Plants have evolved a host of defense mechanisms for fighting infection by viruses, bacteria, and fungi. For instance, when they recognize an infection, plants produce antimicrobial compounds and induce programmed cell death in infected areas. In addition, uninfected parts of a plant can develop a heightened resistance to help stem further infection by a number of pathogens, a phenomenon called systemic acquired resistance (SAR).

In 1990, we discovered that salicylic acid accumulated in infected plant leaves and signals a transmutational change in SAR. Since salicylic acid was known to induce SAR when sprayed on plants, we postulated that it was the signal molecule that moved from infected leaves to uninfected leaves to turn on systemic resistance. Subsequent studies reinforced this notion of salicylic acid as a translocating signal.

I've viewed this concept of salicylic acid as a messenger molecule to hormones in mammals. Salicylic acid is the translocated signal-the hormone, if you like-that moves throughout the plant and turns on systemic resistance.

We've demonstrated that salicylic acid is essential for the development of systemic resistance. Plants that contained a gene coding for an enzyme that degrades salicylic acid did not accumulate the compound upon infection and were incapable of inducing SAR. The oaks we selected were quite susceptible to a range of diseases including oak wilt, and we chose these specimens over other more susceptable hardwoods that indicated a faster degredation of salicylic acid.

Then we did grafting experiments in which one part of the grafted plant contained the salicylic acid-degrading enzyme and the other did not. We then infected leaves on one side of the graft and watched to see if SAR was induced or not. Not one bit of this research was or is
supported by conventional pathology. It turned out that leaves carrying the salicylic-acid-degrading enzyme did not accumulate salicylic acid, but were fully capable of inducing systemic resistance in normal leaves on the other side of the graft. What this argues is that a signal other than salicylic acid moves throughout the plant to induce systemic resistance. The grafting indicated that salicylic acid is required in systemic leaves for proper induction of systemic resistance. This explains the requirement for salicylic acid in SAR.

We then feel through our demonstration that salicylic acid is considered a very important molecule in disease resistance in plant biology. It's one of the few molecules known in the pathway for the induction of SAR. Our commercial work in treating active infected Quercus against C. fagacearum has been successful in Texas but is being ignored by the large schools and has had us cornered against the large market for systemic fungistat use being advocated in the arboriculture industry. For countless years we have been urging caution in the blind use of such fungicidal approaches to disease control fearing principally the mutational responses of this disease to these treatments - resulting in larger scale epidemics possibly resistant to even SAR response in forest areas. In single tree applications of chemicals like Arbotect and Alamo, repeat uses due to dilution and poor translocation will and has killed the tree the treatment intended to save as well as the singular intended mechanism that only inhibits sexual reproduction of the pathogen - not a cure for disease physiology or a adaquate preventive - as industry advocates it is.

I simply wanted to express this warning along with the suggested potential of alternatives to chemical use in disease control - We feel strongly opposed to the market mentality developed we feel - not to assist in saving the priceless resources, but to make money - more and more money. Please exercise caution when selecting treament options and don't always believe what you may read. Oak wilt has become the single most costly hardwood epidemic in North American forest history - we must learn a lesson in this.

Sorry for the rambling, but someone posted a few topics back about wilt and the response hinted at getting lab verification from Texas A&M University - not accurate enough, not fast enough, and the treatment they recommend is not adaquate enough.

Thank you,
Reed

Reply to post by Reed Holt, on June 04, 2000 at 10:40:07:

Fascinating stuff. Russ posted a link some months ago to an article that does seem to touch on some of the mechanisms you describe.

http://www.newscientist.com/features/features.jsp?id=ns22265

Reply to post by Scott Cullen, on June 04, 2000 at 10:40:07:

I have to chime in here. I feel the need to offer some balance to Reed's comments. I know of Reed and his work. I wish I could say I was impressed. Work with salicylic acid is not new. Several companies have been looking at its activity among lower order fungi. There is a distinct difference in that activity and activity against a vascular wilt disease.SAR is nothing new.

I have made overtures to Reed in the past years to review his work and successes for free. In that I am a non-partial party with no interest in anything but success, I would be able to give objective observations. Thus far those offers have been rebuffed. If he has some obvious results, he is keeping them behind closed doors, except for here. Reed appears to have some significant paranoias about. Some of those might be well founded, but he does tend to paint things with a broad brush. He apparently considers me one of "them" as I have dared questioned his output in several forums.

A couple of years ago I went to Reed's area, at invitation, along with other invited guest. At that time Reed was touting a product for sell that was an organic treatment for oak wilt. He presented something he refered to as a research paper which was little more than a testimonial and advertisement. He included a letter from a Phd.plant pathologist who we later found to have dubious credentials. We were shown various trees in areas of oak wilt and told they were successes. The trees were indeed healthy, but there was no evidence that they were ever diseased or challenged. To say the least, I was unimpressed with what I witnessed.

When queried about verification he alluded to some vague results he found on his own. He is right in saying that none of the "research" he has carried out was done under the guise of conventional plant pathology protocol.

If I were to observe, I would require positive (or as close as possible) identification of the disease, monitor treatment protocol, and monitor post-treatment. I would have to see repeated results in seperate non-contiguous plots.

I would like nothing better than to have a product emerge that would do what he suggest. I am a supporter only of results, not chemicals. We have a serious problem with oak wilt. It would make you arborist in the mid-west blush at the devestation is causes here. It is obviously a very emotional and economic issue. In such environments, people will reach out for any and every thing. I try to give them all the tools to make good decisions for oak wilt management.

Reply to post by Dennis Brown, on June 06, 2000 at 19:28:39:

But Dennis, I'm not selling ANYTHING!!!
If you investigate better - I'm the one who turned-in Nigel for false credentials - the only
one. UC Riverside is working with me on this. The verification of the sick motts I demonstrated was done by plant path at A&M - now eight years ago. You seem to want to believe them, so there.
Also - you will notice that in Texas I'm no longer a commercial enterprize - I gave the company away my friend - I make no money on wilt - like the cancer work I have always done - no money my friend - no prejudice then.
If you claim intolerance to chemical uses - why do you then advocate it? If you distrust the labs - why suggest trenching as tested and reported falsely on?
The commercial product ELMGuard, University of Toronto, is a modified avirulence gene that triggers manufacture and distribution of antibodies systemically - hardly a new science but yet again, your position on what the pathologists maintain here in Texas is that tree's have no immune system. If you do not recognize this, you should find work elsewhere.
It's like a surgeon claiming there is no heart
or lungs in our bodies.
There is a reason my northern friends - why the epidemic has been more destructive in Texas - the information sources here and the sick methods for remedy advocated by A&M University.
Too arrogant to even review data from other states - but not too proud to receive research grants from the giant Novartis corporation.
Support common sense approaches to disease control Dennis - quit fighting this.
Reed Holt - close to indigent but still proud!

Reply to post by Reed Holt, on June 07, 2000 at 11:48:19:

I am not going to take up much more space in responding to Reed's comments, as much as I would like to.

I will say that Reed's denouncement of Nigel Greck came only after my own investigation revealed suspicions of his credentials. This was when Reed was using him as a support member of his treatment program and quoted him extensively. Reed only got the pang of suspicion after Mr. Grech started working with a competitor on a similar material.

I doubt there are many who are actually interested in this dialogue between Mr. Holt and myself. I simply wanted to balance the scales a bit with real information after reading his post. However, if anyone would like more information on our oak wilt problem, and the players, feel free to contact me.

Dennis Brown
quercus@texas.net

Reply to post by Dennis Brown, on June 07, 2000 at 15:57:10:

All I can say to that is:

There are choices out there - choices not in finding the best available "product" for treatment, but choices as to how you treat your responsibility for this planet as a dweller and dependent of this planet.

The easiest way to think about that is this - when you get a terminal diagnosis - you can do one of two things - do as they say you must, or find out what it takes to survive. Period.

You make the choice, you have to live with it.
If peer-reviewed data is mandatory for truth - might as well toss-out the bible and torch the churches Dennis. I myself prefer the natural order - which is neither of those.