Mechanism of methyl jasmonate-induced resistance to soft rot disease in kiwifruit based on transcriptomics analysis
[Objective]Methyl jasmonate(MeJA),a biological signaling molecule in plants,can stimulate fruit resistance to biotic or abiotic factors stress and plays an important role in storage.Transcriptome technology has been widely used to explore the regulatory mechanisms associated with postharvest disease control,and it can elucidate the mechanisms of pathogen-plant interactions at the molecular level,which is conducive to the identification and mining of stress-responsive genes.Previous research has demonstrated that by regulating the defense system's improvement,(MeJA)can cause kiwifruit fruit to become resistant to postharvest soft rot.MeJA-induced kiwifruit resistance to soft rot has been linked to the phenylpropane pathway,membrane lipid metabolism,and energy metabolism.A preliminary description of the physiological and molecular mechanisms underlying MeJA-mediated kiwifruit resistance to soft rot has been made.This study aims to analyze MeJA-induced transcriptome data on kiwifruit resistance to Botryosphaeria dothidea and the expression of disease-resistance-related genes in response to pathogen infestation,thus providing a theoretical reference for studying the molecular mechanism of MeJA-mediated resistance to soft rot in kiwifruit.[Method]'Hongyang'kiwifruit was used as the test material.The inoculated B.dothidea group and the MeJA-treated,inoculated group were selected,and 0,1 and 5 d kiwifruit samples were subjected to transcriptome sequencing.Differentially expressed genes(DEGs)were screened by log2FC≥2,Qvalue≤0.05 and FPKM>2,validated by real-time fluorescence quantitative PCR,and analysed by Gene ontology(GO)functional annotation and KEGG pathway enrichment.[Result]About 114.97 GB of clean data were obtained from the transcriptome sequencing,and the clean data of each sample was about 6.39 GB.The percentage of Q30 base was 90.41%or above.Statistics on the number of differentially expressed genes in each period revealed that kiwifruit fruit DEGs gradually increased with the prolongation of B.dothidea infestation;whereas the number of DEGs induced in the main base of DEGs in response to MeJA was gradually reduced at the time of pretreatment,and after inoculation with the pathogen,suggesting that the exogenous MeJA induced a large number of genes involved in fruit resistance at an early stage.The un-treated inoculation group and the MeJA-treated inoculation group shared 164 and 314 DEGs at 0,1 and 5 d,respectively.GO enrichment results indicated that DEGs were mainly associated with cellular processes,metabolic processes,response to stimuli and biological regulation in biological processes;cellular anatomical entities and intracellular in cellular components;and binding,catalytic activity and transcriptional regulatory activity in molecular functions.The results of KEGG pathway enrichment showed that kiwifruit fruits inoculated with B.dothidea after MeJA treatment were specifically enriched in the plant-pathogen interaction pathway,alpha-Linolenic acid metabolism,glutathione metabolism,benzoxazinoid biosynthesis,ascorbate and aldarate metabolism;phenylpropanoid biosynthesis,stilbenoid,diarylheptanoid and gingerol biosynthesis,flavonoid biosynthesis,MAPK signaling pathway-plant were jointly enriched in both treatment groups.A total of 31 DEGs responding to both MeJA and B.dothidea were screened,and it is hypothesized that these genes are associated with MeJA-mediated disease resistance processes.[Conclusion]In this study,RNA-Seq analysis of externally assisted MeJA-treated kiwifruit fruits at different periods(0 d,1 d and 5 d)after inoculation with B.dothidea shows that MeJA induces a large number of genes of physiological metabolic pathways to change during the process of kiwifruit fruits'resistance to soft rot.This change helps to enhance the initiation of the fruit signalling molecules to the defence system,and increase the synthesis of antimicrobial substances and antioxidant capacity,which in turn improves the disease resistance of kiwifruit fruits and prolongs their storage time.
万方数据
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