Question

Flooding stress is also known as:

• A. Chilling stress
• B. Reactive oxygen species
• C. Oxygen deficient stress
• D. Drought stress

Hint:

For questions on abiotic stress, focus on the primary causal factor. For flooding, it's water displacing air, leading to lack of O₂. For drought, it's lack of H₂O. For salinity, it's high salt concentration causing osmotic stress and ion toxicity.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question asks for another name for flooding stress in plants. Flooding stress refers to the adverse conditions experienced by a plant when its root zone is saturated with water for an extended period.
Step 2: Detailed Explanation:
When soil is flooded, the water displaces the air present in the soil pores. Plant roots require oxygen for cellular respiration to produce the ATP needed for nutrient uptake and other metabolic activities.

The lack of air in waterlogged soil leads to a condition of low oxygen (hypoxia) or no oxygen (anoxia) for the roots.
This directly translates to an "oxygen deficient stress" because the primary problem for the plant roots is the inability to respire aerobically.
Let's analyze the other options:

(A) Chilling stress: Caused by exposure to low, non-freezing temperatures. This is unrelated to flooding.

(B) Reactive oxygen species (ROS): ROS are harmful molecules produced as a byproduct of metabolism under various stress conditions, including oxygen deficiency. However, ROS are a {consequence} of the stress, not the stress itself.

(D) Drought stress: This is caused by a lack of water, which is the complete opposite of flooding stress.

Step 3: Final Answer:
The primary physiological challenge imposed by flooding is the lack of oxygen for the root system. Therefore, it is correctly known as oxygen deficient stress.