| Drought and salinity stress seriously affect plant growth and development,and NF-Y transcription factors play an important role in regulating plant growth and development and mediating plant resistance to adversity.In this study,TaNF-YA1,a transcription factor gene of wheat NF-Y family,was used to analyze its resistance to drought and salinity stress.Using online software to interpret the molecular characteristics of TaNF-YAl,the results showed that the total length of TaNF-YA1 gene cDNA was 897 bp,located on the 2D chromosome,and the transcript contained 7 exons encoding 298 amino acid residues,including 23 negatively charged amino acid residues(Asp+Glu)and 34 positively charged amino acid residues(Arg+Lys).The molecular formula of the coding protein is C1404H2212N432O433S14,molecular weight 32.52kDaltons,isoelectric point(pI)9.57.The phylogenetic tree construction results showed that TaNF-YA1 had high homology with one grain of wheat TmNF-YA9 gene.The results of amino acid multiplex sequence alignment showed that TaNF-YAl showed high sequence consistency with wild two-grain wheat TtNF-YA7,common wheat TaNF-YA7 and barley HvNF-YA7.By constructing the TaNF-YA1-GFP fusion expression vector,the bacterial solution was injected into tobacco epidermal cells,and its fluorescence expression site was observed,and the subcellular localization of the gene encoding protein was determined,and it was found that the coding protein was localized in the nucleus,which was consistent with the site where its transcription factor played the regulatory function.qRT-PCR was used to study the expression characteristics of the wheat gene TaNF-YA1 under drought and salinity stress.The results showed that the expression of TaNF-YA1 was upregulated under drought and salinity stress,and the expression at each time point was significantly higher than before treatment,indicating that TaNF-YA1 responded to drought and salinity stress at the transcription level and may play an important role in mediating plant resistance to such stresses.The tobacco and wheat strains of genetic transformation TaNF-YA1 superexpression and inhibition were established by DNA recombination technology,and the function of transgenic lines against osmotic stress was studied.The results showed that under drought and salinity treatment,the growth potential of Sen 1 of the super-expressing TaNF-YA1 transformed strain was enhanced compared with that of wild type,the individual plant increased,the fresh weight increased,the dry mass increased,the photosynthetic carbon assimilation ability was improved,and the antioxidant enzyme activity of cells was enhanced.The stomatal closure rate of this super-expressed strain accelerated under drought and salinity stress,and the water holding rate of ex vivo leaves increased.The above traits of inhibitory expression lines all showed the opposite characteristics of super-expression lines.This paper showed that TaNF-YA1 played an important role in mediating plant resistance to drought and salinity stress.In order to elucidate the mechanism of TaNF-YA1 against osmotic stress,the interaction between this gene and TaNF-Y family-related genes coding proteins,the regulation of downstream protective enzyme genes,root development-related genes and the expression characteristics of ABA receptor genes were further analyzed.The yeast two-hybrid technology was used to construct a TaNF-YA1 yeast two-hybrid vector to study the interaction between TaNF-YA1 and the genes TaNF-YB-A13 and TaNF-YC1 encoding proteins identified by the research group.The results showed that the co-negative control group could not grow normally on the three-deficient medium and the four-deficient medium,while the experimental group containing recombinant proteins AD-TaNF-YA1 and BD-TaNF-YB-A13 and the experimental group containing BD-TaNF-YA1 and AD-TaNF-YC1 could grow normally.It was indicated that TaNF-YA1 interacted with TaNF-YB-A13,and TaNF-YA1 and TaNF-YC1,and the three may combine to form complexes in the nucleus to jointly regulate plant resistance to osmotic stress.qRT-PCR was used to analyze the expression levels of protective enzyme genes,root development-related genes and ABA receptor genes of TaNF-YA1-transforming tobacco strains under drought and salinity treatment,and it was found that compared with wild type,the expression levels of NtSOD1.1,NtPOD1.4,NtCAT2.2,NtPIN1,NtPIN4,NtSPK1,NtSAPK1 and other genes in TaNF-YA1-transforming tobacco strains were up-regulated,while the expression of antisense expression strains was down-regulated.Compared with wild type,the expression of genes in the righteous expression lines NtSOD1.1,NtSOD1.2,NtPOD1.3,NtPOD1.4,NtCAT1,NtCAT1.1,NtPIN3,NtPIN4,NtSPK2,NtSRK7 and other genes were up-regulated,while the expression of antisense expression lines was down.This paper indicates that TaNF-YA1 may regulate the transcription of the above genes,enhance the expression of related genes such as ROS,PIN and SnRK,maintain ROS homeostasis under drought and salinity stress,promote root development,regulate stomatal opening and closing,enhance water absorption and water retention,and then improve the function of plants to resist osmotic stress. |
