| The resumption of growth (or
vegetative resumption) is the
phase when a plant or other
vegetative part (
bud,
seed or other
structure) recommence to
grow after a period of
dormancy.
For example the resumption of
active growth by
perennials in spring
after the winter rest,
the starting of germination
of a dormant seed
after a time of arrested
embryonic
development, the
growing of new
shoot apices and
adventitious buds
or the resumption of growth after
transplantation.
The induction of a
vegetative resumption
subsequent to a
stationary-phase is a
physiological response depending by the interaction of
several external and internal
factors.
Among the external factors
the most important are
temperatures, rains,
photoperiod and
nutrients availability.
The internal factors
include:
• Genetic make up (activation
of genes preferentially
expressed in growing
shoot apices)
• Biochemical changes
(e.g. Carbohydrates
and stored nutrients
availability, enzymes activities, etc.)
• Loss of
inhibition (abscisic
acid) and greater availability than before of
growth factors (
e.g. gibberellins,
auxins and
cytokinins ) |
