- 著者
- Ryo Norikoshi Katsunori Kohata Tomoko Niki Kazuo Ichimura
- 出版者
- The Japanese Society for Horticultural Science
- 雑誌
- The Horticulture Journal (ISSN:21890102)
- 巻号頁・発行日
- pp.UTD-347, (Released:2022-05-25)
Flower opening is associated with the expansion of petal cells. To understand the role played by soluble carbohydrates during cell expansion associated with petal growth, changes in soluble carbohydrate concentrations in petal limbs during flower opening in Phlox drummondii were investigated. The size of adaxial and abaxial epidermal cells in the petal limbs gradually increased during flower opening. 2-C-Methyl-d-erythritol (2-C-ME) was identified using 1H-NMR in P. drummondii petals. 2-C-ME was the most abundant carbohydrate in the petal limbs at five developmental stages, with the concentration of glucose the second highest, although the concentration of the latter was half of that of the 2-C-ME concentration in all five stages. The concentrations of 2-C-ME and glucose increased during flower opening. In contrast, inorganic ion concentrations did not increase during flower opening. The osmotic potential of petal limbs decreased considerably during the final stage of flower opening; this decrease could in part be attributed to the increasing 2-C-ME concentration. Transmission electron microscopic observations showed that the petal limb cells in open flowers were occupied primarily by the vacuole. The concentration of 2-C-ME in the vacuole was estimated to be 131 mM, which was much higher than the concentrations of the other carbohydrates. We conclude that the accumulation of 2-C-ME in the vacuole at a high concentration acts as an osmoticum, decreasing the osmotic potential of petal limbs and thereby increasing turgor pressure, which is thought to be involved in cell expansion of petal limbs during flower opening.
- 著者
- Ryo Norikoshi Katsunori Kohata Hiroko Shimizu-Yumoto Rie Goto Kazuo Ichimura
- 出版者
- 一般社団法人 園芸学会
- 雑誌
- The Horticulture Journal (ISSN:21890102)
- 巻号頁・発行日
- pp.MI-103, (Released:2016-01-13)
- 被引用文献数
- 11
Petal growth associated with flower opening is due to cell expansion. To elucidate the role of soluble carbohydrates in expansion of petal cells in Eustoma grandiflorum, its soluble carbohydrates were identified, and changes in their subcellular concentrations during flower opening were investigated. In addition to glucose, fructose, sucrose, and myo-inositol, d-bornesitol was identified using 1H-NMR. d-Bornesitol was the major soluble carbohydrate in leaves and stems. Given that cyclitols are known to be the translocated carbohydrates in alfalfa, phloem exudate was analyzed. However, the translocated carbohydrate was suggested to be sucrose, and not d-bornesitol. In the petals, glucose and sucrose content increased whereas d-bornesitol and myo-inositol contents were almost constant during flower opening. The fructose content in petals was very low. Glucose, sucrose, myo-inositol, and d-bornesitol were found mainly in the vacuole, although sucrose was also found in the cytoplasm. In the petals of open flowers, glucose and sucrose concentrations in the vacuole increased to 60 and 53 mM. Inorganic ion concentrations in the symplast and apoplast did not increase during flower opening. The osmotic potential of the symplast and apoplast in the petals was lower at the open stage than the potential of those at the bud stage, and this difference was mainly attributed to increases in glucose and sucrose concentrations. The results suggest that the accumulation of glucose and sucrose in the vacuole reduces the symplastic osmotic potential, which appears to be involved in the cell expansion associated with flower opening, but that the contribution of d-bornesitol as an osmoticum to cell expansion is limited in Eustoma.