Identification of a <scp>NAC</scp> transcription factor, <scp>EPHEMERAL</scp>1, that controls petal senescence in Japanese morning glory

<jats:title>Summary</jats:title><jats:p>In flowering plants, floral longevity is species‐specific and is closely linked to reproductive strategy; petal senescence, a type of programmed cell death (<jats:styled-content style="fixed-case">PCD</jats:styled-content>), 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 <jats:styled-content style="fixed-case">NAC</jats:styled-content> transcription factor, designated <jats:styled-content style="fixed-case">EPHEMERAL</jats:styled-content>1 (<jats:styled-content style="fixed-case">EPH</jats:styled-content>1), positively regulates <jats:styled-content style="fixed-case">PCD</jats:styled-content> during petal senescence in the ephemeral flowers of Japanese morning glory (<jats:italic>Ipomoea nil</jats:italic>). <jats:italic><jats:styled-content style="fixed-case">EPH</jats:styled-content>1</jats:italic> expression is induced independently of ethylene signaling, and suppression of <jats:italic><jats:styled-content style="fixed-case">EPH</jats:styled-content>1</jats:italic> resulted in Japanese morning glory flowers that are in bloom until the second day. The suppressed expression of <jats:italic><jats:styled-content style="fixed-case">EPH</jats:styled-content>1</jats:italic> delays progression of <jats:styled-content style="fixed-case">PCD</jats:styled-content>, possibly through suppression of the expression of <jats:styled-content style="fixed-case">PCD</jats:styled-content>‐related genes, including genes for plant caspase and autophagy in the petals. Our data further suggest that <jats:styled-content style="fixed-case">EPH</jats:styled-content>1 is involved in the regulation of ethylene‐accelerated petal senescence. In this study, we identified a key regulator of <jats:styled-content style="fixed-case">PCD</jats:styled-content> in petal senescence, which will facilitate further elucidation of the regulatory network of petal senescence.</jats:p>