scholarly journals Transgenic Bt cotton inhibited arbuscular mycorrhizal fungus differentiation and colonization  

2017 ◽  
Vol 63 (No. 2) ◽  
pp. 62-69 ◽  
Author(s):  
Chen Xiuhua ◽  
Zhang Rui ◽  
Wang Fengling
Keyword(s):  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Hyphal Growth ◽  
Bt Cotton ◽  
Signal Perception ◽  
Bt Toxins ◽  
Am Fungus ◽  
The Impact ◽  
Direct Toxicity

The present study investigated the impact of transgenic Bacillus thuringiensis (Bt) cotton on several aspects of arbuscular mycorrhizal (AM) fungus Funneliformis mosseae. The results showed that Bt cotton significantly inhibited spore germination and pre-symbiotic hyphal growth. The appressorium density, arbuscule frequency and colonization intensity in Bt roots were also decreased. The statistical analysis demonstrated that the transformation event resulted in the inhibition of hyphal development and colonization. The reduced interaction between AM fungi and plants could affect nutrient uptake and transportation in plant-fungus symbiosis. The mechanism might involve the direct toxicity of Bt toxins or the interference of signal perception between AM fungus and Bt cotton.  

scholarly journals Arbuscular Mycorrhizal Fungus Improves Rhizobium–Glycyrrhiza Seedling Symbiosis under Drought Stress

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 572 ◽  
Author(s):  
Zhipeng Hao ◽  
Wei Xie ◽  
Xuelian Jiang ◽  
Zhaoxiang Wu ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Nitrogen Concentration ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Tolerance Index ◽  
Mycorrhizal Dependency ◽  
Plant Nitrogen ◽  
Water Regimes ◽  
Am Fungus

Rhizobia and arbuscular mycorrhizal (AM) fungi can potentially alleviate the abiotic stress on the legume Glycyrrhiza (licorice), while the potential benefits these symbiotic microbes offer to their host plant are strongly influenced by environmental factors. A greenhouse pot experiment was conducted to investigate the effects of single and combined inoculation with a rhizobium Mesorhizobium tianshanense Chen and an AM fungus Rhizophagus irregularis Walker & Schuessler on Glycyrrhiza uralensis Fisch. seedling performance under different water regimes. Drought stress inhibited rhizobium nodulation but increased mycorrhizal colonization. Furthermore, co-inoculation of rhizobium and AM fungus favored nodulation under both well-watered and drought stress conditions. Glycyrrhiza seedling growth showed a high mycorrhizal dependency. The seedlings showed a negative growth dependency to rhizobium under well-watered conditions but showed a positive response under drought stress. R. irregularis-inoculated plants showed a much higher stress tolerance index (STI) value than M. tianshanense-inoculated plants. STI value was more pronounced when plants were co-inoculated with R. irregularis and M. tianshanense compared with single-inoculated plants. Plant nitrogen concentration and contents were significantly influenced by inoculation treatments and water regimes. R. irregularis inoculation significantly increased plant shoot and root phosphorus contents. AM fungus inoculation could improve Glycyrrhiza plant–rhizobium symbiosis under drought stress, thereby suggesting that tripartite symbiotic relationships were more effective for promoting plant growth and enhancing drought tolerance.

Microkamienskia gen. nov. and Microkamienskia peruviana, a new arbuscular mycorrhizal fungus from Western Amazonia

Nova Hedwigia ◽  
2019 ◽  
Vol 109 (3) ◽  
pp. 355-368 ◽  
Author(s):  
Mike Anderson Corazon-Guivin ◽  
Agustin Cerna-Mendoza ◽  
Juan Carlos Guerrero-Abad ◽  
Adela Vallejos-Tapullima ◽  
Santos Carballar-Hernández ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Single Species ◽  
Spore Wall ◽  
Wall Layer ◽  
Am Fungus ◽  
Small Spore ◽  
Plukenetia Volubilis

A new arbuscular mycorrhizal (AM) fungus, Microkamienskia peruviana, was detected in bait cultures for arbuscular mycorrhizal fungi established with rhizospheric soil substrates of the inka nut (Plukenetia volubilis). The field soil derived from three agricultural plantations in the Amazonia lowlands of the province Lamas, San Martin State, in Peru. The fungus was subsequently propagated in single species cultures on Sorghum sp., Brachiaria sp.,Medicago sativa and P. volubilis as host plants. The new species differentiates hyaline spores regularly in spore clusters, up to 500–800×400–600 μm. The spores are 16–31(–36)×13–29(–35) μm in diam, formed on cylindrical or slightly funnel-shaped hyphae, without a septum at or close to the spore base. Phylogenetically, the new fungus belongs to a new genus, named Microkamienskia, which has as type species M. perpusilla comb. nov. and to which also M. divaricata comb. nov. belongs. Both are transferred from Kamienskia to Microkamienskia in the present study. The new fungus can be identified by the ballooning semi-persistent to evanescent outer spore wall layer in PVLG-based mountants that is not known for the other species of these two genera, nor for any other glomeromycotan species of similar small spore sizes. Kamienskia and Microkamienskia species can be distinguished by their position in the phylogenetic tree and by hyaline spores, open pores at the spore bases and in the subtending hyphae, and by their spore sizes that are for Microkamienskia among the smallest spore sizes so far detected for AM fungi (15–35 μm).

scholarly journals Tracking of Zinc Ferrite Nanoparticle Effects on Pea (Pisum sativum L.) Plant Growth, Pigments, Mineral Content and Arbuscular Mycorrhizal Colonization

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 583
Author(s):  
Reda E. Abdelhameed ◽  
Nagwa I. Abu-Elsaad ◽  
Arafat Abdel Hamed Abdel Latef ◽  
Rabab A. Metwally
Keyword(s):  
Pisum Sativum ◽  
Plant Growth ◽  
Zinc Ferrite ◽  
Crop Improvement ◽  
Nanocrystalline Structure ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Transmission Electron ◽  
Agricultural Applications ◽  
The Impact

Important gaps in knowledge remain regarding the potential of nanoparticles (NPs) for plants, particularly the existence of helpful microorganisms, for instance, arbuscular mycorrhizal (AM) fungi present in the soil. Hence, more profound studies are required to distinguish the impact of NPs on plant growth inoculated with AM fungi and their role in NP uptake to develop smart nanotechnology implementations in crop improvement. Zinc ferrite (ZnFe2O4) NPs are prepared via the citrate technique and defined by X-ray diffraction (XRD) as well as transmission electron microscopy for several physical properties. The analysis of the XRD pattern confirmed the creation of a nanocrystalline structure with a crystallite size equal to 25.4 nm. The effects of ZnFe2O4 NP on AM fungi, growth and pigment content as well as nutrient uptake of pea (Pisum sativum) plants were assessed. ZnFe2O4 NP application caused a slight decrease in root colonization. However, its application showed an augmentation of 74.36% and 91.89% in AM pea plant shoots and roots’ fresh weights, respectively, compared to the control. Moreover, the synthesized ZnFe2O4 NP uptake by plant roots and their contents were enhanced by AM fungi. These findings suggest the safe use of ZnFe2O4 NPs in nano-agricultural applications for plant development with AM fungi.

scholarly journals Target of rapamycin, PvTOR, is a key regulator of arbuscule development during mycorrhizal symbiosis in Phaseolus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manoj-Kumar Arthikala ◽  
Kalpana Nanjareddy ◽  
Lourdes Blanco ◽  
Xóchitl Alvarado-Affantranger ◽  
Miguel Lara
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Target Of Rapamycin ◽  
Mycorrhizal Symbiosis ◽  
Energy Status ◽  
Symbiotic Associations ◽  
Expression Of Genes ◽  
Fungal Symbiosis ◽  
Am Fungus ◽  
Am Symbiosis

AbstractTarget of rapamycin (TOR) is a conserved central growth regulator in eukaryotes that has a key role in maintaining cellular nutrient and energy status. Arbuscular mycorrhizal (AM) fungi are mutualistic symbionts that assist the plant in increasing nutrient absorption from the rhizosphere. However, the role of legume TOR in AM fungal symbiosis development has not been investigated. In this study, we examined the function of legume TOR in the development and formation of AM fungal symbiosis. RNA-interference-mediated knockdown of TOR transcripts in common bean (Phaseolus vulgaris) hairy roots notably suppressed AM fungus-induced lateral root formation by altering the expression of root meristem regulatory genes, i.e., UPB1, RGFs, and sulfur assimilation and S-phase genes. Mycorrhized PvTOR-knockdown roots had significantly more extraradical hyphae and hyphopodia than the control (empty vector) roots. Strong promoter activity of PvTOR was observed at the site of hyphal penetration and colonization. Colonization along the root length was affected in mycorrhized PvTOR-knockdown roots and the arbuscules were stunted. Furthermore, the expression of genes induced by AM symbiosis such as SWEET1, VPY, VAMP713, and STR was repressed under mycorrhized conditions in PvTOR-knockdown roots. Based on these observations, we conclude that PvTOR is a key player in regulating arbuscule development during AM symbiosis in P. vulgaris. These results provide insight into legume TOR as a potential regulatory factor influencing the symbiotic associations of P. vulgaris and other legumes.

Hyphal growth and mycorrhiza formation by the arbuscular mycorrhizal fungus Glomus claroideum BEG 23 is stimulated by humic substances

Mycorrhiza ◽  
2005 ◽  
Vol 15 (7) ◽  
pp. 483-488 ◽  
Author(s):  
M. Gryndler ◽  
H. Hršelová ◽  
R. Sudová ◽  
H. Gryndlerová ◽  
V. Řezáčová ◽  
...  
Keyword(s):  
Humic Substances ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Hyphal Growth ◽  
Mycorrhiza Formation

Frequent cultivation prior to planting to prevent weed competition results in an opportunity for the use of arbuscular mycorrhizal fungus inoculum

2011 ◽  
Vol 27 (4) ◽  
pp. 251-255 ◽  
Author(s):  
David D. Douds ◽  
Gerald Nagahashi ◽  
John E. Shenk
Keyword(s):  
Management Practices ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Indigenous Populations ◽  
Paspalum Notatum ◽  
Allium Porrum ◽  
Potential Yield ◽  
Greenhouse Production ◽  
Synthetic Chemicals

AbstractInoculation with arbuscular mycorrhizal (AM) fungi is a potentially useful tool in agricultural systems with limited options regarding use of synthetic chemicals for fertility and pest control. We tested the response ofAllium porrumcv. Lancelot to inoculation with AM fungi in a field high in available P (169 μg g−1soil) that had been repeatedly cultivated to control weeds. Seedlings were inoculated during the greenhouse production period with a mixed species inoculum produced on-farm in a compost and vermiculite medium withPaspalum notatumFlugge as a nurse host. Inoculated and uninoculated seedlings were the same size at outplanting. Inoculated seedlings were over 2.5-fold greater in shoot weight and shoot P content than uninoculated seedlings at harvest. These results demonstrate the potential yield benefits from inoculation with AM fungi in situations where farm management practices may negatively impact on indigenous populations of AM fungi.

scholarly journals Arbuscular Mycorrhizal Symbiosis Limits Foliar Transcriptional Responses to Viral Infection and Favors Long-Term Virus Accumulation

2011 ◽  
Vol 24 (12) ◽  
pp. 1562-1572 ◽  
Author(s):  
Laura Miozzi ◽  
Marco Catoni ◽  
Valentina Fiorilli ◽  
Philip M. Mullineaux ◽  
Gian Paolo Accotto ◽  
...  
Keyword(s):  
Viral Infection ◽  
Virus Titer ◽  
Arbuscular Mycorrhizal ◽  
Defense Responses ◽  
Virus Concentration ◽  
Primary Metabolism ◽  
Transcriptional Responses ◽  
Am Fungus ◽  
Mycorrhizal Plants ◽  
The Impact

Tomato (Solanum lycopersicum) can establish symbiotic interactions with arbuscular mycorrhizal (AM) fungi, and can be infected by several pathogenic viruses. Here, we investigated the impact of mycorrhization by the fungus Glomus mosseae on the Tomato spotted wilt virus (TSWV) infection of tomato plants by transcriptomic and hormones level analyses. In TSWV-infected mycorrhizal plants, the AM fungus root colonization limited virus-induced changes in gene expression in the aerial parts. The virus-responsive upregulated genes, no longer induced in infected mycorrhizal plants, were mainly involved in defense responses and hormone signaling, while the virus-responsive downregulated genes, no longer repressed in mycorrhizal plants, were involved in primary metabolism. The presence of the AM fungus limits, in a salicylic acid-independent manner, the accumulation of abscissic acid observed in response to viral infection. At the time of the molecular analysis, no differences in virus concentration or symptom severity were detected between mycorrhizal and nonmycorrhizal plants. However, in a longer period, increase in virus titer and delay in the appearance of recovery were observed in mycorrhizal plants, thus indicating that the plant's reaction to TSWV infection is attenuated by mycorrhization.

scholarly journals Stable C and N isotope natural abundances of intraradical hyphae of arbuscular mycorrhizal fungi

Mycorrhiza ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 773-780
Author(s):  
Saskia Klink ◽  
Philipp Giesemann ◽  
Timo Hubmann ◽  
Johanna Pausch
Keyword(s):  
Mycorrhizal Fungi ◽  
Isotope Composition ◽  
Fungal Spores ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Mineral Nutrient ◽  
Carbohydrate Source ◽  
Lipid Source ◽  
Am Fungus ◽  
C And N

Abstract Data for stable C and N isotope natural abundances of arbuscular mycorrhizal (AM) fungi are currently sparse, as fungal material is difficult to access for analysis. So far, isotope analyses have been limited to lipid compounds associated with fungal membranes or storage structures (biomarkers), fungal spores and soil hyphae. However, it remains unclear whether any of these components are an ideal substitute for intraradical AM hyphae as the functional nutrient trading organ. Thus, we isolated intraradical hyphae of the AM fungus Rhizophagus irregularis from roots of the grass Festuca ovina and the legume Medicago sativa via an enzymatic and a mechanical approach. In addition, extraradical hyphae were isolated from a sand-soil mix associated with each plant. All three approaches revealed comparable isotope signatures of R. irregularis hyphae. The hyphae were 13C- and 15N-enriched relative to leaves and roots irrespective of the plant partner, while they were enriched only in 15N compared with soil. The 13C enrichment of AM hyphae implies a plant carbohydrate source, whereby the enrichment was likely reduced by an additional plant lipid source. The 15N enrichment indicates the potential of AM fungi to gain nitrogen from an organic source. Our isotope signatures of the investigated AM fungus support recent findings for mycoheterotrophic plants which are suggested to mirror the associated AM fungi isotope composition. Stable isotope natural abundances of intraradical AM hyphae as the functional trading organ for bi-directional carbon-for-mineral nutrient exchanges complement data on spores and membrane biomarkers.

scholarly journals Diversity of Arbuscular Mycorrhizal Fungus Populations in Heavy-Metal-Contaminated Soils

1999 ◽  
Vol 65 (2) ◽  
pp. 718-723 ◽  
Author(s):  
C. Del Val ◽  
J. M. Barea ◽  
C. Azcón-Aguilar
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Agricultural Soils ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Wiener Index ◽  
Life Cycles ◽  
The European Union

ABSTRACT High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge. Relative densities of most AMF species were also significantly influenced by soil treatments. Host plant species exerted a selective influence on AMF population size and diversity. We conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils.

Physiological factors determining vesicular–arbuscular mycorrhizal formation in host and nonhost Ri T-DNA transformed roots

1990 ◽  
Vol 68 (6) ◽  
pp. 1260-1264 ◽  
Author(s):  
G. Bécard ◽  
Y. Piché
Keyword(s):  
Sugar Beet ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Hyphal Growth ◽  
Transformed Roots ◽  
Physiological Factors ◽  
Nonhost Plant ◽  
Mycorrhizal Associations ◽  
Vesicular Arbuscular ◽  
Arbuscular Mycorrhizal Associations

Transformed roots of carrot (Umbelliferae) and sugar beet (Chenopodiaceae) were used as model host and nonhost plant, respectively, for the vesicular–arbuscular mycorrhizal fungus Gigaspora margarita (Becker & Hall). Rapid growth of hyphae from germinating spores of G. margarita and formation of infection units were obtained only in the presence of carrot roots. Root volatiles from both plant species have similar stimulative effects on hyphal growth. However, hyphal growth was stimulated by root exudates of carrot and not by those of sugar beet. These and other results suggest that the nonmycorrhizal roots of sugar beet lack factors that promote mycorrhizal infection rather than producing inhibitory factors. The model used in this study is especially appropriate for further investigations on the recognition mechanisms involved in vesicular–arbuscular mycorrhizal associations.

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