Altered Expression of a Chloroplast Protein Affects the Outcome of Virus and Nematode Infection.
The chloroplast-resident RNA helicase ISE2 (INCREASED SIZE EXCLUSION LIMIT2) can modulate the formation and distribution of plasmodesmata and intercellular trafficking. We have determined that ISE2 expression is induced by viral infection. Therefore, the responses of Nicotiana benthamiana plants with varying levels of ISE2 expression to infection by Tobacco mosaic virus and Turnip mosaic virus were examined. Surprisingly, increased or decreased ISE2 expression led to faster viral systemic spread and, in some cases, enhanced systemic necrosis. The contributions of RNA silencing and hormone-mediated immune responses to the increased viral susceptibility of these plants were assessed. In addition, Arabidopsis thaliana plants with increased ISE2 expression were found to be more susceptible to infection by the beet cyst nematode Heterodera schachtii. Our analyses provide intriguing insights into unexpected functional roles of a chloroplast protein in mediating plant-pathogen interactions. The possible roles of plasmodesmata in determining the outcomes of these interactions are also discussed.
1 Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, U.S.A.
Elena E
EE
Ganusova
2 Department of Plant Sciences, University of Tennessee; and.
J Hollis
JH
Rice
1 Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, U.S.A.
Timothy S
TS
Carlew
1 Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, U.S.A.
Akshita
A
Patel
3 National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY 14623, U.S.A.
Emmanuel
E
Perrodin-Njoku
2 Department of Plant Sciences, University of Tennessee; and.
Tarek
T
Hewezi
1 Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, U.S.A.
Tessa M
TM
Burch-Smith
D000818:Animals; D017360:Arabidopsis / Q000235:genetics* / Q000469:parasitology / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060365:Chloroplast Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000235:genetics* / Q000469:parasitology / Q000821:virology; D030821:Plants, Genetically Modified; D031425:Plasmodesmata / Q000235:genetics / Q000378:metabolism; D017800:Potyvirus / Q000502:physiology; D021381:Protein Transport / Q000235:genetics; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics* / Q000469:parasitology / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000502:physiology; D014431:Tylenchoidea / Q000502:physiology
D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; C523445:INCREASED SIZE EXCLUSION LIMIT2 protein, Arabidopsis; D020365:RNA Helicases