la nutrition azotée des plantes : exploration de la diversité naturelle et études des gènes...

Françoise Vedele : La nutrition azotée des plantes 16 novembre 2012 Montpellier

La nutrition azotée des plantes : Exploration de la diversité naturelle et étude de

gènes candidats

Françoise DANIEL-VEDELE Institut Jean-Pierre Bourgin

INRA

Versailles, France

h"p://www‐ijpb.versailles.inra.fr/ h"p://www6.inra.fr/saclay‐plant‐sciences/


Why working on nitrogen metabolism?

3mM10mM

Vegeta;vestage

HighNitrogen

LowNitrogen

Reproduc;vestage


0

10

20

30

40

21/10/03 20/11/03 20/12/03 19/01/04 18/02/04 19/03/04 18/04/04 18/05/04Time

Dai

ly M

ean

Soil

Wat

er N

itrat

e (m

M)

0

5

10

15

20

Tem

pera

ture

(°C

)

Low N PlotHigh N PlotTemperature

Field experiments – measuring changes in soil nitrate at 30 cm under a wheat crop

FromTMiller,Rothamstedcenter,UK


World yield trends Costs of inputs


Nitrogen use efficiency

N fertilization N mineralization

Yield NUE = dY/dN

0

N total

Ymax

Y0

Capacity of the plant to produce a supplement of yield (dY) for each added unit of N fertiliser (dNf)


From the “Green revolution “ to the “Green Tide”


Nitrogen Assimilation Pathway

N ABSORPTION

NITRATE REDUCTION AA SYNTHESIS

N REMOBILISATION

N TRANSPORT

N SEED FILLING

N TRANSPORT

Nitrogen use efficiency (NUE = NupE+NutE)

Françoise Vedele : La nutrition azotée des plantes 16 novembre 2012 Montpellier 8

7 NRT2 51 NRT1 7 CLC 2 NAR2

Nitrate fluxes: molecular actors

Dechorgnatetal,JEB2011)


Characterization of AtNRT2.7 ExpressionofAtNRT2.7(Q‐RT‐PCR)

2,1

194,5

60,70,3 5,9

050100150200

Silique Dryseed

Imbibed

seedRoot Leaf

%EF1A1

Nitratecontentinseeds

NRT2.7expressionisseedspecific

nrt2.7mutantscontainlessnitrate

pNRT2.7::GFP

Sub‐cellularLocalisa;onofNRT2.7protein

GFPFM4‐64pNRT2.7::GFPNRT2.7proteinislocatedonthetonoplast

Chopinetal,PlantCell,2007


Polarized plasma membrane localisation

Kiba et al, Plant Cell 2012

AtNRT2.4: polarized localization and impact on growth for triple mutant mutants

pNRT2.4::NRT2.4-GFP

Lateral root (N starvation) nrt2.1 nrt2.2 nrt2.4-1nrt2.1 nrt2.2 nrt2.4-2

nrt2.1 nrt2.2

nrt2.1 nrt2.2 nrt2.1 nrt2.2 nrt2.4-1


Developmental variation in Arabidopsis thaliana

Naturalvaria;oninArabidopsisthaliana:Seedcolourandseedsizevaria;onInflorescencearchitecturevaria;onLeafshapeandrose"esizevaria;on


Bay 0 x Shahdara: Summary of N related QTLs

I II III IV V

DM10.6 -

NP10.5 +

NO10.7 -

AA10.8 +

AA10.7 -

+ NP3.7 + AA3.5

- DM3.4

+ NP3.6

DM10.8 +

DM10.7 +

NP10.7 -

NP10.6 - NO10.8 -

AA10.9 +

DM10.5 -

DM10.4 + NP10.2 - NO10.5 -

NO10.4 -

AA10.4 -

DM10.3 -

+ DM3.3 - NP3.5

- AA3.4

+ DM3.2 - NP3.4 - AA3.3

+ DM3.1

+ AA3.1

AA10.2 +

DM10.1 +

DM10.2 +

NP10.1 -

NO10.2 -

NO10.3 +

NO10.1 -

AA10.1 -

AA10.3 +

NP10.4 + AA10.6 +

NP10.3 - NO10.6 -

AA10.5 -

+ NP3.3

- NP3.2

+ NP3.1 + AA3.2 L2

DM: dry matter NO: nitrate content NP: Total N content AA: amino acid content 10 mM / 3 mM

Loudetetal,PlantPhysiol2003

L3

L4L1

Françoise Vedele : La nutrition azotée des plantes 16 novembre 2012 Montpellier BASF 14

An Ideal Plant for NUE


Deciphering the NUE mechanisms in Arabidopsis


Uptake and remobilization in Arabidopsis


0.1

0.2

0.3

0.4

0.5

0.6

0.7N%Gain

0.2

0.4

0.6

0.8

1.0

1.2 BiomassGain

Variability in biomass and N% gains between N+ and N-


Transcriptome

Candidate Genes for increasing NUE

Phenotypes, QTL

Nitrate transport

Physiological analysis

Key metabolic processes

Plant response to nitrogen availability Arabidopsis Response to Nitrogen Availability AReNA

Natural variation Regulation by N

Reverse Genetics

la nutrition azotée des plantes : exploration de la diversité naturelle et études des gènes...

Technology