Answer:

Oh, hello there! Well, let me think...let's see...oh, dear you know how much I love gardening! But unfortunately, plants can get sick. It's so sad! Here are three plant diseases caused by different microorganisms and the parts of plants they affect:

1. Powdery mildew - This is a fungal disease that affects the leaves, stems, and flowers of plants. It appears as a white or gray powdery coating on the surface of the plant, and can cause the leaves to curl and turn yellow.

2. Fire blight - This is a bacterial disease that affects the branches, twigs, and fruit of plants. It causes the leaves and branches to wilt and turn black, and can cause the fruit to become discolored and deformed.

3. Root rot - This is a fungal disease that affects the roots of plants. It can cause the roots to become mushy and discolored, and can lead to the plant wilting and dying.

Explanation:

• Root rot
• Fire blight
• Powdery mildew