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Q: Pseudomonas syringae - biotechnology applications ( Answered,   0 Comments )
Subject: Pseudomonas syringae - biotechnology applications
Category: Science > Technology
Asked by: marmite-ga
List Price: $10.00
Posted: 27 Jul 2003 16:33 PDT
Expires: 26 Aug 2003 16:33 PDT
Question ID: 235757
Pseudomonas syringae - friend or foe? Discuss the applications of this
plant pathogen in biotechnology, and associated safety considerations.
I need to write a 2000 word essay on the above topic. Could you please
point me to some refereneces and information for this. This is a new
subject being taught this year and we have very few text books
available.  The net has so much that is not relevent when you do a
Subject: Re: Pseudomonas syringae - biotechnology applications
Answered By: kutsavi-ga on 09 Aug 2003 17:02 PDT
Hi there Marmite-ga

Sounds like just need some solid references on the topic.  What I’ve
done below is to find articles by recognized academic/governmental
researchers and authors at reputable reference sites. I've provided a
sample of the article, and a list of the references the author/s
cited.  I’ve tried to create a sample of both sides of the issue.

Those activists claim that even precise, minimal genetic modifications
will have unpredictable, potentially disastrous effects. For example,
they predicted that field trials of a recombinant bacterium designed
to prevent crops from freezing ("ice-plus" Pseudomonas syringae
stripped of the gene that promotes ice crystal formation in plant
tissues) could disrupt weather patterns and air traffic control. They
hold that using bovine somatotropin (bST) to increase milk production
in dairy cows will cause breast cancer in women who drink milk. They
whinge endlessly about the horrors of "moth genes in our tomatoes."

Prominent opponents of the new biotechnology are not quixotic
ideologues but well-financed specialists pursuing single-issue
activism. They have battled biotechnology for more than twenty years
and, on occasion, have enjoyed modest successes. They appear at public
hearings claiming, without corroboration, to represent numerous
concerned citizens. I wonder, though, how the rank and file of the
National Wildlife Federation would have polled on their organization's
bitter, tenacious opposition to the development of a recombinant
rabies vaccine for animals in the wild.

References from this article:

Adapted from an article entitled "When Worlds Collide: Science,
Politics, and Biotechnology," Priorities 9, no 4 (1997). Used with
[kutsavi-ga:  And here is that article:]

Available from the Hoover Press is the Hoover Essay in Public Policy
Is the Biodiversity Treaty a Bureaucratic Time Bomb? by Henry I.
Miller. To order, call 800-935-2882.

Henry I. Miller, M.D., is a senior research fellow at the Hoover
Institution. He is former director of the Office of Biotechnology at
the Food and Drug Administration.

And from the opposite side of the table:
From: The Scientist Website:

Perspective: Fears or Facts? A Viewpoint on GM Crops
By Barry A. Palevitz and Ricki Lewis 

In 1977, Steven Lindow, a graduate student at the University of
Wisconsin in Madison, discovered that a mutant strain of the bacterium
Pseudomonas syringae altered ice nucleation on leaves in a way that
enabled plants to resist frost. He continued the work at the
University of California, Berkeley, and a decade later, with the
blessing of the appropriate federal agencies and the townfolk of
Tulelake, Calif., Lindow planted 3,000 potato seedlings coated with
"ice-minus" bacteria. By the next morning, vandals had ripped out half
the plants. Lindow repeated the experiment, successfully.
Similar experiments did not set loose giant carnivorous rutabagas on
the world, and while the Flavr Saver tomato was controversial, hoopla
surrounding genetically modified (GM) plants largely died down in the
United States. But that appears to be changing. In response to anti-GM
decisions by foreign and domestic customers, U.S. grain processing
giant Archer Daniels Midland recently asked its suppliers to segregate
GM crops.

References from this article:

Barry A. Palevitz ( and Ricki Lewis
( are contributing editors for The Scientist.

Note: After several years, Barry A. Palevitz is resigning his
membership in Greenpeace.

M.J. Crawley, "Bollworms, genes and ecologists," Nature, 400:501-2,
Aug. 5, 1999.

Food Safety Authority of Ireland, "Food safety and genetically
modified foods," May 1999,

N. Perian, "Strange new world," Greenpeace Magazine, pages 7-11,
Spring 1999.

F. Wambugu, "Why Africa needs agricultural biotech," Nature, 400:15-6,
July 1, 1999.

G. Gaskell et al., "Worlds apart? the reception of genetically
modified foods in Europe and the U.S.," Science, 285:384-7, July 16,

R. Lewis, "Rice delivery," The Scientist, 13[17]:35, Aug. 30, 1999.
(Requires free registration on *The Scientist* web site.)

The US Environmental Protection Agency is stands firmly behind the
benefits of PS:

Various studies show that Pseudomonas syringae strain ESC-10 and
Pseudomonas syringae strain ESC-11 do not cause adverse effects in
mammals when the bacteria are ingested, inhaled, or put on skin.
Furthermore, the bacteria cannot survive at temperatures above 32o C
(90o F), and therefore cannot grow in humans or birds, whose body
temperatures are considerably higher. For example, normal human body
temperature is 37o C, (98.6o F). No health risks to humans are
expected from use of these bacterial strains in pesticide products
when label directions are followed.

These bacteria are not expected to cause harm to the environment.
Because the fruits are treated in an enclosed area, exposures to the
environment, including wildlife, soil, and water are not expected.

“Prometheus Bound”
By Fred L. Smith, Jr., president of the Competitive Enterprise
in Washington, D.C.
Published by the Cato Review of Business and Government in the journal

“But fear of biotech has done much greater harm than would ever be
likely from new discoveries. For example, Advanced Genetic Sciences
developed a product, Frost Ban, to reduce frost damage to plants. A
common bacteria, Pseudomonas syringae, found on many plants, produces
chemicals which facilitate ice crystal formation. Researchers were
able to delete the responsible gene, providing some protection to
delicate strawberry plants. Rationalizing that the modified bacteria
might replace the "ice plus" bacteria which can be viewed as a "pest,"
the EPA asserted that it was pesticide; even though no new genetic
material was introduced to the environment. Unfortunately, the state
of California required protective moonsuits to be worn during testing
and the industry went along. Thus while industry press releases noted
that the microorganisms being applied to the strawberries were
completely safe, the visual message of the moonsuits was, "This stuff
is dangerous!" The public relations debacle forced the company to drop
attempts to market the product.”
Here’s one that’s a little dated, but still worth a reference:

OSU News; Oregon State University’s News & Communications Services

By David Stauth, 541-737-0787
SOURCE: Heather Scheck, 541-737-5254 

CORVALLIS - A bacterial disease that plagues Oregon's $419 million
nursery industry has recently developed resistance to both of the
chemicals used to control it, according to a new study at Oregon State

These Pseudomonas syringae bacteria, which cause a disease commonly
known as bacterial blight, are already responsible for more than $8
million in annual losses to the nursery industry.

As chemical resistance spreads it's reasonable to believe that problem
will worsen - a survey of 44 Willamette Valley nurseries showed
pathogens are now prevalent everywhere, with 467 strains isolated from
25 plant species.

However, OSU scientists have identified types of chemical treatments
and plant management strategies that will provide some help to
operators of Oregon nurseries, which are the state's most valuable
agricultural sector.”


Biological Control of Plant Pathogens: Research, Commercialization,
and Application in the USA

Brian B. McSpadden Gardener, Department of Plant Pathology, The Ohio
State University-OARDC, Wooster, OH 44691; and Deborah R. Fravel,
Vegetable Laboratory, USDA, ARS, Beltsville, MD 20705

“Over the past one hundred years, research has repeatedly demonstrated
that phylogenetically diverse microorganisms can act as natural
antagonists of various plant pathogens (6) (Fig. 1). The interactions
between microorganisms and plant hosts can be complex. Interactions
that lead to biocontrol can include antibiosis, competition, induction
of host resistance, and predation (7). When testing bacterial and
fungal isolates from the environment for biocontrol activities,
between 1 and 10% show at least some capacity to inhibit the growth of
pathogens in vitro. However, fewer isolates can suppress plant
diseases under diverse growing conditions and fewer still have
broad-spectrum activity against multiple pathogenic taxa. Nonetheless,
intensive screens have yielded numerous candidate organisms for
commercial development. Some of the microbial taxa that have been
successfully commercialized and are currently marketed as
EPA-registered biopesticides in the United States include bacteria
belonging to the genera Agrobacterium, Bacillus, Pseudomonas, and
Streptomyces and fungi belonging to the genera Ampelomyces, Candida,
Coniothyrium, and Trichoderma (20). Screening is a critical step in
the development of biocontrol agents. The success of all subsequent
stages depends on the ability of a screening procedure to identify an
appropriate candidate. Many useful bacterial biocontrol agents have
been found by observing zones of inhibition in Petri plates (Fig. 2).
However, this method does not identify biocontrol agents with other
modes of action such as parasitism, induced plant resistance, or some
forms of competition. Screening methods for parasitism include burying
and retrieving propagules of the pathogen to isolate parasites. For
competition, methods include looking for microbes that quickly
colonize sterilized soil and have the ability to exclude other
organisms that attempt to invade the space, and looking for microbes
that colonize the infection court. Primary screens for new biocontrol
microbes are still undertaken (13), and it seems likely that continued
prospecting will be required to diversify the potential applications
of biocontrol as well as replace more widely used biocontrol products
should resistance develop.”

[--kutsavi-ga:  And there’s a wonderful reference in amongst the tons
of others at the end of this particular article]:

Ligon, J. M., Hill, D. S., Hammer, P. E., Torkewitz, N. R., Hofmann,
D., Kempf, H. J., van Pee, K. H. 2000. Natural products with
antifungal activity from Pseudomonas biocontrol bacteria. Pest Man.
Sci. 56:688-695

This is a HUGE bibliography with at least 25 references to biotech
uses of PS, but I’m not sure if any of them address your specific
need; I included it because of its completeness as a reference, and
the possibility that further research on some of the titles may lead
you where you need to go.

Ok Marmite-ga, here are some references to get you started.  I hope
they are what you’re looking for.  If I can provide further
information or clarify anything, please don’t hesitate to use the
“Request Clarification” button.  Thanks for a challenging question!

There are no comments at this time.

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