PGRs Flashcards
Indole compounds of PGRs
indole-3-acetic acid, IAA
Adenine derivative of PGR
N6 - furfurylamino purine, kinetin
derivatives of carotenoids in PGR
abscisic acid, ABA
derivative of terpenes in PGR
gibberellic acid, GA3
derivative of gas PGR
ethylene, C2H4
Protein bond?
peptide bonds
Polysaccharide bond
Glycosidic bond
The bond between the phosphate and hydroxyl group of
sugar
Ester Bond
Bond between esters on either side
phosphodiester bond
PGR Promoter
auxin, gibberellin, cytokinin
PGR Inhibitor
abscisic acid
Gaseous PGR
Ethylene, C2H4
PGR which is both promoter and inhibitor
Ethylene
Functions of PGR promoter
tropic growth,
pattern, fruit and seed formtion
flowering,
cell division and cell enlargement
____ help to initiate rooting in stem cuttings in plant propagation
Auxin
____ promote flowering in pineapples.
Auxin
____ help to prevent fruit and leaf drop at early stages
Auxin
____ help promote the
abscission of older mature leaves and fruits
Auxin
Removal of shoot tips (decapitation) usually results in the growth of lateral
buds. Why?
because it eliminates the source of auxin, a plant hormone that normally inhibits lateral bud growth through a phenomenon called apical dominance
____ induces parthenocarpy in tomatoes
Auxin
_____ are widely used as herbicides.
2, 4-D, widely used to kill dicotyledonous
weeds but does not affect mature
monocotyledonous plants.
Auxin
____ is used to prepare
weed-free lawns by gardeners
Auxin
____ controls xylem differentiation and helps in cell
division
Auxin
____ causes increase in length of axis
Gibberellins
____ is used to increase the length of grapes stalks
Gibberellins
____ cause fruits like apple to elongate and improve its shape
Gibberellins
____ delay senescence
Gibberellins
the fruits can be left on the tree longer so as to extend
the market period due to ____
Gibberellins
____ is used to speed up the malting process in brewing
industry.
GA3
Spraying
sugarcane crop with ____ increases the length of the stem
gibberellins
_____ increases sugarcane yield by ____
gibberellins; 20 tonnes per acre
Spraying juvenile conifers with ____ hastens the maturity period, thus
leading to _____
Gibberellins; early seed production
What is bolting?
(internode elongation just prior to flowering)
____ promotes bolting in beet, cabbages and many plants with rosette habit
Gibberellins
__________ help overcome the apical dominance
Cytokinins
____ helps delay leaf senescence
Cytokinins
____ promotes nutrient mobilisation
Cytokinins
____ helps to produce new leaves, chloroplasts in leaves, lateral shoot growth and adventitious shoot
formation.
cytokinins
____ promotes
senescence and abscission of plant organs especially of leaves and
flowers
Ethylene
____ is highly effective in fruit ripening by ___.
Ethylene; enhancing the respiration rate during ripening of the fruits
What is respiratory climactic?
Ethylene is highly effective in fruit ripening. It enhances the
respiration rate during ripening of the fruits. This rise in rate of
respiration is called respiratory climactic
____ breaks seed and bud dormancy
Ethylene
____ initiates germination in
peanut seeds
Ethylene
___ sprouting of potato tubers
Ethylene
____ promotes rapid
internode/petiole elongation in deep water rice plants
Ethylene
____ helps leaves/
upper parts of deep water rice plant shoot to remain above water
Ethylene
___ also promotes
root growth and root hair formation
Ethylene
___ is used to initiate flowering and for synchronising fruit-set
in pineapples
Ethylene
___ helps plants increase their absorption surface
Ethylene
____ induces flowering in mango
Ethylene
one of the most widely used PGR in
agriculture
Ethylene
The most widely used compound as source of ethylene is
Ethephon
___ hastens fruit ripening in tomatoes and apples
Ethephon
____ accelerates abscission
in flowers and fruits (thinning of cotton, cherry, walnut)
Ethephon
____ promotes female
flowers in cucumbers thereby increasing the yield
Ethephon
____ inhibits seed germination
ABA
____ stimulates the closure of stomata
ABA
____ increases the tolerance of plants to various kinds of stresses.
ABA
____ called stressed hormone
ABA
____ helps seeds to withstand desiccation
ABA
___ acts as an antagonist
to GAs
ABA
Plants retain capacity for unlimited growth throughout their life due to
Presence of meristems at certain locations of their body
____ and ___ are responsible for elongation of plant
shoot and root apical meristem
____, ____, and ____ are responsible for girth of a plant
Lateral meristem, Vascular cambium and cork cambium
Region of meristematic activity (5)
Cells are small, rich with dense protoplasm, large nuclei and thin primary cell walls with abundant plasmodesmatal connections
Region of elongation
Cells undergo rapid elongation and enlargement. Increased vacuolation and new cell wall deposition are characteristics of cells in this phase
Region of maturation
Maximum size in terms of wall thickening and protoplasmic modification
What is stem?
It is the ascending part of the axis bearing branches, leaves, flowers, and fruits.
Stem develops from the ___ of the ____ of a ___
plumule; embryo; germinating seed
What is node?
Region of stems where leaves are born
Portion between two nodes is called?
Internode
What is a leaf?
The leaf is a lateral, generally flattened structure borne on the stem
Leaves originate from ___ and are arranged in an ____ order
shoot apical meristems; acropetal
Function of petiole
Helps hold leaf blade to light, and allow them to flutter in the wind, thereby cooling leaf and bringing fresh air to its surface
A bud is present
in the ____ in both simple and compound
leaves, but not in the _____ of the compound
leaf.
axil of petiole; axil of leaflets
What is a flower?
A flower is a modified shoot wherein the shoot apical meristem changes to floral meristem
In racemose inflorescence, the flowers are borne ____ in an ____
succession
laterally; acropetal
In cymose type of inflorescence, The
flowers are borne in a ____ order
basipetal
