ABA in plant abiotic stress mitigation

Slide describe the role of ABA in plant abiotic stress mitigation. Slide include role of ABA in cold stress, drought stress and salt stress mitigation along with role of ABA in stomatal regulation.

1. JAI NARAIN VYAS
UNIVERSITY
Department of botany
Seminar: Role of ABA in mitigation of stress
By: Laxmi Choudhary

2. Content
•Introduction
•ABA biosynthesis
•ABA in stress tolerance
•Drought stress
•Salt stress
•cold Tolerance
•Stomata closer
•References

3. Introduction
What is ABA?
• Abscisic Acid (ABA) is a plant hormone that plays a
crucial role in managing plant stress responses,
particularly in drought conditions.
• ABA is involved in various physiological processes
including stomatal closure, seed dormancy, and root
growth.
Importance of Studying ABA in Drought Stress
• Drought Stress in Plants:
• Drought stress is a major limiting factor for crop
productivity globally.
• Understanding the mechanisms of drought
tolerance is essential for developing resilient crops.
Role of ABA in Stress Mitigation:
• ABA helps plants cope with water scarcity by
regulating water loss through stomatal closure.
• It activates the expression of stress-responsive
genes that enhance plant survival under drought
conditions.

4. ABA biosynthesis:
ABAis derived
from the
modification and
cleavage of
Zeaxanthins.
Caretenioid (40
carbon compund)
found abundant
in chloroplast is
precursor of ABA.
NCED- 9-cis-epoxy- careteniodioxygenas
ZEP- zea-xanthin epoxydase
AAO- ABA aldehyde oxidase
MCSU- Molybedium co-factor sulfade

6. 1. Drought stress
In normal condition, ABA do
not synthesized, so
PP2C( phosphate protien 2c) is
activated and binds to
SnRk2s(SNF1 related protien
kinase 2)
And stress related respinse is
not assisted.
In stress conditions ABA is
biosynthesized and attach to
PYL( pyrabaclin resistance like
gene) and PP2C and so SnRK2s
get phosphate and trasfer this
signal to AREB (ABA responsive
elements and other drought
resistant genes that trigger
guard cell chennel activation
and stomata closer

7. 2. Salt stress
Same way LEA inducible
by ABA works:
LEA binds to water and
result in decrease of
water hence due to
osmotic differences.

8. 3. Cold stress
CBF- c protien
binding factor.
Putrescine is an
polyamine that help
in tolerating many
kinds of abiotic
stress including
cold.
Cold tolerance is by
synthesis of CSP
(cold shock protein)
and anti freezing
protien(AFP)

9. ABA regulated stomatal closer
ABA attached to receptor activates
PLD( phospho-lipases D) which
activates PLC ( phospho-lipases C)
via heterotrimeric-G protien and
S1P.
PLC activates K+ outflux chennel
which depolarise membrane and
InsP3 (Inositol trisphosphate
receptor)
Which activates vacuole Ca2+
chennel that outflux calcium in
cytoplasm, the calcium level also
inceases by Ca2+influx chennel on
guard cells via ROS.
Calcium level inhibit H+pump, K+
influxwghich lead to
depolarisation and water loss
hence guad cell become flassid
and stomata close.

10. References
•
https://www.researchgate.net/figure/Pathway-and-
Regulation-of-ABA-Biosynthesis_fig6_11328558
•https://www.researchgate.net/figure/Role-of-abscis
ic-acid-ABA-in-plant-development-and-stress-respo
nse-Abscisic-acid_fig2_336110576
•https://www.mdpi.com/1422-0067/21/13/4607
•https://www.researchgate.net/figure/A-Model-of-th
e-Regulation-of-ABA-Signaling-by-AREB1_fig7_7484
767
•https://phys.org/news/2022-08-pa-aba-cbf-pathwa
ys-synergistically.html

11. Thank you