5. Boost cultivation efficiency :
• Produce phytohormones
• Enzymes to assist phytohormones
synthesis
• Increase soil nutrients
• Protect from harmful pathogens
Biofertilizers
PLANT GROWTH PROMOTING MICROBES
6. ACTINOMYCETES
• Gram positive, aerobic bacteria
• Shape of filamentous length of coccis
• Endure extreme conditions
• Very abundant in soil environment
• Producer of secondary metabolites
• Assemble enzymes for
o Decompose dead organic matters
o Break down nutrients
o Control plant pathogens
8. BIOLOGICAL CONTROL
What is biological control?
• The use of one living organism to control another
• Biological control of plants includes insects and
pathogens.
• Biological control agents of plant diseases are
most often referred to as antagonists.
10. TYPES AND MECHANISM OF BIOCONTROL
Lytic enzymes and other byproducts of microbial life
• Diverse microorganisms secrete and excrete other metabolites that can interfere with
pathogen growth and/or activities.
• Expression and secretion of these enzymes by different microbes can sometimes result
in the suppression of plant pathogen activities directly.
• Currently, it is unclear how much of the lytic enzyme activity that can be detected in the
natural environment represents specific responses to microbe-microbe interactions.
• Microbes that show a preference for colonizing and lysing plant pathogens might be
classified as biocontrol agents.
• Some products of lytic enzyme activity may contribute to indirect disease suppression.
11. APPLICATION OF BIOCONTROL
IN PGP
Plant growth-promoting traits of
biocontrol potential bacteria
isolated from rice rhizosphere
• Seven isolates of bacteria (SRI-156, SRI-158, SRI-178, SRI-211,
SRI-229, SRI-305 and SRI-360) were considered as having
potential for biocontrol of charcoal rot of sorghum and plant
growth promotion (PGP) of the plant.
• The seven isolates were characterized for their physiological
traits (tolerance to salinity, pH, temperature and resistance to
antibiotics and fungicides) and further evaluated in the field for
their PGP of rice.
• Result: 4/7 isolate enhanced microbial biomass carbon,
microbial biomass nitrogen and dehydrogenase activity
15. ACC DEAMINASE
ACC deaminase catalyzes a cleavage of
ACC that includes cyclopropane ring
fragmentation, and deamination of ACC
to form α-ketobutyrate and ammonia
=> Lowering the level of ethylene
16. CHITINASE
• Destroy chitin, a major component
of the cell wall of pathogenic fungi
• Render the fungi inactive
without any negative impacts on
plants
• Strengthen plant defense
mechanism
17. GLUTAMINE SYNTHETASE
A key enzyme in the first step of
NH4+ assimilation, responsible for
the synthesis of glutamine
20. ACC deaminase
Several D-amino acids, notably D-serine and D-cysteine can act
as substrates for ACC deaminase (albeit less efficiently than
ACC), L-serine and L-alanine are effective competitive inhibitors
of the enzyme. ACC deaminase catalyzes a cleavage of ACC that
includes cyclopropane ring fragmentation, and deamination of
ACC to form α-ketobutyrate and ammonia
21. For detection of chitinolytic or cellulolytic
activities, both soluble and insoluble substrates
either natural or chemically modified are used.
Chitinases
Glutamine synthetase
β-Glutamate as a Substrate for Glutamine Synthetase. β-
glutamate is accumulated as an osmolyte in many archaea
while β-glutamine (produced by glutamine synthetase) is
used as an osmolyte only in M. portucalensis.
22. Chitinases
They can be used as a safe and
biodegradable bioregulator in place of
biopesticides. Contribute to the generation
of carbon and nitrogen. Chitin and
chitinolytic enzymes are gaining
importance, especially the chitinases
exploited in to control pathogens.
Glutamine synthetase
Stress tolerance function of GS and its
molecular mechanisms can help improving
crop resistance to abiotic stress and
mitigating the adverse effects of abiotic
stress on crop yield and quality formation.
Agricultural
applications
ACC deaminase
To equilibrate plant ethylene levels
under various abiotic stresses
=> However, the use of ACC deaminase
from PGPR to overcome abiotic stress
has not achieved many outstanding
results. Therefore, it is more effective
to use multiple strains instead of a
single ACC deaminase strain
Agricultural
applications
