简介：Plantcelllinesdifferredgreatlyintheabilitytowithstandshearstresses.Usingto-baccocellsandlicoricecellsasmodelplantcells,westudiedtheeffectsofshearstressesonthevi-abilityofplantcells.OurexperimentswerecarriedoutonahighshearrateCouetterheometerprovidinghomogeneousandconstantshearstressesoflaminarflow.TheviabilitywasdeterminedbyTTC（2,3,5-Triphenyltetrazoliumchloride）.Theresultswereasfollows.（1）Theviability（V）droppedexponentiallywithtime（t）,namelyV=Exp（-kt）,（k>oisaconstant）.Thismeantthetenabilityofstatisticalhomogeneity.（2）Thevalueofkwasafunctionofplantcells’mechanicalpropertiesandtheshearstressactingontheplantcells.Theshearratecorrespondingtok=owasthecriticalshearratethattheplantcellscouldwithstand.Itcanbeeasilydetermindedbyextrapo-lation.For7-day-oldtobaccocells,itwas1090s-1andfor9-day-oldlicoricecells,itwas6566s-1.（3）Theplantcellsuspensionswerepseudoplasticfluidsfittingτ=Kγn.Forthetobaccocellsus-pensiontested,n=O.73,andforthelicoricecellsuspensiontestedn=0.7.Thusthecriticalshearstressforthetobaccocellswas25dynes/cm2andforthelicoricecellsitwas80dynes/cm2.（4）Oneoftheirreasonsforlicoricecellstohavegreatertolerancetoshearstressesthantobacaccocellsmaybethegeometricfeaturesofthecellsandthesizesofthecells.Thelicoricecellswererod-shaped,butthetobaccocellsweresphericalandlargerthanthelicoricecells.

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