Virus-induced gene silencing in the perennial woodyPaeonia ostii

Abstract

Tree peony is a perennial deciduous shrub with great ornamental and medicinal value. A limitation of its current functional genomic research is the lack of effective molecular genetic tools. Here, the first application of a Tobacco rattle virus (TRV)-based virus-induced gene silencing (VIGS) in the tree peony species Paeonia ostii is presented. Two different approaches, leaf syringe-infiltration and seedling vacuum-infiltration, were utilized for Agrobacterium-mediated inoculation. The vacuum-infiltration was shown to result in a more complete Agrobacterium penetration than syringe-infiltration, and thereby determined as an appropriate inoculation method. The silencing of reporter gene PoPDS encoding phytoene desaturase was achieved in TRV-PoPDS-infected triennial tree peony plantlets, with a typical photobleaching phenotype shown in uppermost newly-sprouted leaves. The endogenous PoPDS transcripts were remarkably down-regulated in VIGS photobleached leaves. Moreover, the green fluorescent protein (GFP) fluorescence was detected in leaves and roots of plants inoculated with TRV-GFP, suggesting the capability of TRV to silence genes in various tissues. Taken together, the data demonstrated that the TRV-based VIGS technique could be adapted for high-throughput functional characterization of genes in tree peony.

A Tree Peony Trihelix Transcription Factor PrASIL1 Represses Seed Oil Accumulation

“…The transformed GV3101 were grown in YEP medium with appropriate antibiotics at 28 • C with constant shaking overnight. The bacterial cells were harvested by centrifugation at 4,000 × g and resuspended in infiltration buffer as described previously (Xie et al, 2019), and kept in darkness for 4-6 h at 28 • C. The A. tumefaciens infiltration buffer containing TRV1 and TRV2 vectors were mixed in a ratio of 1:1 to a final OD 600 of 0.8 before infiltration into leaves of P. rockii seedlings. The leaves of WT and infiltrated with TRV2:GFP were used as controls.…”

Paeoniflorin in Paeoniaceae: Distribution, influencing factors, and biosynthesis

“…Additionally, at least at present, the long-life cycle of Paeoniaceae and the immature genetic transformation system make it difficult to overexpress candidate genes in herbaceous peony or tree peony to verify their biological functions. Fortunately, the virus-induced gene silencing system has been established in tree peony (Xie et al, 2019;Wang et al, 2020), which can be used to verify their biological functions by transiently silencing the candidate genes in vivo.…”

A Methodological Advance of Tobacco Rattle Virus-Induced Gene Silencing for Functional Genomics in Plants

“…VIGS silencing of the VTE1 gene in tomato leaves with an Agrobacterium infection solution carrying the TRV vector demonstrated that VTE1 is involved in vitamin E synthesis in tomatoes (Lu et al, 2011). Organ aging issues in petunia flowers and functional analysis of peony genes have also been demonstrated with TRV-VIGS technology (Chen et al, 2005;Xie et al, 2019). Virus-induced gene silencing has also been used for the functional analysis of root genes.…”

“…A study demonstrated that the TRV-based VIGS technique could be adapted for high-throughput functional characterization of genes in the perennial tree peony (Xie et al, 2019). Nishii et al (2020) utilized the broad host range TRV vector to target the SrPDS gene of S. rexii (Gesneriaceae) by agroinfiltration and sap inoculation and successfully obtained SrPDS silenced plants.…”

“…In the past two decades, many VIGS vectors have been developed (Supplementary Table 1), and TRV was preferentially used for VIGS assays in most dicots and some monocots, due to the high susceptibility of a wide range of hosts with mild viral symptoms after infection (Chen et al, 2005;Zhang et al, 2017;Xie et al, 2019). The increase in high-quality genome or transcriptome (EST) data has provided an excellent foundation and sufficient homologous sequence information for VIGS assays to target a specific gene, gene family, gene class, or miRNA mimic (Senthil-Kumar and Mysore, 2011a; Figure 1).…”