This document defines terms commonly used in plant tissue culture. It describes concepts like plasticity, which is a plant's ability to adapt to environmental conditions through changes in metabolism, growth, and development. It also discusses totipotency, which is a cell's potential to produce a whole plant, and recalcitrance, which makes an explant difficult to culture. Other terms defined include explant, culture, contaminants, node, morphogenesis, and meristem. Regeneration, dedifferentiation, redifferentiation, adventitious, determined, heterotrophic, ploidy, and polarity are also defined in the context of plant tissue culture.

2. Terms commonly used in plant tissue
culture
Plasticity:-Plants due to their long-life cycle and lack of
mobility have developed greater capacity to survive
extreme conditions. many of the processes involved in plant
growth and development adapt to environmental
conditions. this plasticity allows plants to alter their
metabolism, growth and development to best suit their
environment.
Totipotency :-Totipotency is the potentiality or property
of a cell to produce a whole organism or whole parent plant
in the presence of correct physical and chemical stimulus

3. Recalcitrant: The opposite of totipotency is
recalcitrant. an explant is said be recalcitrant if it is
difficult to give rise to organism or plant.
Explant : A plant organ or piece of tissue used to
initiate a culture.
Culture: Growing cells, tissues ,plant organs, or
whole plants in nutrient medium , under aseptic
conditions e.g. cell culture , embryo culture , shoot-
tip culture , anther culture.
Contaminants: In tissue culture it refers to the
micro-organisms(Bacteria , Fungi) ,which May
inhibit the growth of cells or tissues in culture

4. Node:-A region on the stem from which a leaf
bearing an axillary bud arises.
Morphogenesis:- The anatomical and
physiological events involved in the growth and
development of an organism resulting in the
formation of its characteristic organ and structures
, or in regeneration.
Meristem :-A localized group of actively dividing
cells , from which permanent tissue system I . e .
root , shoot , leaf and flower are derived . apical
meristem is located at the apices of main and
lateral shoots.
Meristematic :- having the characteristics of a
Meristem , especially high mitotic activity.

5. Meristemoid :- A localized group of meristematic
cells that arise in the callus and maygive rise to
roots and or shoots.
Regeneration:- In a tissue culture , a
morphogenetic response that results in the
formation of new organs , embryos or whole plants
from cultured explants.
Dedifferentiation: -The phenomenon a ture
cells reverting to meristematic state to produce
callus is dedifferentiation . dedifferentition is
possible because the non-dividing quiescent cells of
the explant , when grown in a suitable culture
medium revert to meristematic state.

6. Redifferentiation: The ability of the callus cells
to differentiate in to a plant organ or a whole plant
is regarded as redifferentiation.
Adventitious: Developing from unusual points of
origin , such as shoots or roots arising from a leaf or
stem tissues other than the axils or apex ; and
embryos from any cell other than the zygote.
Determined: Cells that are committed to a
particular pathway of development or
differentiation but which have yet to overtly express
this pathway.
Heterotrophic: Dependent on an external energy
source ; not self-reliant compare to autotrophic.

7. Ploidy : - Term used to describe the number of
genomes present in the nucleus of a cell or plant.
Polarity : -In plants ,like in animals , the axes
appear very early in development and mostly they
are polar in nature .The gradation or change in
character occurs along the axis from one end to the
other and the condition is referred as ‘polarity’