1. Plant Tissue Cultures

2. Conditions required for plant tissue cultures
An original stock of cells.
The use of aseptic techniques when preparing media and cultures.
A suitable container for cell growth.
A growth medium providing essential nutrients.
Plant growth regulators e.g. auxins and cytokinins
Photoautotrophs, such as algae, require only a mineral salt media enriched with CO2.
Heterotrophs, such as bacteria and yeast, need an additional organic carbon source and additional compounds such as amino acids.

3. Features of plant cells
Plant cells are totipotent, unlike animal cells. Their pattern of gene expression means that any cell has the potential to become any part of the plant.
Control of factors such as pH and temperature are usually achieved in large fermenters by the use of thermisters coupled to heaters and pH probes coupled to reservoirs of acid and alkali.

4. Stages to plant Tissue Culture
The cells are often taken from the meristem, the rapidly growing tissue at the point of the root or shoot.
These are sterilised and placed in a nutrient solution in a Petri dish where they multiply, forming an undifferentiated mass of tissue, which is called callus.
If the callus is divided up and given plant growth regulators such as auxins and cytokinins then differentiation takes place, roots and shoots develop, giving rise to plantlets.
These can be grown on in the usual way-and each is genetically identical to the parent

5. Uses of Plant Tissue Cultures
Tissue culture is used to clone plants for :-
Food production e.g. Large variety of potatoes
Raw materials – Palm oil used in production of raw materials used in soap and production of plastics
Energy substitutes – Plant oils produced are now starting to be used as petroleum substitutes
Preservation of endangered species