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Poster: Molecular & Cellular Plant-Microbe Interactions: MPMI


Exchange of HC-Pro cistron between Soybean mosaic virus and Clover yellow vein virus: Impact on pathogenicity
M.R. HAJIMORAD (1), Y. Wang (1,2), J. Abe (3), K. Nakahara (3); (1) University of Tennessee, Knoxville, TN, USA, (2) Jilin Academy of Agricultural Sciences, Jilin, China, (3) Hokkaido University, Japan

Soybean mosaic virus (SMV)-N and Clover yellow vein virus (ClYVV)-no30, members of Potyvirus genus within Potyviridae family, have narrow host range. SMV-N is well adapted to cultivated soybean (Glycine max) while infects systemically wild-type soybean (G. Soja) as well. However, SMV-N is incapable of systemic infection in broad bean (Vicia faba). In contrast, ClYVV-no30 is capable of systemic infection in both broad bean and wild-type soybean; however, incapable of systemic movement in cultivated soybean. Because SMV-N and ClYVV-no30 both establish local infection in all these plants, we hypothesized that lack of systemic movement by SMV-N in broad bean and by ClYVV-no30 in cultivated soybean is due to incompatibility of respective HC-Pro, a key long-distance movement potyviral protein, in these two hosts. To test this hypothesis, chimeras were constructed with precise exchanges of HC-Pro cistrons between SMV-N and ClYVV-no30 and inoculated onto cultivated soybean “Williams”, wild-type soybean “B01167” and broad bean “Windsor”. Analyses showed that pathogenicity of recombinant viruses did not differ from those of the parental viruses. This observation suggests that i) HC-Pro of SMV-N and ClYVV-no30 are functionally equivalent, and ii) the determinant(s) for systemic infection in cultivated soybean by SMV-N and by ClYVV-no30 in broad bean reside elsewhere.