosystems live in symbioses with ectomycorrhizal (ECM) fungi, which provide their hosts with nutrients. Symbioses with ECM fungi are therefore very important. Soil acidification due to dry and/or wet deposition can inhibit the uptake of minerals and water essential for plant growth, and increase the uptake of toxic metals, due to poor differentiation by root meristems. However, colonization by ectomycorrhizal fungi can increase the uptake of essential nutrients and water, and reduce the toxicity of metals such as Al3+ and Mn2+. To evaluate the effects of ectomycorrhizal colonization on the growth of Pinus massoniana Lamb seedlings grown in acidified soils, we grew masson pine seedlings with ectomycorrhizae for 210 days in acidified forest soil originating from Chongqing Municipality, Southwest China. There were two acid treatments; one at pH 3.5 and the control at about pH 5.5, and two ectomycorrhizal treatments (inoculated, non-inoculated). Simulated acid rain in combination with pH 3.5 reduced seedling biomass. Inoculation with ectomycorrhizal fungi was able to increase seedling biomass. Treatment time, acid treatment, and ectomycorrhizae all had remarkable effects on biomass, and we observed interacting effects between treatment time and acid treatment, and between acid treatment and ectomycorrhizae. Treatment time had significant effects on root, stem, and leaf biomass allocation, and acid treatment and ectomycorrhizae had obvious effects on root and leaf percentages. There were interactions between and among treatment time, acid treatment, and ectomycorrhizae. Under simulated acid rain (pH 3.5), the root-shoot ratio initially decreased and then increased. Treatment time and acid treatment had significant effects on the root-shoot ratio, while the ectomycorrhizae showed no effect. We observed interacting effects on the root-shoot ratio between acid treatment and treatment time, treatment time and ectomycorrhizae, and among these three. Compared with the control (pH 5.5), simulated acid rain (pH 3.5) initially increased leaf area, and then significantly reduced leaf area. Treatment time, acid treatment, and ectomycorrhizae had obvious effects on specific hemi-surface area, and there were also significant interactions among these factors. The effects of ectomycorrhizae on biomass allocation and leaf area was opposite to the effects of acid rain. Inoculation with ectomycorrhizal fungi encouraged the growth of masson pine seedlings, and increased specific hemi-surface area, enhancing photosynthesis and elevating biomass accumulation. Ectomycorrhizal fungi were thus able to counteract the effects of simulated acid rain, and protect the growth of the masson pine seedlings. It may be that ectomycorrhizal fungi can be used effectively to increase plant resistance to acid rain in places such as Southwest China. 参考文献 相似文献 引证文献

Ectomycorrhiza affect architecture and nitrogen partitioning of beech (Fagus sylvatica L.) seedlings under shade and drought

The aim of this study was to investigate the influence of ectomycorrhizal fungi (EMF) on the architecture of and nitrogen (N) partitioning in young beech (Fagus sylvatica) plants in response to different light regimes and water deprivation. We hypothesized that EMF modify biomass partitioning and architecture of young beech plants by increased N uptake in comparison with non-mycorrhizal (NM) plants and that therefore, the drought responses of EM and NM plants diverge. We anticipated that full light-exposed plants were more drought tolerant due to improved water status and nutrition, whereas shade-acclimated EM plants were more drought susceptible because of decreased mycorrhizal colonization. To test these hypotheses seedlings were grown in native or sterilized forest soil. To avoid effects of soil pretreatment NM and EM plants were transplanted into sand-peat culture systems and exposed to shade, drought or the combination of both factors. Shade resulted in reduced root biomass production decreasing the root-to-shoot ratio. Mild drought stress (pre-dawn water potential [Ψpd]=−1.3MPa) did not affect biomass partitioning. EMF colonization did not increase plant biomass, but had strong effects on root architecture: the numbers of root tips as well as the absolute and specific root lengths were increased because of formation of thin roots, especially in the diameter classes from 0.2 to 0.8mm. In contrast to our expectation N uptake of well irrigated EM plants was not increased despite their larger potential for soil exploitation. Overall, EM plants exhibited higher amounts of carbon fixed per unit of N taken up than NM plants and shifted N partitioning towards the roots. Beneficial effects of EMFs were apparent under mild drought but the responses differed depending on the light availability: shaded EM plants showed a delay in the decrease of Ψpd; light exposed EM plants showed increased N uptake compared with NM beeches. These results indicate that EMFs are involved in mediating divergent responses of beech to drought depending on the light availability.

Nanoscale channels on ectomycorrhizal‐colonized chlorite: Evidence for plant‐driven fungal dissolution

The roots of many trees in temperate and boreal forests are sheathed with ectomycorrhizal fungi (EMF) that extend into the soil, forming intimate contact with soil minerals, from which they absorb nutrient elements required by the plants and, in return, are supported by the organic carbon photosynthesized by the trees. While EMF are strongly implicated in mineral weathering, their effects on mineral surfaces at the nanoscale are less documented. In the present study, we investigated the effects of symbiotic EMF on the topography of a chlorite mineral using atomic force microscopy. A cleaning protocol was successfully applied to remove fungal hyphae without altering the underlying mineral structure and topography. Examination of the exposed chlorite surface showed the presence of primary channels, of the order of a micron in width and up to 50 nm in depth, the morphology of which strongly indicates a fungal‐induced origin. Smaller secondary channels were observed extending from the primary channels and would appear to be involved in their enlargement. The presence of channels is the first nanoscale demonstration of the effects of fungal interaction, fuelled by plant photosynthate, on the topography of a chlorite mineral, and it provides clear evidence of the ability of EMF to enhance mineral dissolution.

Effects of ectomycorrhizal fungi on damping-off and induction of pathogenesis-related proteins in Pinus tabulaeformis seedlings inoculated with Amanita vaginata

The formation of mycorrhiza on Pinus tabulaeformis (Pt) seedlings by ectomycorrhizal fungi (ECMF), the protective effect of the ECMF on damping-off caused by Rhizoctonia solani and the expression of pathogenesis-related proteins (PR-proteins) induced by Amanita vaginata and/or R. solani in Pt seedlings were investigated. The results indicated that: (i) among the 10 ECMF tested, five species (Gomphidius viscidus, Suillus laricinus, Suillus tomentosus, A. vaginata and Basidiomycetes no. 058) formed mycorrhiza with Pt seedlings. There was a positive correlation between mycorrhizal colonization levels and protective effects (r = 0.9207). Among the five species, A. vaginata had the highest colonization level and the best protective effect against damping-off; however, G. viscidus had no protective effect even though it had a high mycorrhization level. (ii) Chitinases, β-1,3-glucanases and PR-proteins in the seedlings were not induced by A. vaginata colonization, but were induced when A. vaginata-mycorrhizal seedlings were attacked by R. solani. It is possible that chitinases, β-1,3-glucanases and 108, 97, 78, 44, 37 and 14-kDa PR-proteins induced both by A. vaginata and R. solani protect Pt seedlings from R. solani infection.

Effects of isolates of ectomycorrhizal fungi and endophytic Mycelium radicis atrovirens that were dominant in soil from disturbed sites on growth of Betula platyphylla var. japonica seedlings

Effects of ectomycorrhizal fungi and endophytic Mycelium radicis atrovirens Melin (MRA) on growth of Betula platyphylla var. japonica seedlings were investigated under aseptic culture conditions. Three isolates of ectomycorrhizal fungi and two isolates of MRA were used. One MRA isolate was Phialocephala fortinii. Previous field work revealed that these isolates were dominant on the roots of B. platyphylla var. japonica seedlings grown in a mineral subsoil that had been exposed by the removal of surface soil. After a 100‐day incubation, the growth of the seedlings was significantly enhanced by the colonization of these ectomycorrhizal fungal isolates as compared with uninoculated seedlings. In contrast, the growth of seedlings was retarded by the colonization of the MRA isolates. The growth of seedlings that were co‐inoculated with ectomycorrhizal fungi and MRA was similar to that of uninoculated seedlings in most cases. These results suggest that ectomycorrhizal fungi have a beneficial effect on the growth of B. platyphylla var. japonica seedlings and that they suppress the deleterious effect of MRA. Thus, these ectomycorrhizal fungi probably have an important role in establishing B. platyphylla var. japonica seedlings during the initial stage of re‐vegetation following site disturbance by the removal of surface soil.

Ectomycorrhizal mediation of competition between coniferous tree species.

To test the effect of ectomycorrhizal fungi (EMF) on interactions between host plants, Pseudotsuga menziesii (Mirb.) Franco and Pinus ponderosa Dougl. ex. Laws., seedlings were grown in replacement series in pasteurized soil with (a) no EMF added, (A) two EMF species added - Rhizopogon vinicolor Smith (specific to Douglas-fir) and R. ochraceorubens Smith (specific to pine), and (c) tour EMF species added - the two Rhizopogon species plus two host generalists, Laccaria laccata (Scop, ex Fr.) Bk. & Br, and Hebeloma crustuliniforme (Bull.) Quel. A replacement series in unpasteurized forest soil also was included. Seedlings without added EMF were colonized by the greenhouse contaminant, Thelephora terrestris. Without added EMF (but with T. terrestris), the tree species mutually inhibited one another, producing Relative Yield Totals significantly < 1; with EMF added, mutual inhibition disappeared. With four EMF species added, Pseudotsuga menziesii seedlings were significantly larger in mixture than in monoculture, with no corresponding decrease in the size of Pinus ponderoso seedlings; this was due solely to seedlings with L. laccata, which apparently enhanced nitrogen (N) and phosphorus (P) uptake by Pseudotsuga menziesii at the expense of luxury consumption by Pinus ponderosa. Graphical analysis suggested that better growth of Pseudotosuga menziesii in mixture with EMF added was related to improved P nitrogen. Both N and P nutrition of Pinus ponderosa was better in mixture with two than no EMF species added; there was no clear nutrient effect with four EMF species added. Results indicate that EMF can reduce competition between plant species and perhaps increase overall community P uptake. However, patterns were specific to both EMF and tree species and were quite different in unpasteurized soils. Hence generalizations about the effects of EMF on plant-plant interactions must be made cautiously.

Effects of ectomycorrhizal fungi on growth and development of poplar plants derived from tissue culture

Three ectomycorrhizal fungi, Hebeloma crustuliniforme, Paxillus involutus and Thelephora terrestris were inoculated in a peat/vermiculite mixture during the transition period in which plants became adapted from conditions in vitro to conditions in a substrate in the glasshouse. Survival of inoculated plants was generally lower than that of uninoculated controls. Lowest survival (60%) was observed in the presence of T. terrestris. This fungus, however, gave the highest frequency of root infections, a significant increase in shoot height and a doubling of shoot dry weight. The content of N, P and K in plants with ectomycorrhizas was higher than uninfected control plants.