Analysis On Transcrintome Of Copper Tolerance And Complete Chloroplast Genome Sequence Of Elsholtzia Splendens

Elsholtzia splendens is a native copper-tolerant plant growing near copper deposits in southern China.This plant is commonly known as;"copper grass"for its crucial role in phytoremediation of soils contaminated with copper,an important heavy metal species.Nevertheless,most of the studies on copper tolerance of E.splendens have not involved the dynamic changes of transcriptional genes under copper stress of E.splendens.Few studies have analyzed and explored the mechanisms related to copper tolerance from the perspective of genetics and transcriptome.In this study,therefore,on the one hand,the molecular mechanism of copper tolerance of E.splendens was explored by transcriptome technology.The root genes of E.splendens seedlings were analyzed under three concentrations of copper stress(T1:10?mol/L Cu2+?T2:50 ?mol/L Cu2+?T3:100 ?mol/L Cu2+)for 7 days and the transcriptome data of the control(CK)group.58,525 unigenes were obtained from the transcriptome data annotation of E.splendens.Functional analysis of differentially expressed genes was carried out.The main pathways for significant enrichment of differentially expressed genes are ribosome,phage,nitrogen metabolism,keratin,xylem and wax biosynthesis,cytokinin biosynthesis,panquinone and other terpenoids-quinone biosynthesis,photosynthesis-antenna protein,photosynthesis,carbon fixation in photosynthesis,and alpha-linolenic acid metabolism.These metabolic pathways are interrelated and synergistic.Compared with the control group,16,9 and 15 differentially expressed copper-related metal ion transporter genes were screened in the three experimental groups.The KEGG pathway with significant enrichment of differentially expressed genes,such as photosynthesis-antennae protein,photosynthesis,carbon fixation in photosynthesis,and alpha-linolenic acid metabolism,is closely related to chloroplasts.To explore the tolerance mechanism of E.splendens by transcriptome technology in order to provide basic data at transcriptome level and related genes and pathway that may be involved in copper stress resistance for subsequent research.On the other hand,we sequenced and de novo assembled the complete chloroplast genome of E.splendens.The complete chloroplast genome is 150,761 bp(37.8%of GC)in length.The inverted repeats are 25,572 bp,and single-copy regions are 17,473 bp(SSC)and 82,144 bp(LSC),which contain 87 protein encoding genes,38 tRNA genes and 8 rRNA genes.There are 30 long repeats and 65 SSRs in the E.splendens cp genome.Comparative chloroplast genome analysis of 11 Lamiaceae species indicated that a higher similarity was preserved in the IR regions than in the LSC and SSC regions.Phylogenetic analysis revealed that E.splendens are closer to Perilla and divergence from Ocimum.The complete chloroplast genome of E.splendens will be helpful to investigate into genetic relationships among different hyperaccumulator species.