Post on 27-Sep-2020
Multiple stressor effects of ionising (gamma) radiation and non-ionising (UV)
radiation in duckweed (Lemna minor)
Li Xie1,2,3, You Song1,3, Knut Asbjørn Solhaug2,3, Ole Christian Lind2,3, Brit
Salbu2,3, Bjørn Johnsen4, Knut Erik Tollefsen1,2,3
1 Norwegian Institute for Water Research (NIVA)
2 Faculty of Environmental Sciences and Natural Resource Management (MINA), Norway Norwegian
University of Life Sciences (NMBU)
3Centre for Environmental Radioactivity (CERAD), Norwegian University of Life Sciences (NMBU)
4Norwegian Radiation protection Authorty (NRPA)
Contact : Li.Xie@niva.no
LI XIE
LI XIE
10 -14
10 -12
10 -10
10 -8
10 -6
10 -4
10 -2
1 10 2
10 4
10 6
Wavelength in Meters
Broadcast
Short wave TV
FM
Radar Infrared
Near Far
Visible
Ultraviolet
X Rays
Gamma Rays
Cosmic Rays
Ionizing Radiation Nonionizing Radiation
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Ionizing and Non-Ionizing radiation
LI XIE
What will happen in
the aquatic ecosystem?
Additivity
(1+1=2)
Antagonism
(1+1<2)
Synergy
(1+1>2)
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
The challenge
LI XIE
Central function in aquatic ecosystems
Easily cultured in controlled laboratory conditions
Standardised protocols available for regulatory testing
Rapid reproduction capacity
Highly sensitive to contaminants
Genome partly sequenced, molecular tools partly available
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Duckweeds (Lemna minor)
LI XIE
Stressor Molecular Initiating
Event
Key Events
Adverse
Outcome
Population effect
Clarify the individual and combine effect of -radiation and UVR in the duckweed
Study
Develop adverse outcome pathway (AOP) framework
Modeling
Hazard Assessment Application
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Objective
LI XIE
Endpoints:
Growth
ROS formation
Lipid peroxidation
OXPHOS
PSII efficiency
Pigments
DNA damage
Gene expression
Gamma dose rate
DWater (mGy/h)*
Gamma total dose
DWater (mGy)
UV
Dose rate
(W/m2)
13.2 2195
0.5±0.03 20.3 3375
47.1 7831
Study 1: UV radiation effects Study 2: Gamma radiation effects
Study 3: UV and gamma radiation combined effects
60Co
60Co
UV Chamber
Two-way ANOVA
Statistics
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Approach
LI XIE
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Growth
UV did not interrupt gamma radiation effects on frond size and
weight but reproduction rate.
-ra d ia t io n ra te (m G y /h )
Re
pro
du
cti
on
In
hib
itio
n
(%)
0 1 3 .2 2 0 .3 4 7 .1
-1 0
0
1 0
2 0
3 0
4 0
U V -
U V +* *
bb
a ba
b
aa
c
*
-ra d ia t io n ra te (m G y /h )
Fro
nd
siz
e i
nh
ibit
on
(%
)
0 1 3 .2 2 0 .3 4 7 .1
-5
0
5
1 0
1 5
2 0
U V -
U V +
b b
a b
a
b
a b
a
b
-ra d ia t io n ra te (m G y /h )
Fre
sh
we
igh
t in
hib
itio
n (
%)
0 1 3 .2 2 0 .3 4 7 .1
-1 0
0
1 0
2 0
3 0
U V -
U V +
b
b
a b
a
b c
a b
a
c
Reproduction Frond size Frond weight
LI XIE
Activation
antioxidant
defense system
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Oxidative stress
-ra d ia t io n ra te (m G y /h )
RO
S (
Fo
ld I
nc
re
as
e)
0 1 3 .2 2 0 .3 4 7 .1
0 .0
0 .5
1 .0
1 .5
2 .0
U V -
U V +
b
b
a b
a
b
b
a
a
*
*
-ra d ia t io n ra te (m G y /h )L
PO
(F
old
In
cre
as
e)
0 1 3 .2 2 0 .3 4 7 .1
0 .0
0 .5
1 .0
1 .5
2 .0
U V -
U V +
a
a
a
a
cb
aa
*
ROS formation Lipid peroxidation
LI XIE
ROS
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Oxidative phosphorylation
-ra d ia t io n ra te (m G y /h )
MM
P (
Fo
ld I
nc
re
as
e)
0 1 3 .2 2 0 .3 4 7 .1
0 .6
0 .7
0 .8
0 .9
1 .0
1 .1
1 .2
U V -
U V +a
aa
b
a
a ba b
b
**
*
*
Mitochondrial membrane
potential
UVR reduced MMP and interfere gamma radiation effect
LI XIE
RO
S
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
PS II inhibition
-ra d ia t io n ra te (m G y /h )
Fv
/Fm
(F
old
In
cre
as
e)
0 1 2 2 0 4 0
0 .7
0 .8
0 .9
1 .0
1 .1
U V -
U V +a
aa
b
bc
c
a
*
**
*
-ra d ia t io n ra te (m G y /h )
ET
R (
Fo
ld I
nc
re
as
e)
0 1 2 2 0 4 0
0 .7
0 .8
0 .9
1 .0
1 .1
U V -
U V +
aa
aa
a
a b
b
a
*
-ra d ia t io n ra te (m G y /h )
NP
Q (
Fo
ld I
nc
re
as
e)
0 1 2 2 0 4 0
0 .0
0 .5
1 .0
1 .5
2 .0
U V -
U V +
b
a b aa
d
b
a
c
*
*
Maximal PS II efficiency Electron transport rate Non-photochemical
quenching
In combined exposure, -radiation and UV had additive effects on
Fv/Fm
LI XIE
ROS
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
Pigment content
-ra d ia t io n ra te (m G y /h )
Ch
la
+b
(F
old
In
cre
as
e)
0 1 3 .2 2 0 .3 4 7 .1
0 .0
0 .5
1 .0
1 .5
U V -
U V +
a a a
a
a a aa
-ra d ia t io n ra te (m G y /h )
Ca
ro
ten
oid
s
(Fo
ld I
nc
re
as
e)
0 1 3 .2 2 0 .3 4 7 .1
0 .0
0 .5
1 .0
1 .5
2 .0
U V -
U V +
c
b
a
b
a a
aa
* *
*
Total chlorophyll Total carotenoids
Carotenoids are also
antioxidants to quenching
ROS in plant
LI XIE
Stressor Molecular initiating
Event
Key Events
Individual effect
Population effect
PSII efficiency Growth Population trajectories
Pigment
destruction
ROS
ETR blocking
NPQ increase
?
OXPHOS
PSII efficiency Growth
INTRO
DU
CTIO
N
M&
M
RESU
LTS
CO
NCLU
SIO
N
LI XIE
http://footage.framepool.com
THANK YOU!
Li.Xie@niva.no
Tânia Gomes
You Song
Dag Brede
Dag Wenner
Hans Christian Teien
Yetneberk Ayalew Kassaye
Terje Christensen