Project description:Pseudostellaria heterophylla is a traditional Chinese herbal medicine, which has been cultivated for hundreds of years. Viral diseases of P. heterophylla occur widely and limit the yield and quality of this medicinal plant. In this study, five leaf samples of P. heterophylla with typical viral symptoms were collected from four main producing regions that are distributed in Fujian, Guizhou, and Anhui Provinces in China and analyzed by next-generation sequencing. Comprehensive bioinformatics analyses revealed that nine viruses in five genera Carlavirus, Potyvirus, Fabavirus, Cucumovirus, and Amalgavirus infected P. heterophylla. Among these viruses, three novel and two known carlaviruses, tentatively designated Pseudostellaria heterophylla carlavirus 1, 2, and 3 (PhCV1, PhCV2, and PhCV3), Jasmine virus C isolate Ph (Ph-JVC) and Stevia carlavirus 1 isolate Ph (Ph-StCV1), respectively, were first identified in P. heterophylla. PhCV1-3 share a similar genomic organization and clear sequence homology with members in the genus Carlavirus and could potentially be classified as new species of this genus. One novel amalgavirus, tentatively designated P. heterophylla amalgavirus 1 (PhAV1), was first identified in P. heterophylla. It had a typical genomic organization of the genus Amalgavirus. In PhAV1, the + 1 programmed ribosomal frameshifting, which is prevalent in most amalgaviruses, was identified and used in the expression of RNA-dependent RNA polymerase (RdRp). Combined with a phylogenetic analysis, PhAV1 could potentially be classified as new species of the genus Amalgavirus. In addition, multiple Broad bean wilt virus 2 (BBWV2) variants, Turnip mosaic virus (TuMV), and Cucumber mosaic virus (CMV), which have been reported in P. heterophylla, were also detected in this study. The distribution of PhCV1-3, Ph-JVC, Ph-StCV1, TuMV, BBWV2, and CMV in four production regions in Fujian, Guizhou, and Anhui Provinces was determined. This study increased our understanding of P. heterophylla virome and provided valuable information for the development of a molecular diagnostic technique and control of viral diseases in P. heterophylla.
Project description:miRNAs play a crucial role in the development and growth of plants by inhibiting the function of targeted genes at the post-transcription level. However, no miRNAs in Pseudostellaria heterophylla have been reported and their function in the morphogenesis of organs is still unclear. In this study, a total of 159 conserved miRNAs (belonging to 64 families) and 303 level miRNAs were identified from P. heterophylla. Some of them showed specifically up or down-regulated expression in different tissues and numbers of unigenes involved in Plant-pathogen interaction and MAPK signaling pathway-plant were targeted. The significant negative correlation of expression profiles between 30 miRNAs and their target genes (37 unigenes) was observed, respectively. Further, a large number of genes involved with signal transduction of auxin, zeatin, abscisic acid and, jasmonic acid were targeted. Predicated targets of two miRNAs were validated by 5′RLM-RACE, respectively. A large number of mRNAs from four pathogens were targeted by miRNAs from P. heterophylla and some of them were targeted by miR414. In summary, we reported a population of miRNAs from four different vegetative tissues of P. heterophylla by high throughput sequencing, which was analyzed by combining with the constructed transcriptome. These results may help to explain the function of miRNAs in the morphogenesis of organs and defense of pathogens, and may provide theoretical basis for breeding and genetic improvement of P. heterophylla.