Molecular Plant-Microbe Interactions (2009) 22, 18-30

Xiaodong Bai, Valdir R. Correa, Tania Y. Toruño, El-Desouky Ammar, Sophien Kamoun and Saskia A. Hogenhout (2009)
AY-WB phytoplasma secretes a protein that targets plant cell nuclei
Molecular Plant-Microbe Interactions 22 (1), 18-30
Abstract: The fully sequenced genome of aster yellows phytoplasma strain witches' broom (AY-WB; Candidatus Phytoplasma asteris) was mined for the presence of genes encoding secreted proteins based on the presence of N-terminal signal peptides (SP). We identified 56 secreted AY-WB proteins (SAP). These SAP are candidate effector proteins potentially involved in interaction with plant and insect cell components. One of these SAP, SAP11, contains an N-terminal SP sequence and a eukaryotic bipartite nuclear localization signal (NLS). Transcripts for SAP11 were detected in AY-WB-infected plants. Yellow fluorescence protein (YFP)-tagged SAP11 accumulated in Nicotiana benthamiana cell nuclei, whereas the nuclear targeting of YFP-tagged SAP11 mutants with disrupted NLS was inhibited. The nuclear transport of YFP-SAP11 was also inhibited in N. benthamiana plants in which the expression of importin α was knocked down using virus-induced gene silencing (VIGS). Furthermore, SAP11 was detected by immunocytology in nuclei of young sink tissues of China aster plants infected with AY-WB. In summary, this work shows that AY-WB phytoplasma produces a protein that targets the nuclei of plant host cells; this protein is a potential phytoplasma effector that may alter plant cell physiology.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Saskia A. Hogenhout, Sophien Kamoun

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytoplasma asteris