Plant Biotechnology Flashcards
What is ‘Plant Molecular Farming’ (PMF)?
The practice of using plants to produce recombinant proteins, including human therapeutic proteins and also secondary metabolites
What does ‘sessile’ mean?
Unable to move
Approximately how many plant species are there?
More than 400,000
What is a ‘Callus Culture’?
An unorganised plant tissue growing on a solidified medium
Where in the plant is a major site of product (secondary metabolite) accumulation?
Vacuoles
What are TWO major problems with plant cell cultures?
- Poor expression
- Instability of cell lines
What THREE factors can increase the productivity of plant cell cultures?
- Optimisation of culture conditions
- Addition of precursor
- Biotransformation
What are some quantitative techniques used to measure the amount of active ingredients (secondary metabolites) produced in plant cultures?
- UV-Vis spectrophotometry
- TLC
- HPTLC
- HPLC
- NMR
What are some factors that influence biomass accumulation and secondary metabolite synthesis?
- Nutrient medium and salt strength
- Carbohydrate source
- Nitrogen source
- Phosphate levels
- Growth regulators
- Inoculum density
What therapeutic property does Withanolides have?
Anti-cancer
What bacterium is used in biological methods for the production of heterologous proteins in plants?
Agrobacterium tumefaciens
Gram -ve soil bacterium
Used for Crown Gall Disease
What is a Physical method for the production of heterologous proteins in plants?
Biolistics: particle bombardment
The drug ZMapp produced in tobacco leaves combats which disease?
Ebola
What disease does the first PMF-derived enzyme treat?
Gaucher disease
(ELELYSO)
What is ELELYSO based on?
The use of carrot cells to produce recombinant taliglucerase alfa
What are some advantages of using a plant-based production system?
- Common species of plants can be used
- Edible vaccines
- Cheaper to produce
- Simple scale up
- Safer
- Plants able to carry out posttranslational modification of proteins
What are some limitations of using a plant-based production system?
- Few recombinant proteins have been approved
- Initially demonstrate low expression levels
- Very expensive
- Fears of contaminating the food chain
- Regulatory issues
Name TWO secondary metabolites
- Terpenoid alkaloids
- Phenolics
What is ‘whole organ culture’?
Alternative strategy for production of metabolites in vitro
How can hairy roots culture be generated?
Following plant infection with agrobacterium rhizogenes
What is the limitation of hairy phenotypes?
Can only be used for metabolites that are naturally produced in root tissue
What is the plasmid in Agrobacterium tumefaciens?
Large and called Ti-plasmid (~200kbs)
What does the plasmid in Agrobacterium tumefaciens host?
Range didcots (Eudicots)
What is the molecular machinery needed for T-DNA production and transport?
Comprises proteins that are encoded by bacterial chromosome genes and Ti plasmid virulence genes
When was the first plant-derived veterinary vaccine approved?
2006
What was the first plant-derived antibody?
The monoclonal antibody against Hepatitis B surface antigen expressed in tobacco
Liew and Hair-Bejo
Give an example of a posttranslational protein modification that plants are able to carry out
Disulfide bond formation and glycosilation
Is downstream processing of a product from plants cheap or expensive?
Very expensive, about 80% of total cost
What is Taxol?
Anti-cancer agent from Taxus brevifolia
Why are vaccines derived from plants safer?
Less likely to harbour prions or microbes
Why was Agrobacterium rhizogenes improved?
Mediated hairy root culture system of Whithania somnifera
What are the treatments for Dunal?
Sonication and heat treatment
What does Agrobacterium tumefaciens infect?
Monocots but not naturally
Name an indirect method of gene transfer in plants
Transformation of plant cells by Agrobacterium tumefaciens
