Effects Of Salt Stress On Physiological Changes And Gene Expression Of Ipomoea Pes-caprae

Ipomoea pes-caprae(L.)R.Brown)is one of the perennial wild species of sweetpotato,a perennial vine plant which grows on tropical and subtropical beaches.It is one of the landscaping plants in coastal areas with strong salt tolerance.By analyzing the changes of physiological and biochemical indexes of roots and leaves of sweetpotato wild species Ipomoea pes-caprae under different salt concentration stress,the salt stress was simulated by 300,600,900 mmol/L NaCl solution by sand culture method.Proline,malondialdehyde,soluble sugar,total protein content and net photosynthetic rate of leaves and roots at 0,1,3,5,7 days after stress.With the prolongation of salt stress,the content of proline in roots and leaves increased gradually;malondialdehyde,soluble sugar content and net photosynthetic rate increased first and then decreased under different concentrations of salt,and the top 3 The peak value was reached in d;while the total protein content showed a tendency to rise first and then decrease in the roots,and it continued to rise in the leaves.As the salt stress concentration increases,the peaks reached by the content of proline,malondialdehyde and soluble sugar also increase.It is confirmed that lpomoea pes-caprae has strong salt tolerance,and its roots and leaves can resist salt stress through a series of physiological and biochemical changes,which provides a reference for sequencing time and salt stress concentration in the next transcriptome.We performed the experiments in preliminary estimation of the genome size of Ipomoea pes-caprae by flow cytometry,generation of high-throughput sequencing datasets,and the bioinformatics analysis of genomic profiles such as Ipomoea pes-caprae GC content,heterozygosity,and repeat sequences.The results showed that the genomic size by using the flow cytometry was 1012.99 Mb,and the clean data of Ipomoea pes-caprae was 21.71 Gb by genome-wide Survey.By integrated analysis with 30x genomic dataset,its genome size was re-estimated to be 1041.65 Mb.K-mer analysis suggested 74.52%of repeated sequences of the Ipomoea pes-caprae genome.The heterozygosity rate was 0.99%.The initial depth of GC and the content distribution were abnormal after initial assembly.The size and characteristics of the Ipomoea pes-caprae genome were investigated to provide reference information for transcriptome sequencing and assembly strategies.The RNA library of leaves and roots at different times after stress was sequenced using the Ilumina Nova-seq 6000 platform,and differential gene analysis and gene identification were performed after annotation.It is thought that Ipomoea pes-caprae mainly expresses genes mainly,while leaves are mainly regulated by genes;Unigene mainly responds to and participates in salt stress by participating in many ways such as ribosome and carbon metabolism;salt tolerance through transcripts Gene identification,obtaining salt-responsive genes with various functions,such as signal transduction,antioxidant enzymes,ion transport and other candidate genes.Ipomoea pes-caprae has strong salt tolerance and may be closely related to the V-ATPase family of genes involved in ion transport and the CAT,Cu_Zn.SOD and GPX family genes involved in the antioxidant pathway.