different stress effects on the plant and plant's adaption to the stress to manage it,all these discussed in detail in this presentation, what happens to the plants when stress happen is in presentation in details

2. Crop adaptation to
Climate Change

3. Introduction
 Throughout the history, farmers have adopted new crop
varieties and adjusted their practices in accordance with
changes in the environment.
 Climatic changes affect the crops yield and quality.
 Rapidly changing climate is critical to ensuring security of
food supply.

5. Definition of Adaptation
 The adjustment or changes in behavior, physiology,
and structure of an organism to become more suited to
an environment.
 It is derived from Latin word adaptare which means
to fit
 Plants have adaptations to help them live and grow in
different areas

6. How will climatic change affect cropping
system?
 Climate change will increase both abiotic and biotic stresses.
 Abiotic stress: Drought, temperature, concentration of
atmospheric gasses CO2, O3.
 Biotic stresses: insect, pest and crop diseases.

7. Temperature
 It influences the growth and development of all crops
throughout the growing season.
 Higher temperature reduce the cereal and grain yield.
 Less severe winter allow disease and pests to survive
and reduce yield during next cropping season.

9. Biotic stresses
 It include weeds, insects, viruses, bacteria etc.
 Temperature is most important factor to determine
how insects effect crop production and yield.
 Viral, fungal and bacterial pathogens respond greatly
to temperature as well as humidity and rainfall.
 These factors cause the loss in yield.

10. How we can adopt crop and cropping system to climate
change?
 Approaches:
1. Improving existing crop cultivars and developing new
crops.
2. Devising new cropping systems and methods for
managing crops in the field.

11. Drought
Drought is a situation that lowers plant water potential
and turgor to the extent that plants face difficulties in
executing normal physiological functions.
25% of world agricultural land area now affected by
water stress.

12. Effects of drought

13. Effects of drought
Nutrient relation:
Drought generally results in limited total nutrients uptake and
diminished their tissue concentration in crop plant.
An important effect of drought stress is the acquisition of
nutrients by the roots and their transport to the shoot.

15.  Photosynthesis:
Drought induces stomatal closure which limits co2 uptake by
leaves.
This restricted co2 availability lead to decrease in
photosynthesis.
Another important effect is the loss of balance between the
production of reactive oxygen species and anti-oxidant defense,
causing accumulation of ROS which induces oxidative damage.

16. Respiration:
Drought tolerance is a cost intensive phenomenon as a
considerable amount of energy is spent to cope it.
Roots are the major consumer of the carbon fixed in
photosynthesis and use it for growth and maintenance

17. Plant responses to drought

19. Physiological response
1. Loss of turgidity
2. Reduced leaf water potential
3. Decrease in stomatal conductance to co2
4. Decline in net photosynthesis
5. Reduced growth rate

20. Biochemical responses
1. Decreased efficiency of rubisco
2. Increase in antioxidant enzymes like SOD, CAT, GR etc.
3. Reduced ROS accumulation

21. Molecular responses
1. Stress responsive gene expression
2. Synthesis of specific protein like Dehydrins
3. Drought stress tolerance

22. Drought resistance
It involves following mechanism
1. Morphological mechanism
2. Physiological mechanism
3. Molecular mechanism

24. Morphological mechanism
Escape:
Escape from drought is attained through a shortened life cycle or growing
season allowing plant to reproduce before the environment become dry.
 Avoidance:
It consists of mechanism that reduce water loss from plants due to stomatal
control of transpiration and maintain water uptake through a deep, thick
and extensive root system.

25.  Phenotypic flexibility:
1. Plants generally cut down the number and area of leaves in response to
drought stress just to cut down the water budget at the cost of yield loss.
2. Example: plants bearing small leaves are typical of xeric environment.

26. Physiological mechanism
 Cell and tissue water conservation:
Osmotic adjustment allows the cells to decrease osmotic potential and
increases the ingredient for water influx and maintenance of turgor
 Antioxidant defense:
The ROS in plants are removed by a variety of antioxidants. The
antioxidant defense system in plants constitutes both enzymatic and non-
enzymatic components.

27. Molecular mechanism
Aquaporins:
Aquaporins are the proteins that are embedded in the cell membrane and
regulate the flow of water. It is present abundantly in plasma membrane.
 Stress proteins:
Synthesis of stress proteins is a ubiquitous response to cope with prevailing
stressful conditions including water deficit.

29. Develop new crops
 It will play an important role in maintaining and
increasing agricultural production.
 Scientist crossing wild perennial relatives of crops with
their annual domesticated counter part to develop
perennial grain crop.
 Domestication and Breeding of new crops is a long term
solution.
 Domestication began 5000-12000 years ago.

30. Integrate beneficial traits into existing crop
 Adopt selective crops that exhibit desirable traits that
allow crops to achieve optimum yield and withstand
stresses i.e. drought, heat water logging etc.
 Success and speed of breeding depends upon the access
optimal germplasm and quality information about
germplasm material.
 Use of these resources quickly identify adaptive traits
represented by gene or group of gene which contribute to
stress resistance.