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United States Department of Agriculture

Agricultural Research Service

Title: Association of selective deposition of (1-3)-B-glucan in floral tissues with restricted movement of turnip vein-clearing virus in Arabidopsis: A possible mechanism for non-seed transmission

Authors
item Lartey, Robert
item Ghoshroy, Kajal - UNIV. OF SOUTH CAROLINA
item Ghoshroy, Soumitra - UNIV. OF SOUTH CAROLINA

Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 18, 2008
Publication Date: October 1, 2008
Repository URL: http://handle.nal.usda.gov/10113/53805
Citation: Lartey, R.T., Ghoshroy, K., Ghoshroy, S. 2008. Association of selective deposition of (1-3)-B-glucan in floral tissues with restricted movement of turnip vein-clearing virus in Arabidopsis: A possible mechanism for non-seed transmission. Plant Pathology. 7(2):120-130.

Interpretive Summary: After successful infection of a host plant, the virus replicates and move from the infected cell to other cells through plasmodesmata until it arrives at the vasculature from where it spreads to other parts of the plant to cause systemic infection. In some plants, transmission of viruses through seed plays critical role in the spread of plant viral diseases. Some plant viruses, for example, Turnip vein clearing virus (TVCV) systematically infects Arabidopsis thaliana, but is not seed transmissible. Using confocal laser scanning, light transmission, and scanning electron microscopy and immunolabeling techniques, we studied the pattern of the TVCV movement in reproductive parts of the systemically infected Arabidopsis plant to unravel the basis for non-seed transmission of some TVCV. We observed that the virus moved to all parts of the host in the infection process. The virus was located in all parts of the flower except ovules and pollen grains. The viral movement was thus confined to the junction of ovule and ovule stalk in the siliques and outside the pollen grains in anther tissue. We also observed selective deposition of callose in plasmodesmata at the junction of ovule and ovule stalk as well as exine layer of pollen grains. The callose deposition was not observed in uninoculated and mock inoculated control plants. We therefore proposed that the observed callose may be involved in blockage of viral movement into ovules and pollen grains and result possibly in non-seed transmission of TVCV in A. thaliana.

Technical Abstract: Seed transmission is a crucial factor in spread of some viral diseases in plants. Following initial infection, plant viruses move through plasmodesmata to spread cell-to-cell and eventually establish a systemic infection by moving through the vasculature. Turnip vein clearing virus (TVCV) causes systemic infection in Arabidopsis thaliana, but shows no seed transmission. Confocal laser scanning, light, transmission, and scanning electron microscopy and immunolabeling techniques were used to study the pattern of the viral movement in reproductive parts of the systemically infected plant. The virus was located in all parts of the flower except ovules and pollen grains. The viral movement was thus confined to the junction of ovule and ovule stalk in the siliques and outside the pollen grains in anther tissue. Subcellular localization of (1'3)-ß-glucan (callose) indicated selective deposition of this substance in plasmodesmata at the junction of ovule and ovule stalk as well as exine layer of pollen grains. The callose deposition was not observed in uninoculated and mock inoculated control plants. We propose that the observed (1'3)-ß-glucan may be involved in blockage of viral movement into ovules and pollen grains and result possibly in non-seed transmission of TVCV in A. thaliana.

Last Modified: 10/20/2014
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