Hormones Flashcards
What’s the name of the ethylene biosynthetic pathway? What are the intermediate
Yang Cycle
ACC
What inhibits ethylene synthesis
AOA, AVG
CO2, temps greater than 35C
What promotes ethylene synthesis
Fruit ripening, flower senescence, IAA, wounding, ripening,
What enyzmes are involved with the Yang cycle
ACC synthase, ACC oxidase
What does ACC stand for
1-aminocyclopropane- 1-carboxylic acid (ACC)
What is veraison
Onset of ripening in grapevine
What is the difference between climacteric fruits and non-climacteric fruit
Climacteric fruits sensitively respond to the externally applied ethylene (this is due to autocatalytic effect)
Non-climateric fruits do not show this and are difficult to control ripening
Describe the climacteric fruit ripening graph
Cliamacteric fruits show a steady respiration rise before the ripening and then shows a spike of ethylene production immediately before the respiratory rise
What is the cotyledon
An embryonic leaf of seed bearing plants
What is the hypocotyl
The part of the stem of an embryo plant beneath the cotyledon
What is etiolation
process in flowering plants grown in partial or complete absence of light
What is abscission
shedding of various parts of an organism, such as a plant dropping a leaf, fruit, flower or seed
Where is ABA synthesized
Chloroplast
What are the roles of brassinolides
Cell elongation, skotomorphogenesis, germination, leaf senenscence
What is fasciation
abnormal growth of plant tissues. An abnormal occurrence of apical meristems facilitate the cell growth perpendicularly to the direction of main stem (or root)
Bacteria and fungi can produce some cytokinin-like compounds often cause fasciation in plants
What is parthenocarpy
Fruit develops without fertilization
What does A.tumefaciens do
It can infect wounded tissues and alter plant cells to form tumour-like tissue called gall.
Infected plant cells continue to divide throughout the life-cycle of the plants
High auxin lead to ___ growth, high cytokinin leads to ___ growth. Intermediate levels leaf to ___ formation.
Auxin -> root
Cytokinin -> shoot
Intermediate levels lead to callus formation
What is stenospermocarpy
Pollination triggers fruit development but the ovules or embryos abort without producing mature seeds
What is kinase do and what does phosphatase do
Kinase -> adds phosphates
Phosphatase -> removes phosphates
Prokaryotic two component system are composed of ___ + ___.
Sensor protein and response protein
Which domain is phosphorylated in the two-component system
The transmitter domain of the sensor protein and the receiver domain of the response regulator protein
What is lodging
It is the major cause of crop loss
Lodging is a bending of stems to the ground due to the weight of water collecting on the ripened heads. Harvesting becomes difficult
How is lodging overcome
By shorter inter-node
or shorter and thicker stems
A number of chemical inhibitors that block the biosynthesis of GA have been developed and used for greenhouse and for wheat
Where is brassinosteroid synthesized
Cytosol
ABA is dormancy ___
GA is dormancy _____.
Inducing
breaking
Which isoprenoid are synthesized in the chloroplast
C10, C20 and C40
Which isoprenoid are synthesized in the cytosol?
C15 and C30
Where is zeatin synthesized and what type of hormone is it?
Chloroplast
It is a dominance cytokinin in plant
Which amino acids is octopine derived from
Arginine and alanine
What is the full name for the E1 enzyme? And for the E2 enzyme?
E1 is the ubiquitin-activation enzyme
E2 is the ubiquitin conjugation enzyme
What are the two components that are similar to cytokinin in structure?
Kinetin (herring sperm)
Zeatin (immature maize endosperm)
Both have an adenine derivative
