Analysis Of Gene Expression Level Of ’JinHong’ Apple Infected By Cytospora Mali Based On Transcriptome Sequencing

Apple(Malus domestica Borkh.)belongs to the genus Malus(Rosaceae),and is a deciduous tree that grows in temperate and subtemperate regions.The cold apple producing areas in Northeast China include Jilin Province,Heilongjiang Province and Inner Mongolia Autonomous Region,where small apple varieties such as Jinhong and so on are mainly cultivated.Valsa canker of apple is a disease caused by Valsa Mali,which results in a large area of apple production and severely restricts the development of apple industry around the world.The cold and dry climate in Inner Mongolia weakens apple trees and makes them vulnerable to infection,leading to a serious apple rotting disease in the region.There has been no report on the analysis of gene expression of ‘Jin Hong’apple infected by V.Mali by transcriptome sequencing method.In this study,‘Jin Hong’apple was used as the material to analyze the gene expression level of the apple infected by V.Mali by transcriptome sequencing technology and explore the potential disease-resistance genes.The research results are as follows:(1)The transcriptome sequencing method was used to analyze the gene expression in phloem tissues of“Jin Hong”apples infected by V.Mali and at different parts including buds in the same period from the inoculation site.A total of 18633 significantly different genes were obtained,including 10711 for“Jin Hong 1”and 7922 for“Jin Hong 2”.(2)The analysis results of KEGG showed,differential genes were mainly significantly enriched in the two samples: plant hormone signal transduction pathway and flavonoid biosynthesis pathway.And the difference of two samples most genes significantly enriched in proteasome,amino acid biosynthesis and metabolism of carbon and TCA cycle,glycolysis,photosynthesis-these pathways in the antenna,and the trend of the same expression.(3)The possible disease-resistance genes were verified and studied in this study,and the possible disease-resistance genes involved in the anti-decay mechanism of “Jin Hong”apple were finally confirmed as: plant receptor-like kinase(MD03G1233100),NAC family transcription factor(MD09G1053700),and MYB6 family transcription factor(MD16G1040800),which were up-regulated in both samples.Two chitin activated immune receptors(MD13G1277200)up-regulated in “Jin Hong 1 ” and down-regulated in “Jin Hong 2”(MD00G1083800)and ethylene insensitive proteins(MD02G1266200)up-regulated in “Jin Hong 1”.