Transgenic plants and applications

What are some current and possible benefits of GM (transgenic) plants?

- increased productivity - contribution to global food security / elimination of hunger - higher quality crops (tastier, healthier, more valuable economically) -better food, better for the environment, more food

What are the advantages of plant transgenesis?

- wealth of info on strains that can be exploited at the molecular level because plant breeding has a long history - plants have a large # of progeny --> rare mutations and recombs can be discovered w/ more ease - Plants' regenerative capabilities > animals - Species boundaries and sexual compatibility are not issues

What is the old method of cloning multiple genes?

-2 plants produced, each with its own inserted gene -crossing by pollen transfer used to produce hybrid plant -pollen can be transferred to other non-target plants and possibly beneficial insects

What are ways in which transgenic plants can manufacture pharmaceuticals?

-Bioproducts - human GH from transgenic tobacco plants -vaccines - transgenic tomatoes and bananas produce hep B vaccine

What is the process of catalyzation of luciferin with ATP?

-Light is emitted (how fireflies glow in the dark) -transgenic tobacco plant w/ luciferase gene will also glow in the dark when watered with a solution of luciferin

What are some plant based biochemical products and what do they do?

-Long chain polyunsaturates (reduce cholesterol in foods) -aromatic components s-linalool enticing aroma from fresh tomato -plant based fuel (ethanol)

What are some examples of transgenic plants that have been made?

-Oranges resistant to citrus canker -disease resistant sweet potatoes, bananas -salt/mercury/cold /stress tolerant plants -nicotine-free tobacco -decaf coffee -industrial fibers -pest/disease resistant cassava

What are some general concerns about GM foods?

-impact on health/environment -access and intellectual property -labeling -scientific protocol

What are some problems of plant molec bio?

-research funds are not high -plants grow slowly, have long generation times -have large genomes (corn 15bbp is 5x larger than human genome) -plant cells have a cellulose cell wall (wooden box) making them resistant to the intro of foreign DNA

What are some ethical concerns about GM foods?

-violation of natural organisms' intrinsic values -tampering w/ nature by mixing genes among species -consuming animal genes in plants & vice versa

What are characteristics of chloroplast engineering? (3)

1. Chloroplast DNA can accept several new genes at once, unlike DNA in a cells nucleus 2. High percentage of genes inserted into the chloroplast will remain active when the plant matures 3. DNA In chloroplast separate the DNA released in plant's pollen

What are 3 uses for making transgenic plants?

1. improve growth characteristics & yield of agriculturally valuable crops 2. increase nutritional value of crops 3. provide crops with resistance

What are the steps for leaf fragment technique?

1. make leaf discs 2. culture in genetically modified Agrobacter 3. transfer to filter paper over nurse cells- culture 2-3 days- (nurse cells produce growth factors) 5. Transfer to shoot-stimulating medium - culture 2-4 weeks (shoots appear) 6. Transfer to root-inducing medium (roots appear) 7. Transfer to soil after 3 weeks REGENERATED ENGINEERED PLANT

What was the starlink episode?

2000 - USA - GM corn meant for animals was in grocery stores

who regulates GM foods?

2004- Institute of Medicine and the National Research Council - Federal agencies should access any genetically altered food - regardless of whether it is developed by genetic engineering or by conventional cross-breeding

What is the velocity of the gun blast and what is the marker used for?

430 meters/second marker antibiotics is used to select only genetically transformed cells

Plant transgenesis has helped create a strain of cotton with ___________ fibers producing more ________

60% stronger cotton fibers --> more durable, softer clothes --> more profit for farmers

What is the limitation for leaf fragment technique?

Agrobacter can only infect dicotyledonous plants (tomatoes, potatoes, apples, soybeans)

What is the intermediate vector recombined with to generate a cointegrate structure and a selectable plant marker?

An attenuated "disarmed" Ti Plasmid

What does glyphosate block?

An enzyme necessary for photosynthesis (EPSPS)

What are ways in which to prevent insects from infecting crops during storage?

Avidin (protein in egg whites) - from transgenic corn

What is a natural bacterial pesticide?

Bacillus thuringiensis (Bt): toxin = natural bacterial pesticide.

What reporter gene turns x-gal blue?

Bacterial lac (b-galactosidase) gene

How does avidin make corn resistant to pests during storage?

Blocks the availability of biotin - a vitamin required by pests to grow

What is protoplast fusion used to make?

Broccoflower = physical attributes resemble cauliflower but has color and flavor of broccoli

What is antisense tech also used for?

Bruise resistant potatoes and splicing genes for increased protein content from chicken into potatoes

What produces a crystallized protein that kills harmful insects and their larvae?

Bt produces a crystalized protein (Bt toxin)

What was made via the old method of cloning multiple genes?

Cauliflower mosaic virus (CaMV)

The cointegrate structure has the ...? and the Selectable plant marker has ...?

Cointegrate structure has the gene insert of interest selectable plant marker is kanamycin-resistant

Where in the nucleus does the gene gun shoot metal beads into?

Embryonic cells intact leaves soft kernels

Traditional tomatoes are sprayed with _______ to induce ripening and cause ________ flavor

Ethylene after shipping to induce ripening ripe but decreased flavor

What helps tomatoes to ripen on the vine resulting in fuller flavor modifying it so that it remains firm after harvesting?

Flavr savr - ripe and increased flavor

What is the popular term for transgenic crop plants?

GM foods genetically modified foods

What step in making transgenic plants involves introducing a new gene into plants using direct DNA transfer or Agrobacterium mediated gene-transfer?

Gene introduction

What step in making transgenic plants involves identifying and isolating a gene that controls a trait of interest from another species?

Gene manipulation - when you create a new allele by modifying an existing gene

What are the 3 steps of making transgenic plants?

Gene manipulation Gene introduction Selection & regeneration

What revealed the first clear evidence of horizontal gene transfer in plants?

Genome wide analysis of millet and rice (2005)

What is the transgenic rice in which beta carotene for the production of Vit A have been inserted?

Golden rice

What did classical cross breeding do to cotton fibers?

Increase the average strength of cotton fibers by 1.5% / year

What are 3 advantages to the transgenic tomatoes and bananas that produce the hep B vaccine?

Inexpensive Ease of admin (oral) Ease of storage & delivery

What is another name for pesticide producing plants?

Insect resistant plants

Why is the plasmid called a Ti plasmid?

It is tumor inducing - it triggers an uncontrolled growth of the cells (tumor) in the plant

What reporter gene causes cells to glow green under blue light?

Jellyfish green fluorescent gene (GFP)

What is the technique in which you cut small discs from the leaf and use genetically modified agrobacter?

Leaf fragment technique

What catalyzes the reaction of a chemical called luciferin with ATP?

Luciferase gene (reporter gene isolated form fireflies)

How are plants regenerative capabilities better than that of animals?

Many plants can regenerate from a single cell to form a genetic replica *clone* of the parent cell

What is the serious viral disease of papaya which inhibits photosynthesis and stunts growth?

Papaya ring spot - potyvirus

What is the method of plant transgenesis where you shoot (BLAST) tiny metal beads coated with DNA into the nucleus and chloroplast of the cell?

Particle bombardment using gene-gun

What enzyme is used in anti sense technology that digests pectin on the wall of the plant to induce normal decay?

Polyglacturonase (PG)

What are the methods used in plant transgenesis? (5)

Protoplast fusion Leaf fragment technique Particle bombardment using gene-gun Chloroplast engineering Antisense technology

What are the cells with out the cell walls - the cell walls of these cells are removed either mechanically or enzymatically?

Protoplasts

What are used to monitor the function of any gene during development?

Reporter genes

What is inserted into the chromosomal DNA of the host plant during natural genetic transfer?

T-DNA (transfer DNA)

What are some examples of disease resistant plants on which genetic vaccines are used?

TMV resistant tobacco plant Disease resistant papaya plants (hawaii)

What are intermediate vectors used to clone?

The segment of interest (gene of interest)

What contains a gene or genes which have been changed or inserted artificially?

Transgenic plants

What does GUS (b-glucuronidase) reporter gene do to genes during development?

Turns the compound x-gluc blue

How is Agrobacter used in antisense technology?

Used to transfer the new gene that encodes the antisense mRNA molecule that unites with and inactive the normal sense mRNA molecule for PG production

In natural genetic transfer what does the soil bacteria (agrobacter) contain?

a large DOUBLE STRANDED DNA molecule = plasmid

How do you use metabolic engineering to biodegrade plastics and how is plant based plastic better?

both petroleum and plant based have raw material --> resin --> incineration in plant based - amount of CO2 absorbed offsets that of CO2 emitted

What is the order of events for protoplast fusion?

combine plant species: injure plants → callus → callus/plant digestion → fuse protoplasts → grow → "broccoflower"

Traditional weed killers can also kill

desirable plants

Crops can be genetically engineered to resist common herbicides like ...

glyphosate

What is the current trend in production of GM foods?

increasing

What should crops be resistant to?

insects viral pests drought herbicides

in addition to golden rice, there are current efforts to develop ____ & ____

iron-rich rice protein-rich rice

Genetic transfer occurs ______ in plants

naturally

What is a setback for pesticide producing plants?

pollen produced by bioengineered corn could be deadly to monarch butterflies

Beta carotene a provitamin that can be converted to Vit A in the body is valuable in ...

preventing blindness

What step in making transgenic plants is when a plant is transformed (identified by a selectable marker) and the transformed cell regenerates and the transgenic plant is formed?

selection regeneration

Pesticide producing plants have been engineered to contain and propagate ....?

the Bt gene

What is a setback to golden rice?

the provitamin (beta carotene) must dissolve in fat to be used in the body

Herbicide resistant or insect-resistent genes can spread from engineered crops to wild relatives and create ...?

weeds that are difficult to control

When does natural genetic transfer occur?

when their wounds are infected by the soil bacteria = Agrobacterium tumefaciens (Agrobacter)