Arbuscular mycorrhizal fungi induce sucrose cleavage for carbon supply of arbuscular mycorrhizas in citrus genotypes

2013 ◽  
Vol 160 ◽  
pp. 320-325 ◽  
Author(s):  
Qiang-Sheng Wu ◽  
Ying-Ning Zou ◽  
Yong-Ming Huang ◽  
Yan Li ◽  
Xin-Hua He
2000 ◽  
Vol 30 (10) ◽  
pp. 1543-1554 ◽  
Author(s):  
Andrew P Coughlan ◽  
Yolande Dalpé ◽  
Line Lapointe ◽  
Yves Piché

Acer saccharum Marsh. (sugar maple) is one of only few arbuscular mycorrhizal trees to form extensive stands in northern temperate biomes. Recent maple decline could result from altered intensity and quality of root colonization by associated mycobionts or possible shifts in symbiotic fungal community composition following environmental stresses. In this study the effects on arbuscular mycorrhizal fungi of soil acidification, one of several proposed causal stresses underlying forest decline, and remedial liming were investigated under glasshouse conditions. Acer saccharum seedlings were grown in unsterilized, pH altered, forest soils from healthy and declining maple stands. Over a range of treatment pHs normally tolerated by A. saccharum, fungal populations and responses to pH changes differed between the two soils. The declining site with more acidic soil had an initially larger spore population but lower taxonomic diversity than the healthy site. However, liming stimulated sporulation of several taxa initially apparently absent from the declining site spore population. The quantity of colonization generally increased with pH for both sites. Five Glomus taxa and Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders are added to the list of fungi known to form arbuscular mycorrhizas with A. saccharum, and the known range of Acaulospora cavernata Blaszkowski is extended from Poland to eastern North America.


1995 ◽  
Vol 73 (S1) ◽  
pp. 526-532 ◽  
Author(s):  
Vivienne Gianinazzi-Pearson ◽  
Armelle Gollotte ◽  
Benoit Tisserant ◽  
Philipp Franken ◽  
Eliane Dumas-Gaudot ◽  
...  

Arbuscular mycorrhizas represent the most widespread, and probably most ancient, type of plant–fungus association in which the large majority of terrestrial plants must have evolved with compatibility systems towards the fungal symbionts. Cellular interactions leading to reciprocal morphofunctional integration between symbionts during mycorrhiza establishment are complex. Some plant genes and cellular events may be shared with nodulation processes, but there is evidence of molecular modifications specific to arbuscular mycorrhiza formation. Plant defence responses, which are normally weakly activated during the symbiotic state, are strongly elicited by arbuscular mycorrhizal fungi in genetically altered, resistant hosts suggesting control over defence gene expression during establishment of a successful symbiosis. Modifications are also induced in the fungal symbionts during colonization of host tissues, with changes in wall metabolism and protein expression. Nothing is known of the genetic make-up of arbuscular mycorrhizal fungi which are recalcitrant to pure culture. Recent cloning of DNA from these fungi opens the possibility of identifying functional genes in order to study their regulation and role in symbiosis establishment. Key words: arbuscular mycorrhiza, reciprocal symbiosis, molecular mechanisms, plant determinants, fungal molecules.


Author(s):  
Christopher Walker

Most plants have mutualistic symbioses (mycorrhizas) with certain fungi that occupy their roots, the most common of which fall into the category known as arbuscular mycorrhizas (AM). Although most of the arbuscular mycorrhizal fungi (AMF) are entirely subterranean, some form spore masses or sporocarps sufficiently large to be seen with the unaided eye on the surface of the substrate. During several decades of casual observation in the research greenhouses at the Royal Botanic Garden Edinburgh (RBGE), such clumps of spores from several species of AMF have been recorded. A brief introduction to mycorrhizas, with an emphasis on AM, is provided. A list of host plants grown in botanic gardens or similar situations from which AMF have been identified is given. The possible value of AMF is discussed in relation to the ‘ecosystems’ that develop in mature botanic garden greenhouses. Ways of using AMF to improve the establishment or growth of plants are discussed, including a suggestion that adequate controls must always be used, particularly when using previously untested commercially available products.


2014 ◽  
Vol 54 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Santiago Schalamuk ◽  
Silvana Velazquez ◽  
María Rosa Simón ◽  
Marta Cabello

Abstract Arbuscular-mycorrhizal internal structures (i.e. total root colonization, arbuscules, vesicles) and external structures (i.e. spore density), and Glomeromycota spore morphotypes, were evaluated in wheat severely infected with Mycosphaerella graminicola - the causal agent of Septoria leaf blotch. Plots in which the infection was controlled with a commercial fungicide at recommended field doses, were also examined. The commercial fungicide used was an admixture of trifloxistrobin and tebuconazole. No negative effects of the fungicide application on arbuscular-mycorrhizal fungi (AMF) were found. The M. graminicola fungicidal treatment actually favoured the formation of arbuscules and AMF spores, as there was a selective increase in the density of spores belonging to the glomoid morphotype. Arbuscular-mycorrhizal fungi have an absolute dependence on the carbon provided by the plant. A severe foliar disease leading to a diminished carbon supply to the roots would generate decreases in carbon availability. Such decreases would strongly affect mycorrhizal associations and development. Furthermore, the change in the green-leaf area produced by a severe foliar disease and/or a reversal of that condition through fungicide treatment could result in shifts in the composition of the AMF community so as to favour glomoid morphotypes. Glomoid species have been previously considered as r-strategists


2004 ◽  
Vol 82 (8) ◽  
pp. 1235-1242 ◽  
Author(s):  
S Juniper ◽  
L K Abbott

This study investigated the effect of a rapid change in the concentration of the soil solution on hyphal growth from germinated spores of three arbuscular mycorrhizal fungi: isolates of Acaulospora laevis Gerd. & Trappe, Gigaspora decipiens Hall & Abbott, and Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders. Spores of either G. decipiens or S. calospora were incubated between millipore filters buried in sand that had been watered to field capacity with solutions of 0, 150, or 300 mmol/L NaCl. After 11 d, the intact pairs of filters were recovered, left undisturbed, or transferred into and further incubated in soil watered with one of the three solutions. Spores of A. laevis were incubated between filters in sand without NaCl and after 20 d were either left undisturbed or transferred to soil with 0, 50, 150, or 300 mmol/L NaCl in the soil solution for a further 11 d. The filter sandwiches were stained and opened, and determinations of spore germination, number of auxiliary cells, and length of hyphae on each were made. For G. decipiens and S. calospora, the effect of NaCl on hyphal growth was reversible. Hyphae from spores germinated in sand with 300 mmol/L NaCl showed markedly increased growth when transferred to a less saline environment. Hyphae from spores germinated in nonsaline sand continued to grow, but at a slower rate, when transferred to a saline environment. Hyphae of A. laevis continued to elongate after transfer to soil with 50 mmol/L NaCl but not 150 or 300 mmol/L NaCl. Morphological differences were observed between hyphae of G. decipiens grown in a highly saline as compared with a nonsaline substrate.Key words: soil salinity, arbuscular mycorrhizas, species and genera of arbuscular mycorrhizal fungi, hyphae.


2018 ◽  
Vol 285 (1888) ◽  
pp. 20181600 ◽  
Author(s):  
William R. Rimington ◽  
Silvia Pressel ◽  
Jeffrey G. Duckett ◽  
Katie J. Field ◽  
David J. Read ◽  
...  

Arbuscular mycorrhizas are widespread in land plants including liverworts, some of the closest living relatives of the first plants to colonize land 500 million years ago (MYA). Previous investigations reported near-exclusive colonization of liverworts by the most recently evolved arbuscular mycorrhizal fungi, the Glomeraceae, indicating a recent acquisition from flowering plants at odds with the widely held notion that arbuscular mycorrhizal-like associations in liverworts represent the ancestral symbiotic condition in land plants. We performed an analysis of symbiotic fungi in 674 globally collected liverworts using molecular phylogenetics and electron microscopy. Here, we show every order of arbuscular mycorrhizal fungi colonizes early-diverging liverworts, with non-Glomeraceae being at least 10 times more common than in flowering plants. Arbuscular mycorrhizal fungi in liverworts and other ancient plant lineages (hornworts, lycopods, and ferns) were delimited into 58 taxa and 36 singletons, of which at least 43 are novel and specific to liverworts. The discovery that early plant lineages are colonized by early-diverging fungi supports the hypothesis that arbuscular mycorrhizas are an ancestral symbiosis for all land plants.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Emma Mortier ◽  
Olivier Lamotte ◽  
Fabrice Martin-Laurent ◽  
Ghislaine Recorbet

AbstractWalnut trees are among the most important hardwood species in the northern hemisphere, ecologically and economically. They are mainly cultivated for timber and nut production but are also attractive ornamental trees in parks. Establishing walnut orchards is difficult because seedlings have a coarse root architecture and few of them survive to transplanting. Planting success is mainly determined by the root system morphology and the nutrient status of the seedlings, so that rhizosphere conditions are critical for plant performance. Walnut trees can associate with soil-borne arbuscular mycorrhizal fungi, which are obligate biotrophs. In this association, plant-produced carbon compounds are traded against fungus-acquired soil mineral nutrients. The beneficial effect of arbuscular mycorrhizal symbiosis on hardwood seedling quality and field performance has long been known, but an integrated view is lacking about the effects of arbuscular mycorrhizas on walnut cropping. Therefore, we surveyed the literature published over the last 40 years to provide up-to-date knowledge on the relationships between arbuscular mycorrhizas and walnut trees. Our review outlines the major following points: (1) the arbuscular-mycorrhiza-mediated nutrient uptake capacity of walnut trees is associated with first- to third-order roots, and fibrous tip-ended roots are dependent on arbuscular mycorrhizal fungi, whereas pioneer roots are not; (2) early inoculation with arbuscular mycorrhizal fungi improves the survival and seedling performance attributes of transplanted walnut trees: biotization enhances walnut transplant success by increasing the number of lateral roots and plant P uptake, but these benefits are fungus- and host-dependent; (3) in the context of walnut agroforestry, deeply rooted walnut trees play a role as reservoirs of arbuscular mycorrhizal fungal propagules for the surrounding vegetation, but tree shade and soluble phosphate availability decrease walnut mycorrhizal dependency; and (4) the arbuscular mycorrhizal mycelium mediates the transport of juglone and thus plays a role in walnut tree allelopathy.


2017 ◽  
Vol 11 (1) ◽  
pp. 76 ◽  
Author(s):  
Faisal Danu Tuheteru ◽  
Asrianti Arif ◽  
Eka Widiastuti ◽  
Ninis Rahmawati

Pengaruh fungi mikoriza arbuskula (FMA) lokal terhadap pertumbuhan dan serapan logam tanaman Nauclea orientalis L., telah diteliti. Tanaman ditumbuhkan pada kondisi rumah kaca pada media serpentine soil tanpa dan dengan FMA (Glomus sp., Acaulospora tuberculata, dan campuran) selama 2 bulan. Akar tanaman lonkida terkolonisasi FMA dengan ditemukan struktur FMA berupa hifa internal>hifa eksternal>coil> vesikula>arbuskula. Kolonisasi A. tuberculata dan Glomus sp. signifikan meningkatkan berat kering akar (P<0,01, r=0,810) dan pucuk (P<0,05, r=0,802). N. orientalis memiliki ketergantungan tinggi terhadap inokulasi FMA (MIE>65). Nilai Transpor Faktor (TF) <1 untuk semua logam dengan urutan serapan logam Fe>Mn>Ni>Cr. Glomus sp mengurangi serapan Fe dan Ni akar sebesar 13% dan 3%, secara berturutan. A. tuberculata meningkatkan serapan semua logam. Kemampuan serapan logam berbeda antara jenis FMA.Heavy Metal Uptake by Indigenous Arbuscular Mycorrhizas of Nauclea orientalis L. and the Potential for Phytoremediation of Serpentine SoilAbstractEffect of indigenous arbuscular mycorrhizal fungi (AMF) on growth and metal uptake of Nauclea orientalis L. plants, has been investigated. Plants were grown in greenhouse conditions on serpentine soil media without and with the AMF (Glomus sp., Acaulospora tuberculata, and mix) for two months. Lonkida roots was colonized by AMF because it was found structures of AMF: internal hyphae>external hypae>coil>vesicles>arbuscule. Colonization A. tuberculata and Glomus sp. significantly increased dry weight of root (P<0.01, r=0.810) and shoot (P<0.05, r=0.802). N. orientalis has a high dependence on inoculation of AMF (MIE>65). Transport Factor value (TF) <1 for all metals with metal uptake sequence was Fe>Mn>Ni>Cr. Glomus sp reduced Fe and Ni uptake on roots by 13% and 3%, respectively. A. tuberculata increased the uptake of all metals. Metal uptake ability was difference among types of AMF.


Sign in / Sign up

Export Citation Format

Share Document