Post on 05-Dec-2014
description
Influence of Silicon on Cadmium uptake in durum wheat cultivars
Muhammad Arifin Sandhi
Masters Student, EcologyStockholm UniversitySE- 10691, Sweden
Background
Cd is a non-essential metal for plants, present in the soil at very low concentration.
Occurance of Cd by industrial activity, pesticide residues, electronic waste, mining, swedge sludge deposition.
Cd linked with food chain and cause diseases like cancer,bone fracture,hypertension, etc.
In Sweden, the half of total Cd intake in the human body by potato (43%) and wheat (40%)
(Greger & Löfstedt, 2004)
DurumWheat (TriticumturgidumL var.)
• Developed in Late Bronze Age(6000-7000 BC) and difference from bread wheat genome (2n=6x) where durum (2n=4x)
• Evidence to uptake Cd in durum in US, Canada and Sweden.
• Two common varities in Sweden, Helidur (low accumulator)and Grandur(high accumulator).
(Greger & Löfstedt, 2004)
Silicone
• Silicon (Si) helps the plant to recover them from biotic (pest and pathogen) and abiotic stress (heavy metal).
• Some cereal crops under Gramineae and Cyperaceae can uptake high amount of Si.
• Si helps initiation of tolerance mechanism against toxic
metals.
(Gong et al., 2008)
Questions?
Influence of Silicon
on Cd uptake in respect of time. Net uptake of Cd in root regions. Translocation percentage between two durum wheat
cv.
Materials
Durum wheat cultivars; helidur and grandur
Cd isotope (42 nM) and half life 453 days.
Potassium Silicate
Methods
• The wheat seedlings are cultivated in climate chamber on hydroponics medium for 2 weeks.
• There are four treatments of Si (0, 0.5, 2, 5 nM) with 3 replications and each replicate has 4 plants in each.
• After addition of Cd, collect the solution from medium in respect of time (0 min, 12 min,24 min, 36 min, 1 h, 4 h, 20 h, 48 h) and analysed in Scintillation machine (DPM) with addition of Emulsifier.
• After 48 hours plant biomass collected, wet digestated and analysed in scintillation machine.
Result
Cd Uptake
0 min 12 min 24 min 36 min 60 min 240 min 1200 min 2880 min
-10000
-5000
0
5000
10000
15000
20000
25000
0 mM
0.5 mM
2 mM
5 mM
Time (Min)
Cd u
ptak
e in
Hel
idur
(DPM
/ g
Root
DW
)
0 min 12 min 24 min 36 min 60 min 240 min 1200 min 2880 min-5000
0
5000
10000
15000
20000
25000
0 mM0.5 mM2 mM5 mM
Time (Min)
Cd u
ptak
e in
Gra
ndur
(DPM
/ g
DW)
Results
Cd Uptake/minute
12min24min
36min60min
240min
1200min
2880min
-800
-600
-400
-200
0
200
400
600
800
1000
1200
0 mM0.5 mM2 mM5 mM
Time (Minute)
Cd u
ptak
e in
Hel
idur
DPM
/(g
DW*m
in)
12min24min
36min60min
240min
1200min
2880min
-200
-100
0
100
200
300
400
500
600
700
0 mM0.5 mM2 mM5 mM
Time (Minute)
Cd u
ptak
e in
Gra
ndur
DPM
/ (g
DW
* m
in)
Results
Net Uptake Cd by roots
0 0.5 2 50
200
400
600
800
1000
1200
1400
1600
HelidurGrandur
Si Concentration (mM)
Net
upt
ake
of C
d DP
M/(
g DW
root
)
Results
Translocation Percentage
0 0.5 2 50
10
20
30
40
50
60
70
80
90
100
HelidurGrandur
Si concentration (mM)
Cd tr
anslo
catio
n to
shoo
ts (%
)
Discussions
Uptake is higher in grandur cv, but uptake rate/min is faster in helidur cv with increase of Si treatments.It is probably binding of available Cd in the solution with root cell proteins and make it inactive complex molecules .
The net uptake of Cd in root decreased with increase of Si application. This decrease trend is more higher in helidur than grandur.This findings suggested that higher dose of Si application reduce Cd uptake in the roots of helidur.
Si application reduce the translocation percentage of Cd in shoots of helidur than grandur.The common trend of metal sink root>shoot>grain. As Si deposited in the leaf area of wheat, so plant leaf can avoid and reduce the Cd in the shoot with help of Si.
Conclusions
• Research needs for helidur as Si decrease the accumulation of Cd in both root and translocation in shoot.
• Carry out research in field level because hydroponics medium can cause higher stress than field condition.
Acknowledgement
Docent Maria Greger&
FL Tommy Landberg
Questions?
Tack så mycket !