Transcript THE DISCOVERY OF ETHYLENE

THE DISCOVERY OF ETHYLENE - THE GASEOUS
HORMONE
 Ethylene was first discovered around 1901 by Neljubov in
Russia in relation to the “triple response” of pea seedlings.
 In 1910 Cousins showed that “emanations” from oranges
caused premature ripening of bananas.
 In 1934, R. Gane showed that ethylene was produced by
ripening apples.
CONTROL
ETHYLENE
EFFECT OF ETHYLENE ON FRUIT RIPENING
CONTROL
ETHYLENE
Changes during
the ripening of
apples.
Ethylene promotes
ripening and is
produced during
ripening.
Ethylene is
autocatalytic
The respiratory
climacteric of bananas
is associated with a
spike of ethylene
production.
GUS LOCALIZATION OF ACC OXIDASE IN TOMATO FRUIT
(Tissue Print Technique)
EFFECT OF SILVER THIOSULFATE ON CARNATION
SENESCENCE
Ag+ blocks
endogenous
ethylene action
Endogenous
ethylene activity
not inhibited
ETHYLENE STIMULATES ROOT HAIR FORMATION
CONTROL
ETHYLENE
ETHYLENE-INDUCED LEAF EPINASTY - TOMATO
CONTROL
ETHYLENE
CHANGES IN MICROTUBULE ANGLE IN RESPONSE TO
WOUNDING (ETHYLENE) IN PEA STEM
EFFECT OF ETHYLENE ON LEAF ABSCISSION
CONTROL
ETHYLENE
(from apple)
TRIPLE RESPONSE IN ARABIDOPSIS
Hypocotyl hook
maintenance
Screen for the etr1 mutant of Arabidopsis
ethylene
etr1 mutant
Five Related Ethylene Receptor Proteins
1.Similar to the two component system histidine
kinases of bacteria.
2. Located on the ER, not the plasma membrane
Unbound ethylene receptors act to block the ethylene
response pathway.
Screen for Arabidopsis Mutants with a Constitutive
Ethylene Response
air
ctr mutant