The effect of long-term nutrient deficiency on the abundance and - PowerPoint Presentation

Slide1

The effect of long-term nutrient deficiency on the abundance and community composition of arbuscular mycorrhizal fungi in a mountainous grassland

 

K

ian Jenab, Stefan Gorka, Sean Darcy, Lucia Fuchslueger, Alberto Canarini, Victoria Martin, Julia Wiesenbauer, Felix Spiegel, Bruna Imai, Hannes Schmidt, Karin Hage-Ahmed, Erich M. Pötsch, Andreas Richter, Jan Jansa, and Christina Kaiser

1

Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.2Department of Crop Sciences, Institute of Crop Protection, University of Natural Resources and Life Sciences, Vienna, Austria3Agricultural Research and Education Centre, Raumberg-Gumpenstein, Irdning, Austria4Laboratory of Fungal Biology, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic

Kian Jenab

1

, Stefan Gorka

1

, Sean Darcy

1

, Lucia Fuchslueger

1

, Alberto Canarini

1

, Victoria Martin

1

, Julia Wiesenbauer

1

, Felix Spiegel

1

, Bruna Imai

1

, Hannes Schmidt

1

, Karin Hage-Ahmed

2

, Erich M. Pötsch

3

, Andreas Richter

1

, Jan Jansa

4

, and Christina Kaiser

1

Slide2

IntroductionArbuscular mycorrhizal (AM)

symbiosis is the most common type

of mycorrhizae, which form

s obligate mutualistic associations with 80% of the known land plant species.

AM fungi supply host plants with phosphorus (P)

and to a smaller extent, nitrogen (N), potassium (K), sulfur and trace elements  Important partner for plant nutrition and healthArbuscular Mycorrhiza1

Slide3

AM Fungi and Nutrient SupplyPhosphorus supply:

Improve plant growth in P-limited soil

because their extraradical hyphal networks

have better access to immobile inorganic PH

igh amount of P availability in soil might cause a shift from symbiosis to parasitism or commensalism

Nitrogen supply:Several contradictory reports regarding N delivery to plants by AM fungi under N deficiencyThere might not be a mutualistic relationship between AM fungi and plant roots in N-deficient soil  higher demand for N than their host plants

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Nutrient deficiency affects both plant and AM fungal community

Direct

effect

Indirect effect

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Research Question : How does long-term nutrient deficiency of P, N or K affect AM fungal abundance and community composition in a mountainous grassland?

Hypothesis: Long

-term deficiency of essential nutrients, such as P, N or K strongly affect abundance and community composition of AM fungi.

AM fungi abundance and diversity will strongly increase in

P-deficient treatments  Receiving better support from host plant

It will decrease in N deficient plots  No support from host plant, and AM fungi N-limitation

Slide6

Long-Term Nutrient Deficiency ExperimentLong-term nutrient deficiency experiment in a grasslandInstitute of Plant Production and Cultural Landscape, HBLFA

Raumberg-GumpensteinLocation:

Admont, Austria (N 47°34’58’’, E 14°27’02’’)

Starting date: 1946

Experimental design: 24 fertilization treatments (each four blocks)Management: hay meadow, three cuts per year

Experimental Design

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Nutrient Deficiency Treatments

2

NPK

+ Lime

Treatment:

Control (

NPKCa

fertilized)

(

N+P+K+Lime

)

Deficient (only Ca)

(Lime Only)

N deficient (

PKCa

fertilized)

(

P+K+Lime

)

1

NPK Treatment

:

Control (NPK fertilized)

(N+P+K)

Deficient (no fertilizer)

(Unfertilized)

P deficiency (NK fertilized)

(N+K)

K deficiency (NP fertilized)

(N+P)

N deficiency (PK fertilized)

(P+K)

NK deficiency (P fertilized)

(p)

NP deficiency (K fertilized)

(K)

KP deficiency (N fertilized)

(N)

3

Organic fertilization:

Solid manure and liquid slurry (full fertilization)

(

Manure+Slurry

)

Solid manure (NP fertilized, but with less N)

(Manure)

Liquid slurry (mainly N)

(Slurry)

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Sample Collection in Summer 2019Soil samples were collected in 10-cm depth from each plotSoil samples were sieved and

roots were separated from soil

Soil and root samples were freeze-dried and kept in -20 °C freezer

Slide9

MethodsPLFA

1

/NLFA

2

extraction

PLFAs as biomarker for microbial groups (bacteria, fungi, gram+, gram-) and

fingerprint

of

m

icrobial community

composition

NLFA 16:1w5

as biomarker

for AM fungal abundance

Measuring with GC-TOF-MS

S

oil and root samples

DNA and RNA

-

based

amplicon sequencing

AM fungal community composition

WANDA-IL and AML2-IL primers

(

18S rRNA reg

ion

)

DNA

and RNA

extraction

QIAGEN

DNA

extraction kit:

Root samples

phenol-chloroform extraction

:

Soil samples

A

dditional measurement

s

Plant community composition

Soil pH

Soil Ammonium

Soil nitrate

Soil total free amino acid

Soil total inorganic N

Soil dissolved organic carbon (C)

Soil dissolved organic N

Soil dissolved organic P

1. Phospholipid fatty acid

2. Neutral fatty acid

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Results IEffect

of

long-term nutrient

deficiency treatments on AM

fungal biomass

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Lime

increased AM fungal biomass

N enriched

plots had lower AM fungal biomass

Organic plots

had high abundance of AM fungi (Especially Solid Manure)Fully fertilized plots had lower AM fungal biomass than unfertilized plotsAM fungal biomass in response to long-term nutrient deficiencyBased on NLFA (16:1ω5)

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AM fungal biomass in response to inorganic fertilization

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p

H

may affect AM fungal abundance

AM fungal biomass in response to inorganic fertilization plus lime

Slide14

Results IILink

between AM fungal

biomass and

soil parameters

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D

espite nutrient deficiency, other factors altered AM fungi biomass such as:

pH

and

soil water content Major influence of pH

on AM fungal biomassStrong correlation between AM fungal biomass and soil water contentR2= 0.54P= 5.235e-5R2= 0.35

P

=

2.274e-06

Effect

of

soil

parameters

on

AM fungal biomass

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Strong negative correlation between

different sources of N

and

AM fungal biomass

Amount of inorganic N were significantly low in deficient N plots

(near to zero)R2= 0.29P= 2.261e-05R2= 0.26

P

=

6.184e-05

R

2

= 0.24

P

=

0.0001584

R

2

= 0.24

P

=

0.0001

6

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No correlation between soil dissolved inorganic P and AM fungal biomass!

R

2

= 0.00842

P

= 0.5052

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Results IIIEffect

of

long-term nutrient

deficiency on plant and soil

microbial communities

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Soil microbial community in response to long-term nutrient deficiency - based on PLFAs and NLFA

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Plant community in response to

long-term nutrient deficiency

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Effect of abiotic parameters and plant community on microbial community– based on PLFAs and NLFA

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Results IVEffect

of

long-term nutrient

deficiency on soil AMF

communities

Slide23

AM fungal community composition – Soil RNA-based amplicon sequencing

Slide24

Inorganic Plots:

Abundance of Paraglomus

is considerably low in P deficient plots

in N-enriched plots,

Acaulospora is low, and

Ambispora is somehow dominant Glomus abundance is high in K-enriched plots.Lime plots:Abundance of Dominika, Claroideoglomus and Funneliformis is high, however Acaulospora and Scutellospora is low.Organic plots:Abundance of Claroideoglomus is high (Like lime plots)Except Slurry plot, Rhizophagus is low

Slide25

Results VDirect vs

. indirect effects: Contribution of soil parameters and plant community composition to AMF abundance in the soil

Slide26

H

ierarchical P

artitioning

pH

Total inorganic NAmmonium

NitrateTotal free amino acidSoil water contentPlant CommunityDissolved inorganic PContribution to R2 (%)

Slide27

Conclusion

Long

-term nutrient deficiency strongly affects the abundance and community composition of AM fungi

(directly and indirectly)Long-term inorganic N fertilization

has negative influence on AM fungal biomass Interestingly, there is no correlation between AM fungal biomass and dissolved inorganic P (maybe due to AM fungi community composition)Liming and organic fertilizer amendments increase AM fungal

biomassLong-term nutrient deficiency could have indirect effect on abundance and community composition of AM fungi via plant community and soil chemistrySoil properties such as pH, soil water content and different sources of inorganic nitrogen play important role in AM fungal abundance and diversity.

Slide28

Team and Collaborators

Dr. Karin Hage-Ahmed

(

University of Natural Resources and Life Sciences, Austria)Dr.

Alberto Canarini (University of Vienna)Dr. Hannes Schmid (University of Vienna)Dr. Lucia

Fuchslueger (University of Vienna)Stefan Gorka (University of Vienna)Sean Darcy (University of Vienna)Victoria Martin (University of Vienna)Julia Wiesenbauer (University of Vienna)Felix Spiegel (University of Vienna)Bruna Imai (University of Vienna) Dr. Jan JansaCzech Academy of Sciences

Dr. Christina Kaiser

University of Vienna

Dr. Andreas Richter

University of Vienna

Dr. Erich

Pötsch

Agricultural Research and Education Centre

(Austria)

Slide29

Thank You for your attention

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Appendix

30

Slide31

Soil NLFA

Root NLFA

R

2

= 0.36

P= 2.302e-06

Slide32

32

Total PLFA is Indicator of microorganism biomass

Plots containing

organic fertilizers

had the highest microbial biomass

Slide33

33

AM Fungi

Actinomycetes

Bacteria

Fungi

Slide34

34

Slide35

Slide36

36

Soil

PLFAs and NLFAs

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37