How can we help?

You can also find more resources in our Help Center.

30 terms

Biotech II chapter 15-1

Plant Growth-Promoting Bacteria
ACC Deaminase enzyme
Cleaves ACC to α-ketobutyrate
Precursor of ethylene
Way to lower levels of ethylene in plants
Use bacteria that produce ACC deaminase
How bacteria use ACC deaminase and lower levels of ethylene
Bacteria binds to seed coats or plant roots.
Isolates ACC and cleaves
ACC deaminase prevents
Inhibition of root elongation resulting in large healthy plants
Siderophores used to
Solubulize and sequester Iron from soil and provide to plant cells
Ethylene is synthesized by a plant
After environmental stress
ACC produced in response to flood in roots
Can't be converted to ethylene because of no O2.
When ACC in the roots can't be converted to ethylene because of flooding causing anoxic conditions...
ACC is transported up and kills the stem/leaves
Increasing Phosphorous availability
Used to increase phosphorous availability
Transformed bacteria express and secrete phytase
Transposons used to
Move genes into chromosome
Promoter for the tac operon (lac+trp)
Increases biocontrol activity
Solution to fear of antibiotics spreading to other bacteria
Transfer deficient derivative of plasmids
Unable to transfer genes
Enzymes that can degrade fungal cell walls
Biocontrol activity
Indirect promotion of plant growth when PGPB decrease or prevent damage
In order to use PGPB as a biocontrol agent
Must adhere to root surfaces to prevent incursion by pathogens
PGPB activities
Fix Nitrogen.
Sequester Iron.
Iron uptake.
Produce Phytohormones.
Reduce Ethylene.
Examples of how to increase the amount of Nitrogen that can be fixed
Inhibiting synthesis of rhizobial glycogen(modulating the level of O2 within the bacterial cell).
Preventing rhizobial synthesis of polymer poly-B-hydroxybutryrate, which normall acts as a C storage compound)
First small peak which increases plant enhances survival, second peak causes senescence or death
Hydrogenase converts
H2 generated by nitrogenase into H+ to increase efficiency of N. fixation
Other nitrogrenase function
Creates H2 using ATP
Examples of biocontrols
Enzymes that lyse fungal cell walls.
Engineer strains to be better root colonizers, more efficient at lowering ethylene levels, more active producers of antibiotics/enzymes
Direct stimulation by PGPB
N. fixation.
Phosphorous mineralization.
ACC Deaminase
Examples of phytohormones
Auxin, Cytokinin, and Gibberellin do what
Enhance stages of plant growth
One of the most abundant minerals on eart and essential requirement for living organisms