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冰川冻土 2009
MolecularCloningofaCytosolicG6PDHGenefromPopulussuaveolensandItsExpressiontoImprovetheColdResistanceofTobaccoPlants, PP. 1178-1185 Keywords: Populus,suaveolens,glucose-6-phosphate,dehydrogenase,cold,resistance,gene,engineering Abstract: Glucose-6-phosphatedehydrogenase(G6PDH,EC1.1.1.49)isthefirstandmainregulatedenzymeofoxidativepentosephosphatepathway(OPPP),catalyzingtheconversionofglucose-6-phosphateto6-phospho-gluconolactoneandplayingimportantrolesinthegrowthanddevelopmentofplants.WepreciouslyreportedthattheenhancementoffreezingresistanceofPopulussuaveolenscuttingswasclearrelatedtothedistinctincreaseincytosolicG6PDHactivity.Here,a1697bpcDNAfragment(PsG6PDH)wasamplifiedbyRT-PCRfromcold-inducedtotalRNAofthefreezing-tolerantP.suaveolens.ThesequenceanalysisshowedthatPsG6PDHcodingregionhad1530bpandencoded510predictedaminoacidresidues.GenomicSouthernanalysisrevealedthattheisoformisencodedbyafewcopiesofthegeneinthepoplargenome.TheclonedgenePsG6PDHwasclonedintobinaryvectorpBI121andusedtotransformtobacco.PCRandSouthernblottingresultsverifiedintegrationofthisgeneintothegenomeoftobacco.Moreover,coldtreatmentexperimentsandmembranedefenseenzymeactivityanalysisconfirmedthatoverexpressionofthePsG6PDHgenecouldenhancethetolerancetocoldorfrigidstressesintransgenicplants.
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