Question

Which of the following statement(s) is/are CORRECT about 'stringent response' in bacteria?

• A. It is linked to reduced growth rate
• B. Guanosine tetraphosphate (ppGpp) alone is sufficient to trigger the process
• C. Both guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp) are required to trigger the process
• D. RelA and/or SpoT are/is involved in triggering the process

Hint:

The stringent response is regulated by ppGpp and is linked to reduced bacterial growth rate under stress.

Answer 1

The Correct Option is D

Step 1: Understand stringent response.
The stringent response is a bacterial stress response activated under nutrient limitation or other stress conditions. It leads to a slowdown in growth and changes in gene expression to conserve resources.
Step 2: Analyze the options.
- (A) Correct: The stringent response is indeed linked to reduced growth rate as the bacteria slow down their metabolic processes to conserve resources.
- (B) Incorrect: While ppGpp is a key molecule, it is not sufficient alone to trigger the stringent response.
- (C) Incorrect: Both ppGpp and pppGpp are involved in the stringent response, but ppGpp is more critical.
- (D) Correct: The stringent response is regulated by the proteins RelA and SpoT, which synthesize or hydrolyze ppGpp in response to stress.
Step 3: Conclusion.
RelA and SpoT play a critical role in triggering the stringent response in bacteria.
Final Answer: \[ \boxed{\text{RelA and SpoT are critical in triggering the stringent response in bacteria.}} \]