Plant Growth and Development

growth

an abnormal proliferation of tissue

cambium

a formative one-cell layer of tissue between xylem and phloem in most vascular plants that is responsible for secondary growth

growth rate

the rate of increase in size per unit time

arithmetic growth

mitotic cell division, when only one daughter cell continues to divide while the other differentiates and matures.

geometric growth

both the progeny cells following mitotic cell division retain the ability to divide and continue to do so.

lag phase

the initial growth is slow

relative growth rate

measure of the ability of the plant to produce new plant material, referred to as efficiency index

differentiation

The act leading to maturation

dedifferentiation

The living differentiated cells, that by now have lost the capacity to divide can regain the capacity of division under certain conditions.

redifferentiation

tissues that are able to divide and produce
cells once again lose the capacity to divide but mature to perform specific functions

parenchyma

the primary tissue of higher plants composed of thin-walled cells that remain capable of cell division even when mature; constitutes the greater part of leaves

epidermal cell

any of the cells making up the epidermis

development

all changes that an organism goes through during its life cycle from germination of the seed to senescence.

plasticity

Plants follow different pathways in response to environment or phases of life to form different kinds of structures.

plant growth regulators

small, simple molecules of diverse chemical composition.

auxin

a plant hormone that promotes root formation and bud growth

apical dominance

the growing apical bud inhibits the growth of the lateral (axillary) buds

gibberellin

a plant hormone isolated from a fungus; used in promoting plant growth

cytokinin

synthesised in regions where rapid cell division occurs

ethylene

a simple gaseous PGR, synthesized in large amounts by tissues undergoing senescence and ripening fruits.

senescence

loss of a cell's power of division and growth.

parthenocarpy

the development of a fruit without fertilization or seeds

dormancy

a state of quiet inaction

abscisic acid

hormone involved in tuning responses to several abiotic stresses and also has remarkable impacts on plant defense against various pathogens.

ethephon

Ethephon is used to promote fruit ripening, abscission, flower induction, breaking of apical dominance

photoperiodism

response of plants to periods of day/night

vernalisation

There are plants for which flowering is either quantitatively or qualitatively dependent on exposure to low temperature.