Lecture 7 Tuesday January 29 2008

Target of Biotechnology

  • partical bombardment
  • tumerfaciens

resistance

  1. herbicides/ pesticide resistence
  2. insect resistence
  3. pathogen resistence
  1. adaptation for environment = salt, drought and tolerance

improvemnt

  1. improvement of post harvest qualities
  2. improvement of nutrient content
  1. elimination of allergy factor
  2. creation of novel value

production

  • 59% obtained production
  • 15% insects
  • 13% pathogens
  • 13% weeds

Monoculture

  • no diversity in the genotype
  • age structure is uniform
  • high nutrient extraction
  • suceptable to huge outbreaks of a single pathogen
  • a variable age structure enhances the species ability to fight of disease
  • nutrients extraction provides alot of fuel to potential pathogens

weeds

  • compete with crops for nutrients
  • reduce crop yields and quality
  • herbicides are sprayed
  • weeds are dynamic and variable
  • however, most herbicides specifically target certain plants
  • herbicides remain in the soil for upt o a year

round up

  • kills 76-8% of the worst weeds
  • breaks down quickly
  • not toxic to animals and humans
  • glyphosates
  • this product also kills crops so its application is limited

round up ready seeds

  • solves the killing crop issue
  • recombinate DNA techniques used to create it

how round up workds

  • it inhibits amino acid synthesis
  • enzyme that inhibits the EPSP synthase
  • protein - terchiary function
  • protein function
  • round up targets part of the protein and destroys it
  • this causes the protein to loose its function

how round up ready works

  • modified the section of DNA that is vulnerable to round up
  • this altered the protein it created slightly
  • this meant that round up could not find and attach to the part of the protein and kill it

insects

  • BT toxin
  • bacillus thuringiensis
  • soil bacteria -
  • spores contain the crystallines protein
  • protein if ingested by insects will breakdown during digestion and produce a fatal BT toxin
  • BT toxin kills insects in a few days
  • not toxic for mammals
  • organic famrers are allowed to use BT toxins

insect resistance

  • BT toxin gene was created which expressed the BT toxin gene in the plant as opposed to the soil which gets washed away

nutrient content

  • golden rice - engineered to produce beta-carotene
  • gives rice a golden colour and produces vitamin A
  • 250 million people world wide are vitamin A deficient
  • important for eye sight and immune system
  • swiss and german researchers create the crop
  • cross daffodile gene and bacteria gene to introduce beta carotine

poor harvest quality

  • flavr savr
  • first GM crop approved by FDA
  • ethylene - natural plant hormone - rippens tomato
  • researchers try to control the softness
  • PG - enzyme that breaks down cell wall of tomatoe - polygalacturonase
  • anti sense technology - inserting antisesne negative complementry sequence as a positive complementry DNA sequence
  • Mrna will be transcribed and they then become double stranded and this stops the gene from being translated to protein
  • consequently they could stop the expression of this enzyme

creation of novel value

  • vaccine
  • phytoremediation

vaccine

  • weakened pathogen or part of a pathogen
  • body recognizes and memorizes the particular patogen as an epitope
  • recombinant DNA technology is used to create epitopes
  • outside of pathogen is frequently recognized by the body as an epitope and targetted because of a unique shape
  • expressing the small epitope of a gene in fruits
  • the idea is that people in developing counrties can eat fruit with epitopes to innoculate them against pathogens
  • edible vaccines - no refrigeration

Phytoremediation

  • such toxins and pollution out of soil
  • via water and root system
  • the plant can even break down or store the toxins

transgenic mustard sucks up selenium in california
this is dangerous because cross pollenation may occur and crops we eat will start taking on selenium
just use not food crops
in california water disolves selenium in the shale

Hydrocarbons vs. carbohydrates

  • recombinant DNA - gene splicing
  • transgenic crops -
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