title: Activation of defense against Phytophthora infestans in potato by down-regulation of syntaxin gene expression.
abstract: The oomycete Phytophthora infestans is the causal agent of late blight, the most devastating disease of potato. The importance of vesicle fusion processes and callose deposition for defense of potato against Phytophthora infestans was analyzed. Transgenic plants were generated, which express RNA interference constructs targeted against plasma membrane-localized SYNTAXIN-RELATED 1 (StSYR1) and SOLUBLE N-ETHYLMALEIMIDE-SENSITIVE FACTOR ADAPTOR PROTEIN 33 (StSNAP33), the potato homologs of Arabidopsis AtSYP121 and AtSNAP33, respectively. Phenotypically, transgenic plants grew normally, but showed spontaneous necrosis and chlorosis formation at later stages. In response to infection with Phytophthora infestans, increased resistance of StSYR1-RNAi plants, but not StSNAP33-RNAi plants, was observed. This increased resistance correlated with the constitutive accumulation of salicylic acid and PR1 transcripts. Aberrant callose deposition in Phytophthora infestans-infected StSYR1-RNAi plants coincided with decreased papilla formation at penetration sites. Resistance against the necrotrophic fungus Botrytis cinerea was not significantly altered. Infiltration experiments with bacterial solutions of Agrobacterium tumefaciens and Escherichia coli revealed a hypersensitive phenotype of both types of RNAi lines. The enhanced defense status and the reduced growth of Phytophthora infestans on StSYR1-RNAi plants suggest an involvement of syntaxins in secretory defense responses of potato and, in particular, in the formation of callose-containing papillae.
authors.affiliation: Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany.
authors.forename: Lennart
authors.initials: L
authors.lastname: Eschen-Lippold
authors.affiliation: Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany.
authors.forename: Ramona
authors.initials: R
authors.lastname: Landgraf
authors.affiliation: Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Smolka
authors.affiliation: Institute of Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, D-06120 Halle (Saale), Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schulze
authors.affiliation: Department of Cellular Biochemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle (Saale), Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Heilmann
authors.affiliation: Department of Cellular Biochemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle (Saale), Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Heilmann
authors.affiliation: Martin Luther University Halle-Wittenberg, Biocenter, Weinbergweg 22, D-06120 Halle (Saale), Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Hause
authors.affiliation: Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Rosahl
mesh_terms: D016960:Agrobacterium tumefaciens; D020171:Botrytis / Q000472:pathogenicity; D060467:Disease Resistance / Q000235:genetics; D015536:Down-Regulation; D004926:Escherichia coli; D018506:Gene Expression Regulation, Plant; D005936:Glucans / Q000378:metabolism; D052066:N-Ethylmaleimide-Sensitive Proteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D055750:Phytophthora infestans / Q000472:pathogenicity*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D030821:Plants, Genetically Modified; D050765:Qa-SNARE Proteins / Q000235:genetics*; D050767:Qc-SNARE Proteins / Q000235:genetics; D034622:RNA Interference; D020156:Salicylic Acid / Q000378:metabolism; D011198:Solanum tuberosum / Q000382:microbiology* / Q000502:physiology*
chemical_list: D005936:Glucans; D050765:Qa-SNARE Proteins; D050767:Qc-SNARE Proteins; C048306:callose; D052066:N-Ethylmaleimide-Sensitive Proteins; D020156:Salicylic Acid