scholarly journals Diversity loss selects for altered plant phenotypic responses to local arbuscular mycorrhizal communities

2017 ◽  
Author(s):  
Terhi Hahl ◽  
Sofia Julia van Moorsel ◽  
Marc W. Schmid ◽  
Debra Zuppinger-Dingley ◽  
Bernhard Schmid ◽  
...  

1. Biodiversity loss not only impairs ecosystem functioning but can also alter the selection for traits in plant communities. At high diversity selection favours traits that allow for greater niche partitioning, whereas at low diversity selection may favour greater defence against pathogens. However, it is unknown whether changes in plant diversity also select for altered interactions with soil organisms. 2. We assessed whether the responses in plant growth and functional traits to their local arbuscular mycorrhizal fungal (AMF) communities have been altered by the diversity of the plant communities from which both plants and AMF communities were obtained. We grew plants with AMF communities that originated from either plant monocultures or mixtures in a fully factorial design that included both negative and positive controls, by inoculating no AMF or a foreign AMF respectively. 3. We found that AMF from plant mixtures were more beneficial than monoculture AMF for two out of five plant species. Plants from mixtures generally grew better than those from monocultures, but suffered greater damage by leaf pathogens. Although plant growth and phenotypic responses were dependent on the AMF communities with which they associated, we found little evidence for plant growth responses specific to their local AMF communities and results differed between species and traits. 4. Our results show that plants from mixtures were selected for increased growth at the expense of reduced defence and vice versa for plants from monocultures, providing evidence for plant diversity-dependent selection on competitive growth vs. defence. Furthermore, our study suggests that effects of a common history between plants and AMF do not follow a general pattern leading to increased or decreased mutualism. 5. Synthesis: Here we provide evidence that biodiversity loss can alter evolutionary trajectories of plant phenotypes and responses to their local AMF communities. However, the selection for altered plant-AMF interactions differ between plant species. To understand how plant communities respond and evolve under a changing environment requires further knowledge about life strategies of plant species and their above-belowground interactions.

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.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1773
Author(s):  
Janjira Wiriya ◽  
Chakrapong Rangjaroen ◽  
Neung Teaumroong ◽  
Rungroch Sungthong ◽  
Saisamorn Lumyong

Nowadays, oil crops are very attractive both for human consumption and biodiesel production; however, little is known about their commensal rhizosphere microbes. In this study, rhizosphere samples were collected from physic nut and sacha inchi plants grown in several areas of Thailand. Rhizobacteria, cultivable in nitrogen-free media, and arbuscular mycorrhizal (AM) fungi were isolated and examined for abundance, diversity, and plant growth-promoting activities (indole-3-acetic acid (IAA) and siderophore production, nitrogen fixation, and phosphate solubilization). Results showed that only the AM spore amount was affected by plant species and soil features. Considering rhizobacterial diversity, two classes—Alphaproteobacteria (Ensifer sp. and Agrobacterium sp.) and Gammaproteobacteria (Raoultella sp. and Pseudomonas spp.)—were identified in physic nut rhizosphere, and three classes; Actinobacteria (Microbacterium sp.), Betaproteobacteria (Burkholderia sp.) and Gammaproteobacteria (Pantoea sp.) were identified in the sacha inchi rhizosphere. Considering AM fungal diversity, four genera were identified (Acaulospora, Claroideoglomus, Glomus, and Funneliformis) in sacha inchi rhizospheres and two genera (Acaulospora and Glomus) in physic nut rhizospheres. The rhizobacteria with the highest IAA production and AM spores with the highest root-colonizing ability were identified, and the best ones (Ensifer sp. CM1-RB003 and Acaulospora sp. CM2-AMA3 for physic nut, and Pantoea sp. CR1-RB056 and Funneliformis sp. CR2-AMF1 for sacha inchi) were evaluated in pot experiments alone and in a consortium in comparison with a non-inoculated control. The microbial treatments increased the length and the diameter of stems and the chlorophyll content in both the crops. CM1-RB003 and CR1-RB056 also increased the number of leaves in sacha inchi. Interestingly, in physic nut, the consortium increased AM fungal root colonization and the numbers of offspring AM spores in comparison with those observed in sacha inchi. Our findings proved that AM fungal abundance and diversity likely rely on plant species and soil features. In addition, pot experiments showed that rhizosphere microorganisms were the key players in the development and growth of physic nut and sacha inchi.


Botany ◽  
2014 ◽  
Vol 92 (4) ◽  
pp. 277-285 ◽  
Author(s):  
Ülle Saks ◽  
John Davison ◽  
Maarja Öpik ◽  
Martti Vasar ◽  
Mari Moora ◽  
...  

We analyzed arbuscular mycorrhizal fungal (AMF) communities in plant root samples from a natural forest ecosystem — a primeval forest in Järvselja, Estonia. AMF small-subunit (SSU) ribosomal RNA genes were subjected to 454-pyrosequencing and BLAST-based taxonomic identification. Seventy-six AMF sequence groups (virtual taxa, VT) were identified from plant roots. Taken together with seven additional VT recorded in an earlier investigation of soil AMF communities at the site, this represents the highest number of AMF reported from a single ecosystem to date. The six study plant species hosted similar AMF communities. However, AMF community composition in plant roots was significantly different from that in soil and considerably more VT were retrieved from roots than from soil. AMF VT identified from plant roots as a whole and from individual plant species were frequently phylogenetically clustered compared with local and global taxon pools, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped fungal assemblages. In contrast, the phylogenetic dispersion of AMF communities in soil did not differ from random subsets of the local or global taxon pools.


2018 ◽  
Author(s):  
Marc W. Schmid ◽  
Terhi Hahl ◽  
Sofia J. van Moorsel ◽  
Cameron Wagg ◽  
Gerlinde B. De Deyn ◽  
...  

AbstractSoil microbes are known to be involved in a number of essential ecosystem processes such as nutrient cycling, plant productivity and the maintenance of plant species diversity. However, how plant species diversity and identity affect soil microbial diversity and community composition is largely unknown. We tested whether, over the course of 11 years, distinct soil bacterial communities developed under plant monocultures and mixtures, and if over this timeframe plants with a monoculture or mixture history changed in the microbial communities they associated with. For eight species, we grew offspring of plants that had been grown for 11 years in the same monocultures or mixtures (monoculture- or mixture-type plants) in pots inoculated with microbes extracted from the monoculture and mixture soils. After five months of growth in the glasshouse, we collected rhizosphere soil from each plant and used 16S-rRNA gene sequencing to determine the community composition and diversity of the bacterial communities. Microbial community structure in the plant rhizosphere was primarily determined by soil legacy (monoculture vs. mixture soil) and by plant species identity, but not by plant legacy (monoculture- vs. mixture-type plants). In seven out of the eight plant species bacterial abundance was larger when inoculated with microbes from mixture soil. We conclude that plant diversity can strongly affect belowground community composition and diversity, feeding back to the assemblage of rhizosphere microbial communities in newly establishing plants. Thereby our work demonstrates that concerns for plant biodiversity loss are also concerns for soil biodiversity loss.


2021 ◽  
Vol 51 ◽  
pp. e1299
Author(s):  
Azareel Angulo-Castro ◽  
Ronald Ferrera-Cerrato ◽  
Alejandro Alarcón ◽  
Juan José Almaraz-Suárez ◽  
Julián Delgadillo-Martínez ◽  
...  

Background: Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are an alternative for sustainable management of pepper crops. Objective: To investigate the beneficial effects of PGPR and AMF inoculation on the growth of bell pepper plants. Methods: Two PGPR strains were used (Pseudomonas tolaasii P61 and Bacillus pumilus R44) as well as their mixture, and an uninoculated control. In addition, bacterial treatments were combined with an AMF-consortium (Funneliformis aff. geosporum and Claroideoglomus sp.). A 4×2 factorial experiment [four levels for the bacterial inoculation and two levels of AMF-inoculation (non-AMF and AMF)] was performed with eight treatments, at greenhouse conditions for 80 days after inoculation. AMF inoculation was done at sowing and PGPR after 15 days of seedling emergence. Results and Conclusions: Uninoculated control showed lower growth responses than plants inoculated with PGPR and AMF, alone or in combination. Overall, inoculation of the strain P61 or the combination of R44+AMF increased plant growth. AMF improved the photochemical efficiency of PSII in comparison to either control plants or plants inoculated with R44 or with the bacterial mix. Both PGPR and AMF improved growth and vigor of bell pepper plants.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 463A-463
Author(s):  
Rhoda Burrows ◽  
Francis Pfleger

Growing a plant host in association with other plant species (i.e., increasing diversity) changes the composition of the associated arbuscular–mycorrhizal (AM) fungal community. We tested whether this alteration in the fungal community causes significant differences in the growth of Schizachyrium scoparium L. (Little Bluestem, a C4 grass) or Lespedeza capitata L. (Bush clover, a legume). Seedlings were transplanted into pasteurized soil inoculated with soil from monoculture plots of Schizachyrium or Lespedeza, respectively, vs. plots containing one, seven, or 15 additional plant species. Soil washes from a composite of the plots were added to all pots, including non-inoculated controls, to reduce differences in the non-AM microbial communities. Spore counts of the inoculum from Lespedeza plots showed increasing numbers of AM fungal spores and species richness with increasing plant diversity; this was not true with the Schizachyrium plots, possibly because Schizachyrium may be a better host to more species of AM fungi than Lespedeza. Both Schizachyrium and Lespedeza responded to inoculation with increased growth compared to non-inoculated controls. Tissue analyses of both species showed that inoculation increased the percentage of Cu, and lowered the percentage of Mn compared to control plants. Schizachyrium showed no significant differences in growth due to inoculum source (1-, 2-, 8-, or 16-species plots); while Lespedeza showed increases in root and shoot weights with increasing source-plot diversity.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 458B-458 ◽  
Author(s):  
Jianjun Chen ◽  
Russell D. Caldwell ◽  
Cynthia A. Robinson ◽  
Bob Steinkamp

Silicon (Si) is the second most-abundant element in soils, and its concentration in soil solution ranges from 0.1 to 0.6 mm, which is the same concentration range as some of the major nutrient elements such as calcium, magnesium, phosphorus, and sulfur. Increasing evidence has recently suggested that Si plays important roles in improving plant growth. However, little information is available on Si effects on container-grown ornamental plants, particularly since most are grown in soilless media where Si sources are greatly limited. The objectives of this research were to evaluate Si absorption and translocation in diverse container-grown ornamental plants and to determine whether Si absorption could improve plant growth. Liners from 39 plant species were potted in peat and pine bark-based soilless media and grown in a shaded greenhouse. Plants were fertigated with a Peter's 24–8–16 water-soluble fertilizer containing 0, 50, and 100 mg·L–1 of Si. Once marketable sizes were reached, plants were harvested and fresh and dry weights determined; Si and other nutrient elements in roots and shoots were measured. Results indicated that 32 of the 39 evaluated species were able to absorb Si, with large quantities further transported to shoots. Of the 32 Si-responsive species, 17 showed significant dry weight increases, whereas the other 15 only exhibited Si absorption and translocation with no apparent growth responses. The seven non-responsive plant species showed no significant increases in neither Si absorption and translocation, nor dry weight.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marie- Noëlle Binet ◽  
Camille Marchal ◽  
Justine Lipuma ◽  
Roberto A. Geremia ◽  
Olivier Bagarri ◽  
...  

AbstractWe investigated root communities of arbuscular mycorrhizal fungi (AMF) in relation to lavender (Lavandula angustifolia) and lavandin (Lavandula intermedia) health status from organic and conventional fields affected by Phytoplasma infection. The intensity of root mycorrhizal colonization was significantly different between diseased and healthy plants and was higher in the latter regardless of agricultural practice. This difference was more pronounced in lavender. The root AMF diversity was influenced by the plant health status solely in lavender and only under the conventional practice resulting in an increase in the AMF abundance and richness. The plant health status did not influence the distribution of root AMF communities in lavandin unlike its strong impact in lavender in both agricultural practices. Finally, among the most abundant molecular operational taxonomic units (MOTUs), four different MOTUs for each plant species were significantly abundant in the roots of healthy lavender and lavandin in either agricultural practice. Our study demonstrated that the plant health status influences root colonization and can influence the diversity and distribution of root AMF communities. Its effects vary according to plant species, can be modified by agricultural practices and allow plants to establish symbiosis with specific AMF species.


2017 ◽  
Vol 114 (13) ◽  
pp. 3463-3468 ◽  
Author(s):  
Amelia A. Wolf ◽  
Erika S. Zavaleta ◽  
Paul C. Selmants

Observational studies and experimental evidence agree that rising global temperatures have altered plant phenology—the timing of life events, such as flowering, germination, and leaf-out. Other large-scale global environmental changes, such as nitrogen deposition and altered precipitation regimes, have also been linked to changes in flowering times. Despite our increased understanding of how abiotic factors influence plant phenology, we know very little about how biotic interactions can affect flowering times, a significant knowledge gap given ongoing human-caused alteration of biodiversity and plant community structure at the global scale. We experimentally manipulated plant diversity in a California serpentine grassland and found that many plant species flowered earlier in response to reductions in diversity, with peak flowering date advancing an average of 0.6 days per species lost. These changes in phenology were mediated by the effects of plant diversity on soil surface temperature, available soil N, and soil moisture. Peak flowering dates were also more dispersed among species in high-diversity plots than expected based on monocultures. Our findings illustrate that shifts in plant species composition and diversity can alter the timing and distribution of flowering events, and that these changes to phenology are similar in magnitude to effects induced by climate change. Declining diversity could thus contribute to or exacerbate phenological changes attributed to rising global temperatures.


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