Seizo Fujikawa

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The freezing tolerance of asparagus (Asparagus officinalis L.) embryogenic cells, as determined by electrolyte leakage, was increased by the incubation of samples in medium containing 0.8 M sucrose. To elucidate the mechanism involved, we investigated the changes in soluble carbohydrates, cell ultrastructure and proteins accompanying the increase in(More)
Cortical parenchyma cells of mulberry (Morus bombycis Koidz.) trees acquire extremely high freezing tolerance in winter as a result of seasonal cold acclimation. The amount of total proteins in endoplasmic reticulum (ER)-enriched fractions isolated from these cells increased in parallel with the process of cold acclimation. Protein compositions in the(More)
Bryophyte species growing in areas in which temperatures fall below zero in winter are likely to have tolerance to freezing stress. It is well established in higher plants that freezing tolerance is acquired by exposure to non-freezing low temperatures, accompanied by expression of various genes and increases in levels of the stress hormone abscisic acid(More)
Seasonal changes in the accumulation of soluble sugars in extracellular freezing cortical parenchyma cells and deep supercooling xylem parenchyma cells in Japanese white birch (Betula platyphylla var. japonica) were compared to identify the effects of soluble sugars on the mechanism of deep supercooling, which keeps the liquid state of water in cells under(More)
Abscisic acid (ABA) has been postulated to play a role in the development of freezing tolerance during the cold acclimation process in higher plants, but its role in cold tolerance in tower land plants has not been elucidated. The moss Physcomitrella patens rapidly developed freezing tolerance when its protonemata were grown in a medium containing ABA, with(More)
We have shown that two 27-kD proteins, designated as WAP27A and WAP27B, were abundantly accumulated in endoplasmic reticulum-enriched fractions isolated from cortical parenchyma cells of mulberry tree (Morus bombycis Koidz.) during winter (N. Ukaji, C. Kuwabara, D. Takezawa, K. Arakawa, S. Yoshida, S. Fujikawa [1999] Plant Physiol 120: 480--489). In the(More)
Cold acclimation of winter wheat (Triticum aestivum L.) seedlings induces accumulation in the apoplast of taTLPs that are similar to thaumatin-like proteins (TLPs), which are pathogenesis-related proteins. We characterized a cDNA of WAS-3a encoding the major isoform of taTLPs from winter wheat cells and showed that WAS-3a transcripts were markedly increased(More)
The freezing behavior of dormant buds in larch, especially at the cellular level, was examined by a Cryo-SEM. The dormant buds exhibited typical extraorgan freezing. Extracellular ice crystals accumulated only in basal areas of scales and beneath crown tissues, areas in which only these living cells had thick walls unlike other tissue cells. By slow cooling(More)