title: Systemic acquired resistance in sunflower (Helianthus annuus L.).
abstract: Systemic acquired resistance (SAR) to infection by Botrytis cinerea in the leaves of sunflower (Helianthus annuus L.) plants was induced following cotyledon inoculation with B. cinerea or treatment with abiotic inducers. Salicylic acid (SA), benzo-(1,2,3)-thiadiazole-7-carbothioic S-methyl ester (BTH), 2,6-dichloroisonicotinic acid (INA) or EDTA protected sunflower plants against Botrytis infection, that was revealed by a reduction in the number and area of the necrotic lesions in upper leaves after challenge inoculation with the pathogen. SA and BTH were more potent inducers than INA, EDTA or pre-inoculation with the fungus. In addition to resistance to B. cinerea, the upper leaves have also developed resistance to maceration by a mixture of cell wall-degrading enzymes. Calcium nitrate inhibited both the protective effect and the resistance of leaf discs to cell-wall degrading enzymes. All the tested chemicals increased the synthesis and excretion of sunflower phytoalexins--coumarins scopoletin and ayapin and induced the PR-proteins chitinase and 1,3-beta-glucanase, being the inducer effect of each activator correlated with the level of protection against B. cinerea (BTH > SA > INA > EDTA). Thus, SAR induction is mediated by general increase of plant defence responses. This is the first report on SAR in sunflower.
authors.affiliation: National Academy of Sciences of Ukraine
authors.forename: A
authors.initials: A
authors.lastname: Dmitriev
authors.forename: M
authors.initials: M
authors.lastname: Tena
authors.forename: J
authors.initials: J
authors.lastname: Jorrin
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D020171:Botrytis / Q000472:pathogenicity; D017610:Calcium Compounds / Q000378:metabolism / Q000494:pharmacology; D002473:Cell Wall / Q000187:drug effects; D002688:Chitinases / Q000096:biosynthesis / Q000187:drug effects; D004492:Edetic Acid / Q000378:metabolism / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D043326:Glucan 1,3-beta-Glucosidase; D006368:Helianthus / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D007113:Immunity, Innate / Q000187:drug effects*; D007539:Isonicotinic Acids / Q000494:pharmacology; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D010936:Plant Extracts / Q000096:biosynthesis; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D012717:Sesquiterpenes; D013729:Terpenes; D013830:Thiadiazoles / Q000494:pharmacology; D001617:beta-Glucosidase / Q000096:biosynthesis / Q000187:drug effects; D000094162:Phytoalexins
chemical_list: D000890:Anti-Infective Agents; D017610:Calcium Compounds; D007539:Isonicotinic Acids; D009566:Nitrates; D010936:Plant Extracts; D010940:Plant Proteins; D012717:Sesquiterpenes; D013729:Terpenes; D013830:Thiadiazoles; C077261:2,6-dichloroisonicotinic acid; D004492:Edetic Acid; C099403:S-methyl benzo(1,2,3)thiadiazole-7-carbothioate; D002688:Chitinases; D001617:beta-Glucosidase; D043326:Glucan 1,3-beta-Glucosidase; C059948:calcium nitrate; D020156:Salicylic Acid; D000094162:Phytoalexins