1、南開大學碩士學位論文生長素和油菜甾醇在擬南芥根重力應答中的相互作用分析姓名：朱輝申請學位級別：碩士專業(yè)：植物學指導教師：門淑珍201205AbstractAbstractRootgravitropismisanimportantfeatureofplantstoadapttotheenvironmentItcanguidetheroottogrowalongthedirectionofgravityRootgravitropismisa

2、ctuallyacomplexphysiologicalprocessthatincludesgravitysensing，signaltransduction，asymmetricauxindistributionandgrowthresponsesThesiteofthegravitysensingiscolumella，andthesiteofgrowthresponsesisrootelongationzoneAuxinisth

3、eonlyplanthormonethathasthecharacteristicsofpolarVansport，anditsdirectionaltransportinplantsrequirestheinfluxcarrierAUX／LAXproteinfamilyandtheeffiuxcarrierPINfamilyandPGPfamilyThesecarriersarenecessaryforrootgravitropism

4、BRisiflsoinvolvedintheregulationofrootelongationandrootgravitropism，anditinteractswithauxinintheseprocessesButitisuncertainhowauxininteractswithBRduringrootgravitropismMutantstudiesshowthattherootelongationofbril一4、auxl—

5、Tandpin2一Taresignificantlyinhibited，but：det2一JrootelongationhasnodifferencewithwildtypeMutantauxlhasmoresevere‘gravitropismdefectsthanpin2，andauxl；pin2showauxlphenotypeingravitropism，whichshowAUXlplaysamoreimportantrolet

6、hanPIN2duringtheregulationofrootgravitropismWefoundthatexpressionlevelofBRll一∞decreasedinauxlandauxl；pin2buttheexpressionlevelofBRll一GFPhasnoobviouschangeThearticlealsopointsoutthatbril4showingweakrootgravitropismmaybeat

7、tributestothesefinds，forexample，thecellularexpressionlevelofPIN3inthecolumella，isreducedtheexpression1evelof刪2decreasedinepidermalandconicalcell，andtheexpressionpattemofAUXlisabnormalinthelateralrootcapandrootepidermalce