title: Salicylic acid and cysteine contribute to arbutin-induced alleviation of angular leaf spot disease development in cucumber.
abstract: Arbutin induced suppression of angular leaf spot disease in cucumber resulting from lower populations of Pseudomonas syringae pv lachrymans in the infected tissues. This study provides insight into mechanisms that may potentially account for this effect. In the absence of the pathogen, exogenous arbutin-induced expression of PR1, the marker of salicylic acid signaling, increased the content of salicylic acid and modulated the cysteine pool. This suggested that arbutin promoted cucumber plants to a "primed" state. When challenged with the pathogen, the arbutin-treated plants showed strongly reduced infection symptoms 7 days after inoculation. At this time point, they were characterized by higher contents of free and protein-bound cysteine due to higher cysteine biosynthetic capacity related to increased activities of serine acetyltransferase and cysteine synthase when compared with plants infected without arbutin treatment. Moreover, in the arbutin-treated and infected plants the contents of free salicylic acid and its conjugates were also increased, partly owing to its biosynthesis via the phenylpropanoid pathway. We suggest that arbutin-induced abrogation of angular leaf spot disease in cucumber could be mediated by salicylic acid and cysteine-based signaling.
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland. Electronic address: elkuz@biol.uni.lodz.pl.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Kuźniak
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland.
authors.forename: Marzena
authors.initials: M
authors.lastname: Wielanek
authors.affiliation: Department of Environmental Chemistry, Faculty of Chemistry, University of Łódź, Pomorska 163, 90-236, Łódź, Poland.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Chwatko
authors.affiliation: Department of Environmental Chemistry, Faculty of Chemistry, University of Łódź, Pomorska 163, 90-236, Łódź, Poland.
authors.forename: Rafał
authors.initials: R
authors.lastname: Głowacki
authors.affiliation: Institute of Plant Physiology, Polish Academy of Science, Niezapominajek 21, 30-239, Kraków, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Libik-Konieczny
authors.affiliation: Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland.
authors.forename: Milena
authors.initials: M
authors.lastname: Piątek
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Gajewska
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Skłodowska
mesh_terms: D001104:Arbutin / Q000494:pharmacology*; D018553:Cucumis sativus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D003545:Cysteine / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D044224:Pseudomonas syringae / Q000187:drug effects / Q000502:physiology; D020156:Salicylic Acid / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D001104:Arbutin; D010650:Phenylalanine Ammonia-Lyase; D003545:Cysteine; D020156:Salicylic Acid
keywords: ARB; ARB+PSL; CS; CSH; Cysteine synthase complex; PAL; PSL; Pseudomonas syringae pv lachrymans; SA; SAC; SAT; Salicylic acid signaling; arbutin; cysteine; cysteine synthase; dai; days after inoculation; p-CSH; phenylalanine ammonia lyase; plants treated with arbutin and infected; protein-bound cysteine; salicylic acid; salicylic acid conjugates; serine acetyltransferase