successful teamwork cooperation as a strategy in plant defence martin heil cinvestav – irapuato,...

Successful teamwork

Cooperation as a strategy in plant defence

Martin Heil

CINVESTAV – Irapuato, Guanajuato, México

Ant-plant mutualism

Pseudomyrmex ferrugineus

The obligate mutualist

inhabited ant-free

Ant-plant mutualism

Ant-plant mutualism

General problem

All mutualisms are exploited by cheaters or parasites

● Non-pollinating nectar robbers● Non-N-fixing Rhizobia● Pathogenic mycorrhizal fungi● Non-defending ants

How are the rewards in the Acacia-Pseudomyrmex mutualism protected?

Protecting food bodies

A. h A. cFBs

A. h A. cLeaves

SDS-PAGE 13%25 μgA.h: Acacia hindsiiA.c: Acacia cornigera

220

70

50

30

20

15

10

Domancar

Orona-Tamayo et al. (2013) Mol Ecol 22: 4087-4100

Acacia food bodies (FBs) possess a complex proteome that differs from the leaf proteome

Domancar


Storage proteins4%

Protease inhibitor

19%Protein Biosyn-thesis

8%

Stress22%

Protein to micronutrient2%

Transport5%

Secondary metabo-lites pro-

tein5%

Cell process

35%


Acacia cornigera FBs

SKTI

(PU

A) /

(µg

of p

rote

in)

10

102030405060

Ctrl Ah FBs Ac FBsSource of Protease inhibitors (PIs)

Prostephanus truncatus

Zabrotes subfasciatus

Effect on Trypsin activity in beetles


Source of Protease inhibitors (PIs)Ah: Ant larvae fromA. hindsii Ac: Ant larvae from A. cornigera

Ah Ac Ah Ac Ah Ac Ah AcCntl FB h FB c SKTI

00.005

0.010.015

0.020.025

0.030.035

0.040.045

0.05

n = 7

FBs are protected via protease inhibitors (PIs)Ant larval proteases are insensitive to the PIs 'their' FBs

Domancar


Storage proteins4%

Protease inhibitor

19%Protein Biosyn-thesis

8%

Stress22%

Protein to micronutrient2%

Transport5%

Secondary metabo-lites pro-

tein5%

Cell process

35%

Acacia cornigera FBs Effect on Trypsin activity in ant larvae

Orona-Tamayo & Heil Biotropica 45:654-665

Domancar


=> Food bodies are 'exclusive rewards'

Ant-plant mutualism

Ant-plant mutualism

400

200

0

2000

1000

1500

500

A. cochliacantha400

200

0A. farnesiana

400

200

0

50

0

A. macracantha

A. pennatula300

100

0

Non-myrmecophytes

a a b b

con

trol

spra

y co

nt.

dam

age

JA

a a b b

a a b b

a a b b

EF

N [µ

g g

-1D

M 2

4 h-1

]

1000

500

A. chiapensis

A. cornigera

A. globulifera

A. hindsii

Myrmecophytes

a a a a

con

trol

spra

y co

nt.

dam

age

JA

a a a b

a a a a

a a a a

Heil et al.

Fig. 1

Heil et al, Nature 430 (2004), 205-208

EFN

[µg

gMS-1

24h

-1]

Obligate myrmecophytes produce EFN constitutively

EFN is generally an inducible defence trait

Rosario EFN

sec

retio

n

Cont

rol

No

ants

No

ants

ants removed (2 days)

mut

ualis

t

expl

oite

r

ants back (1 day)

Making EFN

The mutualist ant, but not the exploiter, can activate EFN secretion

Making EFN

Rosario

Making EFN

T = 0 1 2

Making EFN

Orona-Tamayo et al. (2013) Plant J 73: 546-554

The biosynthetic machinery in the extrafloral nectary is synthesized and destroyed on a daily basis

Providing the plant with an extremely high phenotypic plasticity in its secretion

Making EFN

Glu

co

se

Fr

uc

to

se

Su

cr

os

e

Su

ga

r-

Mix

A.

c

oc

hlia

ca

nt

ha

A.

f

ar

ne

sia

na

Le

uc

ae

na

A.

c

ollin

sii

A.

h

ind

sii

Wa

te

r

0

1 0

2 020

10

0

20

10

0

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

farn

.

Le

uca

ena

A.

corn

ige

ra

A.

chia

pe

nsis

Wa

ter

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

coch

.

A.

farn

.

Le

uca

ena

A.

colli

nsi

i

A.

hin

dsi

i

Wa

ter

A. Generalistic antscoast

Isthmus

B. Specialized ants

30

20

10

0

P. ferrugineus

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

coch

.

A.

farn

.

Le

uca

ena

A.

colli

nsi

i

A.

hin

dsi

i

Wa

ter

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

coch

.

A.

farn

.

Le

uca

ena

A.

colli

nsi

i

A.

hin

dsi

i

Wa

ter

20

10

0

P. mixtecus% o

f an

ts

Heil et al., Figure 1

Glu

co

se

Fr

uc

to

se

Su

cr

os

e

Su

ga

r-

Mix

A.

c

oc

hlia

ca

nt

ha

A.

f

ar

ne

sia

na

Le

uc

ae

na

A.

c

ollin

sii

A.

h

ind

sii

Wa

te

r

0

1 0

2 020

10

0

20

10

0

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

farn

.

Le

uca

ena

A.

corn

ige

ra

A.

chia

pe

nsis

Wa

ter

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

coch

.

A.

farn

.

Le

uca

ena

A.

colli

nsi

i

A.

hin

dsi

i

Wa

ter

A. Generalistic antscoast

Isthmus

B. Specialized ants

30

20

10

0

P. ferrugineus

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

coch

.

A.

farn

.

Le

uca

ena

A.

colli

nsi

i

A.

hin

dsi

i

Wa

ter

Glu

cose

Fru

cto

se

Suc

rose

Su

gar

mix

A.

coch

.

A.

farn

.

Le

uca

ena

A.

colli

nsi

i

A.

hin

dsi

i

Wa

ter

20

10

0

P. mixtecus% o

f an

ts

Heil et al., Figure 1

site 1

site 2

Heil et al, Science 308 (2005), 560-563

myrmecophytes

non-myrmecophytes

Protecting nectar

Heil et al, Science 308 (2005), 560-563

Lack of sucrose => myrmecophyte EFN unattractive for generalist ants

Invertase activity in the digestive tract of generalist ants and plant-ants

Protecting nectar

Kautz et al (2009) Evolution 63: 839-853

Protecting nectar

Steffi

The larvae of the mutualist ants still possess

– sucrose-inducible – invertase activity

Heil et al (2014) Ecol Lett 63: 839-853

Inve

rtas

e [n

g gl

u an

t-1 m

in-1

]

6

4

2

0 G GS G GS

old workersP > 0.05

from pupaeP = 0.018

Freshly hatched workers possess invertase Alejandro

Protecting nectarIn

vert

ase

[ng

glu

ant-1

min

-1]

6

4

2

0 GS EFN

b

a


Inve

rtas

e [n

g gl

u an

t-1 m

in-1

]

6

4

2

0 G GS G GS

old workersP > 0.05

from pupaeP = 0.018

Freshly hatched workers possess invertase Alejandro

Protecting nectar

PR PRl GS EFN

Inve

rtas

e [n

g gl

u an

t-1 m

in-1

]

a

bb

c8

4

0

Inve

rtas

e [n

g gl

u an

t-1 m

in-1

]

6

4

2

0 GS EFN EFN 100°C

bb

a

which is inhibited by PR-proteins in the EFN


AlejandroInvertase activity in the gut liquid is inhibited by EFN Chitinase

Filtered gut liquids

Protecting nectar


Alejandro

Protecting nectar

=> Partner manipulationA part of the ant phenotype is under the control of the plant,

which renders the ant dependent on host EFN.

The 'interests' of the ant (energy supply) and the host (protection of

its photosynthetic tiusse) are tied together

Ant-plant mutualism

● Protease inhibitors protect FBs from beetles● Metabolic machinery for EFN synthesis is produced daily● Nectar enzymes make the ants dependent on EFN by manipulating their digestive capacities

● Host plant and ant show numerous adaptations that optimize the functioning of the mutualism

Ant-plant mutualism

● The phenotypes of plant and ant change rapidly after the establishment of the symbiosis

● Phenotypic plasticity and mutual control are key factors for the optimized functioning of the mutualism

● Wo controls whom and to which degree?

…. My job for the next years

Acknowledgements

Todologo and graphic design

Alejandro de León

Acknowledgements

http://www.dfg.de/

http://www.mpg.de/index.html

Acknowledgements

I am obviously very fond of this paper, but I have two serious concerns about it. First, it is poorly written. I was completely lost between the Introduction and the Discussion. I may sound like a dumb ecologist who can’t handle biochemistry (and I probably am exactly that) but this is more about the authors’ failure to communicate effectively than my failure to understand. There is absolutely zero context provided for any of the methods described. What hypothesis is being tested with zymography (and WTF is zymography)? What is the point of the MS-BLAST searches? What is the relevance of PR proteins? Why was P. gracilis included in the experiment if the focus of the paper is P. ferrugineus? I could go on and on. Because the methods were un-interpretable, I also could not understand the graphical results…

successful teamwork cooperation as a strategy in plant defence martin heil cinvestav – irapuato,...

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