scholarly journals The m6A RNA Demethylase ALKBH9B Plays a Critical Role for Vascular Movement of Alfalfa Mosaic Virus in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Mireya Martínez-Pérez ◽  
Concepción Gómez-Mena ◽  
Luis Alvarado-Marchena ◽  
Riad Nadi ◽  
José Luis Micol ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Virus Resistance ◽  
Regulatory Mechanism ◽  
Critical Role ◽  
Alfalfa Mosaic Virus ◽  
Phloem Transport ◽  
Viral Titer ◽  
Systemic Movement ◽  
Detailed Evaluation

The N6-methyladenosine (m6A) pathway has been widely described as a viral regulatory mechanism in animals. We previously reported that the capsid protein (CP) of alfalfa mosaic virus (AMV) interacts with the Arabidopsis m6A demethylase ALKBH9B regulating m6A abundance on viral RNAs (vRNAs) and systemic invasion of floral stems. Here, we analyze the involvement of other ALKBH9 proteins in AMV infection and we carry out a detailed evaluation of the infection restraint observed in alkbh9b mutant plants. Thus, via viral titer quantification experiments and in situ hybridization assays, we define the viral cycle steps that are altered by the absence of the m6A demethylase ALKBH9B in Arabidopsis. We found that ALKBH9A and ALKBH9C do not regulate the AMV cycle, so ALKBH9B activity seems to be highly specific. We also define that not only systemic movement is affected by the absence of the demethylase, but also early stages of viral infection. Moreover, our findings suggest that viral upload into the phloem could be blocked in alkbh9b plants. Overall, our results point to ALKBH9B as a possible new component of phloem transport, at least for AMV, and as a potential target to obtain virus resistance crops.

scholarly journals Multifunctional Roles for the N-Terminal Basic Motif of Alfalfa mosaic virus Coat Protein: Nucleolar/Cytoplasmic Shuttling, Modulation of RNA-Binding Activity, and Virion Formation

2012 ◽  
Vol 25 (8) ◽  
pp. 1093-1103 ◽  
Author(s):  
Mari Carmen Herranz ◽  
Vicente Pallas ◽  
Frederic Aparicio
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Nuclear Export ◽  
Rna Binding ◽  
Nuclear Export Signal ◽  
Alfalfa Mosaic Virus ◽  
Binding Activity ◽  
Systemic Movement ◽  
Virion Formation

In addition to virion formation, the coat protein (CP) of Alfalfa mosaic virus (AMV) is involved in the regulation of replication and translation of viral RNAs, and in cell-to-cell and systemic movement of the virus. An intriguing feature of the AMV CP is its nuclear and nucleolar accumulation. Here, we identify an N-terminal lysine-rich nucleolar localization signal (NoLS) in the AMV CP required to both enter the nucleus and accumulate in the nucleolus of infected cells, and a C-terminal leucine-rich domain which might function as a nuclear export signal. Moreover, we demonstrate that AMV CP interacts with importin-α, a component of the classical nuclear import pathway. A mutant AMV RNA 3 unable to target the nucleolus exhibited reduced plus-strand RNA synthesis and cell-to-cell spread. Moreover, virion formation and systemic movement were completely abolished in plants infected with this mutant. In vitro analysis demonstrated that specific lysine residues within the NoLS are also involved in modulating CP-RNA binding and CP dimerization, suggesting that the NoLS represents a multifunctional domain within the AMV CP. The observation that nuclear and nucleolar import signals mask RNA-binding properties of AMV CP, essential for viral replication and translation, supports a model in which viral expression is carefully modulated by a cytoplasmic/nuclear balance of CP accumulation.

Virus symptomatology in accessions of the Medicago truncatula core collection and identification of virus resistance phenotypes

2011 ◽  
Vol 62 (8) ◽  
pp. 686 ◽  
Author(s):  
M. Saqib ◽  
B. E. Gadja ◽  
M. G. K. Jones ◽  
R. A. C. Jones
Keyword(s):  
Mosaic Virus ◽  
Medicago Truncatula ◽  
Virus Resistance ◽  
Core Collection ◽  
Alfalfa Mosaic Virus ◽  
Resistance Breeding ◽  
Yellow Mosaic Virus ◽  
Diverse Range ◽  
Model Legume ◽  
Pasture Legumes

Plants of 212 accessions from the core collection of model legume species Medicago truncatula were inoculated with infective sap containing Alfalfa mosaic virus (AMV, isolate EW), Bean yellow mosaic virus (BYMV, isolate MI) or Cucumber mosaic virus (CMV, isolate SN-1). A diverse range of systemic symptoms were obtained that varied widely in severity depending on the combination of virus isolate and accession, or, especially with AMV, some accessions became infected but did not display symptoms. The delay between virus inoculation and symptom appearance normally varied from 1 to 4 weeks, but with CMV it took up to 8 weeks in two accessions. Five (AMV), 59 (BYMV) and 22 (CMV) core accessions remained uninfected systemically. Plants of most of these accessions, and some that died or gave susceptible phenotypes, were then inoculated with two additional isolates of AMV (eight accessions), or two distinct strains of BYMV (58 accessions) and CMV (21 accessions). Plants of accession 11715 remained uninfected by CMV isolates CP (CMV subgroup 1) and LW (CMV subgroup 2), but those of all other previously uninfected accessions became infected systemically by all three viruses. All accessions inoculated with AMV isolates Aq and Hu, and most inoculated with BYMV isolate LKoj1-NN (generalist strain), BYMV isolate LP-1 (lupin strain), and CMV isolates CP and LW developed typical susceptible phenotypes. However, systemic hypersensitive phenotypes developed with BYMV LKoj1-NN and LP-1 in plants of 4456, or with LKoj1-NN only in 774, 1526, 4327, 14829, 15268, 22922 and 25654; 15268 and 25654 had developed this phenotype previously with MI (generalist strain). Similarly, plants of 21362 developed this phenotype with CMV CP and LW, while plants of 1526, 2748 and 31443 developed it with CP; 2748, 21632 and 31443 had developed it previously with SN-1 (mixture of subgroups 1 and 2). Once the genetic bases of the BYMV and CMV resistances found in M. truncatula are understood, they may prove useful in future virus resistance breeding among crop and pasture legumes.

scholarly journals Robust RNAi-Based Resistance to Mixed Infection of Three Viruses in Soybean Plants Expressing Separate Short Hairpins from a Single Transgene

2011 ◽  
Vol 101 (11) ◽  
pp. 1264-1269 ◽  
Author(s):  
Xiuchun Zhang ◽  
Shirley Sato ◽  
Xiaohong Ye ◽  
Anne E. Dorrance ◽  
T. Jack Morris ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Virus Resistance ◽  
Soybean Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Cauliflower Mosaic Virus ◽  
Systemic Resistance ◽  
35S Promoter ◽  
Virus Infections ◽  
Bean Pod Mottle Virus ◽  
Soybean Plants

Transgenic plants expressing double-stranded RNA (dsRNA) of virus origin have been previously shown to confer resistance to virus infections through the highly conserved RNA-targeting process termed RNA silencing or RNA interference (RNAi). In this study we applied this strategy to soybean plants and achieved robust resistance to multiple viruses with a single dsRNA-expressing transgene. Unlike previous reports that relied on the expression of one long inverted repeat (IR) combining sequences of several viruses, our improved strategy utilized a transgene designed to express several shorter IRs. Each of these short IRs contains highly conserved sequences of one virus, forming dsRNA of less than 150 bp. These short dsRNA stems were interspersed with single-stranded sequences to prevent homologous recombination during the transgene assembly process. Three such short IRs with sequences of unrelated soybean-infecting viruses (Alfalfa mosaic virus, Bean pod mottle virus, and Soybean mosaic virus) were assembled into a single transgene under control of the 35S promoter and terminator of Cauliflower mosaic virus. Three independent transgenic lines were obtained and all of them exhibited strong systemic resistance to the simultaneous infection of the three viruses. These results demonstrate the effectiveness of this very straight forward strategy for engineering RNAi-based virus resistance in a major crop plant. More importantly, our strategy of construct assembly makes it easy to incorporate additional short IRs in the transgene, thus expanding the spectrum of virus resistance. Finally, this strategy could be easily adapted to control virus problems of other crop plants.

scholarly journals Alfalfa mosaic virus nanoparticles-based in situ vaccination induces antitumor immune responses in breast cancer model

Nanomedicine ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 97-107
Author(s):  
Mehdi Shahgolzari ◽  
Maghsoud Pazhouhandeh ◽  
Morteza Milani ◽  
Steven Fiering ◽  
Ahmad Yari Khosroushahi
Keyword(s):  
Breast Cancer ◽  
Mosaic Virus ◽  
Plant Virus ◽  
Alfalfa Mosaic Virus ◽  
Cancer Model ◽  
Immune Effector ◽  
Cytokine Analysis ◽  
Breast Cancer Model

Background: Preclinical and clinical studies show that local and systemic antitumor efficacy is achievable by in situ vaccination (ISV) using plant virus nanoparticles in which immunostimulatory reagents are directly administered into the tumor rather than systemically. Aim: To investigate a minimally studied plant virus nanoparticle, alfalfa mosaic virus (AMV), for ISV treatment of 4T1, the very aggressive and metastatic murine triple-negative breast cancer model. Materials & methods: AMV nanoparticles were propagated and characterized. Their treatment impact on in vivo tumors were analyzed using determination of inherent immunogenicity, cytokine analysis, western blotting analysis and immunohistochemistry methodologies. Results: AMV used as an ISV significantly slowed down tumor progression and prolonged survival through immune mechanisms (p < 0.001). Conclusion: Mechanistic studies show that ISV with AMV increases costimulatory molecules, inflammatory cytokines and immune effector cell infiltration and downregulates immune-suppressive molecules.

scholarly journals Expression of alfalfa mosaic virus RNA 4 in transgenic plants confers virus resistance

1987 ◽  
Vol 6 (7) ◽  
pp. 1845-1851 ◽  
Author(s):  
L. S. Loesch-Fries ◽  
D. Merlo ◽  
T. Zinnen ◽  
L. Burhop ◽  
K. Hill ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Mosaic Virus ◽  
Virus Resistance ◽  
Alfalfa Mosaic Virus ◽  
Virus Rna

THESIS SUMMARY STUDIES OF ALFALFA MOSAIC VIRUS AND SUBTERRANEAN CLOVER RED LEAF VIRUS

1979 ◽  
pp. 163-164
Author(s):  
P.B. Teh
Keyword(s):  
Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Subterranean Clover ◽  
Test Plant ◽  
Transmission Frequency ◽  
Virus Source ◽  
Leaf Virus

AMV was shown to be transmitted by sap, aphids and through lucerne seed, but not by Cuscuta. Virus source and test plant influenced transmission frequency. Sap-inoculation tests showed that 20 species of plants were susceptible to this virus. Thirteen species of plants from the fields where AMV had been detected were tested but only three were found to be infected with the virus.

scholarly journals Transgenic plant generated by RNAi-mediated knocking down of soybean Vma12 and soybean mosaic virus resistance evaluation

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hexiang Luan ◽  
Wenlin Liao ◽  
Yingpei Song ◽  
Haopeng Niu ◽  
Ting Hu ◽  
...  
Keyword(s):  
Transgenic Plant ◽  
Mosaic Virus ◽  
Virus Resistance ◽  
Soybean Mosaic Virus ◽  
Resistance Evaluation
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