Integrated metabolomic and transcriptomic analyses of the parasitic plant Cuscuta japonica Choisy on host and non-host plants

Exploring Information Exchange between Thesium chinense and Its Host Prunella vulgaris through Joint Transcriptomic and Metabolomic Analysis

BACKGROUND

Thesium chinense known as the "plant antibiotic" is a facultative root hemi-parasitic herb while Prunella vulgaris can serve as its host. However, the molecular mechanisms underlying the communication between T. chinense and its host remained largely unexplored. The aim of this study was to provide a comprehensive view of transferred metabolites and mobile mRNAs exchanged between T. chinense and P. vulgaris.

RESULTS

The wide-target metabolomic and transcriptomic analysis identified 5 transferred metabolites (ethylsalicylate, eriodictyol-7-O-glucoside, aromadendrin-7-O-glucoside, pruvuloside B, 2-ethylpyrazine) and 50 mobile genes between T. chinense and P. vulgaris, as well as haustoria formation related 56 metabolites and 44 genes. There were 4 metabolites (ethylsalicylate, eriodictyol-7-O-glucoside, aromadendrin-7-O-glucoside and pruvuloside B) that are transferred from P. vulgaris to T. chinense, whereas 2-ethylpyrazine was transferred in the opposite direction. Furthermore, we inferred a regulatory network potentially involved in haustoria formation, where three metabolites (N,N'-Dimethylarginine/SDMA, NG,NG-Dimethyl-L-arginine, 2-Acetoxymethyl-anthraquinone) showed significant positive correlations with the majority of haustoria formation-related genes.

CONCLUSIONS

These results suggested that there was an extensive exchange of information with P. vulgaris including transferred metabolites and mobile mRNAs, which might facilitate the haustoria formation and parasition of T. chinense.

Intracellular metabolomics and microRNAomics unveil new insight into the regulatory network for potential biocontrol mechanism of stress-tolerant Tricho-fusants interacting with phytopathogen Sclerotium rolfsii Sacc

The present study employed microRNA (miRNA) sequencing and metabolome profiling of Trichoderma parental strains and fusants during normal growth and interaction with the phytopathogen Sclerotium rolfsii Sacc. In-vitro antagonism indicated that abiotic stress-tolerant Tricho-fusant FU21 was examined as a potent biocontroller with mycoparasitic action after 10 days. During interaction with the test pathogen, the most abundant uprising intracellular metabolite was recognized as l-proline, which corresponds to held-down l-alanine, associated with arginine and proline metabolism, biosynthesis of secondary metabolites, and nitrogen metabolism linked to predicted genes controlled by miRNAs viz., cel-miR-8210-3p, hsa-miR-3613-5p, and mml-miR-7174-3p. The miRNAs- mml-miR-320c and mmu-miR-6980-5p were found to be associated with phenylpropanoid biosynthesis, transcription factors, and signal transduction pathways, respectively, and were ascertained downregulated in potent FU21_IB compared with FU21_CB. The amino benzoate degradation and T cell receptor signaling pathways were regulated by miRNAs cel-miR-8210 and tca-miR-3824 as stress tolerance mechanisms of FU21. The intracellular metabolites l-proline, maleic acid, d-fructose, Myo-inositol, arabinitol, d-xylose, mannitol, and butane were significantly elevated as potential biocontrol and stress-tolerant constituents associated with miRNA regulatory pathways in potent FU21_IB. A network analysis between regulatory miRNA-predicted genes and intracellular metabolomics acknowledged possible biocontrol pathways/mechanisms in potent FU21_IB to restrain phytopathogen.

Transcriptome analysis reveals defense-related genes and pathways during dodder (Cuscuta australis) parasitism on white clover (Trifolium repens)

Dodders (Cuscuta australis R. Br.) are holo-parasitic stem angiosperms with an extensive host range that have significant ecological and economic potential impact on the ecosystem and the agricultural system. However, how the host plant responds to this biotic stress remains mostly unexplored. To identify the defense-related genes and the pathways in white clover (Trifolium repens L.) induced by dodder parasitism, we performed a comparative transcriptome analysis of the leaf and root tissues from white clover with and without dodder infection by high throughput sequencing. We identified 1,329 and 3,271 differentially expressed genes (DEGs) in the leaf and root tissues, respectively. Functional enrichment analysis revealed that plant-pathogen interaction, plant hormone signal transduction, and phenylpropanoid biosynthesis pathways were significantly enriched. Eight WRKY, six AP2/ERF, four bHLH, three bZIP, three MYB, and three NAC transcription factors showed a close relationship with lignin synthesis-related genes, which defended white clover against dodder parasitism. Real-time quantitative PCR (RT-qPCR) for nine DEGs, further validated the data obtained from transcriptome sequencing. Our results provide new insights into understanding the complex regulatory network behind these parasite-host plant interactions.

Genomic and Epigenomic Mechanisms of the Interaction between Parasitic and Host Plants

Parasitic plants extract nutrients from the other plants to finish their life cycle and reproduce. The control of parasitic weeds is notoriously difficult due to their tight physical association and their close biological relationship to their hosts. Parasitic plants differ in their susceptible host ranges, and the host species differ in their susceptibility to parasitic plants. Current data show that adaptations of parasitic plants to various hosts are largely genetically determined. However, multiple cases of rapid adaptation in genetically homogenous parasitic weed populations to new hosts strongly suggest the involvement of epigenetic mechanisms. Recent progress in genome-wide analyses of gene expression and epigenetic features revealed many new molecular details of the parasitic plants' interactions with their host plants. The experimental data obtained in the last several years show that multiple common features have independently evolved in different lines of the parasitic plants. In this review we discuss the most interesting new details in the interaction between parasitic and host plants.