Page 289 - PC2019 Program & Proceedings

PLANT CANADA 2019

P151. The Ve-resistance locus in tomato, a plant signalling intercept
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Robb, E. ; R. Nazar ; C. Castroverde ; A. Kurosky ; H. Shittu ; X. Xu
1 University of Guelph
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University of Texas Medical Branch
3
University of Benin
The Ve-resistance locus in tomato, a plant signalling intercept Robb, J.*1, H.O. Shittu1, C.D.M.
Castroverde1, X.Xu1, A. Kurosky2, R.N. Nazar1 Department of Molecular and Cellular Biology,
University of Guelph, Guelph. ON, N1G 2W11 and Department of Biochemistry and Molecular Biology,
University of Texas Medical Branch, Galveston, TX, 775552 Signalling crosstalk in plants has been
recognized for several decades but the manner in which these interactions occur continues to pose many
questions. Examples of crosstalk between plant defense responses and growth have been recognized but
little is known about receptors that may be shared in this crosstalk. In tomato, resistance to Verticillium
dahliae and V. albo-atrum, race 1 has been attributed to the Ve-resistance locus, comprising two closely
related back-to-back genes, Ve1 and Ve2. Both appear to encode plasma membrane receptor proteins.
Ve1 gene expression is induced and Ve2 is constitutive. Recent studies in our laboratories have shown
that Ve2 controls the expression of the defense cascade, which appears to contribute to symptom
development, while induction of Ve1 promotes root growth, which permits the plant to lower the
concentration of Verticillium by outgrowing the fungus. Furthermore, proteomic analyses indicate that the
two receptor proteins act antagonistically, the induction of Ve1 also causing a down regulation of Ve2
gene expression and a subsequent reduction in defense protein levels. These observations suggest strongly
that the Ve-locus is a

Elizabeth Robb (jrobb@uoguelph.ca)

P152. Subcellular localization of prune dwarf virus coat and movement proteins
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Simkovich, A. ; S. Kohalmi ; A. Wang
1 The University of Western Ontario
Agriculture and Agri-Food Canada
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Prune Dwarf Virus (PDV) is an important viral pathogen infecting many fruit trees in the Prunus genus
such as sweet cherry, peach and plum. Phylogenetic relationships of the coat and movement proteins (CP
and MP) of PDV have been major foci of research. Until recently, little research was conducted regarding
intercellular movement of this virus. The aim of this work was to investigate the sub-cellular localization
of these two proteins and findings indicate that CP and MP localize to the tonoplast and plasmodesmata
respectively. After these initial results further studies were performed to identify regions of the viral
protein which produce organelle targeting signals. Truncated versions of each protein show that deletions
of the C terminal regions had minimal impact on organelle targeting, however deletion of the N terminal
region negatively affected the formation of punctate structures of the fluorescent tagged viral proteins at
their putative host protein targets. Future work includes the further identification of organelle targeting
signals encoded by each viral protein, and the impact of mutations of these targeting signals in the PDV
infection movement and infection cycle via the use of a PDV infectious clone on herbaceous indicator
hosts.

Aaron Simkovich (asimkovi@uwo.ca)

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