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Purification/nn-hl of/in-hl the/at-hl conjugates/nns-hl 
In/in attempting/vbg to/to improve/vb specificity/nn of/in staining/vbg ,/, the/at fluorescein-labeled/jj antisera/nns used/vbn in/in both/abx direct/jj and/cc indirect/jj methods/nns were/bed treated/vbn in/in one/cd of/in several/ap ways/nns :/: (/( 1/cd )/) They/ppss were/bed passed/vbn through/in Dowex-2-chloride/np twice/rb and/cc treated/vbn with/in acetone/nn insoluble/jj powders/nns (/( Coons/np ,/, 1958/cd )/) prepared/vbn from/in mouse/nn liver/nn or/cc from/in healthy/jj sweet/jj clover/nn stems/nns or/cc crown/nn gall/nn tissue/nn produced/vbn by/in Agrobacterium/np tumefaciens/np (/( E./np F./np Smith/np &/cc Townsend/np )/) on/in sweet/jj clover/nn stems/nns ./.
(/( 2/cd )/) The/at conjugates/nns as/ql well/rb as/cs the/at intermediate/jj sera/nns were/bed absorbed/vbn for/in 30/cd minutes/nns with/in 20/cd -/in 50/cd mg/nn of/in proteins/nns extracted/vbn from/in healthy/jj sweet/jj clover/nn stems/nns ./.
The/at proteins/nns were/bed extracted/vbn with/in 3/cd volumes/nns of/in Af/nn in/in Af/nn to/to give/vb a/at nearly/ql neutral/jj extract/nn and/cc precipitated/vbn by/in 80%/nn saturation/nn with/in Af/nn ./.
The/at precipitate/nn was/bedz washed/vbn twice/rb with/in an/at 80%/nn saturated/vbn solution/nn of/in Af/nn ,/, dissolved/vbn in/in a/at small/jj quantity/nn of/in 0.1/cd M/nn neutral/jj phosphate/nn buffer/nn ,/, dialyzed/vbn against/in cold/jj distilled/vbn water/nn till/cs free/jj from/in ammonium/nn ions/nns ,/, and/cc lyophilized/vbn using/vbg liquid/jj nitrogen/nn ./.
(/( 3/cd )/) In/in other/ap experiments/nns the/at indirect/jj conjugate/nn was/bedz treated/vbn with/in 3/cd volumes/nns of/in ethyl/nn acetate/nn as/cs recommended/vbn by/in Dineen/np and/cc Ade/np (/( 1957/cd )/) ./.
(/( 4/cd )/) The/at conjugates/nns were/bed passed/vbn through/in a/at diethylaminoethyl/nn (/( DEAE/np )/) cellulose/nn column/nn equilibrated/vbn with/in neutral/jj phosphate/nn buffer/nn (/( PBS/np )/) containing/vbg Af/nn potassium/nn phosphate/nn and/cc Af/nn ./.
Preparation/nn-hl of/in-hl frozen/vbn-hl sections/nns-hl 
The/at technique/nn of/in cutting/vbg sections/nns was/bedz essentially/rb the/at same/ap as/cs that/dt described/vbn by/in Coons/np et/fw-cc al/fw-nns (/( 1951/cd )/) ./.
Root/nn and/cc stem/nn tumors/nns from/in sweet/jj clover/nn plants/nns infected/vbn with/in WTV/nn were/bed quick-frozen/vbn in/in liquid/jj nitrogen/nn ,/, embedded/vbn in/in ice/nn ,/, and/cc cut/vbn at/in 3/cd -/in 6/cd **ym/nn in/in a/at cryostat/nn maintained/vbn at/in -16-degrees/nns to/in -20-degrees/nns ./.
The/at sections/nns were/bed mounted/vbn on/in cold/jj slides/nns smeared/vbn with/in Haupts'/np$ adhesive/nn (/( Johansen/np ,/, 1940/cd )/) in/in earlier/jjr experiments/nns ,/, and/cc in/in later/jjr experiments/nns with/in a/at different/jj mixture/nn of/in the/at same/ap components/nns reported/vbn by/in Schramm/np and/cc Rottger/np (/( 1959/cd )/) ./.
The/at latter/ap adhesive/nn was/bedz found/vbn to/to be/be much/ql more/ql satisfactory/jj ./.
The/at sections/nns were/bed then/rb thawed/vbn by/in placing/vbg a/at finger/nn under/in the/at slide/nn and/cc dried/vbn under/in a/at fan/nn for/in 30/cd minutes/nns ;/. ;/.
until/cs used/vbn they/ppss were/bed stored/vbn for/in as/ql long/rb as/cs 2/cd weeks/nns ./.
Staining/vbg-hl technique/nn-hl 
indirect/jj-hl method/nn-hl ./.-hl

The/at sections/nns were/bed fixed/vbn in/in acetone/nn for/in 15/cd minutes/nns and/cc dried/vbn at/in 37-degrees/nns for/in 30/cd minutes/nns ./.
Some/dti of/in them/ppo were/bed then/rb covered/vbn with/in a/at drop/nn of/in Af/nn in/in a/at moist/jj chamber/nn at/in 24-degrees/nns for/in 30/cd -/in 40/cd minutes/nns ./.
As/cs controls/nns other/ap sections/nns were/bed similarly/rb covered/vbn with/in Aj/nn ./.
Sections/nns were/bed then/rb washed/vbn with/in PBS/nn for/in 15/cd -/in 30/cd minutes/nns ./.
After/cs blotting/vbg out/rp most/ap of/in the/at saline/nn around/in the/at sections/nns ,/, a/at drop/nn of/in Af/nn was/bedz layered/vbn over/in each/dt of/in the/at sections/nns ,/, allowed/vbn to/to react/vb for/in 30/cd minutes/nns ,/, and/cc then/rb washed/vbn with/in PBS/nn for/in 15/cd -/in 30/cd minutes/nns ./.
After/cs blotting/vbg out/rp most/ap of/in the/at liquid/nn around/in the/at sections/nns ,/, the/at latter/ap were/bed mounted/vbn in/in buffered/vbn glycerine/nn (/( 7/cd parts/nns glycerine/nn to/in 3/cd parts/nns of/in PBS/nn )/) ./.
Direct/jj-hl method/nn-hl ./.-hl

After/cs drying/vbg the/at sections/nns under/in the/at fan/nn ,/, fixing/vbg in/in acetone/nn ,/, and/cc drying/vbg at/in 37-degrees/nns as/cs in/in the/at indirect/jj method/nn ,/, the/at sections/nns were/bed treated/vbn with/in conjugated/vbn Af/nn or/cc Af/nn (/( undiluted/jj unless/cs mentioned/vbn otherwise/rb )/) for/in 5/cd -/in 30/cd minutes/nns ./.
As/cs controls/nns ,/, other/ap sections/nns were/bed similarly/rb treated/vbn with/in Af/nn or/cc conjugated/vbn antiserum/nn to/in the/at New/jj-tl York/np-tl strain/nn of/in potato/nn yellow-dwarf/nn virus/nn (/( Wolcyrz/np and/cc Black/np ,/, 1956/cd )/) ./.
The/at sections/nns were/bed then/rb washed/vbn with/in PBS/nn for/in 15/cd -/in 30/cd minutes/nns and/cc mounted/vbn in/in buffered/vbn glycerine/nn ./.
Fluorescence/nn-hl microscopy/nn-hl 
Stained/vbn or/cc unstained/jj sections/nns were/bed examined/vbn under/in dark/jj field/nn illumination/nn in/in a/at Zeiss/np fluorescence/nn microscope/nn equipped/vbn with/in a/at mercury/nn vapor/nn lamp/nn (/( Osram/np HBO/nn 200/cd )/) ./.
The/at light/nn beam/nn from/in the/at lamp/nn was/bedz filtered/vbn through/in a/at half-standard/jj thickness/nn Corning/np 1840/cd filter/nn ./.
In/in the/at eyepiece/nn a/at Wratten/np-tl 2/cd-tl B/nn filter/nn was/bedz used/vbn to/to filter/vb off/rp residual/jj ultra-violet/jj light/nn ./.
A/at red/jj filter/nn ,/, Zeiss/np barrier/nn filter/nn with/in the/at code/nn (/( Schott/np )/) designation/nn BG/nn 23/cd ,/, was/bedz also/rb used/vbn in/in the/at ocular/jj lens/nn assembly/nn as/cs it/pps improved/vbd the/at contrast/nn between/in specific/jj and/cc nonspecific/jj fluorescence/nn ./.



Results/nns-hl 
specificity/nn-hl of/in-hl staining/vbg-hl 
indirect/jj-hl method/nn-hl ./.-hl

In/in the/at first/od few/ap experiments/nns Af/nn was/bedz passed/vbn through/in Dowex-2-chloride/np twice/rb and/cc absorbed/vbn twice/rb with/in 50/cd -/in 100/cd mg/nn sweet/jj clover/nn tissue/nn powder/nn ./.
The/at intermediate/jj sera/nns were/bed also/rb similarly/rb absorbed/vbn with/in tissue/nn powder/nn ./.
Sections/nns of/in sweet/jj clover/nn stem/nn and/cc root/nn tumors/nns were/bed treated/vbn with/in 1/cd :/in 10/cd solution/nn of/in Af/nn for/in 30/cd minutes/nns ,/, washed/vbn in/in buffered/vbn saline/nn for/in 15/cd minutes/nns ,/, stained/vbn with/in Af/nn for/in 30/cd minutes/nns ,/, and/cc washed/vbn for/in 15/cd minutes/nns in/in Aj/nn ./.
Such/jj sections/nns showed/vbd bright/jj yellow-green/jj specific/jj fluorescence/nn in/in the/at cells/nns of/in the/at pseudophloem/nn tissue/nn (/( Lee/np and/cc Black/np ,/, 1955/cd )/) ./.
This/dt specific/jj fluorescence/nn was/bedz readily/rb distinguished/vbn from/in the/at light/jj green/jj nonspecific/jj fluorescence/nn in/in consecutive/jj sections/nns stained/vbn with/in 1/cd :/in 10/cd dilution/nn of/in NS/nn and/cc Af/nn or/cc with/in Af/nn alone/rb ./.
Unstained/jj sections/nns mounted/vbn in/in buffered/vbn glycerine/nn or/cc sections/nns treated/vbn only/rb with/in NS/nn or/cc Af/nn did/dod not/* show/vb such/jj green/jj fluorescence/nn ./.
Sections/nns of/in crown/nn gall/nn tissue/nn similarly/rb stained/vbn with/in either/cc Af/nn and/cc Af/nn or/cc NS/nn and/cc Af/nn also/rb showed/vbd only/rb the/at light/jj green/jj nonspecific/jj fluorescence/nn ./.
However/rb ,/, the/at nonspecific/jj staining/nn by/in the/at Af/nn in/in tumor/nn sections/nns was/bedz considered/vbn bright/jj enough/qlp to/to be/be confused/vbn with/in the/at staining/nn of/in small/jj amounts/nns of/in WTV/nn antigen/nn ./.


	Two/cd absorptions/nns of/in Af/nn with/in ethyl/nn acetate/nn or/cc two/cd absorptions/nns of/in Af/nn (/( which/wdt had/hvd been/ben passed/vbn through/in Dowex-2-chloride/np )/) ,/, NS/nn and/cc Af/nn with/in crown/nn gall/nn tissue/nn powder/nn ,/, or/cc mouse/nn liver/nn powder/nn did/dod not/* further/rbr improve/vb the/at specificity/nn of/in staining/vbg ./.
Treatment/nn of/in all/abn the/at sera/nns with/in sweet/jj clover/nn proteins/nns greatly/rb reduced/vbd nonspecific/jj fluorescence/nn ,/, especially/rb when/wrb the/at treated/vbn conjugate/nn was/bedz diluted/vbn to/in 1/cd :/in 2/cd with/in 0.85%/nn saline/nn ./.
In/in all/abn the/at above/jj procedures/nns ,/, when/wrb the/at intermediate/jj sera/nns were/bed diluted/vbn to/in 1/cd :/in 10/cd or/cc 1/cd :/in 100/cd with/in 0.85%/nn saline/jj ,/, the/at specific/jj and/cc nonspecific/jj fluorescence/nn were/bed not/* appreciably/rb reduced/vbn ,/, whereas/cs ,/, a/at dilution/nn of/in the/at intermediate/jj sera/nns to/in 1/cd :/in 500/cd or/cc diluting/vbg the/at Af/nn to/in 1/cd :/in 5/cd greatly/rb reduced/vbd specific/jj fluorescence/nn ./.
Rinsing/vbg the/at sections/nns with/in PBS/nn before/in layering/vbg the/at intermediate/jj sera/nns did/dod not/* improve/vb the/at staining/vbg reaction/nn ./.
In/in addition/nn to/in other/ap treatments/nns ,/, treating/vbg the/at sections/nns with/in normal/jj sheep/nn serum/nn for/in half/abn an/at hour/nn before/in layering/vbg Af/nn did/dod not/* reduce/vb nonspecific/jj staining/nn ./.


	The/at only/ap treatment/nn by/in which/wdt nonspecific/jj staining/nn could/md be/be satisfactorily/rb removed/vbn was/bedz by/in passing/vbg the/at conjugate/nn through/in a/at DEAE-cellulose/nn column/nn ./.
When/wrb 1/cd ml/nn of/in conjugate/nn was/bedz passed/vbn through/in a/at column/nn (/( Af/nn )/) ,/, the/at first/od and/cc second/od milliliter/nn fractions/nns collected/vbn were/bed the/at most/ql specific/jj and/cc gave/vbd no/at nonspecific/jj staining/nn in/in some/dti experiments/nns ,/, and/cc very/ql little/ap in/in others/nns ./.
In/in the/at latter/ap cases/nns an/at additional/jj treatment/nn of/in the/at DEAE-cellulose-treated/nn Af/nn with/in 50/cd mg/nn of/in sweet/jj clover/nn stem/nn tissue/nn powder/nn further/rbr improved/vbd the/at specificity/nn ./.
After/in these/dts treatments/nns the/at conjugate/nn did/dod not/* stain/vb healthy/jj or/cc crown/nn gall/nn sweet/jj clover/nn tissues/nns or/cc stained/vbd them/ppo a/at very/ql faint/jj green/nn which/wdt was/bedz easily/rb distinguishable/jj from/in the/at bright/jj yellow-green/jj specific/jj staining/nn ./.
With/in this/dt purified/vbn conjugate/nn the/at best/jjt staining/vbg procedure/nn consisted/vbd of/in treating/vbg the/at sections/nns with/in 1/cd :/in 10/cd dilution/nn of/in Af/nn for/in 30/cd minutes/nns ,/, washing/vbg with/in PBS/nn for/in 15/cd minutes/nns ,/, staining/vbg with/in Af/nn for/in 30/cd minutes/nns ,/, and/cc washing/vbg with/in PBS/nn for/in 15/cd minutes/nns ./.
The/at specificity/nn of/in staining/vbg in/in WTV/nn tumors/nns with/in Af/nn and/cc Af/nn but/cc not/* with/in NS/nn and/cc Af/nn or/cc with/in antiserum/nn to/in potato/nn yellow-dwarf/nn virus/nn and/cc Af/nn ,/, and/cc the/at absence/nn of/in such/jj staining/nn in/in crown/nn gall/nn tumor/nn tissue/nn from/in sweet-clover/nn ,/, indicate/vb that/cs an/at antigen/nn of/in WTV/nn was/bedz being/beg stained/vbn ./.
Direct/jj-hl method/nn-hl ./.-hl

Af/nn was/bedz first/rb conjugated/vbn with/in 50/cd mg/nn of/in FITC/nn per/in gram/nn of/in globulin/nn ./.
This/dt conjugate/nn was/bedz passed/vbn twice/rb through/in Dowex-2-chloride/np and/cc treated/vbn with/in various/jj tissue/nn powders/nns in/in the/at same/ap manner/nn as/cs described/vbn for/in the/at indirect/jj method/nn ./.
In/in all/abn cases/nns a/at disturbing/jj amount/nn of/in nonspecific/jj staining/nn was/bedz still/rb present/rb although/cs it/pps was/bedz still/rb distinguishable/jj from/in specific/jj fluorescence/nn ./.


	In/in later/jjr experiments/nns ,/, Af/nn and/cc Af/nn were/bed prepared/vbn by/in conjugating/vbg 8/cd mg/nn of/in FITC/nn per/in gram/nn of/in globulin/nn ./.
These/dts conjugates/nns Af/nn had/hvd much/ql less/ap nonspecific/jj staining/nn than/cs the/at previous/jj conjugate/nn (/( with/in 50/cd mg/nn FITC/nn per/in gram/nn of/in globulin/nn )/) while/cs the/at specific/jj staining/nn was/bedz similar/jj in/in both/abx cases/nns ./.
Nonspecific/jj staining/nn could/md be/be satisfactorily/rb eliminated/vbn by/in passing/vbg these/dts conjugates/nns through/in a/at DEAE-cellulose/nn column/nn as/cs described/vbn for/in Af/nn ./.
The/at best/jjt staining/vbg procedure/nn with/in this/dt purified/vbn Af/nn consisted/vbd of/in staining/vbg with/in the/at conjugate/nn for/in 30/cd minutes/nns and/cc washing/vbg in/in PBS/nn for/in 15/cd minutes/nns ./.
The/at specificity/nn of/in staining/vbg with/in Af/nn was/bedz established/vbn as/cs follows/vbz :/: Af/nn specifically/rb stained/vbn tumor/nn sections/nns but/cc not/* sections/nns of/in healthy/jj sweet/jj clover/nn stems/nns or/cc of/in crown/nn gall/nn tumor/nn tissue/nn from/in sweet/jj clover/nn ./.
Sections/nns of/in tumors/nns incited/vbn by/in WTV/nn were/bed not/* similarly/rb stained/vbn with/in conjugated/vbn normal/jj serum/nn or/cc conjugated/vbn antiserum/nn to/in potato/nn yellow-dwarf/nn virus/nn ./.


	After/in passing/vbg Af/nn through/in DEAE-cellulose/nn ,/, the/at titer/nn of/in antibodies/nns to/in WTV/nn in/in the/at specific/jj fraction/nn was/bedz 1/cd :/in 4/cd of/in the/at titer/nn before/in such/jj passage/nn (/( precipitin/nn ring/nn tests/nns by/in R./np F./np Whitcomb/np )/) ;/. ;/.
but/cc mere/jj dilution/nn of/in the/at conjugate/nn to/in 1/cd :/in 4/cd did/dod not/* satisfactorily/rb remove/vb nonspecific/jj staining/nn ./.
This/dt indicates/vbz that/cs increase/nn in/in specificity/nn of/in Af/nn after/in passing/vbg it/ppo through/in DEAE-cellulose/nn was/bedz not/* merely/rb due/jj to/in dilution/nn ./.


	Specific/jj staining/nn by/in DEAE-cellulose/nn treated/vbn Af/nn and/cc Af/nn ,/, although/cs clearly/rb distinguishable/jj under/in the/at microscope/nn from/in either/cc nonspecific/jj staining/nn or/cc autofluorescence/nn of/in cells/nns ,/, was/bedz not/* satisfactorily/rb photographed/vbn to/to show/vb such/jj differences/nns in/in spite/nn of/in many/ap attempts/nns with/in black/jj and/cc white/jj and/cc color/nn photography/nn ./.
This/dt was/bedz chiefly/rb because/rb of/in the/at bluish/jj white/jj autofluorescence/nn from/in the/at cells/nns ./.
The/at autofluorescence/nn from/in the/at walls/nns of/in the/at xylem/nn cells/nns was/bedz particularly/ql brilliant/jj ./.
Distribution/nn-hl of/in-hl virus/nn-hl antigen/nn-hl 
Results/nns of/in specific/jj staining/nn by/in the/at direct/jj and/cc the/at indirect/jj methods/nns were/bed similar/jj and/cc showed/vbd the/at localization/nn of/in WTV/nn antigen/nn in/in certain/ap tissues/nns of/in tumors/nns ./.
The/at virus/nn antigen/nn was/bedz concentrated/vbn in/in the/at pseudophloem/nn tissue/nn ./.
Frequently/rb a/at few/ap isolated/vbn thick-walled/jj cells/nns or/cc ,/, rarely/rb ,/, groups/nns of/in such/jj cells/nns in/in the/at xylem/nn region/nn ,/, were/bed also/rb specifically/rb stained/vbn ,/, but/cc there/ex was/bedz no/at such/jj staining/nn in/in epidermis/nn ,/, cortex/nn ,/, most/ap xylem/nn cells/nns ,/, ray/nn cells/nns ,/, or/cc pith/nn ./.


	Within/in the/at pseudophloem/nn cells/nns the/at distribution/nn of/in WTV/nn antigen/nn was/bedz irregular/jj in/in the/at cytoplasm/nn ./.
No/at antigen/nn was/bedz detectable/jj in/in certain/ap dark/jj spherical/jj areas/nns in/in most/ap cells/nns ./.
These/dts areas/nns are/ber thought/vbn to/to represent/vb the/at nuclei/nns ./.
In/in some/dti tumor/nn sections/nns small/jj spherical/jj bodies/nns ,/, possibly/rb inclusion/nn bodies/nns (/( Littau/np and/cc Black/np ,/, 1952/cd )/) stained/vbd more/ql intensely/rb than/cs the/at rest/nn of/in cytoplasm/nn and/cc probably/rb contained/vbd more/ap antigen/nn ./.
In/in all/abn cases/nns studied/vbn tissues/nns of/in the/at stem/nn on/in which/wdt the/at tumor/nn had/hvd developed/vbn did/dod not/* contain/vb detectable/jj amounts/vbz of/in WTV/nn antigen/nn ./.



Discussion/nn-hl 
In/in both/abx the/at direct/jj and/cc indirect/jj methods/nns of/in staining/vbg ,/, the/at conjugates/nns had/hvd nonspecifically/rb staining/vbg fractions/nns ./.
In/in the/at indirect/jj method/nn ,/, this/dt was/bedz evident/jj from/in the/at fact/nn that/cs tumor/nn sections/nns were/bed stained/vbn light/jj green/jj even/rb when/wrb stained/vbn with/in NS/nn and/cc Af/nn or/cc with/in Af/nn only/rb ./.
In/in the/at direct/jj method/nn ,/, Af/nn ,/, not/* further/rbr treated/vbn ,/, stained/vbd certain/ap tissues/nns of/in healthy/jj sweet/jj clover/nn stems/nns nonspecifically/rb and/cc WTV/nn tumor/nn sections/nns were/bed similarly/rb stained/vbn by/in comparable/jj Af/nn ./.
After/cs Af/nn and/cc Af/nn were/bed passed/vbn through/in Dowex-2-chloride/np twice/rb and/cc treated/vbn twice/rb with/in healthy/jj sweet/jj clover/nn tissue/nn powder/nn ,/, nonspecific/jj staining/nn was/bedz greatly/rb reduced/vbn but/cc a/at disturbing/jj amount/nn of/in such/jj staining/nn was/bedz still/rb present/rb ./.
Treatment/nn of/in the/at conjugates/nns with/in ethyl/nn acetate/nn ,/, and/cc the/at conjugates/nns (/( which/wdt had/hvd been/ben passed/vbn through/in Dowex-2-chloride/np )/) with/in mouse/nn liver/nn powder/nn ,/, sweet/jj clover/nn crown/nn gall/nn tissue/nn powder/nn ,/, or/cc healthy/jj sweet/jj clover/nn proteins/nns did/dod not/* satisfactorily/rb remove/vb nonspecifically/rb staining/vbg substances/nns in/in the/at conjugates/nns ./.
Such/jj treatments/nns of/in the/at conjugates/nns have/hv usually/rb been/ben successful/jj in/in eliminating/vbg nonspecific/jj staining/nn in/in several/ap other/ap systems/nns (/( Coons/np ,/, 1958/cd )/) ./.
Schramm/np and/cc Rottger/np (/( 1959/cd )/) did/dod not/* report/vb any/dti such/jj nonspecific/jj staining/nn of/in plant/nn tissues/nns with/in fluorescein/nn isocyanate-labeled/jj antiserum/nn to/in tobacco/nn mosaic/nn virus/nn ./.
The/at reason/nn for/in the/at failure/nn of/in these/dts treatments/nns to/to eliminate/vb nonspecific/jj staining/nn in/in the/at conjugates/nns in/in our/pp$ system/nn is/bez not/* known/vbn ./.


	In/in our/pp$ work/nn the/at best/jjt procedure/nn for/in removing/vbg substances/nns causing/vbg nonspecific/jj staining/nn in/in order/nn to/to obtain/vb specific/jj conjugates/nns was/bedz to/to pass/vb the/at conjugates/nns through/in a/at DEAE-cellulose/nn column/nn and/cc in/in some/dti cases/nns to/to absorb/vb the/at first/od and/cc second/od milliliter/nn fractions/nns with/in sweet/jj clover/nn tissue/nn powder/nn ./.


	The/at specific/jj staining/nn by/in both/abx direct/jj and/cc indirect/jj methods/nns showed/vbd that/cs WTV/nn antigen/nn was/bedz concentrated/vbn in/in the/at pseudophloem/nn tissue/nn and/cc in/in a/at few/ap thick-walled/jj cells/nns in/in the/at xylem/nn region/nn ,/, but/cc was/bedz not/* detectable/jj in/in any/dti other/ap tissues/nns of/in the/at root/nn and/cc stem/nn tumors/nns ./.
A/at study/nn of/in the/at distribution/nn of/in WTV/nn antigen/nn within/in the/at pseudophloem/nn cells/nns indicates/vbz that/cs it/pps is/bez irregularly/rb distributed/vbn in/in the/at cytoplasm/nn ./.


	Wound-tumor/nn virus/nn is/bez a/at leafhopper/nn transmitted/vbn virus/nn not/* easily/rb transmissible/jj by/in mechanical/jj inoculation/nn (/( Black/np ,/, 1944/cd ;/. ;/.
Brakke/np et/fw-cc al/fw-nns ,/, 1954/cd )/) ./.
The/at concentration/nn and/cc apparent/jj localization/nn of/in the/at WTV/nn antigen/nn in/in pseudophloem/nn tissue/nn of/in the/at tumor/nn may/md indicate/vb that/cs the/at virus/nn preferentially/rb multiplies/vbz in/in the/at phloem/nn and/cc may/md need/vb to/to be/be directly/rb placed/vbn in/in this/dt tissue/nn in/in order/nn to/to infect/vb plants/nns ./.