Question

In which of the following forms is iron absorbed by plants?

• A. Both ferric and ferrous
• B. Ferric
• C. Free element
• D. Ferrous

Hint:

Iron is the most abundant mineral ion absorbed by the plant in ferrous and ferric forms.

Answer 1

The Correct Option is B

Plants need a tiny amount of iron in order to be healthy.

Plant roots absorb Fe most readily from the soil solution as (ferrous) Fe²⁺, however, but in some cases also as (ferric) Fe³⁺ ions. 

The chemical nature of Fe allows it to have an important role in oxidation and reduction reactions, photosynthesis, respiration, and enzyme reactions.

Answer 2

Option (B) is correct: Plants absorb iron mostly in the form of ferric ( Fe3⁺) ions. 

• However, plants in acidic soil can absorb iron in the ferrous (Fe2⁺) as well as ferric (Fe3⁺) forms. 
• It is an important constituent of proteins that are involved in the transfer of electrons such as ferredoxin and cytochrome. 
• It is reversibly oxidised from Fe2⁺ to Fe3⁺ during electron transfer. 
• It activates the catalase enzyme. 
• It is essential for the formation of chlorophyll.

Answer 3

[B] Iron is absorbed in form of Fe3⁺.

Iron is the most abundant mineral ion absorbed by the plant in ferrous and ferric forms.

Fe²⁺ (ferrous) form is relatively soluble but readily oxidized to Fe³⁺ (ferric) at the intersection of the protoxylem and metaxylem, chelated by citrate. It is then transported in the metaxylem to the other parts of the plant.

Iron is absorbed by plants in the ferric (Fe³⁺) and ferrous (Fe²⁺) forms.

In soil, iron is mostly found in the form of Fe³⁺, which is not readily available for plant uptake. However, plants have developed mechanisms to convert Fe³⁺ into Fe²⁺, which is more soluble and can be absorbed more easily by plant roots. This process is facilitated by iron-chelating compounds that are produced by the roots and help to solubilize iron from soil particles.

Once iron is in the soluble Fe²⁺, form, it can be taken up by the roots and transported throughout the plant, where it is used for various metabolic processes, including photosynthesis and the production of chlorophyll. Iron is an essential micronutrient for plants, and is involved in many important physiological processes, including the regulation of gene expression and the maintenance of proper plant growth and development.

Plants grown in soil with low iron availability may show symptoms of iron deficiency, including chlorosis (yellowing of leaves) and stunted growth. To prevent these symptoms, horticulturists often add iron supplements to the soil to ensure that plants receive an adequate supply of this important micronutrient.