Different arbuscular mycorrhizal fungi induce differences in cellular responses and fungal activity in a mycorrhiza-defective mutant of tomato (rmc)

2009 ◽  
Vol 36 (1) ◽  
pp. 86 ◽  
Author(s):  
Maria Manjarrez ◽  
Meredith Wallwork ◽  
Sally E. Smith ◽  
F. Andrew Smith ◽  
Sandy Dickson
Keyword(s):  
Mycorrhizal Fungi ◽  
Laser Scanning ◽  
Plant Defence ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Cellular Responses ◽  
Wild Type ◽  
Nuclear Movement ◽  
Callose Deposition ◽  
Defence Responses

The reduced mycorrhizal colonisation (rmc) mutant of tomato forms different phenotypes with different arbuscular mycorrhizal (AM) fungi. Our aim was to characterise microscopically the cellular responses in plant and fungus in order to reveal how these varied when colonisation was blocked at different stages. Synchronised colonisation coupled with vital staining, autofluorescence and laser scanning confocal microscopy (LSCM) were used to determine how long the AM fungi stay alive during the interactions with rmc, whether nuclear repositioning occurred in the same way as in wild-type interactions and whether there was evidence for deployment of defence responses. The results showed that (1) all the AM fungi tested were attracted to roots of rmc, on which they developed active external mycelium and appressoria, the latter sometimes in higher numbers than on the wild type; (2) plant cellular responses, such as nuclear movement, occurred only when the AM fungus was able to penetrate the epidermal cells of rmc; and (3) plant defence responses such as autofluorescence were observed only transiently and callose deposition was not involved in blocking AM fungi in rmc. The results demonstrate that multi-step AM colonisation is not only an outcome of cellular processes influenced by both plant and fungus, but is also modified by the capacity of different AM fungi to respond to the plant phenotype induced by the rmc mutation.

scholarly journals Mycorrhizal Fungi Enhance Resistance to Herbivores in Tomato Plants with Reduced Jasmonic Acid Production

Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 131 ◽  
Author(s):  
Ludovico Formenti ◽  
Sergio Rasmann
Keyword(s):  
Plant Growth ◽  
Jasmonic Acid ◽  
Plant Resistance ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Wild Type ◽  
Tomato Plants ◽  
Solanum Lycopersicum L ◽  
Fungal Inoculation

Arbuscular mycorrhizal (AM) fungi favor plant growth by improving nutrient acquisition, but also by increasing their resistance against abiotic and biotic stressors, including herbivory. Mechanisms of AM fungal mediated increased resistance include a direct effect of AM fungi on plant vigor, but also a manipulation of the hormonal cascades, such as the systemic activation of jasmonic acid (JA) dependent defenses. However, how AM fungal inoculation and variation in the endogenous JA production interact to produce increased resistance against insect herbivores remains to be further elucidated. To address this question, three genotypes of Solanum lycopersicum L., a JA-biosynthesis deficient mutant, a JA over-accumulating mutant, and their wild-type were either inoculated with AM fungi or left un-inoculated. Plant growth-related traits and resistance against Spodoptera littoralis (Boisduval) caterpillars, a major crop pest, were measured. Overall, we found that deficiency in JA production reduced plant development and were the least resistant against S. littoralis. Moreover, AM fungi increased plant resistance against S. littoralis, but such beneficial effect was more pronounced in JA-deficient plant than on JA over-accumulating plants. These results highlight that AM fungi-driven increased plant resistance is negatively affected by the ability of plants to produce JA and that AM fungi complement JA-mediated endogenous plant defenses in this system.

Strigolactones seem not to be involved in the nonsusceptibilty of arbuscular mycorrhizal (AM) nonhost plants to AM fungi

Botany ◽  
2011 ◽  
Vol 89 (4) ◽  
pp. 285-288 ◽  
Author(s):  
Antonio Illana ◽  
José M. García-Garrido ◽  
Inmaculada Sampedro ◽  
Juan A. Ocampo ◽  
Horst Vierheilig
Keyword(s):  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Glomus Intraradices ◽  
Experimental System ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Wild Type ◽  
Nonhost Plant ◽  
Plant Families ◽  
Pea Mutant

Although most land plants are hosts for arbuscular mycorrhizal fungi (AMF), a small number of plant families are arbuscular mycorrhizal (AM) nonhosts. There are indications that strigolactone levels in root exudates of AM nonhost plants are lower than in AM host plants, and it has been shown that in the strigolactone-deficient rms1 mutant (ccd8) of the AM host plant pea, the AMF colonization of roots is highly reduced. Application of the synthetic strigolactone analogue GR24 to this strigolactones-deficient mutant restored AMF colonization of roots. Our objective was to determine whether the application of GR24 to AM nonhost plants can affect their susceptibility to AMF. To test whether GR24 affects AMF colonization in our experimental system, we added GR24 to the strigolactone-deficient pea ccd8 mutant. Application of GR24 increased AMF colonization in the pea mutant to a similar level as in the pea wild type with normal strigolactone levels, showing clearly that in our experimental setup, application of the GR24 positively affects AMF colonization in strigolactone-deficient plants. Observation of cleared roots after application of GR24 to four AM nonhost plant species inoculated with the AMF Glomus intraradices showed that colonization did not occur.

scholarly journals Activation of Local and Systemic Defence Responses by Flg22 Is Dependent on Daytime and Ethylene in Intact Tomato Plants

2021 ◽  
Vol 22 (15) ◽  
pp. 8354
Author(s):  
Zalán Czékus ◽  
András Kukri ◽  
Kamirán Áron Hamow ◽  
Gabriella Szalai ◽  
Irma Tari ◽  
...  
Keyword(s):  
Stomatal Closure ◽  
Plant Defence ◽  
Time Of Day ◽  
Light Period ◽  
Ethylene Response Factor ◽  
Wild Type ◽  
Tomato Plants ◽  
Production Of Hydrogen ◽  
Pathogenesis Related ◽  
Defence Responses

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase.

scholarly journals Use of the Signature Fatty Acid 16:1ω5 as a Tool to Determine the Distribution of Arbuscular Mycorrhizal Fungi in Soil

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Ngosong ◽  
Elke Gabriel ◽  
Liliane Ruess
Keyword(s):  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Plant Root ◽  
Background Level ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Biomass Estimation ◽  
Lipid Fatty Acid ◽  
Neutral Lipid Fatty Acid ◽  
Root Symbionts

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.

scholarly journals Response of Arbuscular Mycorrhizal Fungi to Simulated Climate Changes by Reciprocal Translocation in Tibetan Plateau

2015 ◽  
Vol 43 (2) ◽  
pp. 488-493
Author(s):  
Zhaoyong SHI ◽  
Xubin YIN ◽  
Bede MICKAN ◽  
Fayuan WANG ◽  
Ying ZHANG ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Arbuscular Mycorrhizal Fungi ◽  
Reciprocal Translocation ◽  
Mycorrhizal Fungi ◽  
Climate Changes ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Spore Density ◽  
The Tibetan Plateau ◽  
Colonization Frequency

Arbuscular mycorrhiza (AM) fungi are considered as an important factor in predicting plants and ecosystem responses to climate changes on a global scale. The Tibetan Plateau is the highest region on Earth with abundant natural resources and one of the most sensitive region to climate changes. To evaluate the complex response of arbuscular mycorrhizal fungi colonization and spore density to climate changes, a reciprocal translocation experiment was employed in Tibetan Plateau. The reciprocal translocation of quadrats to AM colonization and spore density were dynamic. Mycorrhizal colonization frequency presented contrary changed trend with elevations of quadrat translocation. Colonization frequency reduced or increased in majority quadrats translocated from low to high or from high to low elevation. Responses of colonization intensity to translocation of quadrats were more sensitive than colonization frequency. Arbuscular colonization showed inconsistent trend in increased or decreased quadrat. Vesicle colonization decreased with changed of quadrat from low to high elevations. However, no significant trend was observed. Although spore density was dynamic with signs of decreasing or increasing in translocated quadrats, the majority enhanced and declined respectively in descent and ascent quadrat treatments. It is crucial to understand the interactions between AM fungi and prairie grasses to accurately predict effects of climate change on these diverse and sensitive ecosystems. This study provided an opportunity for understanding the effect of climate changes on AM fungi.

scholarly journals Isolation and identification of indigenous Arbuscular Mycorrhizal Fungi (AMF) of forest clove rhizosphere from Maluku, Indonesia

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Asri Subkhan Mahulette ◽  
Anggra Alfian ◽  
ABDUL KARIM KILKODA ◽  
IMELDA JEANETTE LAWALATA ◽  
DESSY ARIYANI MARASABESSY ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Soil Samples ◽  
Spore Density ◽  
Wild Type ◽  
Isolation And Identification ◽  
Spore Count ◽  
Spore Number ◽  
Total Spore Count

Abstract. Mahulette AS, Alfian A, Kilkoda KA, Lawalata IJ, Marasabessy DA, Tanasale VL, Makaruku MH. 2021. Isolation and identification of indigenous Arbuscular Mycorrhizal Fungi (AMF) of forest clove rhizosphere from Maluku, Indonesia. Biodiversitas 22: 3613-3619. Forest clove is classified as wild-type and endemic to the Maluku (Moluccas) Islands, Indonesia. The different condition of growing areas causes various types of Arbuscular Mycorrhizal Fungi (AMF) associated with forest clove. The study aimed to identify and obtain indigenous AMF inoculums from the forest clove rhizosphere from two distribution areas in Maluku. The results of AMF identification found two types of spores from the genus Glomus in the rhizosphere of forest cloves from Ambon Island with a spore density of 35/50 g of soil. In comparison, three spores were found in Seram Island, two from the genus Scutellospora and one from the Acaulospora. With an overall spore density of 5/50 g of soil. After culture trapping, there was a change in type and an increase in spore density in soil samples from the rhizosphere of the two forest clove distribution areas. Soil samples from Ambon after trapping culture obtained two new types of spores from the genus Acaulospora with a total spore number of 57/50 g soil while in soil samples from Seram found three new types of spores from the genus Glomus with a total spore count of 104/50 g of soil.

scholarly journals Synergistic community responses of plants and arbuscular mycorrhizal fungi to extreme droughts in a cold-temperate grassland

2020 ◽  
Author(s):  
Wei Fu ◽  
Baodong Chen ◽  
Matthias Rillig ◽  
Wang Ma ◽  
Chong Xu ◽  
...  
Keyword(s):  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Community Dynamics ◽  
Environmental Changes ◽  
Environmental Filtering ◽  
Climate Extremes ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Temperate Grassland ◽  
Community Responses

Mutualistic associations between plants and arbuscular mycorrhizal (AM) fungi may have profound influences on their response to climate changes. Existing theories evaluate the effects of interdependency and environmental filtering on plant-AM fungal community dynamics separately; however, abrupt environmental changes such as climate extremes can provoke duo-impacts on the metacommunity simultaneously. Here, we experimentally tested the relevance of plant and AM fungal community responses to extreme drought (chronic or intense) in a cold temperate grassland. Irrespective of drought intensities, plant species richness and productivity responses were significantly and positively correlated with AM fungal richness and also served as best predictors of AM fungal community shifts. Notably, the robustness of this community synergism increased with drought intensity, likely reflecting increased community interdependence. Network analysis showed a key role of Glomerales in AM fungal interaction with plants, suggesting specific plant-AM fungal pairing. Thus, community interdependence may underpin climate change impact on plant-AM fungal diversity patterns in grasslands.

scholarly journals The Synergy of Arbuscular Mycorrhizal Fungi and Exogenous Abscisic Acid Benefits Robinia pseudoacacia L. Growth through Altering the Distribution of Zn and Endogenous Abscisic Acid

2021 ◽  
Vol 7 (8) ◽  
pp. 671
Author(s):  
Xiao Lou ◽  
Xiangyu Zhang ◽  
Yu Zhang ◽  
Ming Tang
Keyword(s):  
Abscisic Acid ◽  
Mycorrhizal Fungi ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Am Symbiosis ◽  
Antioxidant Defense Systems ◽  
Robinia Pseudoacacia L ◽  
Zn Stress

The simultaneous effects of arbuscular mycorrhizal (AM) fungi and abscisic acid (ABA) on the tolerance of plants to heavy metal (HM) remain unclear. A pot experiment was carried out to clarify the effects of simultaneous applications of AM fungi and ABA on plant growth, Zn accumulation, endogenous ABA contents, proline metabolism, and the oxidative injury of black locust (Robinia pseudoacacia L.) exposed to excess Zn stress. The results suggested that exogenously applied ABA positively enhanced AM colonization, and that the growth of plants only with AM fungi was improved by ABA application. Under Zn stress, AM inoculation and ABA application increased the ABA content in the root/leaf (increased by 48–172% and 92%, respectively) and Zn content in the root/shoot (increased by 63–152% and 61%, respectively) in AM plants, but no similar trends were observed in NM plants. Additionally, exogenous ABA addition increased the proline contents of NM roots concomitantly with the activities of the related synthases, whereas it reduced the proline contents and the activity of Δ1-pyrroline-5-carboxylate synthetase in AM roots. Under Zn stress, AM inoculation and ABA application decreased H2O2 contents and the production rate of O2, to varying degrees. Furthermore, in the roots exposed to Zn stress, AM inoculation augmented the activities of SOD, CAT, POD and APX, and exogenously applied ABA increased the activities of SOD and POD. Overall, AM inoculation combined with ABA application might be beneficial to the survival of black locust under Zn stress by improving AM symbiosis, inhibiting the transport of Zn from the roots to the shoots, increasing the distribution of ABA in roots, and stimulating antioxidant defense systems.

scholarly journals Biocontrol of Sclerotium rolfsii in Groundnut by Using Microbial Inoculants

2017 ◽  
Vol 9 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Khirood DOLEY ◽  
Mayura DUDHANE ◽  
Mahesh BORDE
Keyword(s):  
Mycorrhizal Fungi ◽  
Antioxidant Activities ◽  
Sclerotium Rolfsii ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Stem Rot ◽  
Mycorrhizal Dependency ◽  
Trichoderma Species ◽  
Arachis Hypogaea L ◽  
Microbial Strains

Sclerotium rolfsii (Sacc.) is the causal agent of stem-rot in groundnut (Arachis hypogaea L.)crop. With the increase in demand for the groundnut, control of stem-rot efficiently by microbial strains is fast becoming inevitable as the conventional system of chemicals is degrading our ecosystem. This investigation here emphasizes on inoculation of arbuscular mycorrhizal fungi (AMF) and Trichoderma species for growth achievement and disease control. The present investigation showed that these microbial strains were found to be worth applying as they stimulated growth and decreased harmful effects of S. rolfsii (cv. ‘Western-51’). The increased biochemical parameters and antioxidant activities also indicated their defence related activities in groundnut plants. In spite of positive attributes meted out by these microbial strains towards groundnut crop, the interaction among AM fungi and Trichoderma species seemed to be less co-operative between each other which were noted when mycorrhizal dependency and percent root colonization were observed. However, in summary more practical application of low-input AM fungi along with Trichoderma species may be needed for the advancement of modern agricultural systems.

scholarly journals Haustorium Formation in Medicago truncatula Roots Infected by Phytophthora palmivora Does Not Involve the Common Endosymbiotic Program Shared by Arbuscular Mycorrhizal Fungi and Rhizobia

2015 ◽  
Vol 28 (12) ◽  
pp. 1271-1280 ◽  
Author(s):  
Rik Huisman ◽  
Klaas Bouwmeester ◽  
Marijke Brattinga ◽  
Francine Govers ◽  
Ton Bisseling ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Phytophthora Palmivora ◽  
Living Plant ◽  
Mutualistic Symbiosis ◽  
Membrane Compartment ◽  
Microbe Interactions ◽  
Host Genes

In biotrophic plant-microbe interactions, microbes infect living plant cells, in which they are hosted in a novel membrane compartment, the host-microbe interface. To create a host-microbe interface, arbuscular mycorrhizal (AM) fungi and rhizobia make use of the same endosymbiotic program. It is a long-standing hypothesis that pathogens make use of plant proteins that are dedicated to mutualistic symbiosis to infect plants and form haustoria. In this report, we developed a Phytophthora palmivora pathosystem to study haustorium formation in Medicago truncatula roots. We show that P. palmivora does not require host genes that are essential for symbiotic infection and host-microbe interface formation to infect Medicago roots and form haustoria. Based on these findings, we conclude that P. palmivora does not hijack the ancient intracellular accommodation program used by symbiotic microbes to form a biotrophic host-microbe interface.

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