Plants colonized by AM fungi regulate further root colonization by AM fungi through altered root exudation

1999 ◽  
Vol 77 (6) ◽  
pp. 891-897 ◽  
Author(s):  
Alexandra Pinior ◽  
Urs Wyss ◽  
Yves Piché ◽  
Horst Vierheilig
Keyword(s):  
Root Colonization ◽  
Root Exudation ◽  
Am Fungi

Plants colonized by AM fungi regulate further root colonization by AM fungi through altered root exudation

1999 ◽  
Vol 77 (6) ◽  
pp. 891-897 ◽  
Author(s):  
Alexandra Pinior ◽  
Urs Wyss ◽  
Yves Piché ◽  
Horst Vierheilig
Keyword(s):  
Root Exudates ◽  
Glomus Mosseae ◽  
Glomus Intraradices ◽  
Root Colonization ◽  
Root Exudation ◽  
Axenic Culture ◽  
Am Fungi ◽  
Hyphal Growth ◽  
Gigaspora Rosea ◽  
Stimulation Of

The effect of root exudates from non-mycorrhizal and mycorrhizal cucumber (Cucumis sativus L.) plants colonized by one of three arbuscular mycorrhizal fungi (Gigaspora rosea Nicolson & Schenck, Glomus intraradices Smith & Schenck, or Glomus mosseae (Nicolson & Gerdemann) Gerd. & Trappe) on hyphal growth of Gi. rosea and G. intraradices in axenic culture and on root colonization by G. mosseae in soil was investigated. Root exudates from non-mycorrhizal cucumber plants clearly stimulated hyphal growth, whereas root exudates from all mycorrhizal cucumber plants tested showed no stimulation of the hyphal growth of Gi. rosea and only a slight stimulation of the hyphal growth of G. intraradices. Moreover, root exudates from all mycorrhizal cucumber plants inhibited root colonization by G. mosseae compared with the water-treated controls. These results suggest that plants colonized by AM fungi regulate further mycorrhization via their root exudates.Key words: Glomales, Gigaspora rosea, Glomus intraradices, Glomus mosseae, root exudates, regulation.

scholarly journals Mycorrhizal association and influence on growth of Asian pigeonwings (Clitoria ternatea L.)

2017 ◽  
Vol 6 (06) ◽  
pp. 5415
Author(s):  
Mane S. R. ◽  
Kumbhar V. R. ◽  
Birajdar G. M. ◽  
Naryankar R. S. ◽  
Gavali M. T. ◽  
...  
Keyword(s):  
Root Colonization ◽  
Biomass Productivity ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Spore Density ◽  
Clitoria Ternatea ◽  
Treated Condition ◽  
Mycorrhizal Association ◽  
Maximum Root ◽  
Herbal Medicinal

Clitoria ternatea L. is an excellent herbal medicinal plant. Arbusular Mycorrhizal fungal (AMF) colonization and biomass of three different tested conditions of Clitoria ternatea plant was investigated. Inoculums of indigenous AMF and Trichoderma harzianum was tested greenhouse experiment and compared with natural condition after 60th days of treatment. Percentage of Arbuscular mycorrhizal (AM) infection, number of resting spores and AM fungi species varies in different land. Among three different conditions, natural conditions showed maximum root colonization (75.89%) than treated one but minimum spore density (358.8/100gsoil). Highest spore density (481.6/100g soil) was found in T. harzianum treated condition followed by indigenous AMF treatment Acaulospora Glomus and Sclerocystis these three genera were found frequently. AMF inoculums and T.harzianum treatments conditions were observed promising biomass data of 60th days after treatment (DAT).When AMF are more colonized to plants then enhanced the biomass productivity.

scholarly journals Biodiversity and distribution of arbuscular mycorrhizal fungi in Araucaria angustifolia forest

2007 ◽  
Vol 64 (4) ◽  
pp. 393-399 ◽  
Author(s):  
Milene Moreira ◽  
Dilmar Baretta ◽  
Siu Mui Tsai ◽  
Sandra Maria Gomes-da-Costa ◽  
Elke Jurandy Bran Nogueira Cardoso
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Biological Diversity ◽  
Diversity Index ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Araucaria Angustifolia ◽  
Forest Sustainability ◽  
Shannon’S Diversity Index

Araucaria angustifolia (Bert.) O. Ktze. is an endangered Brazilian coniferous tree that has been almost exterminated in the native areas because of uncontrolled wood exploitation. This tree has been shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) and, therefore, AMF may be essential for forest sustainability and biological diversity. Root colonization, density and diversity of AMF spores were assessed in two Araucaria forest stands at the State Park of Alto Ribeira (PETAR), at two sampling dates: May and October. A comparison was made between a mature native stand composed of Araucaria trees mixed into a variety of tropical trees and shrubs, without any sign of anthropogenic interference (FN) and an Araucaria stand planted in 1987 (R), which has been used as a pasture. Assessments included percent root colonization, AMF spore numbers and species richness, Simpson's dominance index (Is), and Shannon's diversity index (H). Mycorrhizal root colonization did not differ between ecosystems in May. In October, however, the native stand (FN) presented a higher colonization than the planted forest (R), and the root colonization was more intense than in May. When considering both sampling periods and forests, 27 species of AM fungi, with higher numbers of spores in FN than in R were found. Canonical discriminant analysis (CDA) indicated Shannon's diversity index as the ecological attribute that contributed the most to distinguish between forest ecosystems, with higher value of H in FN in relation to R. CDA showed to be a useful tool for the study of ecological attributes.

scholarly journals Effect of Biochar Amendments on Mycorrhizal Associations and Fusarium Crown and Root Rot of Asparagus in Replant Soils

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 960-966 ◽  
Author(s):  
Wade H. Elmer ◽  
Joseph J. Pignatello
Keyword(s):  
Root Rot ◽  
Root Colonization ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
First Year ◽  
Root Weight ◽  
Fusarium Spp ◽  
Biomass Waste ◽  
Mycorrhizal Associations ◽  
Crown And Root Rot

Pyrolyzed biomass waste, commonly called biochar, has attracted interest as a soil amendment. A commercial prototype biochar produced by fast pyrolysis of hardwood dust was examined in soils to determine if it could reduce the damaging effect of allelopathy on arbuscular mycorrhizal (AM) root colonization and on Fusarium crown and root rot of asparagus. In greenhouse studies, biochar added at 1.5 and 3.0% (wt/wt) to asparagus field soil caused proportional increases in root weights and linear reductions in the percentage of root lesions caused by Fusarium oxysporum f. sp. asparagi and F. proliferatum compared with a control. Concomitant with these effects was a 100% increase in root colonization by AM fungi at the 3.0% rate. Addition of aromatic acids (cinnamic, coumaric, and ferulic) that are known allelopathic agents affecting asparagus reduced AM colonization but the deleterious effects were not observed following the application of biochar at the higher rate. When dried, ground, asparagus root and crown tissues infested with Fusarium spp. were added to soilless potting mix at 0, 1, or 5 g/liter of potting mix and then planted with asparagus, there was a decrease in asparagus root weight and increase in disease at 1 g/liter of potting mix but results were inconsistent at the higher residue rate. However, when biochar was added at 35 g/liter of potting mix (roughly 10%, vol/vol), these adverse effects on root weight and disease were equal to the nontreated controls. A small demonstration was conducted in field microplots. Those plots amended with biochar (3.5% [wt/wt] soil) produced asparagus plants with more AM colonization in the first year of growth but, in the subsequent year, biochar-treated plants were reduced in size, possibly due to greater than average precipitation and the ability of biochar to retain moisture that, in turn, may have created conditions conducive to root rot. These studies provide evidence that biochar may be useful in overcoming the deleterious effects of allelopathic residues in replant soils on asparagus.

Impact of soil sterilization and irrigation intervals on P and K acquisition by mycorrhizal onion (Allium cepa)

Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Nasser Aliasgharzad ◽  
Saheb Bolandnazar ◽  
Mohammad Neyshabouri ◽  
Nader Chaparzadeh
Keyword(s):  
Allium Cepa ◽  
Crop Production ◽  
Root Colonization ◽  
Sandy Loam ◽  
Arbuscular Mycorrhizal ◽  
Field Capacity ◽  
Am Fungi ◽  
Irrigation Interval ◽  
Water Stress Condition ◽  
Mycorrhizal Plants

AbstractDrought is a world-spread problem seriously influencing crop production. Arbuscular mycorrhizal (AM) association and soil microorganisms can help plant growth under water stress condition by improvement of its nutrient and water uptake. In this experiment, onion plants (Allium cepa L. cv. Red Azar Shahr) were inoculated with three AM fungi species (Glomus versiforme, G. intraradices, G. etunicatum) or left un-inoculated as non-mycorrhizal plants, in a sterile or non-sterile sandy loam soil. Plants were irrigated at 7, 9 or 11-day intervals to keep the soil moisture content to field capacity at the irrigation time. Mycorrhizal root colonization decreased (p < 0.05) with an increase in irrigation interval, and the highest root colonization was achieved at 7-day irrigated onions in symbiosis with G. versiforme. Phosphorus content in plant tissue was significantly increased in mycorrhizal than non-mycorrhizal onions. Plants inoculated with G. versiforme at 9-day interval treatment had the highest leaf P content, while the lowest P was observed in non-mycorrhizal plants at all irrigation intervals. Onions inoculated by G. versiforme or G. etunicatum at 9-day irrigation interval had the highest K content. Results revealed that the inoculation of onion plant with G. versiforme or G. etunicatum and increasing irrigation interval up to 9 days, could improve P and K uptake.

scholarly journals Identification of Root-Secreted Compounds Involved in the Communication Between Cucumber, the Beneficial Bacillus amyloliquefaciens, and the Soil-Borne Pathogen Fusarium oxysporum

2017 ◽  
Vol 30 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Yunpeng Liu ◽  
Lin Chen ◽  
Gengwei Wu ◽  
Haichao Feng ◽  
Guishan Zhang ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Root System ◽  
Root Exudates ◽  
Bacillus Amyloliquefaciens ◽  
Root Colonization ◽  
Plant Root ◽  
Root Exudation ◽  
Soil Borne Pathogens ◽  
Split Root System ◽  
Cucumber Roots

Colonization of plant growth–promoting rhizobacteria (PGPR) is critical for exerting their beneficial effects on the plant. Root exudation is a major factor influencing the colonization of both PGPR and soil-borne pathogens within the root system. However, the tripartite interaction of PGPR, plant roots, and soil-borne pathogens is poorly understood. We screened root exudates for signals that mediate tripartite interactions in the rhizosphere. In a split-root system, we found that root colonization of PGPR strain Bacillus amyloliquefaciens SQR9 on cucumber root was significantly enhanced by preinoculation with SQR9 or the soil-borne pathogen Fusarium oxysporum f. sp. cucumerinum, whereas root colonization of F. oxysporum f. sp. cucumerinum was reduced upon preinoculation with SQR9 or F. oxysporum f. sp. cucumerinum. Root exudates from cucumbers preinoculated with SQR9 or F. oxysporum f. sp. cucumerinum were analyzed and 109 compounds were identified. Correlation analysis highlighted eight compounds that significantly correlated with root colonization of SQR9 or F. oxysporum f. sp. cucumerinum. After performing colonization experiments with these chemicals, raffinose and tryptophan were shown to positively affect the root colonization of F. oxysporum f. sp. cucumerinum and SQR9, respectively. These results indicate that cucumber roots colonized by F. oxysporum f. sp. cucumerinum or SQR9 increase root secretion of tryptophan to strengthen further colonization of SQR9. In contrast, these colonized cucumber roots reduce raffinose secretion to inhibit root colonization of F. oxysporum f. sp. cucumerinum.

scholarly journals Arbuscular cotton-associated mycorrhizal fungi in Yeola region of Maharashtra, India

2018 ◽  
Author(s):  
SUDAM W PATALE
Keyword(s):  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Plant Root ◽  
Fungal Spores ◽  
Am Fungi ◽  
Nutrient Status ◽  
Mineral Nutrient ◽  
High Concentration ◽  
Root Colonisation ◽  
Fungal Propagules

Mycorrhizae are a mutual symbiotic link between the plant root and a fungus that colonizes the cortical tissue of the roots during active plant growth periods. Both the host plant and the fungus have the potential to benefit.The purpose of this study is to evaluate the association of arbuscular mycorrhizal fungi in cotton crops with AM fungal population density in rhizosphere soils, investigate the qualitative composition of AM fungal species and the percentage of root colonization. The results showed that the number of AM fungal propagules collected from different locations in cotton crops ranged from 235 to 1580 spores per 100 g of soil. The distribution of spores, density and composition of AM fungi are observed to be influenced by environmental and physicochemical factors. The AM spore number, root colonization percentage and distribution vary depending on the seasonal fluctuations in moisture, temperature, pH and soil mineral nutrient status such as OC, P2O5, K2O, Zn, Cu, Fe, Mn, etc. The obtained data shows that nitrogen-deficient soils had more AM fungal propagules. The soils with a high concentration of phosphorus and potassium had the least AM fungal spores. Depleted zinc, copper and manganese levels have also been positive for more fungal occurrence and distribution. The presence of high iron levels in the soil, however, encourages more AM spores and a percentage of root colonisation.

scholarly journals Medicago SPX1 and SPX3 regulate phosphate homeostasis, mycorrhizal colonization and arbuscule degradation

2021 ◽  
Author(s):  
Peng Wang ◽  
Roxane Snijders ◽  
Wouter Kohlen ◽  
Jieyu Liu ◽  
Ton Bisseling ◽  
...  
Keyword(s):  
Root Colonization ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Phosphate Starvation ◽  
Negative Regulator ◽  
Fungal Colonization ◽  
Dependent Manner ◽  
Phosphate Homeostasis ◽  
Biosynthesis Gene ◽  
Inner Cortex

AbstractTo acquire sufficient mineral nutrients such as phosphate (Pi) from the soil, most plants engage in a symbiosis with arbuscular mycorrhizal (AM) fungi. Attracted by plant-secreted strigolactones, the fungi colonize the roots and form highly-branched hyphal structures called arbuscules inside inner cortex cells. It is essential that the host plant controls the different steps of this interaction to maintain its symbiotic nature. However, how plants sense the amount of Pi obtained from the fungus and how this determines the arbuscule lifetime is far from understood. Here, we show that Medicago truncatula SPX-domain containing proteins SPX1 and SPX3 regulate root phosphate starvation responses as well as fungal colonization and arbuscule degradation. SPX1 and SPX3 are induced upon phosphate starvation but become restricted to arbuscule-containing cells upon establishment of the symbiosis. Under Pi-limiting conditions they facilitate the expression of the strigolactone biosynthesis gene DWARF27, which correlates with increased fungal branching by root exudates and increased root colonization. Later, in the arbuscule-containing cells SPX1 and SPX3 redundantly control the timely degradation of arbuscules. This regulation does not seem to involve direct interactions with known transcriptional regulators of arbuscule degradation. We propose a model where SPX1 and SPX3 control arbuscule degeneration in a Pi-dependent manner via a yet-to-identify negative regulator.

scholarly journals Influence of AM fungi and its associated bacteria on growth promotion and nutrient acquisition in grafted sapota seedling production

2017 ◽  
Vol 9 (1) ◽  
pp. 621-625 ◽  
Author(s):  
P. Panneerselvam ◽  
B. Saritha
Keyword(s):  
Root Colonization ◽  
Growth Promotion ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Nutrient Acquisition ◽  
Nutrient Concentrations ◽  
Fungal Colonization ◽  
Total Biomass ◽  
Associated Bacteria ◽  
Combined Application

A study was undertaken to know the effect of co-inoculation of Arbuscular Mycorrhizal (AM) fungi and its associated bacteria on enhancing AM root colonization, growth promotion and nutrient acquisition in grafted sapota plants. The best mycorrhiza associated bacteria i.e. Pseudomonas putida (HM590707) isolated from Funneliformis mosseae spore was evaluated along with AM fungi for growth promotion and AM fungal colonization in grafted sapota plants. The combined application of P. putida along with AM fungi significantly increased plant height (39.67 %), stem girth (3.2 cm), total biomass (66.8 g plant-1), AM root colonization (73.4 %)and plant nutrient concentrations viz., N (2.52 %), P (0.18 %), K (2.90 %), Fe (428.4 ppm) and Zn (21.40 ppm) as compared to uninoculated control. This finding clearly demonstrated that grafted sapota plants can be successfully established by combined inoculation of AM fungi and its associated bacteria which have a greater impact on healthy grafted plants.

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