Tree species rather than type of mycorrhizal association drives inorganic and organic nitrogen acquisition in tree-tree interactions

2021 ◽  
Author(s):  
Robert Reuter ◽  
Olga Ferlian ◽  
Mika Tarkka ◽  
Nico Eisenhauer ◽  
Karin Pritsch ◽  
...  
Keyword(s):  
Tree Species ◽  
Mycorrhizal Fungi ◽  
Prunus Avium ◽  
N Uptake ◽  
Organic N ◽  
Acer Pseudoplatanus ◽  
N Sources ◽  
Mycorrhizal Association ◽  
N Acquisition ◽  
Inorganic And Organic

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.

scholarly journals Nitrogen Uptake by Two Plants in Response to Plant Competition as Regulated by Neighbor Density

2020 ◽  
Vol 11 ◽  
Author(s):  
Xuan Jia ◽  
Chaohe Huangfu ◽  
Dafeng Hui
Keyword(s):  
Functional Traits ◽  
N Uptake ◽  
Specific Root Length ◽  
Organic N ◽  
N Recovery ◽  
Dry Matter Content ◽  
N Sources ◽  
Uptake Rates ◽  
N Acquisition ◽  
Root Functional Traits

Plant species may acquire different forms of nitrogen (N) to reduce competition for the same resource, but how plants respond to neighbors with different densities in their N uptake is still poorly understood. We investigated the effects of competition regime on the uptake of different N forms by two hygrophytes, Carex thunbergii and Polygonum criopolitanum, by conducting a hydroponic test of excised roots and an in situ experiment in a subtropical wetland ecosystem. The two species were grown either in monocultures or mixtures with various neighbor densities. Root functional traits and N uptake rates of different N forms were measured. Our results showed that N uptake was mainly determined by N form, rather than species identity. Both species were able to use organic N sources, but they took up relatively more N supplied as NO3- than as NH4+ or glycine, irrespective of competition treatments. Both species preferred NO3- when grown in monoculture, but in the presence of competitors, the preference of fast-growing C. thunbergii persisted while P. criopolitanum acquired more NH4+ and glycine, with stronger responses being observed at the highest neighbor density. The hydroponic test suggested that these divergences in N acquisition between two species might be partially explained by different root functional traits. To be specific, N uptake rates were significantly positively correlated with root N concentration and specific root length, but negatively correlated with root dry matter content. Our results implicated that C. thunbergii has a competitive advantage with relatively more stable N acquisition strategy despite a lower N recovery than P. criopolitanum, whereas P. criopolitanum could avoid competition with C. thunbergii via a better access to organic N sources, partly mediated by competition regimes.

Ammonium, nitrate and glycine uptake of six Ecuadorian tropical montane forest tree species: anin situpot experiment with saplings

2014 ◽  
Vol 31 (2) ◽  
pp. 139-152 ◽  
Author(s):  
Bärbel Wittich ◽  
Jürgen Homeier ◽  
Christoph Leuschner
Keyword(s):  
Tree Species ◽  
N Uptake ◽  
Tropical Trees ◽  
Forest Tree ◽  
Montane Forest ◽  
Tropical Montane Forest ◽  
Organic N ◽  
Coarse Roots ◽  
N Form ◽  
Form Preference

Abstract:Not much is known about the nitrogen (N) uptake capacity and N-form preference of tropical trees. In a replicated labelling experiment with15N-ammonium,15N-nitrate and dual-labelled glycine applied to saplings of six tree species from southern Ecuadorian montane forests, we tested the hypotheses that (1) the saplings of tropical trees are capable of using organic N even though they are forming arbuscular mycorrhizas, and (2) with increasing altitude, tree saplings increasingly prefer ammonium and glycine over nitrate due to reduced nitrification and growing humus accumulation. Three- to 5-y-old saplings of two species each from 1000, 2000 and 3000 m asl were grown in pots inside the forest at their origin and labelled with non-fertilizing amounts of the three N forms;15N enrichment was detected 5 days after labelling in fine roots, coarse roots, shoots and leaves. The six species differed with respect to their N-form preference, but neither the abundance of ammonium and nitrate in the soil nor altitude (1000–3000 m asl) seemed to influence the preference. Two species (those with highest growth rate) preferred NH4+over NO3−, while the other four species took up NO3−and NH4+at similar rates when both N forms were equally available. After13C-glycine addition,13C was significantly accumulated in the biomass of three species (all species with exclusively AM symbionts) but a convincing proof of the uptake of intact glycine molecules by these tropical montane forest trees was not obtained.

scholarly journals Understanding the Differences in the Growth and Toxin Production of Anatoxin-Producing Cuspidothrix issatschenkoi Cultured with Inorganic and Organic N Sources from a New Perspective: Carbon/Nitrogen Metabolic Balance

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 724
Author(s):  
Siyi Tao ◽  
Suqin Wang ◽  
Lirong Song ◽  
Nanqin Gan
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Nitrogen Sources ◽  
Dry Weight ◽  
Toxin Production ◽  
Organic N ◽  
Control Group ◽  
Metabolic Balance ◽  
N Sources ◽  
Inorganic And Organic

Cyanotoxins are the underlying cause of the threat that globally pervasive Cyanobacteria Harmful algal blooms (CyanoHABs) pose to humans. Major attention has been focused on the cyanobacterial hepatotoxin microcystins (MCs); however, there is a dearth of studies on cyanobacterial neurotoxin anatoxins. In this study, we explored how an anatoxin-producing Cuspidothrix issatschenkoi strain responded to culture with inorganic and organic nitrogen sources in terms of growth and anatoxins production. The results of our study revealed that ʟ- alanine could greatly boost cell growth, and was associated with the highest cell productivity, while urea significantly stimulated anatoxin production with the maximum anatoxin yield reaching 25.86 μg/mg dry weight, which was 1.56-fold higher than that in the control group (BG11). To further understand whether the carbon/nitrogen balance in C. issatschenkoi would affect anatoxin production, we explored growth and toxin production in response to different carbon/nitrogen ratios (C/N). Anatoxin production was mildly promoted when the C/N ratio was within low range, and significantly inhibited when the C/N ratio was within high range, showing approximately a three-fold difference. Furthermore, the transcriptional profile revealed that anaC gene expression was significantly up-regulated over 2–24 h when the C/N ratio was increased, and was significantly down-regulated after 96 h. Overall, our results further enriched the evidence that urea can stimulate cyanotoxin production, and ʟ-alanine could boost C. issatschenkoi proliferation, thus providing information for better management of aquatic systems. Moreover, by focusing on the intracellular C/N metabolic balance, this study explained the anatoxin production dynamics in C. issatschenkoi in response to different N sources.

scholarly journals Arbuscular Mycorrhizal Community in Roots and Nitrogen Uptake Patterns of Understory Trees Beneath Ectomycorrhizal and Non-ectomycorrhizal Overstory Trees

2021 ◽  
Vol 11 ◽  
Author(s):  
Chikae Tatsumi ◽  
Fujio Hyodo ◽  
Takeshi Taniguchi ◽  
Weiyu Shi ◽  
Keisuke Koba ◽  
...  
Keyword(s):  
Community Composition ◽  
Mycorrhizal Fungi ◽  
N Uptake ◽  
Arbuscular Mycorrhizal ◽  
Nitrate Content ◽  
N Availability ◽  
Fungal Community Composition ◽  
Mycorrhizal Association ◽  
Understory Trees ◽  
Overstory Trees

Nitrogen (N) is an essential plant nutrient, and plants can take up N from several sources, including via mycorrhizal fungal associations. The N uptake patterns of understory plants may vary beneath different types of overstory trees, especially through the difference in their type of mycorrhizal association (arbuscular mycorrhizal, AM; or ectomycorrhizal, ECM), because soil mycorrhizal community and N availability differ beneath AM (non-ECM) and ECM overstory trees (e.g., relatively low nitrate content beneath ECM overstory trees). To test this hypothesis, we examined six co-existing AM-symbiotic understory tree species common beneath both AM-symbiotic black locust (non-ECM) and ECM-symbiotic oak trees of dryland forests in China. We measured AM fungal community composition of roots and natural abundance stable isotopic composition of N (δ15N) in plant leaves, roots, and soils. The root mycorrhizal community composition of understory trees did not significantly differ between beneath non-ECM and ECM overstory trees, although some OTUs more frequently appeared beneath non-ECM trees. Understory trees beneath non-ECM overstory trees had similar δ15N values in leaves and soil nitrate, suggesting that they took up most of their nitrogen as nitrate. Beneath ECM overstory trees, understory trees had consistently lower leaf than root δ15N, suggesting they depended on mycorrhizal fungi for N acquisition since mycorrhizal fungi transfer isotopically light N to host plants. Additionally, leaf N concentrations in the understory trees were lower beneath ECM than the non-ECM overstory trees. Our results show that, without large differences in root mycorrhizal community, the N uptake patterns of understory trees vary between beneath different overstory trees.

scholarly journals Nitrogen uptake capacity of European beech (Fagus sylvatica L.) only partially depends on tree age

Trees ◽  
2021 ◽  
Author(s):  
Judy Simon ◽  
Silvija Bilela ◽  
Heinz Rennenberg
Keyword(s):  
Inorganic Nitrogen ◽  
N Uptake ◽  
General Pattern ◽  
European Beech ◽  
Tree Age ◽  
Organic N ◽  
Uptake Capacity ◽  
Age Classes ◽  
Incubation Experiments ◽  
N Acquisition

Abstract Key message On calcareous soil, European beech roots prefer organic nitrogen, but only arginine and not glutamine or inorganic nitrogen. Abstract Nitrogen (N) acquisition is a major factor determining the processes and mechanisms involved in tree productivity, development, and competitiveness. However, only few studies have investigated changes in N capturing with tree age. We conducted 15N incubation experiments to quantify inorganic (i.e. ammonium and nitrate) and organic (i.e. glutamine-N and arginine-N) net N acquisition capacity of beech trees of five age classes. Our results showed no general pattern, but that net N uptake capacity was rather N source-specific. Inorganic and glutamine-N uptake did not differ between age classes at all. Arginine-N uptake was highest in the youngest and oldest stands reflecting a high N demand by seedlings for root foraging and biomass production despite low internal N storage capacities and by older trees for storage and reproduction. Organic N was preferred over inorganic N regardless of tree age. Overall, our study shows the high significance of organic N sources for N acquisition in beech trees.

Effects of nitrogen source and ectomycorrhizal association on growth and δ15N of two subtropical Eucalyptus species from contrasting ecosystems

2006 ◽  
Vol 33 (4) ◽  
pp. 367 ◽  
Author(s):  
Susanne Schmidt ◽  
Linda L. Handley ◽  
Tanuwong Sangtiean
Keyword(s):  
Axenic Culture ◽  
Eucalyptus Grandis ◽  
Organic N ◽  
Ammonium Concentration ◽  
Eucalyptus Species ◽  
Plant Nitrogen ◽  
N Nutrition ◽  
N Sources ◽  
N Acquisition ◽  
Foliar Δ15n

Ectomycorrhizal (EM) associations facilitate plant nitrogen (N) acquisition, but the contribution of EM associations to tree N nutrition is difficult to ascertain in ecosystems. We studied the abilities of subtropical EM fungi and nutritionally contrasting Eucalyptus species, Eucalyptus grandis W.Hill ex Maiden and Eucalyptus racemosa Cav, to use N sources in axenic and soil cultures, and determined the effect of EM fungi on plant N use and plant 15N natural abundance (δ15N). As measured by seedling growth, both species showed little dependence on EM when growing in the N-rich minerotrophic soil from E. grandis rainforest habitat or in axenic culture with inorganic N sources. Both species were heavily dependent on EM associations when growing in the N-poor, organotrophic soil from the E. racemosa wallum habitat or in axenic culture with organic N sources. In axenic culture, EM associations enabled both species to use organic N when supplied with amide-, peptide- or protein-N. Grown axenically with glutamine- or protein-N, δ15N of almost all seedlings was lower than source N. The δ15N of all studied organisms was higher than the N source when grown on glutathione. This unexpected 15N enrichment was perhaps due to preferential uptake of an N moiety more 15N-enriched than the bulk molecular average. Grown with ammonium-N, the δ15N of non-EM seedlings was mostly higher than that of source N. In contrast, the δ15N of EM seedlings was mostly lower than that of source N, except at the lowest ammonium concentration. Discrimination against 15N was strongest when external ammonium concentration was high. We suggest that ammonium assimilation via EM fungi may be the cause of the often observed distinct foliar δ15N of EM and non-EM species, rather than use of different N sources by species with different root specialisations. In support of this notion, δ15N of soil and leaves in the rainforest were similar for E. grandis and co-occurring non-mycorrhizal Proteaceae. In contrast, in wallum forest, E. racemosa leaves and roots were strongly 15N-depleted relative to wallum soil and Proteaceae leaves. We conclude that foliar δ15N may be used in conjunction with other ecosystem information as a rapid indicator of plant dependency on EM associations for N acquisition.

Effects of shading on photosynthesis, plant organic nitrogen uptake, and root fungal colonization in a subarctic mire ecosystem

Botany ◽  
2009 ◽  
Vol 87 (5) ◽  
pp. 463-474 ◽  
Author(s):  
Maria Olsrud ◽  
Anders Michelsen
Keyword(s):  
Mycorrhizal Fungi ◽  
N Uptake ◽  
High Irradiance ◽  
Dwarf Shrub ◽  
Organic N ◽  
Mountain Birch ◽  
Fungal Colonization ◽  
Hair Roots ◽  
C And N ◽  
Birch Forests

Arctic dwarf shrub ecosystems are predicted to be exposed to lower light intensity in a changing climate where mountain birch forests are expanding. We investigated how shading at 0%, 65%, and 97% affects photosynthesis, organic N uptake, C and N allocation patterns in plants, and root fungal colonization in an ericoid dwarf shrub ecosystem. The ecosystem was labeled by injection of [2-13C,15N]glycine into the soil, and the uptake of 15N and 13C in roots and leaves 24 h later was analysed. Fungal colonization in hair roots was determined visually. Hair root 13C:15N ratios showed that dwarf shrub ecosystems are capable of taking up organic N as intact glycine both under high irradiance levels and under shaded conditions when photosynthesis is strongly reduced. The allocation of 15N to green leaves of Rubus chamaemorus L. increased with shading, whereas the allocation of 13C to leaves of both deciduous and evergreen plant species decreased. Species dominance was correlated with uptake of 13C, i.e., the most productive species also took up the highest amount of glycine. The ecosystem exhibited a tendency towards lower colonization by ericoid mycorrhizal fungi and dark septate endophytes in hair roots when shaded. Thus, shading has implications for processes central to both C and N cycling in subarctic ecosystems. This should be considered in projections of ecosystem responses to climate change and expanding mountain birch forests.

scholarly journals Nitrogen uptake strategies of mature conifers in Northeastern China, illustrated by the 15N natural abundance method

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Xulun Zhou ◽  
Ang Wang ◽  
Erik A. Hobbie ◽  
Feifei Zhu ◽  
Xueyan Wang ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
N Uptake ◽  
Natural Abundance ◽  
Pinus Koraiensis ◽  
Organic N ◽  
Larix Olgensis ◽  
Total N ◽  
Available N ◽  
N Sources ◽  
Picea Koraiensis

Abstract Background Conifers partition different N forms from soil, including ammonium, nitrate, and dissolved organic N (DON), to sustain plant growth. Previous studies focused on inorganic N sources and specific amino acid forms using 15N labelling, but knowledge of the contribution of DON to mature conifers’ N uptake is still scarce. Here, we quantified the contribution of different N forms (DON vs. NH4+ vs. NO3−) to total N uptake, based on 15N natural abundance of plant and soil available N, in four mature conifers (Pinus koraiensis, Pinus sylvestris, Picea koraiensis, and Larix olgensis). Results DON contributed 31%, 29%, 28%, and 24% to total N uptake by Larix olgensis, Picea koraiensis, Pinus koraiensis, and Pinus sylvestris, respectively, whereas nitrate contributed 42 to 52% and ammonium contributed 19 to 29% of total N uptake for these four coniferous species. Conclusions Our results suggested that all four conifers could take up a relatively large proportion of nitrate, while DON was also an important N source for the four conifers. Given that DON was the dominant N form in study soil, such uptake pattern of conifers could be an adaptive strategy for plants to compete for the limited available N sources from soil so as to promote conifer growth and maintain species coexistence.

scholarly journals Genotypic Difference in the Responses to Nitrogen Fertilizer Form in Tibetan Wild and Cultivated Barley

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 595
Author(s):  
Shama Naz ◽  
Qiufang Shen ◽  
Jonas Lwalaba Wa Lwalaba ◽  
Guoping Zhang
Keyword(s):  
Wild Barley ◽  
Growth Parameters ◽  
Inorganic Nitrogen ◽  
N Uptake ◽  
Total Soluble Protein ◽  
Organic N ◽  
Genotypic Difference ◽  
N Availability ◽  
Tibetan Wild Barley ◽  
Cultivated Barley

Nitrogen (N) availability and form have a dramatic effect on N uptake and assimilation in plants, affecting growth and development. In the previous studies, we found great differences in low-N tolerance between Tibetan wild barley accessions and cultivated barley varieties. We hypothesized that there are different responses to N forms between the two kinds of barleys. Accordingly, this study was carried out to determine the response of four barley genotypes (two wild, XZ16 and XZ179; and two cultivated, ZD9 andHua30) under 4Nforms (NO3−, NH4+, urea and glycine). The results showed significant reduction in growth parameters such as root/shoot length and biomass, as well as photosynthesis parameters and total soluble protein content under glycine treatment relative to other N treatments, for both wild and cultivated barley, however, XZ179 was least affected. Similarly, ammonium adversely affected growth parameters in both wild and cultivated barleys, with XZ179 being severely affected. On the other hand, both wild and cultivated genotypes showed higher biomass, net photosynthetic rate, chlorophyll and protein in NO3− treatment relative to other three N treatments. It may be concluded that barley undisputedly grows well under inorganic nitrogen (NO3−), however in response to the organic N wild barley prefer glycine more than cultivated barely.

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