Drough/High Salt Transcriptome Sequencing Analysis Of Apple And Functional Identification Of MdMYB59

Apple plays an important role in China's agricultural industry,and studying new varieties of resistance can improve its yield and quality and reduce the losses caused by abo living stress.At present,in apples,there are few studies on MYB gene function related to salt stress,and the study of metabolic regulation mechanism of apple MYB gene involved in salt stress reaction has not been reported.This study used Apple's 'golden crown' as a test material,and the analysis and study of transcription sequencing after drought and high salt treatment at different time nodes was carried out,while the gene Md MYB59,which can be induced by high salt stress,was screened by Q-PCR technology and its gene function was identified.The main findings are as follows:1?The response of 10 MYB genes in low temperature,drought and salt stress was detected by Q-PCR technology,and the results showed that the MYB59 gene could be induced by high salt stress.2?According to the landing number MDP00000187872 of the Apple Md MYB59 gene,the full length of the gene sequence was obtained in the Apple'Golden Crown' gene database for PCR amplification,and the results showed that the Md MYB59 gene coding area was 885 bp long,with 294 amino acids encoded and an isotope point of 7.66;Using NCBI software analysis results show that: Md MYB59 sequence has a relatively conservative functional domain as MYB transcription factor;The results of the system evolutionary tree construction show that Md MYB59 is closest to members of the Astigma S22 sub-ethnic group(At MYB4,At MYB70,At MYB73,At MYB77)and to Apple(Md MYB5,Md MYB36,Md MYB90,Md MYB184,Md MYB185).3?The results of amino acid sequence comparison between apple Md MYB59 and MYB members of Arabidopsis thaliana S22 subfamily show that Md MYB59 gene has a conserved domain of R2 and R3 sequence and belongs to a typical Md R2R3 type of transcription factor.In order to study the subcellular localization epidermal cells,the results show that Md MYB59 protein has nuclear localization and is located in the nucleus;To further study the function of the promoter element of the gene,the 1500 bp sequence upstream of the coding region of the gene was cloned,and its functional elements were predicted and analyzed by Plant Care software.It isshown that there are functional elements in the upstream initiators of the Md MYB59 gene that are associated with plant hormones and adversity signaling factors.4?Q-PCR techniques were used to detect the expression of Md MYB59 genes after treatment with drought,low temperature and salt stress at different time nodes.the results showed that the Md MYB59 gene could be up-regulated by drought and high salt stress,indicating that the gene may play a positive regulatory role in high salt stress responses.5?In order to further study the function of the Md MYB59 gene,the results showed that the Md MYB59 gene overex expressed genetically modified apples increased in fresh weight,reduced the content of propylene dealdehyde and relative conductivity under salt stress treatment compared with the control;The Md MYB59 gene was converted into tobacco and stable genetically modified plants were obtained,and salt coercion induction test was carried out,and the results showed that the over-expression of Md MYB59 in tobacco could enhance the salt resistance of genetically modified plants.6?In order to study the transcriptional group sequencing of salt and drought stress reaction in apple seedlings,the results showed that a total of 18,707 differential expression genes were identified,and 12,144 and 7506 differential expression genes were detected to be associated with salt stress and drought stress,respectively.