Reminder - Your Tasks for Monday

1. Home Learning – Assessed ReportUsing drosophila as an example explain the process of differentiation of cells into tissues and organs. (due Monday October 1st)2. Add the red terms from this powerpoint to your glossary with detailed definitions.3. Complete all of the Scholar online activities for differentiation.

Lesson 10 – Plant Tissue Culture

1.5 Plant tissue culture

Regeneration

Somatic cells of all multicellular organisms have the potential to regenerate into a clone. Animals are too complex for this to happen easily but plants can do this!Nuclear totipotency is the ability of a single cell to divide to produce all the differentiated cells in an organism.

Uses of Plant Tissue Culture

Plants are cultured to produce clones for use in a variety of situations:1. Production of pathogen (virus) free plants.2. Ornamental plants.3. Genetically improved plant species through

hybridisation.4. Production of plant metabolites by cultured

plant cells.5. Screening for beneficial traits (such as heat or

salinity tolerance) while the cells are in culture.

6. Micropropagation – rapid upscaling of field trials.

Plant Cell Culture

Step 1 – Selection of tissue from parent plant

A small piece of young growing tissue is cut from the parent plant. This can be from a root, shoot or leaf. These small pieces of tissue are called explants.

Plant Cell Culture

Step 2 – Explant is placed on growth medium The explant will need a growth medium containing plant hormones. The most commonly used are auxins and cytokinins.

Cell Pant Culture

Step 3 – Growth into a Callus

The cells divide to produce a ball of undifferentiated plant cells called a callus.

Carrot Callus Cauliflower Callus

Cell Plant Culture

Step 4 – Growth of roots and shoots

Once the callus is established it is transferred to a different growth medium containing a different combination of growth hormones. This results in the growth of roots and shoots.

Using Protoplasts

To produce hybrid plants protoplasts are used. The cell walls are removed using cellulase and pectinase allowing 2 cells to be fused prior to culturing.

The cell suspension is incubated in a mineral salt solution containing mannitol. Mannitol is a type of sugar that caused plasmolysis allowing for the cell walls to be digested more easily.

Growth of Protoplasts

The protoplasts are placed in a suitable growth medium to produce new cell walls before they start to grow normally to form a callus.

Unit 1 – Section 1 TEST

Monday October 8th

On test day I will be collecting in your jotters to check your notes on the monograph and to make sure your glossary is up to date. I will also check on Scholar to make sure you have completed the Scholar activities from Section 1.