| Soybean is one of the main crops in China.Soybean root rot is a devastating disease in soybean planting and production,which will cause huge economic losses and seriously harm the safety of soybean production.Phytophthora sojae is the pathogen of this diseasel On the one hand,due to the evolution of P.sojae,many fungicides on P.sojae lack of effect.resistant varieties are effective to protect soybean against P.sojae.Therefore,it is very important to study the immune response of soybean in the process of being infected and find stable resistance genes.On the other hand,the effectors of P.changes frequently,it makes resistance breeding using Rps genes not always keep for long.Therefore,it is essential to understand the mechanisms by which these pathogens break down plant defences.by analyzing the changes of the plant after overexpressed PsAvh240,we found an immunity related protein,soybean aspartic protease,which plays an important role in plant resistance.In addition,after the isoelectric points of all effectors were calculated,a special low electric point effector PsAvh109 was found.In this study,the function of soybean aspartic protease and the virulence of PsAvh109 were analyzed in the process of the research.Function analysis of soybean aspartic protease GmAP1 in the process of Phytophthora infection:Based on the previous study,it was found that the expression of the effector PsAvh240 improved the ability to infect N.benthamiana.In addition,we found an aspartic protease protein GmAP1,which played an important role in the process of soybean resistance.The overexpression of GmAPl can improve the resistance of N.benthamiana to P.capsici infection.The enzyme activity was detected,and the result shows that it has protease activity.The enzyme activity mutant can not enhance plant immunity.The results showed that GmAP1,as an exocrine protein of soybean,was synthesized in the cell and processed to form a protease precursor,then secreted to the apoplast and leave the key enzyme active sites as a proteolytic enzyme and promote immunity response.Function analysis of Phytophthora sojae RxLR effector PsAvh109:After the isoelectric points of all effectors of Phytophthora sojae were counted,a special low electric point effector,PsAvh109,was found.Sequence polymorphism analysis showed that PsAvh109 contained homologous genes in the other four Phytophthora genomes,indicating that PsAvh109 is a conservative effector.It was found that PsAvh109 contains not only a signal peptide and a typical RXLR motif,but also a negative/positive charge enrichment region and a random coil at C-terminal.By using CRISPR/Cas9 mediated gene disruption,we found that Avh109 is essential for the full virulence of P.sojae.The overexpression of PsAvh109 gene in soybean hairy roots and in N.benthamiana shows that it can promote the infection of Phytophthora,which indicates that PsAvh109 plays an important role in the process of infection.Analysis of RNA-seq data showed that 819 genes were differentially expressed.There are 341 genes up-regulated and 478 genes down-regulated in the PsAvh109-expressing hairy roots compared with the control hair roots.The results show that PsAvh109 can regulate the expression of genes of soybean and so many defense response related genes were found.Kyoto Encyclopedia of Genes and Genomes(KEGG)terms of overlapped genes in PsAvh109-expressing and GFP roots shows that many resistant genes were found.The analysis of these differentially expressed genes is helpful to study the mechanism of plant defense genes’ expression,and provide the basis for searching the candidate protein that can interact with PsAvh109. |
PDF Full Text Request