Stress physiology

by prachee rajput

1. Zhou YanZhou Yan
School of Life Science NENUSchool of Life Science NENU
Email:[email protected]:[email protected]

Stress PhysiologyStress Physiology

2. Plant PhysiologyPlant Physiology
Study the laws of plant life activities
Contains

◇
growth、development and morphogenesis

◇
material and energy transformation

◇
message transportation、signal transduction

3. Growth 、 development and
morphogenesis
the external appearance of plant life
Material and energy transformation
the basis for growth and development
Message transportation and signal
transduction
an important part of plant adaptation to the
environment

4. Stress ：Environmental damage to plants

◇
Biotic stress Abiotic stress
◇
Resistance ：The adaptability of plants to
adverse environment

◇
Stress avoidance Stress tolerance
◇
Stress Physiology：adversity makes an
impact on plant life activities, resistance of
plants to adversities
Plant Physiology in Environment StressPlant Physiology in Environment Stress
❤❤

5. Types Types oof f SStresstress
Biotic stress

◇
pathogen stress
Abiotic stress

◇
chilling stress

◇
freezing stress

◇
heat stress

◇
wet stress

◇
flood stress

◇
drought stress

◇
salt stress
temperatures stress
water stress
❤❤

6. Types Types oof f ResistanceResistance
stress avoidance
In the whole growth process does not meet with
the face of adversity
stress tolerance
Plant has a capacity of environmental stress
defense, and a variety of physiological processes
remain normal
❤❤

7. `
We all know one of the major reasons of
soil degradation ,land resources shortage
and ecological environment worse is land
salt-alkalization
Distribution
land surface:13.2×10
9
hectare
arable lands:7×10
9
hectare
cultivated lands:1.5×10
9
hectare
saline soil:0.34×10
9
hectare (23%)
alkaline soil: 0.56×10
9
hectare (37%)

8. salinization of soil
main cation: Na
+
,Ca
2+
,Mg
2+
, K
+
main anion: Cl
-
, SO
4
2-
, HCO
3
-
,CO
3
2-
, NO
3
-

main salt
NaCl, Na
2
SO
4
,Na
2
CO
3
, NaHCO
3

saline soil: NaCl, Na
2
SO
4
in soil
alkaline soil: Na
2
CO
3
, NaHCO
3
in soil
saline-alkaline soil

9. soybean
Salt stress is one of the major abiotic
stresses, depress plant growth and limit
crop production. Because of the
increasing salinization in soils, it has been
a great threat to crop productivity.
Soybean is one of the main crops in
China. It is important for agriculture
application and plant improvement that
we can understood the mechanism for its
response to salt stress.

10. Cultivated soybean
salt-sensitive but high yield breed
Wild soybean
salt-tolerant but low yield breed
Semi-wild soybean
has been selected between cultivated
soybean and wild soybean
A stable somatic descendent has been proved to
have inherited salinity-resistant traits

11. In order to address the growing problem
of utilizing salinized and alkalized lands,
halophytes have been studied as the
principal species for exploiting and
recovering saline-alkalinized soil.
An increasing number of reports on
distribution, exploitation, and
physiological mechanisms of saline
resistance of halophytes have been
published.

12. However, few studies have been done on
the alkaline resistance especially cultivated
soybean .
In fact, soil salinization and alkalization
frequently co-occur, and this has caused
severe problems in some areas.
In northeast China, alkalinized grassland
covers more than 70% of land area, and is
expanding.

13. salt stress
The main point I've been studying is the
effects of saline and alkaline stresses on
growth and ionic balance of cultivated
soybean seedlings
salt stress

◇
neutral salt stress

◇
alkaline salt stress
alkali-stress (A)
salt-stress (S)

14. My work
Growth

◇
germination rate

◇
root length

◇
water content

◇
fresh weight
ionic balance

◇
anion:

◇
cation:

15. Mechanism disordered
In these pictures we can find the variation
tendency of ion content of alkali-stress (A) is
more striking than salt-stress (S) except the
chlorine ion and sulfate ion.
the deleterious effects of salt stress result
primarily from osmotic stress and ion toxicities.
But, under alkaline stress, the salinized soil
contains HCO
3
-
and CO
3
2-
, in addition to osmotic
stress and ion toxicities, plants also have to deal
with stress of high pH.

16. Osmotic regulation
Ion regionalization
The mechanism for Plant AdaptationThe mechanism for Plant Adaptation
❤❤

17. Osmotic regulation

◇
reduce volume

◇
reduce water content

◇
absorb the inorganic ions in vacuole
Na
+
、K
+
、Ca
2+
、Mg
2+
、Cl
-
、SO
4
2-
、NO
3
-

◇
synthetic organics accumulate in the
cytoplasm
proline、soluble sugar、organic acid、betaine

18. Ion regionalization
As a result of intracellular ion balance, a
stable tissue pH is necessary for plants to
maintain normal metabolism. In a living
plant, as long as the plant can adapt to
the environment, the pH value in its
tissue should be stable regardless of how
the environmental pH value changes.

19. High-salt environments can break the ion
homeostasis of plant cells, destroy the ion
balance. Under salt stress, it is necessary
to osmotically adjust and re-establish the
ion balance in cells for plants living.
Plants regulate the intracellular pH to
keep ion balance by ion regionalization
❤❤

20. InterestingInteresting

ⅰ
Membrane permeability

ⅱ
Permeability regulator content

ⅲ
MDA content

ⅳ
SOD、POD、CAT activity

ⅴ
The degree of succulent plant tissue

ⅵ
Plant tissue water potential
ⅶ Water content

ⅷ
Osmoregulation material
ⅸ Ion content