Expression of an AtNAP gene homolog in senescing morning glory (Ipomoea nil) petals of two cultivars with a different flower life span.
AtNAP, a NAC family transcription factor, has been shown to promote leaf senescence in Arabidopsis. We isolated an AtNAP homolog in morning glory (Ipomoea nil), designated InNAP, and investigated its expression during petal senescence. We used two cultivars, one showing a normal short flower life span (cv. Peking Tendan) and another a longer life span (cv. Violet). InNAP was highly expressed in both cultivars. Expression was high before that of the senescence marker gene InSAG12. InNAP and InSAG12 expression was high in cv. Peking Tendan before cv. Violet. The expression of both genes was therefore temporally related to the onset of the visible senescence symptoms. An inhibitor of ethylene action (silver thiosulphate, STS) delayed petal senescence in cv. Peking Tendan but had no effect in cv. Violet. STS treatment had no clear effect on the InNAP expression in petals of both cultivars, suggesting that endogenous ethylene may not be necessary for its induction. These data suggest the hypothesis that InNAP plays a role in petal senescence, independent of the role of endogenous ethylene.
United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Yoshihito
Y
Shinozaki
United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Toshimitsu
T
Tanaka
United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Isao
I
Ogiwara
United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Motoki
M
Kanekatsu
Mann Laboratory, Department of Plant Sciences, University of California, Davis, CA 95615, USA.
Wouter G
WG
van Doorn
United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan. Electronic address: teyamada@cc.tuat.ac.jp.
Tetsuya
T
Yamada
D000595:Amino Acid Sequence; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D049915:Ipomoea nil / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
D010940:Plant Proteins
Ethylene; Ipomoea nil; NAC transcription factor; NAP; Petal senescence