Microbe-Plant Interactions

Microbe-plant interactions rely on two-way chemical signaling and can be beneficial, neutral, or harmful.

Endophytic microbes live inside plant tissues and often form symbiotic relationships with their hosts.

For example, legumes, such as soybeans, harbor rhizobia, which are nitrogen-fixing bacteria that typically form nodules on their roots.

They have a mutually beneficial interaction that provides the plant with usable nitrogen through fixation in exchange for sugars.

But non-legume plants, such as the tomato plant, exhibit a neutral interaction with rhizobia. They coexist without significantly affecting each other’s survival or function.

On the other hand, some microbes are harmful. Bacterial pathogens, such as Agrobacterium tumefaciens, enter through wounds and cause crown gall tumors.

Necrotrophs, like the white mold fungus, kill plant cells using toxins or enzymes.