| Aquilegia vulgaris is a perennial flower with excellent ornamental traits and strong adaptability,which has broad application prospects.In recent years,the salinization of land has been increasing,and salt stress can limit the growth of plants and reduce their ornamental effect.In this study,A.vulgaris was used as experimental material,and various growth indexes and physiological indexes of A.vulgaris were measured under different concentrations(0,100mmol·L-1,200 mmol·L-1,300 mmol·L-1)NaCl treatment for 12 days to understand its physiological response to salt stress.Based on the transcriptome sequencing data of A.vulgaris under 200 mmol·L-1 NaCl stress,the AP2/ERF family genes of A.vulgaris were identified,and the expression analysis under salt stress was found out the key genes in response to salt stress.The cloning and bioinformatics analysis of AvAP2/ERF-56,AvAP2/ERF-61 and AvAP2/ERF-80.The study was aimed to provide a theoretical basis for resistance breeding of Aquilegia plants.The main results were as follows:1.With the increase of NaCl concentration,the plant height,crown width,number of leaves and relative water content of leaves of A.vulgaris show a downward trend,SOD and POD activities first increase and then decrease,H2O2,MDA,soluble sugar,proline content and relative electrical conductivity gradually increase,and soluble protein content has no significant change.The 100 mmol·L-1 NaCl stress had little effect on the growth of A.vulgaris,with no significant difference in other indices except for the significant increase in SOD activity.The stress of 200 mmol·L-1 NaCl and 300 mmol·L-1 NaCl had a strong inhibitory effect on the growth of A.vulgaris.The plant height,crown width,leaf number and leaf relative water content of A.vulgaris were significantly reduced compared with CK.POD activity,H2O2,MDA,soluble sugar,proline content and relative electrical conductivity were significantly increased compared with CK.2.86 AvAP2/ERF genes were identified in A.vulgaris,all with AP2 domains,divided into5 subfamilies and 15 subgroups,with different subfamilies having different conserved Motifs except Motif 1 and Motif 2.Some genes respond to salt stress.There were 19 differentially expressed genes,15 up-regulated genes and 4 down-regulated genes in roots.There were 18differentially expressed genes,13 up-regulated genes and 5 down-regulated genes in leaves.The expression of AvAP2/ERF-56,AvAP2/ERF-61 and AvAP2/ERF-80 were significantly up-regulated in both roots and leaves,and were closely homologous to salt tolerance genes in Arabidopsis,so these 3 genes were selected as key genes in response to salt stress.3.The AvAP2/ERF-56,AvAP2/ERF-61 and AvAP2/ERF-80 genes were successfully cloned,and the results of bioinformatics analysis showed that the ORF of AvAP2/ERF-56 was 738 bp long,encoding 245 amino acids;the ORF of AvAP2/ERF-61 was 972 bp,encoding 323 amino acids;and the ORF of AvAP2/ERF-80 was 696 bp,encoding 231 amino acids.All 3 proteins are hydrophilic unstable proteins;no transmembrane structure,no signal peptide,and non-secretory proteins;random coiling andα-helix are the main structures that make up the proteins.AvAP2/ERF-56,AvAP2/ERF-61,AvAP2/ERF-80 proteins and A.coerulea were most closely related,followed by Thalictrum thalictroides.In conclusion,A.vulgaris have a certain tolerance to salt stress,and can resist salt stress by increasing the content of osmoregulatory substances and improving the activity of antioxidant enzymes in the plant.In this study,86 AvAP2/ERF genes were identified for the first time,and AvAP2/ERF-56,AvAP2/ERF-61 and AvAP2/ERF-80 genes responding to salt stress,and then cloned and analyzed,which are well prepared for the subsequent study of gene function and the regulation mechanism of salt tolerance.The study provide a certain theoretical basis for salt tolerance breeding in columbine plants,and are of great significance for the application and promotion of columbine plants. |
