Plants protect themselves from fungi by producing

Options

A. Phytoalexins
B. Prolectins
C. Protoxins
D. Proteases

Answer

### Step-by-Step Solution

1. **Understanding the Question**: The question asks how plants protect themselves from fungi. We need to identify the correct substance produced by plants for this purpose.

2. **Analyzing the Options**:
- **Option 1: Phytoalexins**: These are low molecular weight antimicrobial compounds produced by plants in response to biotic (living organisms like fungi) and abiotic (non-living factors) stresses.
- **Option 2: Prolectins**: These are precursors of plant lectins, which may have a role in defense but are not primarily known for protecting against fungi.
- **Option 3: Protoxins**: These are precursors to toxins and may also play a role in defense mechanisms but are not specifically targeted against fungi.
- **Option 4: Proteases**: These enzymes break down proteins and are not primarily involved in plant defense against fungi.

3. **Identifying the Most Relevant Option**:
- Phytoalexins are specifically produced in response to fungal infections and are known to be broad-spectrum antimicrobial compounds. They are synthesized when plants come into contact with pathogens, particularly fungi.
- While prolectins and protoxins may have some role in plant defense, they are not as directly involved in combating fungal infections as phytoalexins.
- Proteases do not serve a protective role against fungi.

4. **Conclusion**: Based on the analysis, the correct answer is **Option 1: Phytoalexins**. They are the main compounds produced by plants to protect themselves from fungi.