ThecompleteopenreadingframeofOsPIN1awasamplifiedthroughreversetranscriptase-polymerasechainreaction(RT-PCR)basedonthesequencedepositedinGenBanktoexploretherelationshipbetweentheauxineffluxproteinOsPIN1aandthenegativephototropismofriceroots.SequencingresultsshowedthattheGCcontentofOsPIN1awas65.49%.ThefusionexpressionvectorpCAMBIA-1301-OsPIN1a::GFPcontainingtheOsPIN1ageneandacodinggreenfluorescentprotein(gfp)genewasconstructed.ThefusionvectorwastransferredintoonionepidermalcellsbyAgrobacteriumtumefacienstransformation.ThetransientexpressionofOsPIN1a-GFPwasmainlylocatedinthenucleusandcellmembrane.Moreover,thetransgenicplantswereobtainedbyAgrobacterium-mediatedgenetictransformation.MoleculardetectionperformedbyusingPCRandβ-glucuronidasestainingshowedthatthetargetconstructwasintegratedintothegenomeofrice.Thenegativephototropiccurvaturesofthetransgenicricerootswerehigherthanthoseofthewildtype.Similarly,theexpressionlevelsofOsPIN1ainthetransgenicplantswereconsiderablyhigherthanthoseinthewild-typeplants.TheseresultssuggestthatOsPIN1aiscrucialinthenegativephototropiccurvatureofriceroots.
