Correct option is C
Explanation:
Let's evaluate each statement about the strategies adopted by fungal pathogens:
A. HC toxin inhibits histone deacetylase of the host plant.
This statement is correct. HC toxin produced by some fungal pathogens is known to inhibit histone deacetylases (HDACs) in the host plant. Histone deacetylases play a role in regulating gene expression by modifying histones. Inhibition of HDACs can alter the plant's gene expression patterns, leading to weakened defense responses and facilitating fungal infection.
B. Oxalic acid produced by fungal pathogens suppresses early plant defense responses.
This statement is correct. Oxalic acid is a toxin produced by many fungal pathogens, including Fusarium and Sclerotinia. It can suppress plant defense responses by lowering the pH in the infected tissue and by interfering with the plant's signaling pathways that are critical for early defense responses. This allows the fungus to invade the plant more effectively.
C. Oxalic acid produced by fungal pathogens induces callose deposition in the infected tissues.
This statement is incorrect. Callose deposition is typically a response of the plant to restrict pathogen spread, and this usually occurs in response to various stressors, including pathogen attack. However, oxalic acid produced by fungal pathogens does not induce callose deposition but may suppress other aspects of plant defense.
D. HC toxin targets plasma membrane-localized H+-ATPase in the host plant.
This statement is incorrect. The HC toxin is primarily known for inhibiting histone deacetylase (HDAC) in the plant host, not for targeting the plasma membrane-localized H+-ATPase.
Conclusion:
A and B are correct statements regarding the HC toxin and oxalic acid produced by fungal pathogens.
C and D are incorrect because oxalic acid does not induce callose deposition and HC toxin does not target the H+-ATPase.
Thus, the correct answer is Option 3: A and B.
