Analysis The Response Mechanism Of Lonicera Japonica Thunb. Cold Stress Based On Transcriptome Sequencing

Lonicera japonica Thunb.belongs to the genus Lonicerae,its dry flower bud is an important traditional Chinese medicine.Lonicera japonica Thunb.also has strong adaptability,cold tolerance,drought tolerance and light,so it is planted in large areas.In order to explor the response of Lonicera japonica Thunb.under cold stress,this experiment determined and analyzed the Malondialdehyde,Electrical Conductivity,Ultrastructure,Antioxidant Enzyme and Chlorophyll fluorescence of one-year planting Lonicera japonica Thunb.;According to the transcriptome sequencing process and data analysis method,the cold treatment and control of four materials were separately transcribed without reference genome through Hi Seq2500 doubleend sequencing technology.The Unigene sequences assembled by transcriptome sequencing datas were analysis with GO and KEGG classification statistics,functional annotations and metabolic pathway,and the differentially expressed genes were screened and analyzed.The main results were as follows:1)The effect of cold stress at 4 °C on the leaf structure and physiological index of Lonicera japonica Thunb.showed that the content and conductivity of malondialdehyde(MDA)increased first and then decreased with the increase of stress time;the structure of chloroplast membrane was destroyed,the chloroplast gradually disintegrated,the starch granules expanded and deformed,and the Addictive drop increased with the increase of stress time;the activity of SOD,POD and CAT increased during 3h,then decreasing with the increase of stress time: Chlorophyll fluorescence parameters include Fv/Fm and Y(II),which gradually decrease at the beginning of cold stress and finally stabilize.2)A total of 36.26 Gb Clean Data was obtained from transcriptome sequencing,and 102912 transcripts of Unigenes and 181 DEGs were obtained.There are 48 unigenes with functional classification,and 122 unigenes are annotated with GO function annotations.Only 28 unigenes were annotated in the KEGG database and annotated in 22 KEGG metabolic pathways.Twenty transcription factors were screened by SMART and PFAM.We found that c53859.graph_c0 was highly expressed under low temperature stress,and c34863.graph_c1,c56695.graph_c0,c67307.graph_c0,c35634.graph_c0,c40764.graph_c0 and c19817.graph_c0 were highly expressed at high temperature through RT-q PCR.3).The genes involved in the synthesis of trehalose and starch are differentially expressed during low temperature stress;the expression of related genes in the GSH-ASA metabolic pathway plays an important role in the maintenance of cell membrane stability by scavenging reactive oxygen species.4)34 AP2 transcription factors with “RAYD”and“YRG” Conserved domain,30 WRKY transcription factors with "WRKYGQK" sequence and zinc finger structure,11 Dof transcription factors with “C2-C2” zinc finger structure were screened by SMART and PFAM based on transcriptome sequencing data.The reason of Lonicera japonica Thunb.adapted to cold tolerance may be that the plant initiates a series of cellular pathways by synthesizing some cold-induced transcription factors,such as eliminating free radicals under cold stress,regulating the synthesis of enzymes such as SOD,and adapting to cold by increasing the content of osmotic substances such as proline based on the results of comprehensive physiological indicators and transcriptome sequencing data.Throughout the process,a large number of enzyme genes are involved in the expression,thereby initiating a series of cellular activities that adapt to the cold environment.This study provides genetic resources for further analysis of Lonicera japonica Thunb.resistance.