title: Photocontrol of Elicitor Activity of PIP-1 to Investigate Temporal Factors Involved in Phytoalexin Biosynthesis.
abstract: The peptide elicitor PIP-1 can induce various immune responses in tobacco cells. Previously, we showed that types of responses induced by PIP-1 are different depending on its stimulation periods; short-term stimulation induces weak responses, whereas long-term stimulation leads to strong responses including production of the phytoalexin capsidiol. However, key components that directly regulate the initiation of capsidiol biosynthesis in response to continuous stimulation with PIP-1 remain unclear. In this study, we designed a photocleavable PIP-1 analog containing 3-amino-3-(2-nitrophenyl)propionic acid as a photocleavable residue. The activity of the analog can be "switched off" using ultraviolet (UV) irradiation without undesired side effects. This analog induced a significant level of capsidiol production unless UV-irradiated, whereas no capsidiol production was observed when tobacco cells were UV-irradiated 1 h after treatment. Using this analog, we found that the elicitor-inducible 3-hydroxy-3-methylglutaryl-CoA reductase activity is regulated based on the duration of the stimulation with PIP-1, which could be associated with the initiation of capsidiol biosynthesis.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Yonghyun
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Miyashita
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Miyagawa
mesh_terms: D010455:Peptides / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D014466:Ultraviolet Rays; D000094162:Phytoalexins
chemical_list: D010455:Peptides; D010940:Plant Proteins; D012717:Sesquiterpenes; C081843:capsidiol; D000094162:Phytoalexins
keywords: MAP kinase; peptide; photocleavable analog; phytoalexin; plant immunity