Most have body shapes of round, rodlike or filaments and some have flagella or appendages to help move. Most are only seen under a microscope. They are carried by water or transported in soil, media, or the air. Some bacteria live on dead material and are called saprophytes. These types of bacteria are important for plants because they recycle dead material and make the nutrients available for plants.
Some bacteria are autotrophic, or they make their own food.
These are of limited importance to the plants. Bacteria that live on living plants or animals are called pathogens or parasites. These are the bacteria that must be controlled or your plants will become ill. Bacteria enter their host through wounds or small openings. They can easily be spread from one plant top another.