172. One of the most popular genes used for developing rice tolerant to flooding stress is:
1. Sub1A
2. LEA
3. HSP70
4. DREB1A

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Introduction to Flooding Stress in Rice

Flooding stress is a significant challenge for rice cultivation, particularly in regions prone to monsoons or irregular flooding. In response to this, researchers have identified key genes that can help rice plants survive and thrive in waterlogged conditions. Among these, Sub1A is one of the most widely used and effective genes in developing rice varieties that are resistant to flooding.

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The Role of Sub1A Gene in Flooding Tolerance

The Sub1A gene is part of a Submergence 1 (Sub1) gene cluster, which is a key determinant of flooding tolerance in rice. This gene helps the plant respond to submergence by regulating the expression of various stress-responsive proteins and metabolic pathways. It does so by:

• Enhancing the plant’s ability to withstand submerged conditions.

• Limiting energy consumption during periods of low oxygen availability.

• Increasing the survival rates of rice plants under waterlogged conditions.

The Sub1A gene works through anoxic stress signaling and helps rice plants avoid irreversible damage due to flooding.

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Other Genes for Stress Tolerance

While Sub1A is a major gene for flooding tolerance, several other genes are involved in plant stress responses:

1. LEA (Late Embryogenesis Abundant proteins): These genes help in drought and salt stress tolerance by protecting cellular structures during dehydration.

2. HSP70 (Heat Shock Proteins): Involved in protecting the plant from heat stress, these proteins are important in cellular repair mechanisms.

3. DREB1A (Dehydration Responsive Element Binding protein): This gene is crucial for drought and cold tolerance by regulating the expression of genes involved in the plant’s response to dehydration.

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Conclusion:

For flooding tolerance in rice, the Sub1A gene is one of the most widely used and effective markers. It plays a crucial role in enabling rice plants to survive submerged conditions, especially in areas where flooding is a common occurrence.

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Correct Answer:

1. Sub1A

The Sub1A gene is a key factor in developing rice varieties that can withstand flooding stress.