Question

Suppose an Arabidopsismutant lacking functional aquaporin proteins has a root mass three times greater than that of wild-type plants. Suggest an explanation.

Short answer

Aquaporin channels help in the transfer of water molecules across the biological membrane of the cell. If the Arabidopsis mutant lacks functional aquaporin, water permeability is low, compensated by greater root mass.

Step-by-step solution

Arabidopsis

Arabidopsisare flowering plants that possess short generation time. They are related to cabbage and mustard. They are helpful for genetic experiments due to their features. Thus, they are adopted as model organisms. They produce many seeds and are inexpensive to grow.

Function of aquaporin proteins

Aquaporin is the channel that is located at the biological membrane of living organisms. In plants, aquaporin helps transport water molecules and small proteins such as urea and boric acid across the cell.

Gases such as ammonia and carbon dioxide also are transported in plants by aquaporin channels.

Reason for high root mass and lack of aquaporin in Arabidopsis mutant

High root mass in the Arabidopsis mutant compensates for the water permeability in the plant that is altered by the lack of aquaporins in them. This is because lack of aquaporins prevents entry of water inside the cell and can result in the death of the plant.

High root mass means the high mass of actual roots that influences the growth of plants by helping in respiration and nutrient exchange. They allow them to survive by maintaining the permeability of water.