Involvement of <em>Pseudomonas fluorescens</em> pyoverdine in growth, defence responses and iron homeostasis in <em>Arabidopsis thaliana</em>

(1)

HAL Id: hal-02743921

https://hal.inrae.fr/hal-02743921

Submitted on 3 Jun 2020

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Involvement of Pseudomonas fluorescens pyoverdine in growth, defence responses and iron homeostasis in

Arabidopsis thaliana

Pauline Trapet

To cite this version:

Pauline Trapet. Involvement of Pseudomonas fluorescens pyoverdine in growth, defence responses and iron homeostasis in Arabidopsis thaliana. 4. Journée des Doctorants, Institut National de la Recherche Agronomique (INRA). FRA., Mar 2015, Dijon, France. �hal-02743921�

(2)

Involvement of Pseudomonas fluorescens pyoverdine in

growth, defence responses and iron homeostasis in

Arabidopsis thaliana 4ème Journée des Doctorants de l’UMR

Agroécologie

Lundi 16 Mars 2015

Pauline Trapet

(3)

Iro n

•

4th most common element in the Earth’s crust but weakly bioavailable

•

Essential element for living organisms

- Incorporated into several key proteins

- Involved in respiratory chain

(4)

Iro n

Plants display strategies to

efficiently assimilate iron from the soil

(5)

(6)

(7)

(8)

Iro n

Bacteria also developed a specific

system to assimilate iron

(9)

Iro n

Bacteria also developed a specific

system to assimilate iron

(10)

Iro n

Bacteria also developed a specific

system to assimilate iron

(11)

Iro n

Bacteria also developed a specific

system to assimilate iron

(12)

Iro n

•

Chelates other metals

•

Specific receptors in bacteria

•

Chain of 8 to 15 amino-acids together with a chromophore

•

Pseudomonas fluorescens C7R12 :

-

Pyoverdine

-

Ornicorugatine

-

Pseudomonine

•

High affinity for iron ( Ka = 1032)

(13)

•

Some siderophoresPf can induce plant

defence response

•

They can also reduce disease severity

Disease severity

•

Pyoverdine → assimilated by roots of in vitro Arabidopsis thaliana (unknown mechanism)

•

Pyoverdine plant growth, iron content, chlorophyll content ↗

(14)

•

Some siderophoresPf can induce plant defence response

•

They can also reduce disease severity

Disease severity

•

Pyoverdine → assimilated by roots of in vitro Arabidopsis thaliana (unknown mechanism)

•

Pyoverdine plant growth, iron content, chlorophyll content ↗

(15)

(16)

(17)

(18)

Experimental design

Hydroponic culture → nutritive conditions tightly regulated

(19)

Experimental design

Hydroponic culture → nutritive conditions tightly regulated

(20)

Experimental design

Hydroponic culture → nutritive conditions tightly regulated

(21)

Experimental design

Hydroponic culture → nutritive conditions tightly regulated

(22)

Phenotypical analysis

After 7 days of treatment : A.

Fe 25

Fe 25 Apo-

Pyo

Pictures at day 7

Lower face Upper

face

(23)

Phenotypical analysis

After 7 days of treatment : A.

Fe 25

Fe 25 Apo-

Pyo

Fe 0

Pictures at day 7

Lower face Upper

face

(24)

Phenotypical analysis

After 7 days of treatment :

Reversion of the Fe 0 phenotype by apo-pyoverdine treatment A.

Fe 25

Fe 25 Apo-

Pyo

Fe 0

Fe 0 Apo- Pyo

Pictures at day 7

Lower face Upper

face

(25)

Phenotypical analysis

After 7 days of treatment :

Reversion of the Fe 0 phenotype by apo-pyoverdine treatment

0 A. B.

Fe 25

Fe 25 Apo-

Pyo

Fe 0

Fe 0 Apo- Pyo

Weight at day 7

a a

0 2 4 6 8 10

12

a

b

Pictures at day 7 Lower face Upper

face Leaf weight in mg

(26)

Phenotypical analysis

After 7 days of treatment :

Reversion of the Fe 0 phenotype by apo-pyoverdine treatment

0 2 4 6 8 10 12

0 A. B.

Fe 25

Fe 25 Apo-

Pyo

Fe 0

Fe 0 Apo- Pyo

Weight at day 7

a a

0 2 4 6 8 10

12

a

a a

b

b c

Pictures at day 7 Lower face Upper

face Leaf weight in mg Root weight in mg

(27)

(28)

(29)

Microarray experiment

(30)

Microarray experiment

[Fe 0 condition]

[Fe 25 condition]

(31)

Microarray experiment

[Fe 0 condition]

[Fe 25 condition]

(32)

Microarray experiment

[Fe 0 condition]

[Fe 25 condition]

(33)

Microarray experiment

[Fe 0 condition]

Highly induced genes :

-

Development

-

Transport

-

Iron import and in planta transport

[Fe 25 condition]

Highly repressed genes :

-

Abiotic stress

-

Biotic stress

-

SA and ABA related genes

-

Iron chelation

(34)

Defence

Preliminary results :Pyoverdine effect on defence response to Botrytis cinerea

0 2 4 6 8 10 12

Botrytis cinerea infection

A ir e d e s lé si o n s b ab

(35)

Defence

0 2 4 6 8 10 12

Botrytis cinerea infection

A ir e d e s lé si o n s Plants are more resistant

to infection

Fe 0

b ab

c

Preliminary results :Pyoverdine effect on defence response to Botrytis cinerea

(36)

Defence

0 2 4 6 8 10 12

Botrytis cinerea infection

A ir e d e s lé si o n s Plants are more resistant

to infection

Fe 0

Fe 0 Apo- pyo

Plants are more sensitive to infection in iron deficiency

b ab

c

a

Preliminary results :Pyoverdine effect on defence response to Botrytis cinerea

(37)

Mode of action

Research of genes involved in pyoverdine mode of action

(38)

Mode of action

Research of genes involved in pyoverdine mode of action

(39)

Mode of action

Research of genes involved in pyoverdine mode of action

(40)

Mode of action

Research of genes involved in pyoverdine mode of action

(41)

Modification of

genes expression

(42)

Modification of

genes expression

(43)

Modification of

genes expression

(44)

Pyoverdine seems to affect Growth/Defence balance

Last mutant to screen : HBI 1

Modification of

genes expression

(45)