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United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCING SUSTAINABILITY OF FOOD PRODUCTION SYSTEMS IN THE NORTHEAST Title: Silicon delays tobacco Ringspot virus systemic symptoms in Nicotiana tabacum

Authors
item Zellner, Wendy -
item Frantz, Jonathan
item Leisner, Scott -

Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2011
Publication Date: April 1, 2011
Citation: Zellner, W., Frantz, J., Leisner, S. 2011. Silicon delays tobacco Ringspot virus systemic symptoms in Nicotiana tabacum. Journal of Plant Pathology. 168(15):1866-1869. DOI:10.1016/j.jplph.2011.04.002.

Interpretive Summary: Silicon is one of the most common elements in the earth’s crust, yet its role in plant nutrition is under considerable debate. Soluble silicon (Si) has been reported to provide protection to plants against a variety of abiotic and biotic stress. However, the role of Si in viral infections has not been extensively studied. To investigate the role of Si in viral infections, hydroponic studies were conducted in the model plant tobacco with two pathogens: Tobacco ringspot virus (TRSV) and Tobacco mosaic virus (TMV). Plants fed with supplemental Si showed a delay in TRSV symptom formation and a reduction in disease severity, compared to the non-supplemented control plants. Additionally, TRSV-infected plants showed significantly higher levels of silicon concentration in the leaves compared to control plants. However, the Si effect appeared to be virus-specific since TMV infections were not altered by silicon treatment, nor were foliar silicon levels. It appears as though increased foliar Si levels correlate with Si-modulated protection against viral infection. These results are especially interesting since tobacco is classified as a low silicon accumulator and therefore believed to be non-responsive to supplemental Si. Taken together, these data suggest that silicon is able to provide specific protection against TRSV in tobacco, but the mechanism is not broadly applicable to all virus.

Technical Abstract: Soluble silicon (Si) provides protection to plants against a variety of abiotic and biotic stress. However, the role of Si in viral infections has been elusive. To investigate the role of Si in viral infections, hydroponic studies were conducted in Nicotiana tabacum with two pathogens: Tobacco ringspot virus (TRSV) and Tobacco mosaic virus (TMV). Plants grown in elevated Si showed a delay in TRSV systemic symptom formation and a reduction in symptomatic leaf area, compared to the non-supplemented controls. TRSV-infected plants showed significantly higher levels of foliar silicon compared to mock-inoculated plants. However, the Si effect appeared to be virus-specific since TMV infections were not altered by silicon treatment, nor were foliar silicon levels. Hence, increased foliar Si levels appear to correlate with Si-modulated protection against viral infection. This is all the more intriguing since N. tabacum is classified as a low silicon accumulator. Taken together, these data suggest that silicon is able to provide specific protection against TRSV in N. tabacum, but the mechanism is not broadly applicable to all virus.

Last Modified: 10/22/2014
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