Drought tolerance mechanism in plant

Abiotic stress: how the effect on plant and what it's mechanism

2. Abdul AwalChowdhury Masud
RegNo. 10-03844
Department of Agronomy
Sher-e-Bangla Agricultural University

3. STUDY THE MECHANISM OF
DROUGHT TOLERANCE IN
PLANT

4. Presentation Outline
Background Information
Abiotic stress & Drought
Drought effect on crop
Stress tolerance mechanism
Conclusion & Recommendations
Q & A
4

5. Objectives
Get an overview on abiotic stress induced drought stress
Study plant responses to drought stress
Discuss Drought effect on crop growth and yield
Outline drought tolerance mechanism in plant
To…
5

6. Background

7. 7.5 Bln
current population
7

8. 8

9. Stress?
Unfavourable
conditions that affects
or blocks a plant’s
metabolism, growth or
development
(gasparet al., 2002)
Adverse situation that
create mental or
emotional strain
9

10. Plant
10

11. Nutrient
Imbalance
Water
stress
Mechanical
stress
Temp.
stress
Pollutants
Radiation
(Light,UV)
Heavy
Metal
Salinity
Figure. Plant faces Abiotic Stresses
Drought
Abiotic
Stress
11

12. Introduction

13. Drought
Unavailabilityofwaterasrequiredbyplantsduetophysical
orphysiologicalreason
Physical:insufficientrainfall,hightemperature
Physiological:salinity,ionimbalance,osmoticregulation
13

14. Drought: World Scenario
Affects35%oftheworld’sagriculturalland
DroughtproneApprox.26%ofworldarableland
Limits>50%ofworldagriculturalproductivity
(Comas et al. 2013)
Duetodroughtanddesertificationeachyear12million
hectaresarelost,where20milliontonsofgraincould
havebeengrown (FAO,2014)
14

15. Fig: world trends in Drought (20-21th C)
(Sheffield et al, 2011)
15

16. DroughtTypes
Meteorological Drought
Rainfall < 25 % of the average of the region.
(<50 %-severe drought)
16

17. DroughtTypes
Agricultural Drought
lack of rainfall result in insufficient moisture in the root zone
17

18. DroughtTypes
Hydrological Drought
•Extended dry period
•Marked depletion of surface water
•Drying up of reservoir, lacks ,streams, rivers etc.
18

19. Materials & Methods

20. Materials & Methods
Materials
Different crop species
Methods
Stress defense mechanism by plant
Drought stress mechanism in plant
Drought effect on plant
Tolerance mechanism
* Information collected from secondary sources ( Journals, Books,
thesis, online, etc.) 20

21. ROS
Reactive oxygen species
(
1
O
2, O
2
-
,OH
-
,H
2O
2)
AOX
Enzymatic
(SOD, CAT,
GPX, GR)
Non-Enzymatic
(AsA, GSH, GS
SG, DHA)
Balance
Normal Plant
Plant stress defense mechanism
21

22. What happens, while
Plant got stressed ??
What is oxidative
stress??
22

23. Imbalance
Stressed Plant
23

24. Protein
degradation
ROS effects
on plant
Enzyme
inactivation
DNA damage
Lipid
peroxidation
24

25. Drought stress Mechanism
Drought stress
(reduced water
availability)
ABA signaling
Stomatal closure
Diminished CO
2influxROS Production
Oxidative
Stress
Fig: Drought stress mechanism in plant 25

26. Effect of Drought on plant
1.Reduced seed germination & seedling development
2.Poor vegetative growth
3.Effect on Photosynthesis
4.Affect reproductive growth
5.Reduced plant height and leaf area
6.Severely reduce leaf weight
7.Reduce stomatalconductance
26

27. Drought effect on plant growth
Drought stress
(Reduced water
availability)
Impaired
mitosis
Limited cell
division
Obstructed cell
elongation
Loss of turgor
Diminished
growth
Fig. Mechanisms of growth reduction under drought stress
(Farooq et al., 2009)
27

28. Drought Effect on crop yield
Crop Growth stage Yield reduction
Barley Seed filling 49–57%
Maize Grain filling 79-81%
Maize Vegetative 25–60%
Maize Reproductive 63–87%
Rice Reproductive 24–84%
Chickpea Reproductive 45–69%
Pigeon pea Reproductive 40–55%
Soybean Reproductive 46–71%
Cowpea Reproductive 60–11%
Table. 1 Economic yield reduction by drought stress in
some representative field crops. (Farooq et al., 2009)
28

29. DroughtTolerance Mechanism
Includes..
Morphological,physiological and biochemical
modification in plant to cope with drought
Escape
Avoidance
Tolerance
29

30. DroughtTolerance Mechanism
Drought Escape
Complete crop life-cyclebefore soil water depletion
Form dormant seed before dry season commence
30

31. DroughtTolerance Mechanism
Drought avoidance
Maintain relative water balance despite low soil water
Deeper root growth in the soil
Stomatalcontrol of transpiration
Reduced surface by smaller and thicker leaves
Figure: Drought Avoidance : Reduced surface by
smaller and thicker leaves
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32. DroughtTolerance Mechanism
Drought tolerance
withstand water deficit with low tissue water potential
osmotic adjustment (a process which induces solute
accumulation in cell)
32

33. Plant stress tolerance protectants
Osmoregulators
Proline
Sucrose
Trehalose
Glycine betaine
Alaninebetaine
Prolinebetaine
Phyto-hormones
Auxin
Cytokinins
Abscisicacid
Ethylene
Gibberellins
Salicylic acid
Brassinosteroids
Jasmonates
Signaling molecules
H
2O
2
Nitric oxides
Antioxidants
Ascorbic acid
Glutathione
α-Tocopherol
Trace elements
Micro-nutrients
K, Ca, Mg, S,
Zn,Mo, Cu, etc.
Polyamines
Arginine
Ornithine
Spermidine
33

34. Conclusion & Recommendation

35. Conclusion
Globalwarmingincreasingdroughteffectoncrop
productivity
Tofeedtheincreasingpopulationstressesneedto
managetoensurefoodsecurity
Integrationofthemolecularapproaches,morpho-
physiologicalanalysis,andconventionalbreeding
strategieswillacceleratecultivatingdrought-resistant
plantsforagriculturalproduction.
35

36. Recommendation
Thecropplanthaveinvolvedcertainresistance
againstdroughtstress
Weshouldidentifythesemechanismandtraits
Needtodevelopmoredroughttolerant
varieties
36

37. Recommendation
Nonconventionalapproachesi.e.molecular
breedingcanplayasignificantroletobuilt
droughttolerance.
Genomicregionscarryingdroughttolerant
genecancontributeforabioticstress
tolerance.
37

38. Feed me to feed you…….
17
th
June
World day to combat desertification