Carbon Fluxes in Mycorrhizal Plants

Řezáčová, Veronika; Konvalinková, Tereza; Jansa, Jan

doi:10.1007/978-3-319-57849-1_1

Cited by 19 publications

(17 citation statements)

References 121 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Each symbiosis may consume around 3–20% of recently fixed C to maintain the growth and activity and to build up energy reserves of the participating microbes (Jakobsen and Rosendahl, 1990; Kaschuk et al, 2009; Slavíková et al, 2016). The plants can partly compensate for C needs of their symbionts by increased CO 2 assimilation (Paul and Kucey, 1981), either due to C sink stimulation or indirectly through the nutritional benefits received from the symbioses (Kaschuk et al, 2009; Řezáčová et al, 2017). …”

Section: Introductionmentioning

confidence: 99%

Arbuscular Mycorrhiza Stimulates Biological Nitrogen Fixation in Two Medicago spp. through Improved Phosphorus Acquisition

et al. 2017

Self Cite

View full text Add to dashboard Cite

Legumes establish root symbioses with rhizobia that provide plants with nitrogen (N) through biological N fixation (BNF), as well as with arbuscular mycorrhizal (AM) fungi that mediate improved plant phosphorus (P) uptake. Such complex relationships complicate our understanding of nutrient acquisition by legumes and how they reward their symbiotic partners with carbon along gradients of environmental conditions. In order to disentangle the interplay between BNF and AM symbioses in two Medicago species (Medicago truncatula and M. sativa) along a P-fertilization gradient, we conducted a pot experiment where the rhizobia-treated plants were either inoculated or not inoculated with AM fungus Rhizophagus irregularis ‘PH5’ and grown in two nutrient-poor substrates subjected to one of three different P-supply levels. Throughout the experiment, all plants were fertilized with 15N-enriched liquid N-fertilizer to allow for assessment of BNF efficiency in terms of the fraction of N in the plants derived from the BNF (%NBNF). We hypothesized (1) higher %NBNF coinciding with higher P supply, and (2) higher %NBNF in mycorrhizal as compared to non-mycorrhizal plants under P deficiency due to mycorrhiza-mediated improvement in P nutrition. We found a strongly positive correlation between total plant P content and %NBNF, clearly documenting the importance of plant P nutrition for BNF efficiency. The AM symbiosis generally improved P uptake by plants and considerably stimulated the efficiency of BNF under low P availability (below 10 mg kg-1 water extractable P). Under high P availability (above 10 mg kg-1 water extractable P), the AM symbiosis brought no further benefits to the plants with respect to P nutrition even as the effects of P availability on N acquisition via BNF were further modulated by the environmental context (plant and substrate combinations). As a response to elevated P availability in the substrate, the extent of root length colonization by AM fungi was reduced, the turning points occurring at about 8 and 10 mg kg-1 water extractable P for M. sativa and M. truncatula, respectively. Our results indicated competition for limited C resource between the two kinds of microsymbionts and thus degradation of AM symbiotic functioning under ample P supply.

show abstract

Section: Introductionmentioning

confidence: 99%

Arbuscular Mycorrhiza Stimulates Biological Nitrogen Fixation in Two Medicago spp. through Improved Phosphorus Acquisition

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…Mycorrhiza-mediated N acquisition is particularly important when soil N is predominantly in organic forms or under moderate drought ( Tobar et al, 1994 ; Hodge and Storer, 2015 ; Bukovská et al, 2018 and the references therein). In return for the supply of such mineral nutrients as P or N, the host plant provides the AMF with reduced C in the forms of simple carbohydrates and/or fatty acids ( Lekberg et al, 2010 ; Roth and Paszkowski, 2017 ; Řezáčová et al, 2017a ). The plant C allocation into the AMF hyphae ranges between 0.9 and 20% of its gross photosynthetic production ( Jakobsen and Rosendahl, 1990 ; Bryla and Eissenstat, 2005 ; Konvalinková et al, 2017 ; Řezáčová et al, 2017a , b ; Slavíková et al, 2017 ).…”

Section: Introductionmentioning

confidence: 99%

Little Cross-Feeding of the Mycorrhizal Networks Shared Between C3-Panicum bisulcatum and C4-Panicum maximum Under Different Temperature Regimes

et al. 2018

Self Cite

View full text Add to dashboard Cite

Common mycorrhizal networks (CMNs) formed by arbuscular mycorrhizal fungi (AMF) interconnect plants of the same and/or different species, redistributing nutrients and draining carbon (C) from the different plant partners at different rates. Here, we conducted a plant co-existence (intercropping) experiment testing the role of AMF in resource sharing and exploitation by simplified plant communities composed of two congeneric grass species (Panicum spp.) with different photosynthetic metabolism types (C3 or C4). The grasses had spatially separated rooting zones, conjoined through a root-free (but AMF-accessible) zone added with 15N-labeled plant (clover) residues. The plants were grown under two different temperature regimes: high temperature (36/32°C day/night) or ambient temperature (25/21°C day/night) applied over 49 days after an initial period of 26 days at ambient temperature. We made use of the distinct C-isotopic composition of the two plant species sharing the same CMN (composed of a synthetic AMF community of five fungal genera) to estimate if the CMN was or was not fed preferentially under the specific environmental conditions by one or the other plant species. Using the C-isotopic composition of AMF-specific fatty acid (C16:1ω5) in roots and in the potting substrate harboring the extraradical AMF hyphae, we found that the C3-Panicum continued feeding the CMN at both temperatures with a significant and invariable share of C resources. This was surprising because the growth of the C3 plants was more susceptible to high temperature than that of the C4 plants and the C3-Panicum alone suppressed abundance of the AMF (particularly Funneliformis sp.) in its roots due to the elevated temperature. Moreover, elevated temperature induced a shift in competition for nitrogen between the two plant species in favor of the C4-Panicum, as demonstrated by significantly lower 15N yields of the C3-Panicum but higher 15N yields of the C4-Panicum at elevated as compared to ambient temperature. Although the development of CMN (particularly of the dominant Rhizophagus and Funneliformis spp.) was somewhat reduced under high temperature, plant P uptake benefits due to AMF inoculation remained well visible under both temperature regimes, though without imminent impact on plant biomass production that actually decreased due to inoculation with AMF.

show abstract

“…Both direct and indirect contributions to nutrient and water extractability from soils require that hyphae proliferate beyond the ambit of roots which are developed with sustenance by plant C fixed in photosynthesis (Smith and Read 2008). Hence, mycorrhizal plants possess an additional and significant C sink (as reviewed in: Řezáčová et al 2017, 2018), which can be compensated by photosynthesis, provided that AMF do not only substitute other plant C sinks in the symbiotic interaction (Kaschuk et al 2009; Řezáčová et al 2018). Indeed, rates of photosynthesis of mycorrhizal plants are commonly altered in comparative studies with non-mycorrhizal (NM) counterparts (Augé 2001; Augé et al 2014, 2016; Boldt et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Atmospheric drought and low light impede mycorrhizal effects on leaf photosynthesis—a glasshouse study on tomato under naturally fluctuating environmental conditions

2018

View full text Add to dashboard Cite

Arbuscular mycorrhiza fungi (AMF) consume plant carbon and impact photosynthesis, but effects of AMF on plant gas exchange are transient and hardly predictable. This is at least partially because plant-internal nutrient-, water-, and sink-related effects, which can be influenced AMF, and atmospheric conditions integrate at the photosynthesis level. In nature and in plant production, plants face periodical and random short-term switches of environmental conditions that limit photosynthesis, which may impede stimulatory effects of AMF on leaf photosynthetic capacities. We hypothesized that mycorrhizal effects on plant internal-photosynthetic potentials will only translate to actual photosynthetic rates, if atmospheric conditions do not superimpose limitations to the photosynthetic process. We aimed to cover wide ranges of within and between-day variations in light intensities and vapor pressure deficits with an untargeted approach. We grew tomato plants hydroponically for 8 weeks in open pots and irrigated beyond pot water capacity every morning. Plants were inoculated or not with Funneliformis mosseae and were fertilized with a low-strength nutrient solution, which guaranteed good AMF colonization and comparable sets of mycorrhizal and non-mycorrhizal plants regarding developmental stage and leaf age. Instantaneous leaf photosynthesis was monitored continuously with transparent chambers during 3 days under naturally fluctuating greenhouse conditions on the two uppermost fully expanded leaves. We fitted mechanistic gas exchange models and modeled continuous daytime dynamics of net photosynthetic rates and stomatal conductance for representative sunlit canopies of random populations of mycorrhizal and non-mycorrhizal plants. Depending on time, mycorrhizal plants showed enhanced or decreased stomatal conductance over wide ranges of light intensities. Higher or lower stomatal opening in mycorrhizal plants became ineffective for photosynthetic rates under low light. In contrast and in accordance with the effects on stomatal conductance, photosynthetic rates were comparatively increased or decreased in mycorrhizal plants under high light conditions. This required at least moderate vapor pressure deficits. Under high atmospheric drought, stomatal conductance strongly declined in all plants, which also capped maximum photosynthetic rates under high light. Leaf photosynthetic capacities were higher in mycorrhizal plants when leaves contained more proteins and/or the plant-internal moisture stress was lower than in non-mycorrhizal plants. However, this only resulted in enhanced photosynthetic rates as long as leaves were not exposed to low radiation or high atmospheric drought. We conclude that light and atmospheric moisture are decisive factors for potential carbon cost and gain scenarios of plants associated with AMF.

show abstract

Carbon Fluxes in Mycorrhizal Plants

Cited by 19 publications

References 121 publications

Arbuscular Mycorrhiza Stimulates Biological Nitrogen Fixation in Two Medicago spp. through Improved Phosphorus Acquisition

Arbuscular Mycorrhiza Stimulates Biological Nitrogen Fixation in Two Medicago spp. through Improved Phosphorus Acquisition

Little Cross-Feeding of the Mycorrhizal Networks Shared Between C3-Panicum bisulcatum and C4-Panicum maximum Under Different Temperature Regimes

Atmospheric drought and low light impede mycorrhizal effects on leaf photosynthesis—a glasshouse study on tomato under naturally fluctuating environmental conditions

Contact Info

Product

Resources

About