Plant Biotechnology and Genetics: Principles, Techniques and Applications

(Brent) #1
returned to my Hawaiian roots to work
for the Agricultural Research Service
of USDA in Hilo, Hawaii
I gravitated from classical virology to mol-
ecular biology and biotechnology in the
mid-1980s because of the prospects for
developing virus-resistant transgenic
crops. The pioneering work by Roger
Beachy’s group provided the proof-of-
concept. My lab in collaboration with
others have developed commercial virus-
resistant squash and papaya. However,
the papaya story has garnered the most
interests for several reasons. A nutshell
summary of the papaya work follows.
We developed, for Hawaii, transgenic
papaya that resists papaya ringspot virus
(PRSV), the most widespread and dama-
ging virus of papaya worldwide. We
started developing the transgenic papaya in
the mid-1980s and had obtained a resistant
transgenic papaya line by 1991.
Coincidentally,PRSVinvadedpapayaplan-
tationsin Puna onHawaiiIsland in 1992 and
by 1995, the papaya industry was severely
affected because 95% of Hawaii’s papaya
was being grown in Puna. Essentially, we
had a potential technology to control the
virus but it had to be deregulated by
APHIS and EPA, and pass consultation
with FDA. We worked feverishly to test
the papaya, develop data for deregulation,
and getitcommercialized. In 1998,we com-
mercially released the SunUp and Rainbow
papaya and essentially saved the industry
from being devastated by PRSV. Nine
years after commercialization, the trans-
genic papaya is widely grown in Hawaii
and its resistance has held up well.
Aside from helping the Hawaiian papaya
industry, our papaya work showed that
“small” scientists can develop and
commercialize a transgenic product.
Basically, the work was done on a
shoe-string budget and without funding
from private companies. I and the team
did the work because we were com-
mitted to help the papaya growers and
to do it in a timely manner. If one ana-
lyzes the papaya story, one sees the
ingredients for successful research and

implementation because: (1) work was
done proactively by anticipating the
potential damage that PRSV could do
in Hawaii, (2) the research was focused
so we could go from concept to
practicality in a timely manner, (3) the
research team had a strong commitment
to good science and to achieving practi-
cal results in a timely manner, (4) the
clientele was brought in and consulted
early, and (5) we ventured out of our
fields of expertise to get the job done.
This last step involved collecting data
needed for deregulation, assembling
the package for submission to the
regulatory agencies, working on the
intellectual properties of the project,
and making the clientele well aware of
events as the project progressed.
Today, the papaya case is often used as
a model on how to get the job done in
timely manner and make an impact,
even though your group is small and
your resources rather limited.

Plant virology is in an academic heyday,
in part, because the technologyof develop-
ing virus resistant transgenic crops is now
rather routine, and much is known about
the mechanism that a governs resistance:
post-transcriptional gene silencing. I
expect to see continued incremental
improvements on the development of
effective virus-resistant transgenic crops.
However,Iam ratherdisappointed andsur-
prised that so few transgenicvirus-resistant
crops (papaya, squash, and potato) have
been commercialized. It is not due to lack
of technology; numerous scientific
reports have validated the effectiveness of
virus-resistant transgenic plants with a
number of plants and viruses. Yet, only
transgenic squash and papaya are in com-
mercial production today. We need to
seriously ask why? Unless we effectively
address this question, the huge promise
that biotechnology has shown for
virus-resistant crops will largely remain
in the field of academia with little
practical application. I suspect that the
answers to this question do not lie in the
technology arena, but more in the
people’s arena.

212 GENES AND TRAITS OF INTEREST FOR TRANSGENIC PLANTS

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