Substances that accumulate around a site of infection in plants is

Options

A. Phytolexins
B. Proteinome
C. Saponins
D. All the above.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the substances that accumulate around the site of infection in plants. This indicates a defensive response by the plant to protect itself from pathogens.

2. **Identifying the Substances**: The substances that are known to accumulate at the site of infection in plants are called **phytoalexins**. These are specialized compounds produced by plants in response to stress or pathogen attack.

3. **Function of Phytoalexins**: Phytoalexins play a crucial role in the plant's defense mechanism. They help to inhibit the growth of pathogens, thereby curbing the infection. This means that they act as a chemical barrier against disease-causing agents.

4. **Generalization**: The phenomenon of phytoalexin production is not limited to one type of plant; many plants exhibit this response when faced with infection. In some cases, these substances can also prevent the growth of nearby plants, indicating their broad-spectrum defensive capability.

5. **Conclusion**: Based on the information provided, the correct answer to the question is **phytoalexins**.

### Final Answer:
The substances that accumulate around a site of infection in plants are called **phytoalexins**.

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