Elsevier

Virology

Volumes 452–453, March 2014, Pages 264-278
Virology

The coat protein of Alternanthera mosaic virus is the elicitor of a temperature-sensitive systemic necrosis in Nicotiana benthamiana, and interacts with a host boron transporter protein

https://doi.org/10.1016/j.virol.2014.01.021Get rights and content
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Highlights

  • Alternanthera mosaic virus CP is an elicitor of systemic necrosis in N. benthamiana.

  • Virus-induced systemic necrosis is enhanced at 15 °C compared to 25 °C.

  • Induction of systemic necrosis is dependent on as few as two CP amino acid residues.

  • These residues are at subunit interfaces within the same turn of the virion helix.

  • Inducer/non-inducer CPs interact differentially with a boron transporter protein.

Abstract

Different isolates of Alternanthera mosaic virus (AltMV; Potexvirus), including four infectious clones derived from AltMV-SP, induce distinct systemic symptoms in Nicotiana benthamiana. Virus accumulation was enhanced at 15 °C compared to 25 °C; severe clone AltMV 3-7 induced systemic necrosis (SN) and plant death at 15 °C. No interaction with potexvirus resistance gene Rx was detected, although SN was ablated by silencing of SGT1, as for other cases of potexvirus-induced necrosis. Substitution of AltMV 3-7 coat protein (CPSP) with that from AltMV-Po (CPPo) eliminated SN at 15 °C, and ameliorated symptoms in Alternanthera dentata and soybean. Substitution of only two residues from CPPo [either MN(13,14)ID or LA(76,77)IS] efficiently ablated SN in N. benthamiana. CPSP but not CPPo interacted with Arabidopsis boron transporter protein AtBOR1 by yeast two-hybrid assay; N. benthamiana homolog NbBOR1 interacted more strongly with CPSP than CPPo in bimolecular fluorescence complementation, and may affect recognition of CP as an elicitor of SN.

Keywords

Potexvirus
Host–pathogen interaction
Alternanthera mosaic virus
Systemic necrosis
Protein–protein interactions
Coat protein
Boron transporter

Cited by (0)

1

Current address: Department of Bioscience II, Bio-Medical Science, Daejeon 305-301, Republic of Korea.

2

Current address: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.

3

Retired.