Mycorrhizae confer aluminum resistance to tulip-poplar seedlings

2001 ◽  
Vol 31 (4) ◽  
pp. 694-702 ◽  
Author(s):  
Heidi B Lux ◽  
Jonathan R Cumming

Aluminum (Al) toxicity may limit the growth and nutrient acquisition of sensitive tree species in regions receiving acidic deposition. Symbioses between tree roots and mycorrhizal fungi may offset the negative impacts of Al in the root zone. Liriodendron tulipifera L. (tulip-poplar) is an important tree species in the Appalachian Mountains of the southeastern United States and may be at risk from the high levels of acidic deposition in that area. Mycorrhizal and non-mycorrhizal tulip-poplar seedlings were exposed to Al levels of 0, 50, 100, and 200 µM in sand culture for 6 weeks. Mycorrhizal plants accumulated two to seven times the shoot and root biomass of non-mycorrhizal plants and demonstrated no decreases in biomass with Al exposure. Non-mycorrhizal plants exhibited significant reductions in biomass at and above 100 µM Al. Aluminum toxicity in non-mycorrhizal plants appears to be the result of the disruption of P translocation to leaves and Ca, Mg, P, Cu, and Zn uptake in roots. Mycorrhizal plants accumulated 2 and 1.5 times the concentration of Al in shoots and roots, respectively, indicating that Al resistance was not associated with the exclusion of Al from the plant. Patterns of labile Al in solution, nutrients, and Al accumulation in tissues suggest that arbuscular mycorrhizal fungal ecotypes may alter the form or compartmentation of Al within the rhizosphere and plant, thus protecting seedlings from the effects of exposure to Al in the soil solution.

1999 ◽  
Vol 29 (12) ◽  
pp. 2003-2007 ◽  
Author(s):  
Heidi B Lux ◽  
Jonathan R Cumming

Atmospheric deposition of nitrogen and sulfate is acidifying some ecosystems, potentially increasing the availability of aluminum in the soil solution. The effects of Al on tulip-poplar (Liriodendron tulipifera L.) were investigated with seedlings grown in sand culture. Seedlings were exposed to Al at four concentrations ranging from 0 to 800 µM. Reductions of 77% in shoot biomass and 71% in root biomass were observed at 200 µM Al. Aluminum reduced the concentrations of multivalent cations in leaves and roots. The Ca concentration of leaves was reduced at 400 µM Al, and the Mg concentration of roots was significantly reduced at 200 µM Al. Relationships between tissue Ca, Mg, and Al indicated that Al alters the translocation of Ca and Mg to the shoots and the accumulation of Mg in the roots. If mature trees respond in a similar fashion as seedlings noted here, then tulip-poplar has a low threshold for A1 toxicity, which may lead to declines in the health of tulip-poplar populations in ecosystems exposed to elevated levels of acidic deposition.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1402
Author(s):  
Sebastian Przybyłko ◽  
Wojciech Kowalczyk ◽  
Dariusz Wrona

The desire to reduce the negative impact of crops on the environment, as well as the growing concern for consumer health, is increasing interest in organic fruit production. In this context, the development of new environmentally friendly agrotechnical methods which allows for reducing the use of organic fertilizers by improving the nutrient use efficiency and consequently decreasing the leaching of them is a task of a great importance. The main purpose of this study was to evaluate the effect of mycorrhizal arbuscular fungi (AMF) combined with plant-growth-promoting rhizobacteria (PGPR) on growth and nutritional status of apple trees cultivated on a silty-loam, rich in clay minerals and humus soil under organic farming conditions. Thus, a trial was established in an experimental orchard in Wilanów in Central Poland with three cultivars (‘Topaz’, ‘Odra’, and ‘Chopin’) and a promising clone, U 8869. Trees were or were not inoculated with AMF + PGPR within a split-block experimental design with four replicates. According to the results, mycorrhizal frequency obtained in the inoculated tree roots was on average two-fold higher than in the roots of the control plants. After four years of AMF + PGPR inoculation, 24% higher trunk cross-section area (TCSA) was observed, with the nitrogen and magnesium concentrations in leaves increasing, on average, by 7.8% and 64.2%, and phosphorus and potassium content decreasing by 37.2% and 46.5%, respectively. This study shows that using AMF + PGPR inoculum supports tree roots colonization by AMF. As a result, better nitrogen nutrition status is observed that promote vigorous growth of trees and more efficient uptake of magnesium from the bulk soil. On the other hand, lower phosphorus content in inoculated tree leaves might be explained by a dilution effect, and potassium decrease could occur as a result of fungus–plant competition in conditions of this element deficiency in soil.


2021 ◽  
Author(s):  
Robert Reuter ◽  
Olga Ferlian ◽  
Mika Tarkka ◽  
Nico Eisenhauer ◽  
Karin Pritsch ◽  
...  

Abstract Mycorrhizal fungi play an important role for the nitrogen (N) supply of trees. The influence of different mycorrhizal types on N acquisition in tree-tree interactions is, however, not well understood, particularly with regard to the competition for growth-limiting N. We studied the effect of competition between temperate forest tree species on their inorganic and organic N acquisition in relation to their mycorrhizal type (i.e., arbuscular mycorrhiza or ectomycorrhiza). In a field experiment, we quantified net N uptake capacity from inorganic and organic N sources using 15N/13C stable isotopes for arbuscular mycorrhizal tree species (i.e., Acer pseudoplatanus L., Fraxinus excelsior L., and Prunus avium L.) as well as ectomycorrhizal tree species (i.e., Carpinus betulus L., Fagus sylvatica L., and Tilia platyphyllos Scop.). All species were grown in intra- and interspecific competition (i.e., monoculture or mixture). Our results showed that N sources were not used complementarily depending on a species´ mycorrhizal association, but their uptake rather depended on the competitor indicating species-specific effects. Generally, ammonium was preferred over glutamine and glutamine over nitrate. In conclusion, our findings suggest that inorganic and organic N acquisition of the studied temperate tree species is less regulated by mycorrhizal association, but rather by the availability of specific N sources in the soil as well as the competitive environment of different tree species.


Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 370
Author(s):  
Murugesan Chandrasekaran

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts of higher plants which increase the growth and nutrient uptake of host plants. The primary objective was initiated based on analyzing the enormity of optimal effects upon AMF inoculation in a comparative bias between mycorrhizal and non-mycorrhizal plants stipulated on plant biomass and nutrient uptake. Consequently, in accomplishing the above-mentioned objective a vast literature was collected, analyzed, and evaluated to establish a weighted meta-analysis irrespective of AMF species, plant species, family and functional group, and experimental conditions in the context of beneficial effects of AMF. I found a significant increase in the shoot, root, and total biomass by 36.3%, 28.5%, and, 29.7%, respectively. Moreover, mycorrhizal plants significantly increased phosphorus, nitrogen, and potassium uptake by 36.3%, 22.1%, and 18.5%, respectively. Affirmatively upon cross-verification studies, plant growth parameters intensification was accredited to AMF (Rhizophagus fasciculatus followed by Funniliforme mosseae), plants (Triticum aestivum followed by Solanum lycopersicum), and plant functional groups (dicot, herbs, and perennial) were the additional vital important significant predictor variables of plant growth responses. Therefore, the meta-analysis concluded that the emancipated prominent root characteristics, increased morphological traits that eventually help the host plants for efficient phosphorus uptake, thereby enhancing plant biomass. The present analysis can be rationalized for any plant stress and assessment of any microbial agent that contributes to plant growth promotion.


1998 ◽  
Vol 28 (1) ◽  
pp. 150-153
Author(s):  
J N Gemma ◽  
R E Koske ◽  
E M Roberts ◽  
S Hester

Rooted cuttings of Taxus times media var. densiformis Rehd. were inoculated with the arbuscular mycorrhizal fungi Gigaspora gigantea (Nicol. & Gerd.) Gerd. & Trappe or Glomus intraradices Schenck and Smith and grown for 9-15 months in a greenhouse. At the completion of the experiments, leaves of inoculated plants contained significantly more chlorophyll (1.3-4.1 times as much) than did noninoculated plants. In addition, mycorrhizal plants had root systems that were significantly larger (1.3-1.4 times) and longer (1.7-2.1 times) than nonmycorrhizal plants, and they possessed significantly more branch roots (1.3-2.9 times). No differences in stem diameter and height or shoot dry weight were evident at the end of the experiments, although the number of buds was significantly greater in the cuttings inoculated with G. intraradices after 15 months.


2021 ◽  
Vol 35 (2) ◽  
pp. 269-275
Author(s):  
Camila Abarca ◽  
Marcelo Daniel Barrera ◽  
Marta Cabello ◽  
Fabricio Valdés ◽  
María Silvana Velázquez

2021 ◽  
Vol 10 (1) ◽  
pp. e10010111435
Author(s):  
Emanuela Lima dos Santos ◽  
Brena Coutinho Muniz ◽  
Beathriz Godoy Vilela Barbosa ◽  
Marcia Maria Camargo Morais ◽  
Francineyde Alves da Silva ◽  
...  

Arbuscular mycorrhizal fungi (AMF) are known to provide plant species with several benefits, such as an increased production of bioactive compounds. However, it is yet to be defined whether extracts of mycorrhizal plants are more efficient in vitro antibacterial actions when compared to non-mycorrhizal plants. We tested the hypothesis of whether or not, methanolic extracts of Libidibia ferrea fruits, from plants established in the field and inoculated with AMF, have higher antibacterial action when inoculated with Acaulospora longula, Claroideoglomus etunicatum or Gigaspora albida. In addition, native L. ferrea fruits collected from the Caatinga area were also tested. The extracts of L. ferrea fruits inoculated with A. longula had higher in vitro antibacterial action in relation to the extracts of fruits from non-inoculated plants (p <0.05) thus characterizing the first record of different antibacterial actions of plant extracts due to inoculation with AMF. The extracts of L. ferrea fruits inoculated with A. longula were more efficient in inhibiting growth of Gram-negative bacteria. The zone diameters of inhibition ranged from 2.48 % to 7.56 % larger than the zones of the non-inoculated L. ferrea fruit extracts. The inoculation of L. ferrea with AMF may represent an alternative way of producing fruits with different antibacterial activity.


2014 ◽  
Vol 23 ◽  
pp. 47-62
Author(s):  
J. Philip Robinson ◽  
K. Nithya ◽  
R. Ramya ◽  
B. Karthikbalan ◽  
K. Kripa

Plant growth and physiological response of sesame (Sesamum indicum L.) were studied in controlled environment using normal soil and indigenous Vesicular-arbuscular mycorrhiza (VAM) fungi treated soil. The seedlings of Zea mays were inoculated with Giguspora species of VAM (Glomus fasiculatum) and the inoculum was multiplied with help of Zeamays seed bed. Sesame seeds were then inoculated into the bed and it was found that the plant height, shoots lengths, roots, biomass of shoot and roots were considerably increased in the mycorrhizal plants. The effect of VAM infection was assessed in pot experiment. In this comparative study, specific mycorrhizal fungi had consistent effects on various growth parameters such as the number of leaves, number of roots, shoot length, biomass of shoot and roots and biochemical parameters were observed at various time intervals by statistical analysis using two way ANOVA, it was confined with mycorrhizal and non-mycorrhizal infected plants. It was found that the ability of isolates to maintain the plant growth effectively in the case of mycorrhizal seedlings shows a maximum absorbtion of 0.77 ±0.2, shoot length is about 8.34 ±0.2, count of root and leaves are about 8.10 ±0.3, 5.6 ±0.3 respectively under mycorrhizal infection in 30days of analysis and had a positive effect on the growth at all intervals. Biochemical analysis were carried out to estimate the total chlorophyll, chrophyll A, chlorophyll B and Carotenoids contents and it was analyzed to be 9 ±0.5 mg/g, 8.3 ±0.5 mg/g, 3.6 ±0.5 mg/g, 4 ±0.3 mg/g respectively. At the 30th day of analysis for the mycorrhizal plants, it was found to be high in mycorrhizal seedlings which shows the symbiosis had improved the nutrient uptake of cultivated plants. Nevertheless G. fasiculatum was found to be the most efficient fungus and exhibited the highest levels of mycorrhizal colonization, as well as the greatest stimulation of physiological parameters.


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