Effects of ambient calcium concentration on morphological form of callus-like cells in Saccharina japonica (Phaeophyceae) sporophyte

• Published in: Journal of applied phycology Vol. 24; no. 4; pp. 701 - 706
• Main Authors: Kanamori, Miwa, Mizuta, Hiroyuki, Yasui, Hajime
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.08.2012; Springer Netherlands
• Subjects: Biomedical and Life Sciences; calcium; Ecology; explants; Freshwater & Marine Ecology; Life Sciences; NADP (coenzyme); oxygen; Phaeophyceae; Plant Physiology; Plant Sciences; plasma membrane; Saccharina japonica; sporophytes; thallus; Development; Callus; Calcium; Phaeophyta; Reactive oxygen
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-011-9688-x

Explants obtained from young sporophytes of Saccharina japonica were cultured in an artificial medium with different concentrations of Ca2+ (0–20 mM). The culture with 10 mM Ca2+ promoted the formation of unpigmented filamentous callus-like cells in the cortical layer. In contrast, explants cultured with 5 mM Ca2+ formed pigmented round callus-like cells in the epidermis at a high percentage. The thallus regeneration rate of explants in 5 mM Ca2+ was ten times higher than those of explants cultured in 10 mM Ca2+. Ambient Ca2+ concentrations also influenced the production of radical oxygen species (ROS) in explants. Explants cultured in 10 mM Ca2+ produced higher ROS than did those cultured in 5 mM. The ROS production was histologically observed mainly in the plasma membrane of callus-like cells using 2′, 7′-dichlorodihydrofluorescein diacetate. Moreover, a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, diphenyleneiodonium chloride, inhibited the ROS production with propagation of filamentous callus-like cells. These results suggest that Ca2+ concentration in medium influences the development of callus-like cells and thallus regeneration by affecting NADPH oxidase activity and ROS production in the plasma membrane of the callus-like cells. Therefore, the morphological form of callus-like cells and the development of thallus will be controlled by Ca2+ concentration in the medium.