Lecture 13 - GM crops Flashcards
even if CO2 emmisions drop, what are long term effect that need to stabilise
- accCO2 levels
- temp
- sea levels (will rise first befvore stabilsing)
definition of genetic engineering/recomb DNA technology/GM ?
involve the direct manipulation of an organism’s genes
def of GMO
genetically modified organism
involve the direct manipulation of an organism’s genes
what is transgenic vs cisgenic
trans = gene exchange between diff organism
cis= rearragning/modifying genes in same organism
what bact is crown gall disease caused by
agrobacterium (usually tumefaciens)
what bit of the agrobacterium’s dna gets transfwrred into plant
T-DNA region from the Ti plasmid
nothing from chromosomal DNA
what surrounds the T dna
LB and RB
left and right borders
what 2 things are manipulated by the genes in T DNA
- plant growth hormones synthesised - uncontrolled growth ie tumours
- synthesis of octopine - AAs only the bacteria can use
what is role of virulence genes
- get TDNA out of bacteria and into plant
- overcome plant defence mechanisms
what does wound in plant cell release
acetysyringone
what does agrobacterium use to detect the acetosyringone
VirA/G
2 effects of VirA and Vir G detecting acetosyringone
detects acetosyringone which causes it to move towards wound site
also
triggers transc of other Vir genes
what Vir gene allows excision excision of T DNA from plasmid
VirD2
role of VirD4 and VirB
allow direct connection between bact and plant
how come most cells are able to detect protein components of flagellin
highly conserved in almost all bacteria
what happens after plant detects flagellin
VIP1 gets phosphorylated and moves into nucleus
this activates pathogenesis related proteins, activating the defence response
how does bacteria overcome the plant celll defence response
VirF moves into nucleus
degrades VIP1
what coats the TDNA to allow it to be transported into the nucleus
VIP1 VirE2 and VirF
how can we exploit the TDNA region
replace hormone and opine genes with gene of interest and antibiotic resistant
how to get over porblem of Ti plasmid being too big
use bindary vector system
a helper plasmid with all genes needed
and a small TDNA section
2 common slectable markers used to detect plant transformation
- neomycin phosphotransferase = kanamycin resistance
- bar (bialaphos resistance) = phosphothricin resistance or gluphosinate (a herbicide) resistance
how can single cell plant grow into entire plant
most plant cells are totipotent
can add growth hormones
what plant used in labs in dipping method of transformation
arabidopis
