title: Agatharesinol biosynthesis-related changes of ray parenchyma in sapwood sticks of Cryptomeria japonica during cell death.
abstract: The work demonstrates a relationship between the biosynthesis of the secondary metabolite, agatharesinol, and cytological changes that occur in ray parenchyma during cell death in sapwood sticks of Cryptomeria japonica under humidity-regulated conditions. To characterize the death of ray parenchyma cells that accompanies the biosynthesis of secondary metabolites, we examined cell death in sapwood sticks of Cryptomeria japonica under humidity-regulated conditions. We monitored features of ray parenchyma cells, such as viability, the morphology of nuclei and vacuoles, and the amount of starch grains. In addition, we analyzed levels of agatharesinol, a heartwood norlignan, by gas chromatography-mass spectrometry in the same sapwood sticks. Dramatic changes in the amount of starch grains and in the level of agatharesinol occurred simultaneously. Therefore, the biosynthesis of agatharesinol appeared to originate from the breakdown of starch. Furthermore, we observed the expansion of vacuoles in ray parenchyma cells prior to other cytological changes at the final stage of cell death. In our experimental system, we were able to follow the process of cell death and to demonstrate relationships between cytological changes and the biosynthesis of a secondary metabolite during the death of ray parenchyma cells.
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan. nakaba@cc.tuat.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakaba
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Arakawa
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Morimoto
authors.affiliation: Forestry and Forest Products Research Institute, Forest Tree Breeding Center, Hokkaido Regional Breeding Office, 561-1 Bunkyodai-midorimachi, Ebetsu, Hokkaido, 069-0836, Japan.
authors.forename: Ryogo
authors.initials: R
authors.lastname: Nakada
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Bito
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Imai
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Funada
mesh_terms: D016923:Cell Death; D032485:Cryptomeria / Q000166:cytology* / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D017705:Lignans / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D059828:Plant Cells / Q000378:metabolism / Q000648:ultrastructure; D064210:Secondary Metabolism; D013213:Starch / Q000378:metabolism; D014934:Wood / Q000166:cytology / Q000378:metabolism
chemical_list: D017705:Lignans; C445733:agatharesinol; D013213:Starch
keywords: Agatharesinol; Cell death; Cryptomeria japonica; Heartwood substance; Ray parenchyma cell