Transformation of ApHRD Gene and Drought-tolerance Identification of Transgenic Plants in Tobacco

According to the sequence of HRD gene from Arabidopsis thaliana,ApHRD gene was cloned from A.pumila by PCR,and the plant expression vector pBIN-ApHRD was constructed.NC89 tobacco plants were transformed via Agrobacterium tumefaciens,PCR and RT-PCR analysis indicated that the foreign gene ApHRD had been integrated into the genome.The drought-tolerance was analyzed between the ApHRD genetic and the wild type tobacco by water stress and PEG-6000 drought simulated.The results prove that the similarity between the ApHRD gene of A.pumila cloned and the AtHRD gene of A.thaliana is 99.1%,and the similarity between their corresponding amino acid sequence is 98.37%.There are only three sites real mutations.ApHRD tobacco embody are more sturdy taproot and more develop stair roots than that of the wild type tobacco,and the survived transplanting grow fast.Under the drought-tolerance and the 30% PEG-6000 drought simulated conditions,the reduction of leaf relative water content,the increasing of MDA activity,relative conductivity and the reduction of relative quantum yield of PSⅡ of ApHRD tobacco are lesser than that of control tobacco evidently.Transgenic plants leaves wilting symptoms appeared later to a lesser extent,faster and complete recovery after re-watering,minor injuries in drought-tolerance.ApHRD tobacco have more tolerance to drought,which testify that ApHRD gene of A.pumila showed fine physical,growth advantage and excellent characteristics of drought resistance.ApHRD gene has a better application prospect on the drought-tolerance genetic engineering.