Do plants have an immune system? How does it work?

Question

When you consider that they absorb chemicals through their
roots and all the crud that's in the soil, how is it possible that
they can survive?

I'm placing the address to a radio broadcast that I heard yesterday---it's
sort of related.

It will be on my Yahoo 360 today!

Oops! I should have mentioned that it's
my Yahoo 360 BLOG page. Hope that can-
cels the confusion.

Answer 1

Sap is a form of immunity.

As for soil absorption they generally take up anything which is why if the environment is sick plants are the first to die.

Answer 2

Here is some information i found from wikipedia:

"If microorganisms successfully breach the surface barriers, the cells and mechanisms of the innate immune system are present, and ready to be mobilized to defend the host. Innate immune defenses are non-specific, meaning that the innate system recognizes and responds to, pathogens in a generic way.[2] The innate system does not confer long-lasting or protective immunity to the host. It is thought to constitute an evolutionarily older defense strategy, and is the dominant system of host defense in plants, fungi, insects, and in primitive multicellular organisms. [3] The innate immune system protects the host by establishing humoral, chemical and cellular barriers to infection."

Basically, plants will destroy any particles that enter the plant that they deem harmful. Regarding the fact that their roots are in the soil, they do not absorb everything that is in the soil. They only absorb specific nutirents (the cells in their roots have a selectivley permeable barrier that only allows specific ions to enter) and water that they require to grow. The rest of the rubbish in the soil is left behind.

Answer 3

They get nutrients from the soil, but if it's tainted, it can hurt the plant. I don't think they have a self-cleansing system.

Answer 4

yes they do