Zusammenfassung der Ressource
POSTHARVEST BIOCHEMISTRY
- PLASMA MEMBRANE DEGRADATION ENZYMES
- Plasma
Membrane
- Role of plasma membrane during ripening
- 70% of total lipids in mammalian cells are
phospholipids - acidic phospholipid (minor but
have important role)
- Monoacidic - has phosphate but no headgroup
(carry one -ve charge that link the headgroup)
- Phosphatic acid: carry two -ve charges on the
phosphate( has phosphate but no headgroup)
- phosphatidylinositol(Ptdlns) : one -ve charged
phosphate linking an inostol headgroup to lipid
backbone
- Phospholipases
- Lipase enzyme that hydrolyses phospholipid molecules
- Phospholipase D
- a) Phospholipase D(PLD)
hydrolysed
phosphatidylcholine (PC)
into phosphatidic acid
(PA) b) Phospholipase
C(PLC) hydrolyses
phosphatidylinositl
diphosphate (PIP) into
diacylglycerol(DAG)
- Hexanal- strong PLD inhibitor
- PLD- membrane degrading
enzyme and initiates
phospholipid degradation
- ETHYLENE BIOSYNTHESIS INHIBITION
- 1-methylcyclopropene
(1-MCP)
- prevent ethylene action
- competitive inhibitor
- stronger affinity
than that of
ethylene
- irreversible
binding
- interferes
ethylene action
- delays
ethylene
biosynthesis
- Silver
thiosulfate
(STS)
- sodium
thioshulfate
+ silver
nitrate
- prolong the
vase life of cut
flower
- Ag+ ion blocks
ethylene
receptor site
- delays
senescence
- not
commercialized
due to
- complicated &
sensitive with
time of exposure
- issue with waste
management
- GENETIC ENGINEERING
- goal : add one/more new
traits that are not already
found in an organim
- genetically
modifed organism
- process of manually
adding new DNA to an
organism
- common techniques
used
- RNA interface (RNAi)
- gene overexpression
- anti-sense
- plant genetic engineering
- agrobacterium
- gene gun
- ETHYLENE BIOSYNTHESIS
- Pathway of biosynthesis
- Amino acid methionine convert to SAM (S-adenosylmethionine)
through SAM synthase
- SAM convert to ACC (1-aminocyclopropane-1-carboxylic acid)
through ACC synthase (ACS)
- ACC convert to ethylene through ACC oxidase (ACO)
- System in Ethylene Biosynthesis
- System I ethylene - Autoinhibition of ethylene synthesis.
- System II ethylene - Ethylene production increases due to autocatalytic regulation.
- ETHYLENE SIGNALLING