Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Jul 17;104(29):12157-62.
doi: 10.1073/pnas.0705114104. Epub 2007 Jul 5.

Infection and coaccumulation of tobacco mosaic virus proteins alter microRNA levels, correlating with symptom and plant development

A A Bazzini  1 , H E Hopp, R N Beachy, S Asurmendi
Affiliations

Infection and coaccumulation of tobacco mosaic virus proteins alter microRNA levels, correlating with symptom and plant development

A A Bazzini et al. Proc Natl Acad Sci U S A. .

Abstract

Infections by plant virus generally cause disease symptoms by interfering with cellular processes. Here we demonstrated that infection of Nicotiana tabacum (N.t) by plant viruses representative of the Tobamoviridae, Potyviridae, and Potexviridae families altered accumulation of certain microRNAs (miRNAs). A correlation was observed between symptom severity and alteration in levels of miRNAs 156, 160, 164,166, 169, and 171 that is independent of viral posttranscriptional gene silencing suppressor activity. Hybrid transgenic plants that produced tobacco mosaic virus (TMV) movement protein (MP) plus coat protein (CP)(T42W) (a variant of CP) exhibited disease-like phenotypes, including abnormal plant development. Grafting studies with a plant line in which both transgenes are silenced confirmed that the disease-like phenotypes are due to the coexpression of CP and MP. In hybrid MPxCP(T42W) plants and TMV-infected plants, miRNAs 156, 164, 165, and 167 accumulated to higher levels compared with nontransgenic and noninfected tissues. Bimolecular fluorescence complementation assays revealed that MP interacts with CP(T42W) in vivo and leads to the hypothesis that complexes formed between MP and CP caused increases in miRNAs that result in disease symptoms. This work presents evidence that virus infection and viral proteins influence miRNA balance without affecting posttranscriptional gene silencing and contributes to the hypothesis that viruses exploit miRNA pathways during pathogenesis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
miRNAs accumulation is altered by viral infections. (Left) Northern blot analysis to detect the accumulation of various miRNAs and miRNA* after infection with selected viruses. Ethidium-bromide-stained rRNA shown below each blot was used to normalize data. (Right) Average and standard error of miRNA level of two independent biological replicates. The data were derived based on hybridization of RNAs derived from noninfected plants, established as 1.0.
Fig. 2.
Fig. 2.
Abnormal phenotyes of line MPxCPT42W. (A)WT tobacco (N. tabacum, cv Xanthi nn; Sx) and (B and C) flowers of plant line MPxCPT42W. (D) Leaves of nontransgenic (Left) and of MPxCPT42W plants highlighting the rounded shape of the leaves (Right). (E) Normal bipartite stigma of WT plants and (F) tripartite stigma of line MPxCPT42W. (G and H) MPxCPT42W seedlings showing cup-shaped or partially fused cotyledons. (I) WT stamens and pistils. (J) Stamens of MPxCPT42W. (K) Symmetric leaves of WT seedlings and (L) asymmetric leaves of line MPxCPT42W. (M) Normal morphology of flowers of Sx, MP, CPT42W, and mpxcpT42W*, respectively. (N) Phenotypes of flowers of MPxCPT42W. (O–Q) Scanning electron micrographs of abaxial surfaces of MP, CPT42W, and MPxCPT42W leaves. P, Q, and R, respectively, show altered shapes of epidermal cells, as well as altered sizes. (Scale bars: 50 μm).
Fig. 3.
Fig. 3.
Effects of TMV MP and CPT42W and TMV infection on accumulation of miRNAs. (A and B) Northern blot analyses to detect the accumulation of miRNA and miRNA*. Ethidium-bromide-stained rRNA shown below each blot was used to normalize data. Relative accumulation of miRNA compared with noninoculated and nontransgenic N. tabacum plants (Sx = 1.0) is shown. The average of two independent biological replicas and standard errors (in parentheses) is shown.
Fig. 4.
Fig. 4.
TMV MP interacts with CPT42W in vivo by BiFC. YFP epifluorescence microcroscope images of N. benthamiana epidermal leaf cells in leaves agroinfiltrated with a mixture of Agrobacterium strains harboring constructs encoding the indicated fusion proteins. Each image is a representative picture of several experiments.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Zaitlin M, Hul R. Annu Rev Plant Physiol. 1987;38:291–315.
    1. Finnegan EJ, Matzke MA. J Cell Sci. 2003;116:4689–4693. - PubMed
    1. Voinnet O. Nat Rev Genet. 2005;6:206–220. - PubMed
    1. Baulcombe D. Trends Biochem Sci. 2005;30:290–293. - PubMed
    1. Roth BM, Pruss GJ, Vance VB. Virus Res. 2004;102:97–108. - PubMed

Publication types

LinkOut - more resources