The Preliminary Study On Molecular Structure And Function Of ICE1 Gene And BZIP Transcription Factors In Celery

Celery(Apium graveolens L.)is a type of Apiaceae,which is an important leafy vegetable.Celery is native to the Mediterranean and Middle East and has a long history of cultivation in China.Celery contains high nutritional and medicinal values,which is rich in apigenin,carotenoids,vitamins,flavonoids,and volatile aromatic components.The whole plant of celery can be used as medicine.Abiotic stresses(such as high temperature,low temperature,drought,and high salt)are important factors affecting plant growth and development,as well as yield and quality.They will damage the membrane structure of plant cells,and disrupt the own water balance in plants,which will have a greater impact on the growth and development of the plant,and then affect the yield and quality.Transcription factors play an important role in plant defense response and stress response.In this paper,we screened and identified celery ICE1 gene,AgbZIP16 gene,and 62 members of the bZIP transcription factors family.The structure,physicochemical properties,and their response to different abiotic stresses also were analyzed.The main results are as follows:1.A transcription factor gene,AgICE1,was cloned from celery cultivar ’Jinnan Shiqin’.Sequence analysis showed that AgICEl gene contained a 1455 bp of open reading frame(ORF),which encoded 484 amino acids.Theoretical relative molecular mass of AgICEl amino acids was 53.14 kD.Theoretical isoelectric point(p1)was 5.09,and AgICEl was a hydrophilic protein.Quantitative real-time PCR analysis showed that the expression level of AgICEl in celery leaf blades was higher than that in root and petioles.Under the conditions of high temperature,low temperature,drought,and salt stresses,the relative expression levels of AgICEl gene were up-regulated,and its response to low temperature stress was more obvious.2.In this study,we analyzed and identified the AgbZIP16 transcription factor of the bZIP transcription factor family in celery,and the result showed that the expression of AgbZIP16 gene was induced by high salt stress.AgbZIP16 is a nucleus-located protein.In celery,the expression level of AgbZIP16 gene upregulation under NaCl treatment.Overexpression AgbZIP16 in Arabidopsis thaliana increase the tolerance of transgenic plants to salt treatment,and expression levels of three genes(CBF3,RD29A and COR15A)were obviously increased in transgenic plants under 48 h salt treatment.3.Based on the celery genome and transcriptome data provided by our research group,we screened and identified 62 celery bZIP transcription factors.According to the phylogenetic tree,we divided the bZIP proteins of celery and Arabidopsis into 10 subfamilies.Phylogenetic and evolutionary analysis showed that the number of bZIP family members gradually increased during the evolution process from lower plants to higher plants.The analysis of protein interaction networks indicated that celery bZIP transcription factors may be involved in various biological processes.In addition,we selected 12 AgbZIP genes to analyze their expression in different tissues(root,petiole,and leaf blade)of celery and abiotic stresses.The results showed that AgbZIP16 gene had the ability to respond to high temperature,low temperature,drought,and high salt stresses.This study provides useful information for the study of adversity response in celery.At the same time,this study can provide a basis for studying the regulation mechanism of AgICEl and bZIP transcription factor in celery and lay a foundation for further breeding of new celery varieties.