Microbes in Agriculture

Question 1

Induced systemic resistance in plants involves:

a) Activation of a hyper immune response through leaf-microbe interactions
b) Priming of the immune response through plant-rhizobacteria interactions
c) Suppression of the immune response in response to rhizosphere interactions
d) Neutralisation of the immune response through stem-microbe interactions

Answer 1

b) Priming of the immune response through plant-rhizobacteria interactions

Question 2

Which oomycete is the cause of potato blight?

Answer 2

Phytophthora infestans

Question 3

Which fungus is a major pathogen of rice?

Answer 3

Magnaportha oryzae

Question 4

Is Streptomyces scabies gram +ve or gram -ve?

Answer 4

Gram +ve actinomycete causing potato scab

Question 5

Is Xanthomonas oryzae gram +ve or gram -ve?

Answer 5

Gram -ve

Question 6

What is on the surface of Gram +ve cell membranes?

Answer 6

LTA (Lipoteichoic Acid)
WTA (Wall Teichoic Acid)

Question 7

What is on the surface of Gram -ve cell membranes?

Answer 7

LPS (Lipopolysaccharide)

Question 8

How can Rhizobacteria promote plant growth?

Answer 8

1. Production of plant hormones such as Indole Acetic Acid (auxin)
2. Increasing the availability of nutrients to the plant (P, S, N)
3. Restriction of the action of pathogens

Question 9

How does Pseudomonas fluorescens F113 inhibit Pythium ultimum?

Answer 9

Production of 2, 4-diacetyl phloroglucinol

Question 10

What oomycete is the causal agent of early damping-off disease in sugar beet?

Answer 10

Pythium ultimum

Question 11

What are some Indirect Plant Growth Promotion mechanisms?

Answer 11

• Antifungal metabolites production
• ISR responses

Question 12

What are some Direct Plant Growth Promotion mechanisms?

Answer 12

• N2 fixation
• Phosphate solubilisation
• Iron production
• Auxin production
• ACC deaminase production
• Cytokinin production