Transgene- and tissue culture-free heritable genome editing using RNA virus-based delivery in wheat.

CRISPR-Cas genome editing technology is a cutting-edge strategy for crop breeding. However, the delivery of genome-editing reagents remains to be a technological bottleneck in monocot plants. Here we engineered barley yellow striate mosaic virus (BYSMV) into a negative-strand RNA virus-based vector system for delivery of both Cas9 and single guide RNA to achieve heritable gene editing in different wheat cultivars.

Characterization of chenopodium trirhavirus 1, a novel tri-segmented virus of the family Rhabdoviridae.

A novel tri-segmented virus, tentatively named "Chenopodium trirhavirus 1" (CheTRV1), was identified in Chenopodium album in China using high-throughput sequencing combined with conventional Sanger sequencing after RT-PCR. The genome of CheTRV1 consists of three negative-sense single-stranded RNAs designated as RNA1, RNA2, and RNA3. RNAs 1-3 of CheTRV1 share 57.

The E3 ligase HRD1 enhances plant antiviral immunity by targeting viral movement proteins.

The ubiquitin-26S proteasome system (UPS) is a conserved protein degradation process involved in plant growth and immunity. However, whether some UPS E3 ligases directly target plant viruses in the endoplasmic reticulum (ER) remains less understood. Here, we identify an E3 ubiquitin ligase Hmg-CoA reductase degradation 1 of Nicotiana benthamiana (NbHRD1) interacting with the triple gene block (TGB) movement proteins of beet necrotic yellow vein virus (BNYVV) in the ER.

One-Step Multiplex RT-PCR Method for Detection of Melon Viruses.

This study presents a one-step multiplex reverse transcription polymerase chain reaction (RT-PCR) method for the simultaneous detection of multiple viruses affecting melon crops. Viruses such as (WMV), (CMV), (ZYMV), (SqMV), (TMV), (PRSV), and (MYSV) pose a great threat to melons. The mixed infection of these viruses is the most common observation in the melon-growing fields.

The P2 protein of wheat yellow mosaic virus acts as a viral suppressor of RNA silencing in Nicotiana benthamiana to facilitate virus infection.

Wheat yellow mosaic virus (WYMV) causes severe viral wheat disease in Asia. The WYMV P1 protein encoded by RNA2 has viral suppressor of RNA silencing (VSR) activity to facilitate virus infection, however, VSR activity has not been identified for P2 protein encoded by RNA2. In this study, P2 protein exhibited strong VSR activity in Nicotiana benthamiana at the four-leaf stage, and point mutants P70A and G230A lost VSR activity.

A potyvirus provides an efficient viral vector for gene expression and functional studies in Asteraceae plants.

Plant virus-derived vectors are rapid and cost-effective for protein expression and gene functional studies in plants, particularly for species that are difficult to genetically transform. However, few efficient viral vectors are available for functional studies in Asteraceae plants. Here, we identified a potyvirus named zinnia mild mottle virus (ZiMMV) from common zinnia (Zinnia elegans Jacq.

The plant rhabdovirus viroporin P9 facilitates insect-mediated virus transmission in barley.

Potassium (K+) plays crucial roles in both plant development and immunity. However, the function of K+ in plant-virus interactions remains largely unknown. Here, we utilized Barley yellow striate mosaic virus (BYSMV), an insect-transmitted plant cytorhabdovirus, to investigate the interplay between viral infection and plant K+ homeostasis.

A vicinal oxygen chelate protein facilitates viral infection by triggering the unfolded protein response in Nicotiana benthamiana.

Vicinal oxygen chelate (VOC) proteins are members of an enzyme superfamily with dioxygenase or non-dioxygenase activities. However, the biological functions of VOC proteins in plants are poorly understood. Here, we show that a VOC in Nicotiana benthamiana (NbVOC1) facilitates viral infection.

Sixteen Novel Mycoviruses Containing Positive Single-Stranded RNA, Double-Stranded RNA, and Negative Single-Stranded RNA Genomes Co-Infect a Single Strain of .

In the present study, sixteen novel RNA mycoviruses co-infecting a single strain of (strain D40) were identified and molecularly characterized using metatranscriptome sequencing combined with a method for rapid amplification of cDNA ends. The fungal strain was isolated from diseased seedlings of sugar beet with damping-off symptoms. Based on genome analysis and phylogenetic analysis of amino acid sequences of RNA-dependent RNA polymerase, the sixteen mycoviruses associated with strain D40 contained three genome types with nine distinct lineages, including positive single-stranded RNA (, , , and ), double-stranded RNA (Phlegiviridae, , Megatotiviridae, and Yadonushiviridae), and negative single-stranded RNA (), suggesting a complex composition of a mycoviral community in this single strain of (strain D40).

The P1 protein of wheat yellow mosaic virus exerts RNA silencing suppression activity to facilitate virus infection in wheat plants.

Wheat yellow mosaic virus (WYMV) causes severe wheat viral disease in Asia. However, the viral suppressor of RNA silencing (VSR) encoded by WYMV has not been identified. Here, the P1 protein encoded by WYMV RNA2 was shown to suppress RNA silencing in Nicotiana benthamiana.

A plant cytorhabdovirus modulates locomotor activity of insect vectors to enhance virus transmission.

Transmission of many plant viruses relies on phloem-feeding insect vectors. However, how plant viruses directly modulate insect behavior is largely unknown. Barley yellow striate mosaic virus (BYSMV) is transmitted by the small brown planthopper (SBPH, Laodelphax striatellus).

Transcriptomic and Proteomic Analyses of Carrying Brassica Yellows Virus.

Viruses in the genus infect a wide range of crop plants and cause severe economic crop losses. BrYV belongs to the genus and is transmitted by . However, the changes in transcriptome and proteome profiles of during viral infection are unclear.

A selective autophagy receptor VISP1 induces symptom recovery by targeting viral silencing suppressors.

Selective autophagy is a double-edged sword in antiviral immunity and regulated by various autophagy receptors. However, it remains unclear how to balance the opposite roles by one autophagy receptor. We previously identified a virus-induced small peptide called VISP1 as a selective autophagy receptor that facilitates virus infections by targeting components of antiviral RNA silencing.

Anastomosis Groups and Mycovirome of Isolates Causing Sugar Beet Root and Crown Rot and Their Sensitivity to Flutolanil, Thifluzamide, and Pencycuron.

Anastomosis groups (AGs) or subgroups of 244 isolates recovered from sugar beet roots with symptoms of root and crown rot were characterized to be AG-A, AG-K, AG-2-2IIIB, AG-2-2IV, AG-3 PT, AG-4HGI, AG-4HGII, and AG-4HGIII, with AG-4HGI (108 isolates, 44.26%) and AG-2-2IIIB (107 isolates, 43.85%) being predominate.

Identification and Functional Analyses of Host Proteins Interacting with the P3a Protein of Brassica Yellows Virus.

Viruses are obligate parasites that only undergo genomic replication in their host organisms. ORF3a, a newly identified non-AUG-initiated ORF encoded by members of the genus , is required for long-distance movement in plants. However, its interactions with host proteins still remain unclear.

Effect of Oligogalacturonides on Seed Germination and Disease Resistance of Sugar Beet Seedling and Root.

Oligogalacturonides (OGs) are a bioactive carbohydrate derived from homogalacturonan. The OGs synthesized in this study significantly inhibited the mycelial growth of AG-4HGI in vitro, even at a low concentration (10 mg/L). The seed vigor test demonstrated that the application of 50 mg/L OGs to sugar beet seeds significantly increased average germination percentage, germination energy, germination index, and seedling vigor index.

Palmitoylation of γb protein directs a dynamic switch between Barley stripe mosaic virus replication and movement.

Viral replication and movement are intimately linked; however, the molecular mechanisms regulating the transition between replication and subsequent movement remain largely unknown. We previously demonstrated that the Barley stripe mosaic virus (BSMV) γb protein promotes viral replication and movement by interacting with the αa replicase and TGB1 movement proteins. Here, we found that γb is palmitoylated at Cys-10, Cys-19, and Cys-60 in Nicotiana benthamiana, which supports BSMV infection.

Barley stripe mosaic virus γb protein targets thioredoxin h-type 1 to dampen salicylic acid-mediated defenses.

Salicylic acid (SA) acts as a signaling molecule to perceive and defend against pathogen infections. Accordingly, pathogens evolve versatile strategies to disrupt the SA-mediated signal transduction, and how plant viruses manipulate the SA-dependent defense responses requires further characterization. Here, we show that barley stripe mosaic virus (BSMV) infection activates the SA-mediated defense signaling pathway and upregulates the expression of Nicotiana benthamiana thioredoxin h-type 1 (NbTRXh1).

The Carboxyl Terminal Regions of P0 Protein Are Required for Systemic Infections of Poleroviruses.

P0 proteins encoded by poleroviruses Brassica yellows virus (BrYV) and (PLRV) are viral suppressors of RNA silencing (VSR) involved in abolishing host RNA silencing to assist viral infection. However, other roles that P0 proteins play in virus infection remain unclear. Here, we found that C-terminal truncation of P0 resulted in compromised systemic infection of BrYV and PLRV.

Comparative Analysis of Biological Characteristics among P0 Proteins from Different Brassica Yellows Virus Genotypes.

Brassica yellows virus (BrYV) is a tentative species of the genus , which has at least three genotypes (A, B, and C) in China. The P0 protein of BrYV-A (P0) has been identified as a viral suppressor of RNA silencing (VSR), which can also induce cell death in infiltrated leaves. In this study, we demonstrated that the cell death induced by P0 was accompanied by the accumulation of reactive oxygen species (ROS) and increased () expression.