The document summarizes plant response mechanisms to abiotic stress. It discusses various types of abiotic stresses including waterlogging, drought, salinity, oxidative stress, temperature extremes, and nutrient deficiencies. It describes how plants avoid or tolerate stresses through mechanisms like osmotic adjustment, antioxidant production, and heat shock protein expression. Gene expression changes allow plants to acclimate to stresses and regulate processes like ion homeostasis and phospholipid signaling. Certain solutes and compounds, such as pinitol and mannitol, help plants respond to salt and oxidative stresses.

1. Seminar -I
PLANT RESPONSE TO ABIOTIC
STRESS
Deepak Barsaiya Gupta
M.Sc(Ag), 3rd semester
Department of Ag.
Biochemistry
Seminar leader & Chairman
Prof. A Chakravorty
Prof. Sri Kumar Pal
Department of Agriculture
biochemistry
Bidhan Chandra Krishi Vishwavidyalaya
Department of Agriculture Biochemistry
Faculty of Agriculture,
Mohanpur-741252, Nadia, West Bengal, India.
Course No.- ABC-591

2. INTRODUCTION
• Plant stress is defined as any change in
environmental conditions that adversely
affect development, growth and
productivity.
• Two types of stress:
– Abiotic stress
– Biotic stress

3. ABIOTIC STRESS
Abiotic stress arising from an excess or deficit
in the physical or chemical environment.
• Water logging
• Drought
• Salinity stress
• Oxidative stress
• High or low temperature
• Inadequate mineral nutrients in the soil

4. Source: Biochemistry & molecular biology of plants 2007,22 1158-1159.

5. STRESS RESISTANCE MECHANISMS
Mechanism that permit stress survival are termed
stress resistance mechanisms.
Stress resistance mechanisms can be grouped into
three categories
• Avoidance mechanisms - which prevent exposure to stress.
• Tolerance mechanisms - which permit the plant to withstand
the stress.
• Acclimation - Alter the physiology in response
stress (drew et al. 1997).

6. Changes in gene expression to
stress
• A stress response is initiated when plants recognizes stress at
the cellular level.
• Stress recognition activates signal transduction pathways that
transmit information within the individual cell and throughout
the plant.
• Changes in gene expression may modify growth and
development and even influence reproductive capabilities.

7. Regulation of ion (e.g., Na+ and K+) homeostasis by the sos
(Salt Overly Sensitive) pathway
Source :-Na+ uptake by plant cells 1999;29:75–112.

8. PHOSPHOLIPID SIGNALING
Source : Inositol phosphate and cell signaling. Nature. 1989;341:197–205.

9. GENE EXPRESSION RESULTS IN
• Increase amounts of specific mRNA
• Enhance translation
• Stabilize proteins
• Altered protein activity

10. Source: Biochemistry & molecular biology of plants 2007,22 1158-1159.

11. WATER STRESS
Water related stresses could affect plants if the
environment contains insufficient water to meet
basic needs.
Water logging
Drought condition

12. Water logging cause:
• hypoxia i.e. shortage of oxygen
• anoxia i.e. total lack of oxygen
Which causes the reduced growth, inhibits the
metabolic processes and finally reduces the yield of
plant.
When soil is completely saturated with water is in
general referred to the water logging.

13. Source: Biochemistry & molecular biology of plants 2007,22 1164-1165.
A prolonged period of abnormally low rainfall, leading to a
shortage of water.

14. SOLUTES THAT CONTRIBUTES TO
OSMOTIC ADJUSTMENTS

15. SALT STRESS
• Plant salt stress is a condition where excessive
salts in soil solution cause inhibition of plant growth
or plant death.
• salt stress Osmotic forces exerted on plants when
they are growing in a salt marsh or under other
excessively saline conditions.
• Sodium chloride (NaCl):
NaCl ambiguously found in nature 
• deserts, coastal areas.

16. Source: Protein Contribution to Plant Salinity Response and Tolerance Acquisition, 2013

17. PINITOL RESPONSE TO SALT
STRESS
source: Biochemistry & molecular biology of plants 2007,22 1168-1169.

18. MANNITOL RESPONSE TO
PLANT STRESS
Plant inhibit sucrose synthesis and promotes accumulation of
manitol in salt stress condition.
Source: Biochemistry & molecular biology of plants 2007,22 1168-1169.

19. OXIDATIVE STRESS
• Oxidative stress is a complex chemical and
physiological phenomenon that accompanies
virtually all biotic and abiotic stresses in higher
plants and develops as a result of overproduction
and accumulation of reactive oxygen species (ROS).
• Oxidative stress result from conditions promoting
the formation of active oxygen species that damage
or kill cells.

20. FACTOR CAUSED OXIDATIVE
STRESS

21. HEAT STRESS
• Heat stress is often defined as a period in which temperatures are
hot enough for a sufficient period of time to cause irreversible
damage to plant function or development. Plants can be
damaged by either high day or high night temperatures and by
either high air or soil temperatures.

22. HIGH TEMPERATURE
STRESS
• Heat stress is a decrease in the synthesis of normal
proteins, accompanied by an accelerated transcription
band translation of new proteins known as heat shock
proteins (HSPs)
• Heat stress has been shown to cause problems in
mitochondrial functions and can result
in oxidative damage. Activators of heat stress receptors
and defenses are thought to be related to ROS.

23. NUTRIENT DEFICIENCY
A lack of one or more essential elements needed by plants
for optimum growth lead to plant stress.

24. NUTRIENT DEFICIENCY SYMPTOMS

25. Other Factors
• Chemical Injury
• Mechanical Injury
• Transplant Shock
• Chilling injury

26. Conclusion
• None of the mechanisms by which higher plants precive
abiotic stresses has been elucidated. Progress in this
crucial area will advance substantially our knowledge of
stress initiated signal transduction events stress related
signal propagated by several different agents in some
cases, these signal transduction events involve at least
one of the five best harmones ABA, Auxin, cytokinins
ethylene, and gibberellins. However perhaps signaling
molecules not yet identified also participate in
controlling plant response to the environment.

27. Thank
You