Dr. James Saunders April 7, 1997
Lecture Outline Protoplast Lecture
I - Protoplasts Produced
A. Mechanical
1 - cut off wall
2 - slicer - random cut-off wall
B. Enzyme (5.5. - 6.0 pH, sucrose osmoticum)
buffer, cellulase
4 hours digest cell wall - obtain membrane-bound cell - (like animal)
Apolar proplasts - chloroplasts
even distribution, have large vacuoles - repository
Garbage dump bag
Found nictotine stored in vacuole - contains defense compounds - insect
attack, natural insecticide
Lower sugar concentration-cells burst releasing vacuole
Density gradient centrifuge to obtain purified vacuolar preparation
Intact vacuoles
II - APPLICATION OF RESEARCH
A. Herbivore - (Larva - Army Worm larva stores nicotine and serves as chemical
protection against parasitoid wasps)
B. Cell fusion - hybrids (of plants that are NOT sexually compatible)
Promoted by:
1 - Solutions - such as PEG
2 - Electrical charge used to damage membrane - come back together as
single membrane; however, the cells must be in close contact so that low
voltage electrical current can be used to charge cells (Dielectroporesis).
C. Maintain cell viability
Divide:
1 - Cell wall reforms
2 - Hanging drop culture used to form small callus
Formed new plant
Fusion: all genes or lose some genes
D. Sheep
Took out nucleus of egg and put in new somatic nucleus - shocked
Put back into mother - used egg to provide cloning environment
Dolly-Lamba
E. Video - Colorado Potato Beetle
Beetle tolerant to pesticides
Leptine in plants associated with insect resistance
Somatic mating to produce potato plants high in leptine which resists
herbivory by Colorado Potato Beetles
F. Applications
Contaminated soil - high heavy metals such as zinc.
Small number of plants will grow in high zinc
remediation of soil - plants
Phyto
Concentrated in leaves, leaves harvested and then recover zinc in
smelter - no longer a disposal problem.
Used protoplast fusion between small zinc accumulating plant and
larger plant Brassica
Produced larger plant which can accumulate zinc
Can extend studies - use genes which are associated with capacity to
accumulate metals - DNA specific for metal uptake
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