Genetic Engineering of Grapevine and Progress toward Commercial Deployment - Transgenic Horticultural Crops: Challenges and Opportunities - page 320

with.an.endogenous.proprietary. Vitis .gene.( EG2 ). exhibited.signiicantly.lower. devel-
opment. of. powdery. mildew. ( Uncinula necator ). compared. to. control. grapevines. 22-24 .
Resistance. to. fungal. diseases. in. grapevines. transformed. with. other. PR. proteins. has.
also.been.reported. 25,26 .Low.molecular.weight.chain.antimicrobial.peptides,.also.known.
as.lytic.peptides,.have.been.widely.tested.to.impart.bacterial.resistance.in.grapevines..
Transgenic. 'Chardonnay',. carrying. an. antimicrobial. peptide. magainin,. exhibited. sig-
niicant.reduction.in.crown.gall.symptoms.caused.by. Agrobacterium vitis . 27 .'Merlot',.
'Shiraz',. and. 'Thompson. Seedless'. grapevines. transformed. with. proprietary. hybrid.
lytic. peptides,. LIMA-A. and. LIMA-B,. exhibited. enhanced. resistance. to. Pierce's. dis-
ease.( Xylella fastidiosa ).in.greenhouse.tests. 28 .Field.tests.are.currently.underway.to.test.
resistance.of.a.number.of.transgenic. Vitis .varieties.and.rootstocks.to.Pierce's.disease. 29,30 .
Virus. resistant. transgenic. grapevines. have. also. been. developed. using. virus-derived.
genetic.elements..Grapevine.varieties.and.rootstocks.carrying.the.coat.protein.for.grape.
fan.leaf.virus.(GFLV).and.grape.leaf.roll.virus.(GLRV).have.been.produced 31-34 .and.tests.
are.under.way.to.study.the.response.of.vines.to.virus.infection.under.ield.conditions.
f Ield t eStS
Field.trials.of.GE.grapevines.( Vitis vinifera .and.other. Vitis .species).have.been.con-
ducted.worldwide.since.the.mid-1990s.(Table.16.1)..Early.trials.in.Colmar,.France,.
consisted. of. gene. constructs. for. resistance. to. GFLV.. Other. trials. in. the. United.
States.(several.locations),.Canada,.and.Germany.were.designed.to.evaluate.resis-
tance. to. fungal. diseases. (powdery. mildew. and. botrytis,. primarily).. Those. trials.
included. a. number. of. different. genes. including. chitinases/endochitinases,. glu-
canases,. a. ribosome. inactivating. protein,. a. polygalacturonase. inhibiting. protein,.
lytic. peptides,. antimicrobial. peptides,. a. lignin. biosynthesis. protein,. and. endog-
enous.grape.genes..Field.trials.that.have.ended.include.work.in.Canada.by.Chateau.
des. Charmes. to. develop. both. fungal. resistance. and. improved. cold. tolerance. in.
vines. (Cordts,. personal. communication);. work. by. AgriVitis/GenApps. in. the.
United.States.to.develop.resistance.to.GFLV,.GLRV,.and.crown.gall.(http://www.
isb.vt.edu/cfdocs/ieldtests1.cfm);. research. in. Italy. to. improve. berry. number. and.
size. (http://www.gmo-compass.org/eng/database/plants/73.grape_vine.html) 35 ;.
research.by.SUNY/Geneseo.to.develop.mildew.resistant. V. labrusca .(http://www.
isb.vt.edu/cfdocs/ieldtests1.cfm);. and. trials. by. the. University. of. California. and.
Anton.Caratan.&.Son.for.fungal.resistance.and.improved.product.quality.(http://
www.isb.vt.edu/cfdocs/ieldtests1.cfm).
Current. ield. trials. of. Vitis . species. worldwide. are. being. conducted. by. Cornell.
University,. the. University. of. Florida,. and. by. the. Commonwealth. Scientiic. and.
Industrial.Research.Organisation.(CSIRO).(http://www.isb.vt.edu/cfdocs/ieldtests1.
cfm,. http://www.ogtr.gov.au/internet/ogtr/publishing.nsf/Content/ir-1).. The. Cornell.
vines. have. been. developed. to. evaluate. resistance. to. GFLV,. GLRV,. crown. gall.
disease,. fungal. pathogens,. and. Xylella fastidiosa . (http://www.isb.vt.edu/cfdocs/
ieldtests1.cfm)..The.University.of.Florida.vines.are.being.evaluated.for.resistance.to.
Xylella .and.fungal.diseases..CSIRO.is.evaluating.vines.for.a.number.of.traits.includ-
ing. alterations. to. tannins,. anthocyanins,. sugars,. browning,. and. various. lowering/
fruiting.parameters.(Table.16.1).