impacts of ozone pollution on plant-pollinator interactions · 2019-12-20 · impacts of ozone...
TRANSCRIPT
Impacts of Ozone Pollution on Plant-Pollinator Interactions
Daniel Stabler, Geraldine Wright, Jerry Barnes
Potential Influences on Bumblebee Foraging
Introduction Aims: • Investigate effect of ozone stress on plant
resource provisioning
• How nectar and pollen quality and quantity influences pollinator behaviour
Plant resource allocation • Dwarf broad beans (Vicia faba)
• Chronic stress
• Clean air control • 110 ppb ozone for 8 hours per day
• Acute stress • Transfer from O3 to clean air at flowering • Transfer from clean air to O3 at flowering
• Nectar and pollen collected
• HPLC analysis for carbohydrates and
amino acids
• Measured dry weight
Results • Number of flowers
Treatment
Trans - clean air Trans - O3 Clean air control Permanet O3
Ave
rage
num
ber o
f flo
wer
s pe
r gro
up
0
2
4
6
8
• No significant differences in number of flowers between any treatment
Results • Dry weight (biomass) • Ozone fumigation
has no influence on biomass
Treatment
Trans - clean air Trans - O3 Clean air control Permanent O3
Dry
wei
ght (
g)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
• So, are broad beans ozone tolerant?
Treatment
Trans - clean air Trans - O3 Clean air O3
Vol
ume
(ul)
0
1
2
3
4
5
6
7
Results • Volume of nectar
• Transfer causes
an increase in the volume of nectar provided
Results • Carbohydrate profile
Treatment
Trans -
clea
n air
Trans -
O3
Clean a
ir con
trol
Perman
ent O
3
conc
entra
tion
(Mol
es/li
tre)
0.0
0.5
1.0
1.5
2.0
2.5
FructoseGlucoseSucrose
• Plants moved from ozone into clean air at flowering produce twice the concentration of sucrose in the nectar
Results • Amino acid profile
0
500
1000
1500
2000
2500
conc
entr
atio
n (n
M/m
l)
Amino acids
Clean air control
Permanent O3
Trans into clean air
Trans into O3
Results • Amino acid total nectar composition
Treatment
Trans - clean air Trans - O3 Clean air control Permanent O3
Con
cent
ratio
n (n
M/m
l)
0
1000
2000
3000
4000
5000
6000
7000
• Total amino acid composition of nectar in plants grown under ozone and moved to clean air at flowering is more than double found in other treatments
Bumblebee taste • Can bees detect changes in carbohydrates
and amino acids?
• Representative solutions from HPLC analysis
• Consumption measured after 24 hours
Results • Bee choice experiments
Treatment
1M sucrose 2M sucrose
Vol
ume
cons
umpt
ion
(ml)
0.0
0.1
0.2
0.3
0.4
0.5
Treatment
sucrose-only 1µM amino acids 5µM amino acids
Vol
ume
cons
umpt
ion
(ml)
0.0
0.2
0.4
0.6
0.8
1.0
Carbohydrates Amino acids
Results • Honeybee PER to antennal stimulation with 0.1M Amino acids
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Prob
abili
ty o
f res
pons
e
Amino acids
Results
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
thre phe isoleu suc1 lys meth hist suc2 lecu tryp val suc3
Prob
abili
ty o
f res
pons
e
Stimuli
•Honeybee drink responses on proboscis to 0.1M Amino acids
Future plans... • Pollen analysis from broad beans
• Identify amino acid and carbohydrate allocation in plant
tissue
• Free-flying bee experiments: • Effect of ozone on navigation to flowers • How affected reward quality influence foraging decisions
• Acknowledgements: • Sophie Derveau and Daniel Reed - bumblebee photography
• Koppert Uk Ltd. Bumblebee colonies