Plant Growth Regulators Video Lecture | Biology Class 11 - NEET

plant growth hormones there are five
major types of phyto hormones or plant
growth substances which are involved in
the control and coordination in plants
organs
Gilliland's cytokinins axis ik acid
ethene ethylene auxins are synthesized
at the shoot tip and help the cells to
grow longer when light is coming from
one side of the plant toxin diffuses
towards the shady side of the shoot this
concentration of aux-in stimulates the
cells to grow longer on the side of the
shoot which is away from light thus the
plant appears to bend towards light
give villains these promotes cell
enlargement and cell differentiation in
plants in the presence of auxins these
also promote growth in stems and fruits
these also induce partha no carpi that
is the formation of seedless roots
without fertilization in many plants
cytokinins these remote cell division
and occur in greater concentration in
areas of rapid cell division such as in
fruits and seeds they help in breaking
the dormancy in seeds and buds
these delay the aging in leaves and also
promote the opening of stomata
abscisic acid it promotes the dormancy
in seeds and buds and thereby inhibits
growth it also promotes the closing of
stomata and thus effects wilting of
leads it also promotes the falling of
leaves abscission ethene or ethylene it
removes growth and ripening of fruits it
helps in breaking the dormancy in buds
and seeds it stimulates the formation of
separation layer abscission zone in
leaves
flowers and fruits
it remotes yellowing of leaves