Question: You refer to plants fighting disease, do plants have an immune system in any way similar to humans?

Steven Kiddle answered on 22 Jun 2010:

The do have an immune system, but it works very differently to ours. Our immune system mostly involves antibodies, these are proteins that recognise foreign proteins, like the cell wall of a bacteria. Plants do not have antibodies, instead their defence system is a mixture of gene regulation, hormone balance and the production of “weapons”.

Like antibodies in humans, plants have detector proteins in their cell wall that can recognise dangerous proteins. These typically cause a signalling cascade that result in genes being turned on to produce specific weapons. Hormones are used to prioritise weapons when the plant is under attack by multiple diseases.

By weapons i mean proteins that can destroy the bacteria/virus/fungus/oomycete that is causing the disease.

I apologise if the answer was a bit technical, plants have a very intricate way of defending themselves! 🙂