Selenium (Se) is a widely studied trace element in human and animal due to its role in antioxidant defense system which is needed for the maintenance of health and hormone balance. During last two decades the beneficial role of Se in plants has been explored by researchers.

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2. Beneficial Role of Selenium in Plants
Mohammad Abu Naim
Reg. No: 09-03659
Session: January-June/2014
MS Student
Department of Agronomy
Sher-e-Bangla Agricultural University
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3. • Introduction
• Materials and Methods
• Source of Information
• Selenium uptake and metabolism
• Role of Selenium
Seed germination
Growth
Physiology (Photosynthesis, gas exchange)
crop Quality
• Role of Selenium under stressful condition
Salinity
Drought
Toxic metals
High temperature
Low temperature
UV-radiation
• Selenium fortification to enhance food quality
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4. Introduction
• Selenium (Se) is a non-metal, whose Greek
name (Selene) means moon.
• Se is demonstrated as trace element which is
needed for the maintenance of animal and
human health.
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5. Objectives
• To study the role of selenium in plants.
• To study growth and yield of crops through the
application of selenium.
• To study the role of selenium on the stressful
condition.
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6. Materials and Methods
• Materials
Different types of plants like garden pea,
rapeseed, sorghum and rice.
• Methods
Different concentrations of selenium
application like 5 mg/L, 20 mg/L, 100 mg/L,
300 mg/L, 500 mg/L.
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7. Source of Information
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8. • Plants play a unique role in recycling and
delivering Se from the soil to the food chain.
• Se uptake and metabolism differ due to the
plant species, growth stage and the plant
organs.
Selenium Uptake and Metabolism
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9. Fig. 1. Selenium in the Soil-Plant-Water system.
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Source: Hasanuzzaman et al., 2010

10. Role of Selenium on Seed
Germination
• Priming of seeds with selenate promotes
germination of bitter gourd, radish, tomato etc.
• The positive effect on germination is linked to
antioxidative activity.
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11. Fig. 2. Garden pea’s germination (%) in the presence of sodium
selenite, Se (IV) and sodium salinate, Se (VI)
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Source: Alžbeta Hegedűsová et al. 2012

12. Plant Growth
• Se applied at low concentrations enhances
growth of both mono and dicotyledonous
plants.
• Se can delay senescence and promote the
growth of aging seedlings
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13. Fig. 3. Roots and shoots growth in the presence of sodium
selenite, Se (IV) and sodium salinate, Se (VI)
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Source: Alžbeta Hegedűsová et al. 2012

14. Photosynthesis and Gas Exchange
• Abiotic stress decreases the stomatal density
significantly.
• Reduction of stomatal conductance inhibits
supply of CO2 and consequently reduces CO2
assimilation.
• As a result photosynthesis of the plants is also
reduced.
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15. Crop Quality
Fig. 4. Effect of Se supply on the iron (Fe) contents of grain
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Source: Fahim Nawaz et al., 2014

16. Fig. 5. Effect of Se supply on the Phosphorous (P)
contents of grain
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Source: Fahim Nawaz et al. (2014)

17. Fig. 6. Effect of Se supply on the Magnesium (Mg)
contents of grain
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Source: Fahim Nawaz et al., 2014

18. Role of Selenium under
Stressful Condition
• Salinity: Soil salinity is one of the most severe
abiotic stresses that negatively affect on crop
production worldwide.
• Selnium reduces salt stress damage by
enhancing their antioxidant defense and
detoxification systems.
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19. Table 1. Malondialdehyde (MDA), H2O2 content, reduced ascorbate (AsA),
reduced glutathione (GSH) and oxidized glutathione (GSSG) in rapeseed seedlings
induced by selenium under salt stress conditions (Hasanuzzaman et al., 2011)
Treatment
MDA content
(μmol g–1 fresh
weight)
H2O2
content
(μmol g–1
fresh
weight)
AsA content
(μmol g–1
fresh
weight)
GSH content
(μmol g–1
fresh
weight)
GSSG
content
(μmol g–1
fresh
weight)
Control 25.58 d 3.70 d 5210.56 a 251.45 e 7.17 d
Na1 43.34 b 6.50 ab 4064.22 b 432.56 c 13.48 b
Na2 58.68 a 7.02 a 3141.51 c 358.68 d 16.95 a
Se 24.22 d 3.95 d 4890.04 a 261.28 e 8.14 cd
Se+Na1 34.71 c 5.25 b 4973.40 a 568.79 a 9.43 c
Se+Na2 43.29 b 6.06 c 3980.97 b 479.86 b 12.06 b
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20. Fig. 7. Phenological appearance of rapeseed seedlings induced by selenium under
salt stress conditions. S1, S2, Se, Se+S1 and Se+S2 indicates 100 mM NaCl, 200
mM NaCl, Na2SeO4, 100 mM NaCl+Na2SeO4, 200 mM NaCl+Na2SeO4 treatment,
respectively.
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Source: Hasanuzzaman et al. (2011)

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Source: Mirza Hasanuzzaman personal contact
Fig. 8. Effect of selenium application under salinity stress in BRRI
dhan45. (a) 100 mM NaCl, (b) 100 mM NaCl + 0.5 μM Sodium
Selenate

22. Drought
• Drought is one of the most devastating
environmental stresses that affects on the
growth and development of plants.
• Se has the ability to regulate the water status of
plants under conditions of drought.
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23. Table 2. Malondialdehyde (MDA), H2O2 content, reduced ascorbate (AsA),
reduced glutathione (GSH) and oxidized glutathione (GSSG) in rapeseed
seedlings induced by selenium under drought stress conditions
(Hasanuzzaman and Fujita, 2011)
Treatment
MDA
content
(µmol g–1
fresh
weight)
H2O2
content
(µmol g–1
fresh
weight)
AsA
content
(µmol g–1
fresh
weight)
GSH
content
(µmol g–1
fresh
weight)
GSSG
content
(µmol g–1
fresh
weight)
Control 21.16 c 4.44 c 4970.52 d 283.31 d 8.48 d
D1 30.77 b 5.92 b 5923.34 bc 439.93 bc 18.26 c
D2 42.06 a 7.36 a 5203.01 d 414.97 c 32.61 a
Se 19.87 c 4.69 c 5476.88 cd 269.73 d 9.84 d
Se+D1 23.42 c 5.00 c 7006.01 a 514.72 a 17.61 c
Se+D2 29.46 b 5.82 b 6295.85 b 467.83 b 21.52 b
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24. Table 3. Activities of antioxidant enzymes in rapeseed seedlings induced by
selenium under drought stress conditions (Hasanuzzaman and Fujita, 2011)
Treatment
CAT
activity
(µmol
min–1
mg–1
protein)
APX
activity
(µmol
min–1
mg–1
protein)
MDHAR
activity
(µmol
min–1
mg–1
protein)
DHAR
activity
(µmol
min–1
mg–1
protein)
GR
activity
(µmol
min–1
mg–1
protein)
GST
activity
(µmol
min–1
mg–1
protein)
GPX
activity
(µmol min–
1 mg–1
protein)
Control 24.98 a 0.344 bc 37.40 c 201.73 e 33.67 c 45.17 c 0.1177 d
D1 18.79 b 0.366 b 41.09 b 233.38 cd 41.54 b 56.52 b 0.1390 c
D2 16.02 b 0.307 c 34.42 c 261.90 bc 39.25 bc 59.24 b 0.1402 c
Se 25.52 a 0.343 bc 37.48 c 212.83 de 36.52 bc 49.98 c 0.1306 c
Se+D1 25.32 a 0.432 a 45.30 a 270.46 b 54.48 a 67.39 a 0.1748 a
Se+D2 23.68 a 0.453 a 44.66 a 314.15 a 51.89 a 69.73 a 0.1595 b
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25. Toxic Metals
• Under the toxic metal stress condition, plant`s
growth and development are reduced.
• Protective effects of Se are due to the
formation of non toxic Se-metal complexes.
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26. Fig. 9. Phenological appearance of Brassica napus leaves induced
by Se under Cd stress. a. control; b. 0.5 mM CdCl2, 48 h; c. Se
treatment (100 μM Na2SeO2, 24 h) followed by treatment with 0.5
mM CdCl2, 48 h.
26Source: Hasanuzzaman and Fujita, 2011

27. High Temperature
• High temperature (HT) or heat stress results to
damage plant tissues, substantially influencing the
growth and metabolism of plants.
• HT stress results the lower grain yield compared with
control temperature (32/22°C).
• The increase in antioxidant enzyme activities and
decrease in ROS content by selenium was greater in
HT.
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28. Fig. 10. Effect of temperature stress (OT, optimum temperature, 32/220C and
HT, high temperature, 40/300C) during seed-set and seed-filling stages on (A)
chlorophyll content (SPAD units) and (B) thylakoid membrane damage (Fo/Fm
ratio) of grain sorghum leaves
28Source: M. Djanaguiraman et al. 2010

29. Fig. 11. Effect of selenium application (C, control, water spray and Se,
selenium as foliar spray, 75 mg L-1 of sodium selenate) during seed-set and
seed-filling stages on (A) stomatal conductance (molm-2 s-1) and (B)
transpiration rate (mmolm-2 s-1) of grain sorghum leaves. Data were recorded
from day 7 to 28 of high temperature stress.
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Source: M. Djanaguiraman et al. 2010

30. Low Temperature
• Low temperature affects germination, seedling
growth, early leaf development and overall crop
growth and productivity.
• Se treatments significantly increased anthocyanins,
flavonoids, and phenolic compound contents of
seedlings subjected to low temperature stress.
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31. Total soluble sugars
Fig. 12. Total soluble sugars content of sorghum seedlings grown under
cold stress conditions as influenced by seed soaking in selenium
concentrations prior to germination
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Source: Salwa Mohamed Abbas, 2013

32. Electrolyte leakage
Fig.13. Estimation of electrolyte leakage (EL) of sorghum plumules
grown under cold stress conditions as influenced by seed soaking in
selenium concentrations prior to germination
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Source: Salwa Mohamed Abbas, 2013

33. Proline content
Fig. 14. Proline content of sorghum seedlings grown under cold stress
conditions as influenced by seed soaking in selenium concentrations prior to
germination.
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Source: Salwa Mohamed Abbas, 2013

34. UV radiation
• Enhanced UV-B radiation alters transpiration and
photosynthesis, respiration potential, growth,
development and morphology of plants.
• Se treatments significantly increased root activity,
flavonoids and proline content, and activities of
POD and SOD in wheat roots exposed to enhanced
UV-B.
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36. Conclusion
• The research work conducted on the beneficial role
of Se under stressful condition is scarce.
• Complete elucidation of the role of Se as well as
detailed protective mechanisms would be helpful for
developing stress tolerance in plants.
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