| Potato have surpassed corn and become the third food crop in the world,which is behind rice and wheat.In early 2016,the strategy of staple food for potatoes was launched in China,and potato was used as a staple food product for industrial development,it high-lights the important position of potato in Chinese agriculture.Potato late blight,caused by Phytophthora infestans,has always been the most serious disease in potato production.It is the most fundamental and effective way to plant resistant cultivated to control the disease.The further study on the interaction between potato and Phytophthora infestans can lay a theoretical foundation for identifying the candidate genes and deeply revealing the disease resistance mechanism in potato.In this study,the resistance of 76 germplasms including home and abroad were evaluated,and the transcriptome of Huasong 7 infected by Phytophthora infestans was analyzed.The affinity and non affinity molecule interaction mechanism were explored when potatoes response to Phytophthora infestation.The results are as follows:1.A total of 76 potato germplasms were tested by spray inoculation and detached leaflets inoculation for resistance evaluation to Phytophthora infestans T30-4(race 1,3,4,5,6,7),428-2(race 5,6,9,blb1,blb2,blb3),90128(race unknown),F80029(race unknown),CN152(typical full-virulence strain 13_A2,race 1,3b,4,5,6,7,8,9,10,11),and avirulence strain 89148-9(race 0),of which 22 germplasms showed varying degrees of resistance.Huasong 7 was evaluated resistance against 428-2,and there was obvious HR reaction in the back of blade,showed non affinity interaction;and sensitivity to T30-4,showed affinity interaction.2.The transcriptome sequencing and data analysis of huasong 7 infected with 428-2 and T30-4 at different time(0,24,48,72 hpi,hours post inoculation)were carried out respectively,the expression profiles of resistance gene in the whole genome were constructed,the molecular mechanism of affinity and non affinity interaction between potato and Phytophthora infestans were analyzed,and the transcription factors resistance-related and protein kinase genes were screened.(1)Under 428-2,T30-4 inoculation and H2O control treatments for potato huasong 7,the total number of differential expression genes were 9,290,9,289 and 8,838,respectively,the number of unique differential expression genes were 920,1,189,and 740,respectively,and the number of common expression genes were 6,794.It was indicated that T30-4-induced affinity interaction initiated more differential expression genes than 428-2-induced non affinity interaction.(2)The results of gene ontology(GO)enrichment and kyoto encyclopedia of genes and genomes(KEGG)metabolic pathway of differential expression genes showed that differential expression genes treated with 428-2 were significantly enriched in immune system process,immune response,regulation of defense response and other GO items related to disease-resistant immunity,as well as KEGG metabolize antioxidant pathways such as glutathione metabolism,flavonoid and flavonol biosynthesis,sesquiterpenes and triterpenes biosynthesis;and differential expression genes treated with T30-4 inoculation were mainly enriched in GO items such as translation,gene expression,cell macromolecule biosynthesis,and KEGG metabolic pathways such as phosphoinositol metabolism,phospholipid signaling system and receptor-mediated endocytosis related to pathogen invasion.It was indicated that resistance-related pathway was initiated and differential expression of resistance-related genes were induced when huasong 7 potatoes were infected by 428-2.(3)Treated by 428-2 and T30-4 inoculation,the number of differential expression genes encoding transcription factors in huasong 7 were 23 and 24,respectively,encoding WRKY,bZIP,BHLH,MYB,ERF and zinc finger protein transcription factors.Most of transcription factor genes were up-regulated when inoculated with 428-2,including 2 WRKY,1 bZIP TGA7 and 4 AP2/ERF transcription factor genes,which were positively regulated on the interaction between huasong 7 and 428-2.When infected by T30-4,the genes encoding transcription factor were TSRF1,WRKY10,ERF13,MYB161,JimC,NLP7-like,TAGL12,etc.,which played an important role in T30-4-mediated affinity interaction.(4)Under 428-2 inoculation treatment,there were 78 differential expression kinase genes in huasong 7,of which 30 genes were up-regulated and 48 genes were down-regulated,37.2%(29)and 30.8%(24)of kinase genes were differential expressed at 24 h and 48h after inoculation.It was indicated that most kinase genes played a negative regulatory role in the non affinity interaction between Huasong 7 potato and 428-2,moreover,most kinase genes developed effect in PTI and ETS stages.Under T30-4 inoculation treatment,there were 70 differential expression kinase genes,of which 46 genes were up-regulated and 24 genes were down-regulated,suggesting that most differential expression genes played a positive role in the affinity interaction between huasong 7 potato and T30-4,and it works in ETI stage. |
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