Analysis Of Gene Expression Changes In Wheat Leaves In Response To WDV Infection Using RNA-Seq

Wheat dwarf disease is becoming an increasingly severe geminivirus disease on triticeae cropswhich caused by Wheat dwarf virus(WDV) and transmitted by Psammotettix striatus L. The exactpathogenesis of this disease have not been deeply explored. In this present study, RNA-Seq was used forgene expression analysis in wheat in response to wheat dwarf virus infection.Differentially expressed genes related to symptoms and plant defense response were validated by q PCR.In addition, differentially expressed mi RNA were analyzed preliminarily. These results illustrate thedynamic nature of the wheat–WDV interaction at the transcriptome level and confirm that symptomdevelopment is a complex process that can be the basis to further understand pathogenesis of WDV.Firstly, comparative transcriptome profiling of Triticum aestivum L. in response to wheat dwarfvirus infection was conducted by RNA-Seq. A total of 77221 unigenes were available after Trinityassembly and cluster analysis, 4324 of which were differentially expressed if compared to the control.Gene ontology(GO) annotation revealed that a list of candidate genes involved in aging, response tobiotic stimulus, gene silencing, phytohormone metabolism, photosynthesis, DNA metabolic processre,regulation of defense response and so on. Twenty-three differentially expressed genes associated withphytohormone metabolism, photosynthesis and plant defense response were selected and validated byq PCR. The results indicated that metabolism changes and transport suppression of auxin, gibberellinsand brassinosteroid may contribute to severe dwarfism in the infected wheat plants. Abnormal tilleringmaybe due to the metabolic disorder about auxin and cytokinin. Furthermore, genes expression changerelated to photosynthetic enzymes and chlorophyll may induce chlorosis of leaves. In a word, the WDVinfection broke the dynamic equilibrium among some kinds of phytohormone or metabolic pathway.Differentially expressed genes involved in antioxidant or gene silencing pathways revealed the defenseresponse against virus infection.Meanwhile, the differential expression of the known mature mi RNAs in the samples wasdiscovered by RNA-Seq. The data analysis of high-throughput sequencing showed that the expressionpatterns of 10 mi RNAs in leaves had been significantly changed in response to WDV infection. Theirtarget genes were predicted by ps Target software. GO analysis demonstated that they were mainlyinvolved in auxin response factor, tubulin folding cofactor, potassium transporter, hydrolase,cytochrome P450 family protein and some disease resistance protein. Then significant information wasobtained according to negative correlation analysis between differentially expressed genes and mi RNAs:tae-mi R5384-3p targets FACT complex subunit SPT16 which plays important roles during DNAtranscription, replication and repair; tae-mi R2275-3p targets Pentatricopeptide repeat which isassociated with the chlorophyll content and chloroplast development; tae-mi R1123 targets Rubberelongation factor which is related to plant defense response; tae-mi R160 targets high affinity potassiumtransporter; tae-mi R9774 targets NB-ARC domain-containing disease resistance protein involved inapoptosis and defense response. The results provide new insights into the regulatory networks ofmi RNAs and their targets in response to virus infection.In addition, a WDV infectious clone of China isolate had been successfully constructed and used toinfect wheat(Triticum aestivum L.). It provided a useful tool for study of pathogenesis about WDV.