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: Concept Overview:
The question seeks an alternative term for flooding stress in plants. Flooding stress occurs when a plant's root zone is saturated with water for a prolonged duration, creating unfavorable conditions.
Step 2: Detailed Explanation:
Flooding displaces air from soil pores. Plant roots need oxygen for cellular respiration, which generates ATP for nutrient absorption and metabolic processes.

Waterlogged soil results in low oxygen (hypoxia) or no oxygen (anoxia) for the roots.
This is directly referred to as "oxygen deficient stress" because the main problem is the roots' inability to respire aerobically.
Analyzing the other options:

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

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

(D) Drought stress: Results from water scarcity, the opposite of flooding stress.

Step 3: Conclusion:
Flooding's primary physiological impact is oxygen deprivation for the root system. Therefore, it's accurately termed oxygen deficient stress.