jasmonic acid is a plant immune hormone whicch are imortant for plant defence mechanism and development..its have important role in root growth inhibition,tuber formation,trichome formation ,senescence,flower developmentand increasing arbasculer mycorrhizal activity in root plants,recently it has been reported in various development in rice crop like spikelet development etc.....in defence its play a crucial role against insect and pathogen resistance.Recent insights into the JAs mediated plant defense cascade and better knowledge of key regulation of plant growth and development processes will help us to design future crops with increased biotic stress resistance and better adaptability under changing climate

1. Role of Jasmonic Acid in Plant
Development and Defense
Response
1
Speaker : Rakesh Sharma
ID. 48030
GOVIND BALLABH PANT UNIVERSITY OF
AGRICULTUREE&TECHNOLOGY,PANTNAGAR,INDIA
DEPARTMENT OF PLANT PHYSIOLOGY

2. INTRODUCTION
• Novel plant immune
hormone derived from
α- linolenic acid.
• Methyl Jasmonate was
first time isolated from
the essential oil of
Jasminum grandiflorum.
• Ubiquitous in plant
kingdom and also
produced by certain
fungi (Lasiodiplodia
theobromae).
2

3. Figure 1: Jasmonic acid responses (a) Chewing insects (b) Necrotropic pathogens
3

4. Figure 2. Biosynthesis of jasmonic acid (JA) and (+)-7-iso-JA-L-
isoleucine. 4

5. Wang and Wu, 2013
5

6. Mutant
Biochemical
Significance
Role
Expression of
JAs responsive
genes
Effects
coi
Coronatine
Insensitive
JA Signaling Reduced
Sensitivity to insect and
necrotrophic pathogens
increased
fad
Defective Fatty
Acid Desaturase
JA
Biosynthetic
Reduced
Sensitivity to insect and
necrotrophic pathogens
increased
cev
Constitutive
Expression of
VSP
JA Signaling Increased
Increased sensitivity to
biographic pathogens
jar JA Resistant JA Signaling Reduced
Increased sensitivity to
necrotrophic pathogens
opr
Defective OPDA
Reductase
JA
Biosynthetic
Reduced
Increased sensitivity to
insects
jin JA Insensitive JA Signaling Reduced
Increased sensitivity to
pathogens
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Jasmonic acid mutant

7. Jasmonic
Acid
Perception
7

8. Wasternack and Hause, 2013 8
Figure3: Jasmonic acid perception via the COI1–JAZ co-receptor complex –
mechanisms in JA-induced gene expression.

9. Role of Jasmonic Acid
in plant defense and
development
9

10. Fig. 4: Schematic overview of the effect of leaf wounding on the interaction of
Medicago truncatula with root-colonizing microorganisms. The arbuscular mycorrhiza
(AM) with G. intraradices was found to be promoted by repeated leaf wounding,
whereas the colonization with the pathogenic oomycete Aphanomyces euteiches was
reduced. Both effects might be triggered by the increased levels of jasmonic acid (JA).
Wasternack and Hause 2013.
10

11. Taiz and Zeiger 3rd ed.
11
Figure 5: Schematic presentation of mechanism of JA in
response to Insect attack

12. Figure 6: JA induces root growth inhibition by stimulating auxin biosynthesis via anthranilate
synthase α1(ASA1) and inhibiting the expression of genes encoding the TFs PLETHORA1 (PLT1)
and PLT2, which ensure the maintenance and activity of stem cells in the root. Root growth
inhibition by 100 mM methyl jasmonate in wild-type (Col) and the JA-insensitive mutant coi1-16
Wasternack and Hause 2013
Root Growth Inhibition
12

13. Figure 7: In tuber formation, jasmonates [JA, tuberonic acid (TA) and TA
glucoside (TAG)] might act directly after their rise following activity of
LIPOXYGENASE 1 (LOX1).
Wasternack and Hause 2013.
TUBER FORMATION
13

14. Wasternack and Hause 2013.
TRICHOME FORMATION
14

15. Wasternack and Hause 2013.
Flower Development
Fig.8 Flower development in tomato. Flower buds, open flowers and
mature fruits from wild type and the JA-insensitive mutant jai1. Note
the seedless fruits of jai1.
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16. Wasternack and Hause 2013. 16
Senescence

17. Diverse functions of jasmonates in rice.
Liu et al., 2015.
17

18. 18

19. Interaction of
Jasmonic Acid with
other hormone
19

20. Schematic representation of the series of events leading to defense activation.
When plants are attacked by pathogens or herbivores, different types of
receptors, including pattern-recognition receptors (PRRs) and resistance (R)
proteins, recognize non-self (or damaged-self) molecular patterns or signals,
including pathogen-, damage-, and herbivore-associated molecular patterns
(PAMPs, DAMPs, and HAMPS, respectively), as well as effector molecules.
Ballare, 2014 20

21. Fig.9 Schematic overview of the common defense system activated by JA and SA in rice.
Ballare, 201421

22. Wasternack and Hause 2013
The cross-talk between jasmonate (JA), ethylene (ET) and abscisic acid (ABA) triggered in response to
herbivorous insects and necrotrophic pathogens. Attack by herbivorous insects induces JA- and ABA-
dependent signalling pathways, whereas infections by necrotrophic pathogens induce JA- and ET-dependent
signalling pathways. Both branches are antagonistically regulated. Solid lines, known interactions; dashed lines,
hypothetical interactions; green arrows, positive effects; blue inhibition lines, negative effects. Compounds are
given in rectangles, transcriptional regulators in circles, regulated genes in purple. ERF1, ethylene response
factor 1; ORA59, octadecanoid-responsive Arabidopsis AP2/ERF-domain protein 59; PYL4, PYR1-like protein 4
(ABA receptor)
22

23. Figure: Model Describing that DELLAs Modulate JA Signaling via
Competitive Binding to JAZs.
Hou et al., 2010 23

24. CONCLUSION
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25. 25
Jasmonic acid & sallicylic acid pathway can be effectively
use in biotic &abiotic stress resistance development.
 Jasmonic acid & sallicylic acid cascades helps in
understanding specific host pathogen interaction strategy .
It can be used in enhancing nutrient uptake under stress
condition
It can help in proper growth and development activating
factor.

26. Future perspective
• Plants lack an immune system like in animals but posses mechanism
that recognize potential pathogens and initiate defense responses.
During their biochemical evolution, the plants are devised with
certain magic molecules of defense like JA.
• Recent insights into the JAs mediated plant defense cascade and
better knowledge of key regulation of plant growth and
development processes will help us to design future crops with
increased biotic stress resistance and better adaptability under
changing climate.
• In future, there is need to obtain higher crop yields to fulfill demand
of increasing population. It might be achieved by increasing the
pathogen/insect resistance by manipulating the expression of the
key genes involved in JA biosynthesis and signaling cascades.
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27. THANK YOU
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