2. Definition
• Plant tissue culture is a term used to refer to the
growth of plants or plant parts on nutrient media
under sterile conditions.
• A technique whereby small pieces of plant
cells/tissues/organs are cultured in a medium
(substrates) containing nutrients, hormones,
vitamins to support the growth of cells/tissue under
sterile/aseptic conditions (free of microorganisms
contamination such as virus, bacteria, fungi).
3. • Tissue culture is also known as in vitro culture or
micropropagation.
• In vitro: performed or taking place in test tubes, petri
dishes, outside living organism. What are in vivo, ex
vitro, ex vivo, in situ, ex situ, in silico?
• Micropropagation: a method of propagating plants
that uses very small parts of plants that are grown in
sterile culture.
4. History
• To some degree, it involves the whole history of
botany!
• Antonie van Leeuwenhoek (1632-1723) – design a
microscope.
• Schleiden (botanist, 1834) and Schwann (zoologist) -
the cell theory: all plant and animal tissues are
composed of cells. Rudolf Virchow (1855) - in an
individual organism, all the cells are identical (all cells
arise from pre-existing cells).
*Leeuwenhoek – not the first person that invented microscope, he
made better lenses, and observed cells in great details. The first to
observe nucleus.
7. • Based on the cell theory, Haberlandt (botanist, 1902)
developed the concept of in vitro cell culture. He
predicted that plant embryos could be produced
through the cultivation of vegetative cells.
Unfortunately, his cultures were unsuccessful.
• Hannig (1904) successfully cultured embryogenic
tissue. He found that excised conifer embryos
produced plantlet instead of developing embryos.
8. • White (1934) reported cultured root tips could grow
and could be subcultured to fresh media repeatedly.
• Gautheret ( 1934) and Nobecourt (1937) -
independently successful in developing callus culture
from carrot cambium cells.
• White (1939) - successful culture of tobacco callus.
9. • Skoog & Miller (1957), proposed the concept of
hormonal control of organ formation. They worked
on tobacco pith cultures - high conc. of auxin
promote rooting & high kinetin induces bud
formation/shooting.
*However, now other factors are known to be involved such as source
of explants, environmental factors, media composition, polarity,
growth substances for organogenesis.
10. • Murashige & Skoog (1962) – develop MS medium
formula, higher in salts, can be used to culture many
plants, consider universal medium.
* After the development of reliable culture medium e.g. MS medium,
the progress in research and commercialization of plant tissue culture
has increased.
11. Toshio Murashige
b. 1930
Folke Skoog
1908 - 2001
*Toshio Murashige is the student of Folke Skoog at the University of Wisconsin,
later became a profesor at the University of California at Riverside.
12. Concepts
Plasticity
highly adaptable to environmental condition.
ability to initiate cell division from almost any tissue.
ability regenerate lost organ.
ability of being shaped.
Totipotency
total potential
an individual cell can regenerate into a whole organism.
all plant cells can express the total genetic potential of the parent
plant if given the right stimuli.
maintenance of genetic potential.
13. Totipotency
It is the ability of plant cells or tissue to
generate into whole complete plants
14. PTC Terminology
• Adventitious: developing from unusual points of origin, such as
shoot or root tissues, from callus or embryos, from sources other
than zygotes.
• Agar: a polysaccharide powder derived from algae used to gel a
medium.
• Aseptic: Free of microorganisms.
• Aseptic technique: procedures used to prevent the introduction of
fungi, bacteria, viruses, mycoplasma or other microorganisms into
cultures.
• Callus: an unorganized, proliferate mass of differentiated plant cells,
a wound response. Plural - calli
• Contamination: being infested with unwanted microorganisms such
as bacteria or fungi.
• Culture: a plant growing in vitro.
• Differentiated: specialized plant structure or organs.
15. PTC Terminology
• Explant: tissue taken from its original site and transferred to an artificial
medium for growth or maintenance.
• Hormones: growth regulators, generally synthetic in occurrence, that
strongly affects growth (i.e. cytokinins, auxins, and gibberellins).
• Medium: a nutritive solution, solid or liquid, for culturing cells. Plural –
media.
• Micropropagation: in vitro clonal propagation of plants from shoot tips or
nodal explants, usually with an accelerated proliferation of shoots during
subcultures.
• Node: A part of the plant stem from which a leaf, shoot or flower
originates. Internode - the space between two nodes on a stem
• Regeneration: a morphogenetic response to a stimulus that results in the
development of organs, embryos, or whole plants.
• Somaclones: plants derived from any form of cell culture involving the use
of somatic plant cells.
16. PTC Terminology
• Somaclonal variation: genetic variation observed among progeny of
plants regenerated from somatic cells cultured in vitro.
Theoretically all plants regenerated from somatic cells should be
clones, but a number of observations have indicated that this is not
the case.
• Subculture: the process by which the tissue or explant is first
subdivide, then transferred into fresh culture medium.
• Totipotency: a cell characteristic in which the potential for forming
all the cell types in the adult organism are retained.
• Undifferentiated: cells or tissues that do not have specialized
structures or functions. A state of cell development characterized
by isodiametric cell shape, very little or no vacuole, a large nucleus.
18. • Totipotent – ability of a cell to generate into complete organism,
e.g. somatic embryogenesis
• Pluripotent – cell can give rise to different cell types, cannot
generate into whole organism e.g. meristematic cells
• Multipotent – cell can develop into more than one cell type, but
limited compared to pluripotent.
• Differentiated – meristem to mature specialized cell or tissue
• Dedifferentiated – organized tissue (differentiated) to callus
(undifferentiated)
• Redifferentiated – from callus (undifferentiated) to organ or plant
(differentiated)
• Caulogenesis – shoot formation
• Rhizogenesis – root formation
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22. Basics of plant tissue culture
• Explants – parts of plant – cells, organ, tissues
• Medium – macronutrient, micronutrient, iron, vitamins, growth
regulators/hormones, pH, solid/liquid, medium strength
• Environment - must be controlled, temperature, moisture, oxygen,
light, mechanical/agitation
• Sterilization – aseptic technique, washing, ethanol, UV, laminar air
flow, autoclave
• Acclimatization – moisture, plantlet, ramet, hardened plant
