Jasmonic_Acid an overview on its role and application

plant grown in open field

1. JAVED IQBAL
1
st
Semester
PhD Horticulture
Plant Growth Regulators
MNS-University of Agriculture, Multan

2. Discovery of JA
JA’s are derivatives of lipid-based hormone signals that
regulates
Growth & development, Photosynthesis
Differentiation i.e. reproductive development
Plant defense against biotic & abiotic stresses
Some JA releases asvolatile organic compounds(VOCs) for
communication between plants in anticipation of mutual
dangers
Isolatedmethyl jasmonatefrom jasmine oil derived
fromJasminum grandiflorumled to the discovery of the
molecular structure of jasmonates and their name

3. Biosynthesis of Jasmonates
Jasmonates(JA)areanoxylipin,i.e.aderivativeofoxygenatedfatty
acid
Linolenicacidinchloroplastmembranes
Conversion12-oxo-phytodienoicacid(OPDA)
Reductionandthreeroundsofoxidationtoform(+)-7-iso-JA,jasmonic
acid
OnlytheconversionoflinolenicacidtoOPDAoccursin
thechloroplast;allsubsequentreactionsoccurintheperoxisome
JAitselfcanbefurthermetabolizedintoactiveorinactivederivatives.
MethylJA(MeJA)isavolatilecompoundthatispotentiallyresponsible
forinterplantcommunication
JAconjugatedwithaminoacidisoleucine(Ile)resultsinJA-Ile,which
iscurrentlytheonlyknownJAderivativeneededforJAsignaling.
JAundergoesdecarboxylationtogivecis-jasmone

4. JA biosynthesis
Jasmonicacid(JA)isanorganiccompoundfoundin
severalplants
Moleculeisamemberofthejasmonateclassofplant
hormones
Biosynthesizedfrom linolenicacidby
theoctadecanoidpathwayinchloroplasts.

5. Function
Defenseagainstwounding
Insects
Microbialpathogens
JAactssynergisticallywiththestresshormone
ethylene

6. α-Linolenic Acid
(ALA)isann−3fattyacid.Itisoneoftwoessential
fattyacids(theotherbeinglinoleicacid),socalled
becausetheyarenecessaryforhealthandcan,tbe
producedwithinthehumanbody.Theymustbe
acquiredthroughdiet.
ALAisanomega-3fattyacidfoundinseeds
(chia,flaxseed,hemp,seealsotablebelow),nuts
(notablywalnuts),andmanycommonvegetableoils

7. Derivatives
Jasmonicacidisalsoconvertedtoavarietyof
derivativesincludingtheestermethyljasmonate
Itisalsobeconjugatedtoaminoacidsinsome
biologicalcontexts
Decarboxylationaffordstherelatedfragrancejasmone.

8. Function as germination…?
TherewasareciprocalrelationshipbetweenMeJA
concentrationsappliedandseedgerminationand
radiclegrowth(Norastehnia,2003)
Alphasamylaseactivityisdecreasedinthepresenceof
MeJM
ReductioninEthyleneproduction,whichisnecessary
forseedgermination

10. RESEARCHABLE ISSUES
Vivipary…….
Pre-harvest seed sprouting
Wheat
Rice
Barley
Oat
maize
China, Japan, Florida efforts to inhibit the pre-harvest
seed sprouting in cereals by exogenous application of
MeJM