- 著者
- Kumi YOSHIDA Naoko MIKI Kazumi MOMONOI Miki KAWACHI Kiyoshi KATOU Yoshiji OKAZAKI Nobuyuki UOZUMI Masayoshi MAESHIMA Tadao KONDO
- 出版者
- The Japan Academy
- 雑誌
- Proceedings of the Japan Academy, Series B (ISSN:03862208)
- 巻号頁・発行日
- vol.85, no.6, pp.187-197, 2009 (Released:2009-06-12)
- 参考文献数
- 42
- 被引用文献数
- 27 45
Petal color change in morning glory Ipomoea tricolor cv. Heavenly Blue, from red to blue, during the flower-opening period is due to an unusual increase in vacuolar pH (pHv) from 6.6 to 7.7 in colored epidermal cells. We clarified that this pHv increase is involved in tonoplast-localized Na+/H+ exchanger (NHX). However, the mechanism of pHv increase and the physiological role of NHX1 in petal cells have remained obscure. In this study, synchrony of petal-color change from red to blue, pHv increase, K+ accumulation, and cell expansion growth during flower-opening period were examined with special reference to ItNHX1. We concluded that ItNHX1 exchanges K+, but not Na+, with H+ to accumulate an ionic osmoticum in the vacuole, which is then followed by cell expansion growth. This function may lead to full opening of petals with a characteristic blue color.(Communicated by Ryoji NOYORI, M.J.A.)