Functional Analysis Of Transcription Factor Genes ABI4 And DREB1 Related To Salt Tolerance In Peanut (Arachis Hypogaea L.)

Peanut?Arachis hypogaea L.?is one of the most important oil and economic crops in the world.In order to give full play to the advantages of peanuts increasing in salt and alkali land of increasing value,production and efficiency,the key of peanut molecular breeding is to excavate the salt tolerance gene of peanut.ABI4?Abscisic acid-insensitive 4?and DREB1?Dehydration responsive element binding protein?are hot spots in the research of plant transcription factors.They play a key role in regulating the expression of stress-inducible related genes and participating in the response and adaptation of plants to salt stress.In this study,the peanut cultivar Fenghua 2 was used as a material.The AhABI4 was cloned and the bioinformatics analysis was carried out.The tissue specificity of the AhABI4 and the expression pattern under salt stress were explored.The virus induced AhABI4 silencing expression vector was constructed,and analysed the salt tolerance of the transgenic plants was transformed by Agrobacterium mediated transformation.Meanwhile,the AhDREB1 function was identified by the changes of physiological characters such as plant phenotype,AhDREB1expression,SOD and POD activity,MDA and soluble protein content of T₂ transgenic peanut plants of AhDREB1.The main results are as follows:1.Homologous cloning method was used to obtain the cDNA full-length sequence of AhABI4-A and AhABI4-B of cultivar Fenghua 2.The cDNA full-length of AhABI4-A is1753bp and the CDS which encoding 363 amino acids is 1092 bp.The c DNA full-length of AhABI4-B is 1807 bp and the CDS which encoding 357 amino acids is 1074 bp.AhABI4belongs to the DREB-A3 subfamily member of the AP2/EREBP transcription factor family,no transmembrane domain,no intron.2.AhABI4 expresses in germinated seeds,and roots,stems and leaves of the seedling;among which the expression of AhABI4 is the highest in germinated seeds and relatively lower in stems.The salt stress response patterns of AhABI4 in toproots,lateral roots and functional leaves of peanut seedlings were all induced by up regulation.The transcriptional level of AhABI4 was decreased in the seed germination of strong salt tolerance Shanhua11,and it was speculated that AhABI4 negatively regulated the tolerance of peanut to salt stress.3.The virus induced AhABI4 silencing expression vector,TRV2-AhABI4,was constructed to convert the peanut through agrobacterium tumefaciens vacuuming infiltration and silenced plants with AhABI4 silencing efficiency up to 59%were obtained.4.The plants with AhABI4 silencing were treated with salt.The study found that the plant wilting degree was lighter than that of the wild type after salt stress.The silenced plants could grow normally and the resurrection rate was higher than that of the wild type.The salt tolerance coefficient of the silenced plants was significantly higher than that in the wild type,and the salt tolerance amplification by 18.9-21.7%.It indicates that AhABI4 negatively regulates the salt tolerance of peanut seedlings.5.171mM NaCl was treated at the seedling stage of T₂ transgenic peanut plants of AhDREB1 that the initial acquisition of the project group.The results showed that the green degree and root growth of the transgenic plants were significantly higher than the control.The expression of AhDREB1 in transgenic plants was increased and the response speed faster than the control;The activity of SOD and POD and the content of soluble protein were higher than the control,while the content of MDA was lower.It indicated that the overexpression of AhDREB1 could improve the salt tolerance of transgenic plants.4 transgenic plants with better salt tolerance were screened,namely D254,D380,D385 and D448.