Question

Describe one beneficial and one harmful way in which microorganisms interact with agricultural crops

Answer 1

Interaction of microorganisms with agricultural crops in a beneficial way:

Plants require macro nutrients and micronutrients for the growth of plants. Phosphorous is one of the macro nutrients required by plants. Phytic acid a large source of organic phosphorous in soil is not readily available to plants as the Phytic acid form complex compounds in the soil and plants donot have Phytases. The Phosphate solubilizing microorganisms can help in making the phosphorous available to plants. These Phosphate solubilizing microorganisms secrete Phytases and phosphatases and helping in the growth of plant. Microorganisms helps in maintaing the Phosphorous cycle between nature and plants. The Phosphate solubilizing microorganisms are Sorotrichum thermophile, Discosia (fungus), Pseudomonas, Bacillus amyloliquefaciens make the phosphorous available to plants by the action of Phytases. These microbes are called as Plant Growth Promoting Microorganisms(PGPM) which exert beneficial effects on plant growth and development.

a) Phytic Acid

b) Phytic acid interactions with metal ions

Interaction of microorganisms with agricultural crops in a Harmful way:

The microorganisms also cause harmful diseases in plants causing huge economic loss to farmers and the economy.

Microorganism	Plant/Crop	Disease	Symptoms
Phytopthora infestans (fungus)	Potato	Late blight of potato	water soaked spots on the leaves and later infect the tubers
Xanthomonas oryzae(bacteria)	Rice	Bacterial blight of rice	streaks and lesions on the leaves
Xanthomonas citri (bacteria)	Citrus	Citrus canker	Twigs and fruits are affected
Glomerella (fungus)	Sugarcane	Red Rot of sugarcane	Red stripes in the cane
Tobamovirus	Tobacco	Mosaic disease of Tobbaco	mosaic pattern of light and dark green patches on leaves