Roses / Immune systems

What sort of immune systems do roses have?

In theory (money/cost issues aside) is it biologically possible to engineer vaccines for rose that would for example prevent the development of blackspot in the vaccinated plant in the first place?

gvarden at bigpond dot net dot au

We were just discussing this yesterday. Systemic Acquired Immunity is the oldest described plant resistance to pathogens. It worked first with viruses I believe, then with other pathogens. Basically it is to inoculate the plant with the virus or bacterium it’s likely to be attacked by. That stimulates it to produce chemical signals that spread around the whole plant and make the rest of it more resistant to the invader.

More recently it has been found that plants produce small RNA molecules that interfere with virus replication. The same effect turns out to suppress genetically engineered plant genes, such as those for flower color in petunias.

Yes, if it is not cost-prohibitive, we might design selective inhibitors that boost the defense responses of the plant. The key word here is cost. Some squash plants are already engineered to be resistant to a virus, and papaya is engineered for resistance to ringspot. I don’t think either of those is permitted into Australia or Japan, and I know they’re forbidden from the EU.

If you look up plant RNAi, wiki, you will get a full description of the process in plants. Also a correct historical perspective on the major contributions made by plant scientists to understanding the phenomenon. Unfortunately the Nobel prize went not to a plant person, like David Balcoumbe, but to animal folks.

"To enhance powdery mildew resistance, an antimicrobial protein gene, Ace-AMP1, was introduced into

Sorry I didn’t reply earlier but I got hijacked and the list got spammed and I’m just getting back to it.

The Ace AMP-1 is Allium cepa (onion) antimicrobial protein. It was introduced by infecting with a bacterium having the gene’s DNA, carried on a plasmid, into a cultured rose callus. Then plants were regenerated. There was another gene for antibiotic resistance co-introduced and then selected for (Kanamycin I think).

So this is a genetically engineered plant. The DNA lands in random places in the chromosomes, carried in by the Ti plasmid of the bacterium, so each plant may be more or less able to express the protein. Good ones which are highly resistant to the pathogen have to be identified and then bred with other CV to make them (seedlings from certain CV) resistant too. It could be a direct fix for Carefree Beauty, if mildew were a problem. But I’ve never seen it and I don’t think it amounts to much problem in most parts of the U.S.

But this is a genetically engineered plant. So it has to go through all the regulatory hoops that the blue rose did. This was a “proof of principle” study, I think. The costs would make in unaffordable except for something that sells as well as Knock Out. For release into the environment, costs are in the range of 50 million+. That is why we have only half a dozen crops out there now. (Maize, soybean, cotton, canola, sugar beet[on hold}. Not even wheat or rice yet.

Unfortunately the RNAi spray might be considered engineering, but maybe it’s only a pesticide. Indian scientists have engineered RNAi to delay ripening of tomato, but no simple inoculation yet.

Successful disease immunization technologies for rose would be great for the rose gardener / consumer, and would no doubt raise demand for roses in general, which is also a great thing for those in the business of roses generally.

Utility-type patents would no doubt apply.