CHANGES IN ORGANELLE AND DNA QUALITY, QUANTITY, AND DISTRIBUTION IN THE WOOD OF CRYPTOMERIA JAPONICA OVER LONG-TERM STORAGE

Changes in the quantity and quality of DNA during storage (0, 1, 3, 5, 11, 15, 23, 27, 40, 44, 75 years) were investigated for the wood of Cryptomeria japonica. Fresh sapwood yielded more DNA than fresh heartwood. The amount of DNA extracted from wood samples stored for 1 year or more after cutting was below the limit of detection by measurement with a UV spectrophotometer. A chloroplast DNA region with a length of 527 bp was amplified by the polymerase chain reaction from the DNA extracted from sapwood stored for 0, 1, 3, 5, 11, 15 and 23 years, and from heartwood stored for 0, 3, 11, 15 and 23 years. A shorter length of chloroplast DNA with a length of 82 bp was amplified for all of the wood samples used in this study. Using fluorescence microscopy, we observed changes in the abundance of cell organelles containing DNA such as nuclei and amyloplasts during storage. Microscopy showed that the DNA content of latewood ray parenchyma was greater than the DNA content of earlywood ray parenchyma in the sapwood, and amyloplasts were present in ray cells in the heartwood of the stored wood. Our results suggest that optimizing DNA extraction protocols for wood stored for long periods will improve the utility DNA identification of wood products.