X-Message-Number: 30856
Date: Sat, 12 Jul 2008 08:49:14 -0700 (PDT)
From: 
Subject: Spray Improves Plants' Cold Tolerance

http://uanews.ua.edu/anews2008/jul08/spray070808.htm

Spray Co-Developed by UA Researcher Improves Plants' Cold Tolerance

TUSCALOOSA, Ala. - Studies indicate a spray co-developed by a University
of Alabama scientist increases plants' tolerance of cold temperatures by
several degrees.

The spray, which is not yet commercially available, can improve plants'
cold tolerance between 2.2 and 9.4 degrees Fahrenheit, depending upon the
species, according to Dr. David Francko, a professor of botany who
co-developed the spray and who serves as dean of The University of
Alabama graduate school and assistant vice president for academic affairs.

Research results indicate the spray, which the developers have named
Freeze-Pruf, is effective on a variety of plants, including palms,
tropical houseplants, bananas, citrus plants and flowers. Commercial
growers, including those growing edible bananas in south Alabama, would
benefit from the longer growing season that a more cold tolerant plant
would provide.

"It moves your temperature zone about 200 miles, so it's highly
significant," Francko said of the spray's impact on banana plants. "For
growers in the Mobile area, for example, treated plants would sustain the
same damage that someone in Orlando would have who's not treating their
plants."

Francko, who developed the spray along with Kenneth Wilson, Quinn Li and
Alejandra Equiza, all from Miami (Ohio) University, envisions the spray
also appealing to backyard gardeners looking to protect flowers from a
late frost and nursery owners looking to cash in on an approved
appearance for their high dollar ornamentals.

A patent application on the product, a novel mixture that combines five
ingredients in a water-based spray formula, was filed earlier this
year. The inventors are working with UA's Office for Technology Transfer
on the possibility of licensing the product to a company for commercial
production or, alternatively, forming a UA spin-off venture to
commercialize the technology.

"Each ingredient has a different function, but when you put them all
together you get an effect that is larger than any single component,
alone," Francko said. "It's non-toxic, it's cheap, and the idea is to
apply it once per season." Each of the ingredients in Freeze-Pruf is
already used, for other reasons, in various foods or in food production.


Although -3 degrees Celsius kills tropical foliage, as demonstrated by
the five control leaves, the leaves sprayed with the formulation (bottom
row, middle and right) are unharmed by -6.4 degrees Celsius.

Francko, who received widespread media attention, including a national
television appearance alongside Martha Stewart, following his 2003
publication of "Palms Won't Grow Here and Other Myths," called cold
tolerance products "one of the holy grails of horticulture.

"There are a number of existing patents designed to improve cold
tolerance," Francko said, "but the best that is out there gets you about
1 to 2 degrees centigrade, or 2 to 4 degrees Fahrenheit, of freeze
protection."

And the existing sprays, Francko says, typically protect plants in
weather only as low as the mid to upper 20s Fahrenheit. "Our spray works
all the way down to below zero Fahrenheit, depending on the plant you're
working on. It really does take advantage of the plant's genetic
pre-adaptation and improves it."

Plants naturally use two mechanisms in attempts to survive cold, said
Francko, former chair of the department of botany at Miami University in
Ohio. Similar to how a vehicle's radiator contains a cryoprotectant which
prevents it from freezing, plants have a built-in non-toxic version which
allows cells to "super cool" below the normal temperature at which water
freezes. Secondly, Francko said, even when ice does form within some
plants, another natural mechanism enables them to sometimes survive ice
crystal damage.

An untreated ornamental and fruit-producing banana Musa orinoco
(right) was destroyed after some 20 minutes of exposure while a treated
plant of the same species exhibits increased heartiness after three hours
exposure.

"Anything that you do to improve plant cold tolerance, you want to
enhance those two mechanisms," Francko said. "Nothing in our formulation
is part of the normal pathway that a plant uses to acclimate to the
cold. So, we are adding extra capacity to what the plant normally can do,
not replacing or diminishing that native capacity," said Francko.

Freeze-Pruf lowers both the temperature at which damage first becomes
noticeable in plants as well as the temperature that would normally kill
the plant, according to the research results. "It protects both the
foliage and the flower," Francko said.

The formula was scientifically tested in the laboratory and in the field,
using both visual damage and the results of photosynthetic assays to
measure foliar and flower damage. The photosynthetic assay was a
biochemical analysis to check the spray's effectiveness at the
sub-cellular level.

The spray is already cost effective, Francko said, and researchers are
exploring possible ways to perfect it so even smaller quantities of spray
would bring similar results.

The University of Alabama, a student-centered research university, is in
the midst of planned, steady enrollment growth with a goal of reaching
28,000 students by 2010. This growth, which is positively impacting the
campus and the state's economy, is in keeping with UA's vision to be the
university of choice for the best and brightest students. UA, the state's
flagship university, is an academic community united in its commitment to
enhancing the quality of life for all Alabamians.

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