Research On MiRNAs Responsive To Phytoplamsa Infection

Paulownia Witches Broom(Pa WB)is caused by phytoplasma(Candidatus Phytoplasma australiense).Pa WB,a disastrous disease,the incidence arrived 85% in some cultivation district of China and other parts of the world,which has resulted in billions of dollars in economic losses to the industrialization of Paulownia production.In the past years,many researches focus on finding the interaction of phytoplasma-Paulownia,but the pathogenesis of Paulownia Witches Broom is still unclear.mi RNAs are a kind of endogenous single-stranded non-coding RNAs which play the roles of the gene expression at the transcription and post-transcriptional levels.Until now,increasing evidence has indicated that mi RNA-mediated gene expression may play important roles in the responses of plants to abiotic and biotic stresses.In this study,we sequenced small RNA libraries and degradome sequencing libraries were created from healthy,Pa WB-infected,and 75 mg·L-1 DMS-treated in Paulownia fortunei,P.tomentosa and P.tomentosa ×P.fortunei species.by using Illumina platform.The main results as follow:(1)We constructed nine small RNA libraries and nine degradome libraries from healthy,Pa WB-infected,and 75 mg·L-1 DMS-treated in three species of Paulownia fortunei,P.tomentosa and P.tomentosa ×P.fortunei,and used Illumina platform to sequence these 18 libraries(2)In this present study,558 mi RNAs(336 conserved and 222 novel mi RNAs)had been identified in three Paulownia species.Among them,456 mi RNAs(293 conserved and 163 novel mi RNAs),440 mi RNAs(267conserved and 173 novel mi RNAs)and 488 mi RNAs(313conserved and 175 novel mi RNAs)were obtained in the P.tomentosa,P.fortunei and P.tomentosa ×P.fortunei,respectively.(3)A total of40 differentially expressed mi RNAs were identified(27 conserved and 13 novel mi RNAs),and seven of them were common in the three paulownia species.There were less diversity mi RNA members that common between the hybrid P.tomentosa×P.fortunei and its male parent(10)than that in the female parent(71).(4)TargetFinder was used to predicted the potential target of miRNAs that identified in Paulownia fortunei,P.tomentosa and P.tomentosa ×P.fortunei.Then,GO classfication and Nr annotation showed that these target genes were mainly involved in encoding callose synthase,protein serine/threonine kinase activity,elongation factor EF-Tu and the squamosa promoter binding protein...