Question

Which one of the following helps in absorption of phosphorus from soil by plants?
A. Anabaena
B. Glomus
C. Rhizobium
D. Frankia

Answer 1

Hint: Phosphorus is absorbed in the form of phosphate ions from the soil. It is stored in developing fruits, seeds, storage organs, and young meristematic tissue. It is a constituent of cell membranes, certain proteins, nucleotides, nucleic acids (DNA and RNA), ATP, NADP, and nucleoproteins.

Complete answer:
Anabaena: It is a filamentous cyanobacterium. They are also known as blue-green algae. Cyanobacteria like Anabaena are associated with symbiotic relationships with almost every group of plants and have been used for reclaiming usar soils. They have nitrogen-fixing abilities and as they can live in a damp or aquatic habitat, they enrich the root environment in any wetland condition as in rice fields.
Glomus: It is a mycorrhizal fungus and participates in symbiotic relationships with plant roots. They benefit the plants in uptake of phosphorus from the soil, production of growth hormones, increase of proteins, lipids, and sugars. It plays a significant role in mobilizing phosphorus from the impenetrable layers of the soil and supplying it to the plant.
Rhizobium: It is gram-negative, motile, diazotrophic bacteria that fix nitrogen in a symbiotic relationship with the roots of a leguminous plant. To express nitrogen-fixing genes, it requires the association of a leguminous plant. It is present in the root nodule which usually appears pink in color due to the presence of leghemoglobin pigment which acts as an O2 scavenger.
Frankia: It is a nitrogen-fixing bacteria that participate in a symbiotic relationship with actinorhizal plants.

Therefore, the answer is (B) Glomus.

Note:
Phosphorus is required for all phosphorylation reactions. ATP contains energy-rich phosphate bonds. Its deficiency causes purple or red spots on leaves and delay in seed germination.