論文

査読有り
2011年7月

Corolla of the Large-flowered Petunia (Petunia hybrida Vilm.) Cultivars Exhibit Low Endogenous Cytokinin Concentration through Enhanced Expression of the Genes Encoding Cytokinin Oxidases

JOURNAL OF THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE
  • Takaaki Nishijima
  • ,
  • Tomoya Niki
  • ,
  • Tomoko Niki

80
3
開始ページ
334
終了ページ
342
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.2503/jjshs1.80.334
出版者・発行元
JAPAN SOC HORTICULTURAL SCI

We previously reported that cytokinin (CK) application enlarged the corolla of petunia (Petunia hybrida Vilm.). In this paper, the effect of the large-flowered trait of petunia caused by the Grandiflora (G) allele to CK biosynthesis was investigated. Concentrations of endogenous CK nucleobases (i.e., N-6-(Delta(2)-isopentenyl)adenine (iP) and trans-Zeatin (tZ)), CK nucleosides (IF riboside and tZ riboside), and a CK glucoside (iP-7-glucoside) in the developing corolla were markedly lower in large-flowered cultivars with a Gg genotype than small- and medium-flowered cultivars with a gg genotype. We isolated the cDNAs encoding CK biosynthesis enzymes expressed in the young corolla, i.e., cDNAs of an adenosine phosphate-isopentenyltransferase gene (SHO), a CK riboside 5'-monophosphate phosphoribohydrolase gene (PhLOG), and two CK oxidase/dehydrogenase genes (PhCKX1 and PhCKX2). Expression levels of SHO and PhLOG in the developing corolla were not markedly different among small-, medium-, and large-flowered cultivars. However, expression levels of PhCKX1 and PhCKX2, which catalyze CK degradation through removal of the isoprenoid side chain, were much higher in large-flowered cultivars than in small- and medium-flowered cultivars. Therefore, low CK concentrations in large-flowered cultivars are very probably induced by the promoted expressions of PhCKX1 and PhCKX2, which may partially repress corolla enlargement.

Web of Science ® 被引用回数 : 8

リンク情報
DOI
https://doi.org/10.2503/jjshs1.80.334
CiNii Articles
http://ci.nii.ac.jp/naid/40018904637
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000293113100011&DestApp=WOS_CPL