title: Identification of a NAC transcription factor, EPHEMERAL1, that controls petal senescence in Japanese morning glory.
abstract: In flowering plants, floral longevity is species-specific and is closely linked to reproductive strategy; petal senescence, a type of programmed cell death (PCD), is a highly regulated developmental process. However, little is known about regulatory pathways for cell death in petal senescence, which is developmentally controlled in an age-dependent manner. Here, we show that a NAC transcription factor, designated EPHEMERAL1 (EPH1), positively regulates PCD during petal senescence in the ephemeral flowers of Japanese morning glory (Ipomoea nil). EPH1 expression is induced independently of ethylene signaling, and suppression of EPH1 resulted in Japanese morning glory flowers that are in bloom until the second day. The suppressed expression of EPH1 delays progression of PCD, possibly through suppression of the expression of PCD-related genes, including genes for plant caspase and autophagy in the petals. Our data further suggest that EPH1 is involved in the regulation of ethylene-accelerated petal senescence. In this study, we identified a key regulator of PCD in petal senescence, which will facilitate further elucidation of the regulatory network of petal senescence.
authors: NARO Institute of Floricultural Science, Tsukuba, 305-8519, Japan.
authors: Kenichi
authors: K
authors: Shibuya
authors: Keiichi
authors: K
authors: Shimizu
authors: Tomoko
authors: T
authors: Niki
authors: Kazuo
authors: K
authors: Ichimura
mesh_terms: D017209:Apoptosis; D005030:Ethylenes / Q000494:pharmacology*; D035264:Flowers / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D049915:Ipomoea nil / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D009928:Organ Specificity; D010641:Phenotype; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018547:Plant Stems / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D060888:Real-Time Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D014157:Transcription Factors; C036216:ethylene
keywords: Ipomoea nil; Japanese morning glory; NAC; ethylene; flower; petal senescence; programmed cell death