Exploring the role of root anatomy in P-mediated control of colonization by arbuscular mycorrhizal fungi

Botany ◽  
2010 ◽  
Vol 88 (2) ◽  
pp. 165-173 ◽  
Author(s):  
J. N. Sharda ◽  
R. T. Koide

Alterations of root anatomy have been largely ignored as potential mechanisms for phosphorus-mediated control of arbuscular mycorrhizal colonization. However, at least three anatomical traits including the proportion of root length with a suberized hypodermis, the distribution of hypodermal passage cells, and the proportion of root volume as intercellular air space may influence the degree of colonization. In the present study, we determined whether these traits could be altered by variation in plant phosphorus (P) status. We grew 15 angiosperm species from 13 families, each at two P availabilities, and determined how P status influenced the three root traits. Of the three traits, only the distribution of passage cells was significantly affected by phosphorus status; high P plants possessed a reduced proportion of root length with passage cells. Therefore, in species with passage cells, change in the proportion of root length with passage cells may represent one mechanism for phosphorus-mediated control of mycorrhizal colonization. However, individual species responses to P treatment varied widely, and no single anatomical mechanism appeared to be responsible for the control of mycorrhizal colonization in all species.

2021 ◽  
Vol 51 ◽  
pp. e1360
Author(s):  
Rocío Vega-Frutis ◽  
Ana M. Hanan-Alipi

  Background: Nutrient foraging strategies between thin and thick roots, including mycorrhizal symbionts are resource-costly, and therefore a trade-off could exist. These strategies can vary with the synanthropy index (degree to which a species associates with anthropogenic habitats), thus maximizing the benefits for the acquisition of soil resources. Objectives: To quantify the arbuscular mycorrhizal colonization of Melampodium species with different synanthropy index, and to determine the correlations between arbuscular mycorrhizal colonization and the architectural and morphological root traits. Methods: Roots of Melampodium divaricatum, M. perfoliatum and M. tepicense, with highest to lowest synanthropy index, respectively were collected. The root branching rate (RBR), total root length (TRL), diameter of first-order root, (FOR), root tissue density (RTD), specific root length (SRL), and arbuscular mycorrhizal colonization were quantified. Additionally, soil chemistry analyses were done. Results and conclusion: Melampodium tepicense had lowest FOR, highest SRL and lowest arbuscular mycorrhizal colonization, whereas M. divaricatum and M. perfoliatum had the opposite values. Additionally, M. divaricatum and M. perfoliatum had higher TRL, RTD, and RBR, suggesting that both strategies, arbuscular mycorrhiza and fine roots, are used for acquisition of nutrients, independently of their phylogenetic relationship and soil nutrients.


1997 ◽  
Vol 75 (10) ◽  
pp. 1778-1784 ◽  
Author(s):  
R. M. Miller ◽  
B. A. D. Hetrick ◽  
G. W. T. Wilson

Although arbuscular mycorrhizal symbiosis was initially believed to have little or no impact on root morphology, we now recognize that subtle changes do occur and that these changes may be of considerable consequence to host growth and nutrition, as well as functional growth strategy. In examining the stele and root diameters of C3 and C4 grasses, C4 grasses were demonstrated to have a significantly larger proportion of their fibrous roots occupied by stele tissue than do C3 grasses. In fact, functional growth strategy (C3 versus C4) was observed to be a relatively good predictor of stele area. Mycorrhizal fungi also influenced the amount of stele tissue, but the effect was not the same for both C3 and C4 grasses. The stele area of all C4 grasses except for Sorghastrum nutans was greater in the presence of mycorrhizal colonization. Among the C3 grasses, only Bromus inermis showed a significant increase, although Elymus cinereus and Lolium perenne displayed significant decreases in response to arbuscular mycorrhizal colonization. Changes in the stele area of the plant species were closely related to their responsiveness to mycorrhizal symbiosis and might in part explain both beneficial and detrimental responses of plants to mycorrhizae. An increase in stele circumference induced by mycorrhizae would allow for greater uptake and passage of water and nutrients to the vascular cylinder, and growth depressions could be a direct outcome of reduced stele circumference. Thus, differences in stele circumference represent a possible mechanism for mycorrhizal impacts on host plants. These findings indicate that structural differences among grasses are related to different functional capabilities and further emphasize the need for better integration of comparative anatomy and morphology procedures in the study of mycorrhizal symbiosis. Key words: stele, root anatomy, mycorrhizal dependency, functional growth strategy, mycorrhiza, C3 and C4 grasses.


2001 ◽  
Vol 79 (3) ◽  
pp. 300-306 ◽  
Author(s):  
M Kubota ◽  
T P McGonigle ◽  
M Hyakumachi

The mycorrhizal status of Clethra barbinervis, in the family Clethraceae of the order Ericales, was investigated. Mycorrhizal colonization of C. barbinervis roots collected from naturally occurring trees in two forests in Japan was determined monthly for 12 months. In addition, mycorrhizal colonization of C. barbinervis seedlings grown in pots of field-collected soil was evaluated. Field-collected C. barbinervis roots were extensively colonized by arbuscular mycorrhizal fungi that exhibited the Paris-type morphology. At both sites, total colonization ranged from 42–87% of root length and arbuscular colonization ranged from 6–31% of root length during the year. At one site, hyphal-coil colonization was between 37–61% year round; at the other site, it increased from between 30–56% during August-November to as high as 80% in January. Year round at both sites, vesicular colonization was 7% of root length or less. The Paris-type morphology was also seen in pot-grown C. barbinervis seedlings. Total colonization of pot-grown C. barbinervis seedlings was 34–56% of the root length over 5–20 weeks. To our knowledge, this study is the first report of the mycorrhizal status of a plant in the Clethraceae and the first report of arbuscular mycorrhizae in any member of the Ericales.Key words: Paris-type, Japan, seasonal pattern, arbuscular mycorrhiza, Ericales.


2019 ◽  
Author(s):  
Coline Deveautour ◽  
Suzanne Donn ◽  
Sally Power ◽  
Kirk Barnett ◽  
Jeff Powell

Future climate scenarios predict changes in rainfall regimes. These changes are expected to affect plants via effects on the expression of root traits associated with water and nutrient uptake. Associated microorganisms may also respond to these new precipitation regimes, either directly in response to changes in the soil environment or indirectly in response to altered root trait expression. We characterised arbuscular mycorrhizal (AM) fungal communities in an Australian grassland exposed to experimentally altered rainfall regimes. We used Illumina sequencing to assess the responses of AM fungal communities associated with four plant species sampled in different watering treatments and evaluated the extent to which shifts were associated with changes in root traits. We observed that altered rainfall regimes affected the composition but not the richness of the AM fungal communities, and we found distinctive communities in the increased rainfall treatment. We found no evidence of altered rainfall regime effects via changes in host physiology because none of the studied traits were affected by changes in rainfall. However, specific root length was observed to correlate with AM fungal richness, while concentrations of phosphorus and calcium in root tissue and the proportion of root length allocated to fine roots were correlated to community composition. Our study provides evidence that climate change and its effects on rainfall may influence AM fungal community assembly, as do plant traits related to plant nutrition and water uptake. We did not find evidence that host responses to altered rainfall drive AM fungal community assembly in this grassland ecosystem.


Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 246
Author(s):  
Edilson Nonato Da Silva ◽  
Aline Torquato Tavares ◽  
Cândida Pereira Da Silva ◽  
Tiago Alves Ferreira ◽  
João Victor Gonçalves Carline ◽  
...  

O experimento foi realizado na Estação Experimental de Engenharia Florestal do Campus Universitário de Gurupi, Universidade Federal do Tocantins (UFT), com objetivo de determinar a melhor dose de fósforo na presença de fungos arbusculares em mudas de guanandi (Calophyllum brasiliense Camb.) O delineamento experimental utilizado foi inteiramente casualizado com três repetições em esquema fatorial 6 x 2. Os tratamentos foram seis doses de fósforo (0; 400; 800; 1200; 1600 e 2000 g de P2O5 por m³) no substrato na presença e ausência de Fungos Micorrízos Arbusculares (FMAs). As características avaliadas foram altura das plantas, diâmetro do caule, massa seca da parte aérea (MSPA), massa seca da raiz (MSR), massa seca total (MST) e colonização micorrízica. Os diferentes níveis de adubação influenciaram a colonização micorrízica arbuscular. Nas doses 400 e 1600 g de fósforo por m3 de substrato observou-se maior porcentagem de colonização. A altura e o diâmetro das plantas foram significativamente afetados pela presença de P2O5. A massa seca da parte aérea e massa seca total não é afetada por doses de P2O5. O melhor desempenho das mudas de C. brasiliense ocorreu aos 90 dias com dose de 1.421 g de P2O5 por m3 de substrato.Palavras-chave: Calophyllum brasiliense Camb., adubação, micorrização. MYCORRHIZAL FUNGI AND PHOSPHORUS DOSES IN THE DEVELOPMENT OF GUANANDI SEEDLINGS ABSTRACT:The experiment was carried out at the Forest Engineering Experimental Station of the Federal University of Tocantins (UFT), University Campus of Gurupi, with the objective of determining the best dose of phosphorus in the presence of arbuscular fungi in guanandi (Calophyllum brasiliense Camb. The experimental design was completely randomized with three replicates in a 6 x 2 factorial scheme. The treatments were six doses of phosphorus (0, 400, 800, 1200, 1600 and 2000 g of P2O5 per m³) on the substrate in the presence and absence of Arbuscular mycorrhizal fungi (FMAs). The evaluated characteristics were plant height, stem diameter, shoot dry mass (MSPA), root dry mass (MSR), total dry mass (MST) and mycorrhizal colonization. The different levels of fertilization influenced arbuscular mycorrhizal colonization. At 400 and 1600 g of phosphorus per m3 of substrate, a higher percentage of colonization was observed. The height and diameter of the plants were significantly affected by the presence of P2O5. Dry shoot mass and total dry mass are not affected by P2O5 doses. The best performance of C. brasiliense seedlings occurred at 90 days with a dose of 1421 g of P2O5 per m3 of substrate.Keywords: Calophyllum brasiliense Camb., fertilization, mycorrhization. DOI:


2021 ◽  
Vol 10 (7) ◽  
pp. e45410716972
Author(s):  
José Luís Trevizan Chiomento ◽  
João Eduardo Carniel de Paula ◽  
Fabiola Stockmans De Nardi ◽  
Thomas dos Santos Trentin ◽  
Fernando Brollo Magro ◽  
...  

The inoculation of strawberry cultivars with arbuscular mycorrhizal fungi (AMF) is a profitable and viable biotechnological tool, with potential to improve the horticultural performance of plants. However, this biotechnology is lacking and unknown to producers. The aim of the research was to investigate whether strawberry cultivars in the absence and presence of inoculation with AMF differ in their horticultural performance. The treatments, delineated in a bifactorial scheme, were four strawberry cultivars in the absence and presence of two AMF-based inoculants. The experiment was designed in randomized blocks, with three replications. The root system of ‘Albion’ cultivar showed the highest mycorrhizal colonization. Claroideoglomus etunicatum showed greater capacity to infect plant roots. ‘Portola’ was the most productive cultivar and ‘Albion’ and ‘Aromas’ produced strawberries with the highest levels of total anthocyanins. It is concluded that the use of mycorrhizal biotechnology enhances the levels of total flavonoids in fruits of the ‘Albion’ cultivar inoculated with the fungal species C. etunicatum. The root system of ‘Albion’ cultivar has greater mycorrhizal colonization. The fungal species C. etunicatum is more effective in colonizing the roots of the plant host. It is suggested to use the ‘Portola’ cultivar to obtain higher fruit yields and the ‘Albion’ and ‘Aromas’ cultivars for producers who aim to obtain strawberries with higher levels of total anthocyanins. ‘Aromas’ is recommended for those seeking a dual purpose (production and quality).


2019 ◽  
Vol 32 (2) ◽  
pp. 345-353
Author(s):  
JOHNY DE JESUS MENDONÇA ◽  
LARISSA DE SOUZA GOIS ◽  
JACILENE FRANCISCA SOUZA SANTOS ◽  
TAMIRIS APARECIDA DE CARVALHO SANTOS ◽  
FRANCISCO SANDRO RODRIGUES HOLANDA ◽  
...  

ABSTRACT Paspalum millegrana grass is a member of the family Poaceae native to the Americas, whose interaction with native symbiotic fungi has not yet been reported. The objective of this study was to evaluate the interactions between the native microorganisms and arbuscular mycorrhizal fungi in the development of P. millegrana Schrad. The experimental design was completely randomized with seven treatments (control, without AMF; native microbial inoculant; native + UFLA05 Gigaspora albida; native + UFLA351 Rhizoglomus clarum; native + UFLA372 Claroideoglomus etunicatum; native + UFLA401 Acaulospora morrowiae, and a mix of all treatments). The substrate was autoclaved sand and coconut powder at 2:1, with eight repetitions. The variables analyzed were: mycorrhizal colonization, dark septate endophytic fungi colonization, number of mycorrhizal spores, dry shoot mass, dry root mass, root length and volume, number of tiller and mycorrhizal dependence. Mycorrhizal arbuscular fungi and dark septate endophytic fungi colonized P. millegrana. The sporulation of arbuscular mycorrhizal fungi associated with P. millegrana was influenced by mycorrhizal colonization, depending on the fungus-plant interaction. P. millegrana was responsive to native + UFLA05 and native + UFLA351. No correlation between tiller emergence and mycorrhizal colonization of P. millegrana was observed.


2010 ◽  
Vol 21 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Mónica Fernández-Aparicio ◽  
Koichi Yoneyama ◽  
Diego Rubiales

AbstractStrigolactones are apocarotenoids regulating shoot branching. They are also known to be exuded by plant roots at very low concentrations, stimulating hyphal branching of arbuscular mycorrhizal fungi and germination of root parasitic weed seeds. We show that strigolactones play a major role in host specificity ofOrobancheandPhelipanche(the broomrapes) seed germination. This observation confirms that host-derived germination stimulants are an important component determining the host specificity of these parasitic plants. Weedy broomrape species were less specialized in germination requirements than the non-weedy species except forO. cumanaandO. foetidavar.broteri. Similar results were obtained with the root exudates. Some species, such asP. aegyptiacaandO. minor, showed a broad spectrum of host specificity in terms of seed germination, which was stimulated by exudates from the majority of species tested, whereas others, such asO. cumana,O. hederaeandO. densiflora, were highly specific. Some species, such asO. minor,P. aegyptiacaandP. nana, were responsive to the three strigolactones studied, whereas others were induced by only one of them, or did not respond to them at all. The synthetic strigolactone analogue GR24, generally used as a standard for germination tests, was not effective on someOrobancheandPhelipanchespecies. Seeds of some species that did not respond to GR24 were induced to germinate in the presence of fabacyl acetate or strigol, confirming the role of strigolactones in host specificity.


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