One such molecule is resveratrol which provides defense in plants against fungi and modulates immunity at the cellular level.

The universe has build up with similarities in many species with molecules, that's now science.

As per my knowledge ,The clear variations were defined between plant and human immune system.Even though molecule is different the immune function has high impacts of similarity.

I can explain you that, in very precisely ..

The innate immune system majorly starts with antigen rcognition by host cell, for example in drasophila and human they were called Toll,or TLR receptors, a rich Leucine repeats. With activation of this it triggers various intra cellular signals to produce anti microbial peptides and finally to transcriptional activation to induce Immune complexes(Various immune responses of gene or specific loci) .

Here the interest is the same Leucine rich repeats were observed on plasma membrane of plant cell, with same kind of immune response but the signalling mechanism was highly different.

The similarity between animal cell and plant cell...

The flagella r bacteria is a strong ligand in both cases that activates the innate immune response....

In the case of animal cells it activates Leucin rich repeat called TLR4 domain,to activate protein kinase leads various secondary signals and immune response for invasive infection.(The secondary signals generates adaptive immunity)

In the case of plant cell the flagella of bacteria activates FLS2(flagellin sensitive 2)and starts secondary signal as protein kinase finaly to transcriptional activation and immune response.

Here animal cell (TLR4) and plant cell (Fls2) do the same function, but the sequence qnd motifs were different.

Hope my explanation gives you an idea..how plant cell and animal cell sensitized upon infection

Srikanth

One such molecule is resveratrol which provides defense in plants against fungi and modulates immunity at the cellular level.

Remember that plants don't have an adaptive immune system like animals do (i.e. antibodies, dedicated immune cells etc.) Plants only have innate immunity, and as Srikanth mentioned, there are some similar mechanisms involved, such as recognition of pathogen associated molecular patterns (PAMPs) or gene-for-gene resistance.

Actually, it exists one kind of molecules that is common to human and plant immunity : reactive oxygen species, commonly known as ROS. In plant, they are synthesized during the hypersensitive response and lead to the oxidative burst, which is a chemical destruction of infected cells. In human immunity, ROS are used to help the destruction of antigens after their phagocytocis by an immune cell.

You can also focus on defensins, which are small cysteine-rich proteins, with strong antimicrobial properties, and conserved in vertebrate/invertebrate/plants.

I think you should read this article

Innate immunity in plants and animals: striking similarities and obvious differences.

Nürnberger T, Brunner F, Kemmerling B, Piater L

http://www.ncbi.nlm.nih.gov/pubmed/15199967

First of all, to my knowledge, there is no immune system in plants. They only have lot of defense molecules like antioxidants, flavonoids, , defense-related enzymes like SOD, , glutathione per oxidase, ascorbate per oxidase and reductants as well.

Please let me know, Which system is active for plant to defense plant pathogen? These molecules are active for defense but the procedure name is unknown to me.

As I mentioned in my previous comment, the plant cell containing receptors able to sense different microbiol products.Let say , a well known laborotary plant Arabidopsis infected with purified gram negative bacterial cell wall component (LPS) can able to trigger various immune cascading ,these signalling mechanisms are all comes under innate immunity.

As plant does not have the memory immunity (adaptive) ,its always struggle do eliminate or die.In case of classical bacterial infections ,plant cell try to eliminate microbe by producing excessive ROS that increases the intracellular pH and kills the bacteria.

Since the discovery of innate mechanism key playesrs,various sensible molecules and receptors proved plant cell have the innate immunity,but not adaptive,due to this cause we cannot say plant do not have the immune system.It was cleared engineered plants have more resistance than WT type.

A recent study proved,immunity defensing related plant metabolism with some striking results.