dean w. gabriel gm citrus with potential to control greening integrated plant genetics, inc. alachua...
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Dean W. GabrielDean W. Gabriel
GM Citrus with Potential to Control Greening
Integrated Plant Genetics, Inc.Integrated Plant Genetics, Inc.AlachuaAlachua
andand
Plant Pathology DepartmentPlant Pathology DepartmentUniversity of Florida, GainesvilleUniversity of Florida, Gainesville
Strategies for greening disease control
o No practical resistance breeding. o Eradication impossible. o Chemical control of insects may require 25 sprays per year.
o Genetically modified (GM) citrus (add a resistance gene).
APHIS/PPQ intercepted the vector40 times in US ports between 1985-98.
APHIS/PPQ intercepted the vector40 times in US ports between 1985-98.
Citrus greening, likely trapped in dooryard citrus, nationwide.
6 year lag from psyllid establishment to greening diagnosis.
Canker bacteria
Greening bacteria
Why don't chemicals work on greening?
Nucleus
How to make a "GMO"
1. Start with DNA cloning vector.2. Add gene of interest + plant selection gene.3. Add cloned genes on vector to specialized bacterial pathogen.
4. Contact pathogen with target plant cell.5. The pathogen injects the cloned genes into the plant cell, and the
genes are guided to the nucleus by DNA vector.
1 2
1. In a test tube, construct a gene encoded on vector DNA.
2. Add the vector DNA to a specialized bacterial pathogen.
3. Contact wounded citrus with the pathogen; the vector DNA is injected by the pathogen into the plant cell.
--Essenberg & Richardson
Transformation process for GM Citrus
Transformation process for GM Citrus
Bacteria with clonedgenes applied to cut end of citrus stem section.Antibiotic selection applied.
Transformation process for GM Citrus Transformation process for GM Citrus
Greenhouse testing
Grafting onto rootstock
1 2
4 weeks --- 26% juvenile stem pieces survive; 1/2 of these are transformed
Mature Valencia & Hamlin regenerated
Juvenile grapefruit after grafting
May, 2008: Growth of transgenic citrus trees, each with 1 of 3 IPG DiseaseBlock genes.
Current status: GM citrus trees currently being evaluated by IPG. Technology (IP) is co-owned by UF.
Citrus has natural defenses
Transgenes that interfere with defense are more susceptible...
Citrus has natural defensesHarder to prove are transgenes that enhance defense... a negative result (determined by PCR). To date, negative.
IPG DiseaseBlock® added
Transgenic tobacco as proxy... to date negative
IPG DiseaseBlock® added
GMOs can be accepted in the U.S.
Transgenic and nontransgenic papaya in Hawaii. Work by: D. Gonsalves, Cornell U.; S. Ferreira and R. Manshardt, U.Hawaii; M. Fitch, USDA; J. Slightom, Pharmacia
Transgenic 'UH Rainbow' to be graded in a commercial packinghouse.
Adoption Rates: Principal GM Crops in US
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1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
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Soybean
Corn
Cotton
The Regulatory Process---Who's minding the Store?
NIH mandated IBC review USDA-APHIS facility review• USDA-APHIS field-release approval• USDA-APHIS shipping authority
approval• USDA-APHIS permission to
commercialize or non-regulatory status (public comment, 12-24 mo)
The Regulatory Process
• EPA experimental use permit (if > 10 acres)
• EPA determines if limits needed on % gene product (public comment, 24-30 mo.)
• EPA product registration (public comment)
• FDA review (public comment (12-18 mo.)Earliest time to market: 2015
Integrated Plant Genetics, Inc.
12085 Research DriveAlachua, Florida 32615 USA
http://www.ipgenetics.com
IPG Research Sponsored by:
Southern Gardens CitrusUSDA-APHISNSFFischer USAGoldsmith Plants