Chemical Ecology and Biodiversity

Martine HOSSAERT-McKEYCentre

Fonctionnelle et Evolutive-CNRS, Montpellier, France

Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010

Chemical mediation and the dynamicsof biodiversity

At the heart of fundamental questions in

evolutionary biology and functional ecology

The functioning of ecosystems

The origin and maintenance of biodiversity

Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010

Practical applications: « ecological

chemistry », « green chemistry »

Incredible diversity of natural substances

potentially useful to humans

How to inventory them ?

Going beyond inventory

Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010

How to inventory them ?

- Random (screening)

- Use chemotaxonomy as a guide

“Ecology-driven”: use the exceptional metabolic creativity that organisms employ in mediating their biotic interactions

“Ethnobiology-driven”: use folk knowledge as a guide

Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010

“Natural substances" : Products of natural selection

The principle of biomimicry : Natural selection has had

millions of years to invent solutions to problems.

“Imitating nature” is often the most efficient means to

resolve some problems.

Sharkskin and the high performance of a new

kind of swimsuit

Moth cocoons and a next-generation glue

Natural substances are also at the foundation of biotic

interactions

GDR Ecologie Chimique – created in 2003

15 laboratories

Exchanges and collaborative research

Shared tools: Plate-formes for chemical analysis, MS

libraries, GC-EAD, ….

A website: www.gdrec.univ-rennes1.fr

Annual meetings

‘Eco-chimiothèque’ (see poster at this meeting)

Organization of this meeting!

Chemical mediation in mutualistic interactions

Chemical mediation in insect societies

Functional ecology of chemical mediation

Sensory ecology of chemical mediation

Chemical communication in vertebrates

GDR Ecologie Chimique: principal researchthemes

Collaborations with the Chinese

Academy of Science :

Xishuangbanna Tropical Botanical Garden Yunnan

Kunming Institute of Botany, Yunnan

Pollen transport

Breeding site

Obligatory & specific

Insect Plant

Fig/fig wasp mutualism: a model system in evolutionary

biology

Roughly this coevolved mutualism

NURSERY POLLINATION MUTUALISMSThe pollinators reproduce in the flowers they pollinate

The fig / fig wasp mutualism

Development of wasps and seeds

Female pollinators

Receptive fig

Male-phase fig

A new generation of pollinating wasps

Pollination and oviposition

Signal facilitating the encounter of the two mutualists

- Mutualism : the two partners benefit from the encounter

- Species-specific interactions :

A strong signal

A specific signal

Collection of volatile compounds by headspace

Figs enclosed in a bag

made of inert plastic

Filter retaining the

molecules of volatile

compounds

(adsorption)

Charcoal filter to purify

the entering air

Ficus semicordata at XTBG4-methylanisole = 90% of the floral scent of figs atreceptivity

(Chen Chun et al. Functional Ecology 2009)

Species-specific mutualisms: both partners have an interest in efficient signal transmission and reception

Selection favours a strong and SIMPLE signal

SIMPLE signal: unambiguous signal in complex

environments

« Private channels » (Soler et al. 2010)

Biosynthesis of rose scent compounds

Sylvie Baudino-CaissardLaboratoire Bvpam

Université de Saint-Etienne

Laboratoire Reproduction et Développement des Plantes

ENS Lyon

Laboratoire GenhortINRA Angers

W.-B. Sun Botanical Institut

Kumning

Introduction

2 very different fragrances in different rose species

Typical rose scent

Rosa gallicaRosa gigantea

PE

G

Ci

H3CO OCH3

Geraniol and derivatives2-Phenylethanol

3,5 Dimethoxytoluene

DMT

« Tea scent »

Benzenoids/

Phenylpropanoids

Monoterpenealcohols

DMT

GDIo

Diversity of scent and phylogeny

ChinenseSynstylaeCaninae

Genus Rosa : 150 species, 10 sections

Gallicanae

Banksiae

Bracreatae

Caninae

CaninaeGallicanae

LaevigataeSynstylae

SynstylaeSynstylae

PimpinellifoliaePimpinellifoliae

Cinnamomeae

CinnamomeaeCinnamomeae

SynstylaeCinnamomeae

Carolinae

Tea scent

Roses from the Chinense section

OH

2-phenylethanol

Roses from other sections : Synstylae, Cinnamomeae, Pimpinellifoliae, Caninae, Gallicanae, Carolinae

Question n°1

Why don’t they make DMT ?

3HCO

CH3

3,5-dimethoxytoluene

HO OCH3

CH3

orcinolHO OH

CH3

MHT DMT

OOMT1 OOMT2OCH31 2

Chinese section

R. chinensiscvOld Blush

R. gigantea R. chinensis spontanea

R. xodorata R. xodorataochroleuca

Tyr Phe

ߟ Roses from the Chinense section have both OOMT1 and OOMT2 genes

ߟ Roses from other sections only have OOMT2 genes

Sca

lliet

et a

l., P

NA

S 2

008

OOMT1 & OOMT2

Phe

Tyr Phe

ancestral OOMT2 gene

OOMT2

OOMT1 - OOMT2

3HCO

CH3

3,5-dimethoxytoluene

HO OCH3

CH3

orcinolHO OH

CH3

MHT DMT

OOMT1 OOMT2

OCH3

Petal specificOOMT2 gene

Hypothesis on OOMTs evolution

An association between soil fungi and roots of >85% of plants

Reciprocal nutrient exchanges + protection:

PLANT FUNGUS

Sugars, B vitamins

Water and N, P, K

Protection against soil pathogens and abiotic stress

MYCORHIZAL SYMBIOSIS

MYCOHETEROTROPHY

400 forest species in 87 genera (Leake 1994)

Achlorophyllous, without stomata: heterotrophic

Not direct parasites on other plants : a fungus is providing food to the roots: mycoheterotrophy (MH)

Sarcodessanguinea

Gymnosiphon minutus

MYCOHETEROTROPHY

Mycorrhizal association

GREENTREE

MYCOHETERO-TROPHIC PLANT

FUNGUSMycorrhizal association

Carbon flow

Cf. 14C labelling (McKendrick et al., 2000and 13C abundance (Trudell et al., 2003)

Under (or at) compensation point, for various reasons

Partial heterotrophy, by using fungal carbon (0-80%):

Curious green orchids ?

Mixotrophic plant, performing photosynthesis andcarbon compounds from its fungal symbiont(s)

Carbon flow

Mycorrhizal association

GREENPLANT

MIXOTROPHIC, GREEN PLANT

FUNGUSMycorrhizal association

Photosyntheticcarbon

The ubiquity of chemical mediation

Chemical mediation plays key roles in these

interspecific interactions

These interactions are the structural « glue » that

binds ecological communities and determines their

functioning

Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010