Clone Of Maize ZmbZIPs Gene Family And Select And Study The Function Of The Gene Which Can Resist Stress

Basic region/leucine zipper(bZIP)transcription factors commonly exist in eukaryotic organisms,including higher plants.Functional information available concerning Arabidopsis bZIPs suggests their roles in the defense against pathogens,photomorphism and stress signaling.The plant hormone abscisic acid(ABA)is a key regulator of plants development,plant responses to biotic and abiotic stresses.101 cDNA sequences of ZmbZIPs in maize were gained.The rest was 84 genes without the redundant sequences.There were 112 genes added 24 genes which have been reported.The tree of bZIP genes in maize,Arabidopsis and rice were analysised,the cloning,prediction and expression of subcellular localization of 84 ZmbZIPs without been reported in maize were studied.The results indicated that some ZmbZIPs responsed drought,ABA and ER stress in maize.The transformations of Arabidopsis thaliana with the successful cloning genes,22 homozygous lines were sieved.Two genes,similar to Arabidopsis ABI5 Like,were named as ZmbABI5 Like1(ZmABL1)and ZmbABI5 Like2(ZmABL2)according to the positions in the chromosome,respectively.The functions of them were studied by transgenic Arabidopsis.Result showed that transgenic Arabidopsis seedings were sensitive to ABA,but there was a difference phenotype in overexpression transgenic plants under stress.ZmABL2 could resist drought and alkali stress,but ZmABL1 only responsed to drought in germination.Two genes transiently expressed into epidermal cells of Nicotiana benthamiana leaves to study the subcellular localization.The results indicated that ZmABL2 protein was localized in the nucleus,but ZmABL1 was localized in the nucleus,cell membrane and endoplasmic reticulum(ER)membrane.Relayed on the results of the tree and the expression in maize,an ER-resident transmembrane transcription factor,bZIP gene from maize which was highly similar to AtbZIP17 and induced by ER-stress-eliciting agents such as dithiotreitol(DTT)and tunicamycin(TM)was identified as ZmbZIP17.The transient expression assay revealed that ZmbZIP17 localized in the ER,but translocated to the nucleus after TM treated.The truncation of the transmembrane domain from ZmbZIP17 restricted the signals in nucleus under untreated condition.When over-expressed in Arabidopsis,ZmbZIP17 triggered the expression of ER-stress response genes and resulted in enhanced tolerance to DTT.Ectopic expression of ZmbZIP17 also elevated the expression of ABA-responsive genes,and enhanced the sensitivity to ABA during post-germination growth stage.In addition,the relation of ER-stress and ABA signal pathways were checked in the way of qRT-PCR method,result shown that ABA could trigger the expression of ER-stress response genes alone or synergistically with ZmbZIP17 without DTT or TM.