Isolation And Function Analysis Of Plant Stress Tolerance-related Genes

Drought,salinity,cold and freeze are the key environment factors affecting plant growth and development,and seriously limit the increase of yield and improvement of quality of crops. Under abiotic stress,plants could sense and transduce the signals caused by stress to transcription factors through a series of phosphorization responses.A large number of studies have proved AP2/EREBP and NAC transcription factors play important roles in response to biotic and abiotic stresses.In this paper,New AP2/EREBP and NAC genes was cloned from switchgrass(Panicum virgatum L.) and wheat(Triticum aestivum),and study their characteristics and functional Identifications.This study make the these following progresses1.Gene Isolation and sequence analysis:Using the homology cloning methods,it was isolated three AP2/EREBP genes and a NAC gene from switchgrass which were designated PvEREBP,PvDREB1,PvDREB2,PvNAC respectively.Homology trees analysis showed that PvEREBP had higher homology with EREBP transcription factors from corn,rice and wheat,PvDREB1 and PvDREB2 had higher homology with DREB transcription factor from maize and Pennisetum glancum,PvNaC had higher homology with NAC transcription factors from corn,rice and wheat.A NAC transcription factor gene which was designated TaNAC from wheat was isolated.Homology tree analysis showed that TaNAC had low homology with other plant families transcription factors.2.Gene expression analysis:By the method of fluorescence quantitative,PvEREBP, PvDREB1,PvDREB2,PvNAC and TaNAC genes expression was analyzed under abiotic stress and ABA.The results showed that PvEREBP gene was induced by drought,high salinity,low temperature and ABA,PvDREB1 gene only by high salt,PvDREB2 gene by high salt and ABA,PvNAC by drought,high salinity,and ABA,and TaNAC by drought, high-salt and low temperature.3.Subcellular localization analysis:PvEREBP and PvNAC proteins were localized inside nucleus inonion epidermal cells by constructing GFP-PvEREBP and GFP-PvNAC fusion expression carriers and transformed by particle bombardment.4.Functional analysis of transgenic tobacco:constructed four gene expression vector and transformated tobacco through the leaf discs transformation.Transgenic tobacco were treated by PEG,NaCl and ABA.The results showed that over-expression of PvERE-BP,PvDREB2, PvNAC and TaNAC improved transgenic tobacco toleranceto salt,also,over-expression of PvEREBP and TaNAC improved transgenic tobacc resistance to drought.