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Seizo Fujikawa - One of the best experts on this subject based on the ideXlab platform.

  • Endoplasmic reticulum-localized small heat shock protein that accumulates in Mulberry Tree (Morus bombycis Koidz.) during seasonal cold acclimation is responsive to abscisic acid
    Tree physiology, 2010
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Yuri Kanno, Mitsunori Seo, Seizo Fujikawa
    Abstract:

    Summary With seasonal changes, several proteins accumulate in the endoplasmic reticulum (ER)-enriched fraction in the bark of Mulberry Tree (Morus bombycis Koidz.). Results of partial amino acid sequence analysis in our previous study suggested that one of these proteins is the ER-localized small heat shock protein (sHSP), designated 20-kD winteraccumulating protein (WAP20). In the present study, molecular and biochemical properties of WAP20 were investigated in detail. The deduced amino acid sequence of the cDNA has the predicted signal sequence to the ER, retention signal to the ER and two consensus regions conserved in sHSPs. Recombinant WAP20 expressed in Escherichia coli also showed typical biochemical features of sHSPs, including the formation of a high-molecular-mass complex between 200 and 300 kD under native conditions, promotion of the renaturation of chemically denaturated citrate synthase and prevention of heat stress-induced aggregation of the enzyme. Transcript levels of WAP20 in the bark tissue were seasonally changed, showing high expression levels from mid-October to mid-December, and the transcript levels were additionally increased and decreased by cold treatment and warm treatment, respectively. WAP20 transcripts were detected abundantly in bark tissue rather than xylem and winter bud tissues during seasonal cold acclimation. The bark tissue specificity of WAP20 accumulation was also observed by exogenous application of phytohormone abscisic acid (ABA) in de-acclimated twigs, whereas WAP20 transcripts were increased in all of these tissues by heat shock treatment at 37 °C in summer twigs. The results suggest that ABA may be involved in the expression of the WAP20 gene in bark tissue of the Mulberry Tree during seasonal cold acclimation.

  • accumulation of pathogenesis related pr 10 bet v 1 protein homologues in Mulberry morus bombycis koidz Tree during winter
    Plant Cell and Environment, 2004
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    Seasonal evaluation of total soluble protein fractions extracted from cortical parenchyma cells of Mulberry ( Morus bombycis Koidz.) Tree identified a predominant 18 kDa protein that was directly correlated to periods of cold acclimation. The 18 kDa protein, designated as WAP18 ( w inter a ccumulating 18 kDa p roteins) increased from September to December and then gradually decreased until June. The maximum levels of WAP18 were detected in mid-winter, which corresponds to the maximum freeze tolerance in cortical parenchyma cells of Mulberry Tree. Two-dimensional gel electrophoresis confirmed that WAP18 consists of at least three proteins that range between an isoelectric point of 5.0 and 6.0. All three proteins reacted with anti-WAP18 antibodies, thereby suggesting that they represent individual isoforms. Furthermore, N-terminal amino acid sequence analysis demonstrated that all three proteins contain high sequence similarity to each other and high homology to pathogenesis-related (PR) - - 10/Bet v 1 protein families. The purified WAP18 exhibited in vitro cryoprotective activity for the freeze labile L -lactate dehydrogenase (LDH) enzyme. These results suggest that WAP18 may function in the freezing tolerance mechanism of cortical parenchyma cells of Mulberry Tree during winter.

  • Cold Acclimation-Induced WAP27 Localized in Endoplasmic Reticulum in Cortical Parenchyma Cells of Mulberry Tree Was Homologous to Group 3 Late-Embryogenesis Abundant Proteins
    Plant physiology, 2001
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    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 present study, cDNA clones encoding WAP27A and WAP27B were isolated and characterized. The deduced amino acid sequences of WAP27A and WAP27B cDNAs had 12 repeats of an 11-mer amino acid motif that was the common feature of group 3 late-embryogenesis-abundant proteins. Under field conditions, transcripts of WAP27 genes were initially detected in mid-October, reached maximum level from mid-November to mid-December, and then gradually decreased. The transcript levels of WAP27 genes in cortical parenchyma cells harvested in October was drastically induced by cold treatment within a few days, whereas those in cortical parenchyma cells harvested in August were low even by cold treatment for 3 weeks. Immunocytochemical analysis by electron microscopy confirmed that WAP27 was localized specifically in vesicular-form ER and also localized in dehydration-induced multiplex lamellae-form ER. The role of WAP27 in the ER is discussed in relation to acquisition of freezing tolerance of cortical parenchyma cells in Mulberry Tree during winter.

Norifumi Ukaji - One of the best experts on this subject based on the ideXlab platform.

  • Endoplasmic reticulum-localized small heat shock protein that accumulates in Mulberry Tree (Morus bombycis Koidz.) during seasonal cold acclimation is responsive to abscisic acid
    Tree physiology, 2010
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Yuri Kanno, Mitsunori Seo, Seizo Fujikawa
    Abstract:

    Summary With seasonal changes, several proteins accumulate in the endoplasmic reticulum (ER)-enriched fraction in the bark of Mulberry Tree (Morus bombycis Koidz.). Results of partial amino acid sequence analysis in our previous study suggested that one of these proteins is the ER-localized small heat shock protein (sHSP), designated 20-kD winteraccumulating protein (WAP20). In the present study, molecular and biochemical properties of WAP20 were investigated in detail. The deduced amino acid sequence of the cDNA has the predicted signal sequence to the ER, retention signal to the ER and two consensus regions conserved in sHSPs. Recombinant WAP20 expressed in Escherichia coli also showed typical biochemical features of sHSPs, including the formation of a high-molecular-mass complex between 200 and 300 kD under native conditions, promotion of the renaturation of chemically denaturated citrate synthase and prevention of heat stress-induced aggregation of the enzyme. Transcript levels of WAP20 in the bark tissue were seasonally changed, showing high expression levels from mid-October to mid-December, and the transcript levels were additionally increased and decreased by cold treatment and warm treatment, respectively. WAP20 transcripts were detected abundantly in bark tissue rather than xylem and winter bud tissues during seasonal cold acclimation. The bark tissue specificity of WAP20 accumulation was also observed by exogenous application of phytohormone abscisic acid (ABA) in de-acclimated twigs, whereas WAP20 transcripts were increased in all of these tissues by heat shock treatment at 37 °C in summer twigs. The results suggest that ABA may be involved in the expression of the WAP20 gene in bark tissue of the Mulberry Tree during seasonal cold acclimation.

  • accumulation of pathogenesis related pr 10 bet v 1 protein homologues in Mulberry morus bombycis koidz Tree during winter
    Plant Cell and Environment, 2004
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    Seasonal evaluation of total soluble protein fractions extracted from cortical parenchyma cells of Mulberry ( Morus bombycis Koidz.) Tree identified a predominant 18 kDa protein that was directly correlated to periods of cold acclimation. The 18 kDa protein, designated as WAP18 ( w inter a ccumulating 18 kDa p roteins) increased from September to December and then gradually decreased until June. The maximum levels of WAP18 were detected in mid-winter, which corresponds to the maximum freeze tolerance in cortical parenchyma cells of Mulberry Tree. Two-dimensional gel electrophoresis confirmed that WAP18 consists of at least three proteins that range between an isoelectric point of 5.0 and 6.0. All three proteins reacted with anti-WAP18 antibodies, thereby suggesting that they represent individual isoforms. Furthermore, N-terminal amino acid sequence analysis demonstrated that all three proteins contain high sequence similarity to each other and high homology to pathogenesis-related (PR) - - 10/Bet v 1 protein families. The purified WAP18 exhibited in vitro cryoprotective activity for the freeze labile L -lactate dehydrogenase (LDH) enzyme. These results suggest that WAP18 may function in the freezing tolerance mechanism of cortical parenchyma cells of Mulberry Tree during winter.

  • Cold Acclimation-Induced WAP27 Localized in Endoplasmic Reticulum in Cortical Parenchyma Cells of Mulberry Tree Was Homologous to Group 3 Late-Embryogenesis Abundant Proteins
    Plant physiology, 2001
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    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 present study, cDNA clones encoding WAP27A and WAP27B were isolated and characterized. The deduced amino acid sequences of WAP27A and WAP27B cDNAs had 12 repeats of an 11-mer amino acid motif that was the common feature of group 3 late-embryogenesis-abundant proteins. Under field conditions, transcripts of WAP27 genes were initially detected in mid-October, reached maximum level from mid-November to mid-December, and then gradually decreased. The transcript levels of WAP27 genes in cortical parenchyma cells harvested in October was drastically induced by cold treatment within a few days, whereas those in cortical parenchyma cells harvested in August were low even by cold treatment for 3 weeks. Immunocytochemical analysis by electron microscopy confirmed that WAP27 was localized specifically in vesicular-form ER and also localized in dehydration-induced multiplex lamellae-form ER. The role of WAP27 in the ER is discussed in relation to acquisition of freezing tolerance of cortical parenchyma cells in Mulberry Tree during winter.

Masaki Tateno - One of the best experts on this subject based on the ideXlab platform.

  • Benefit to N_2-fixing alder of extending growth period at the cost of leaf nitrogen loss without resorption
    Oecologia, 2003
    Co-Authors: Masaki Tateno
    Abstract:

    This study examines the adaptive role of not resorbing N in N_2-fixing deciduous Trees in terms of their energy balance. The autumnal growth of N_2-fixing Alnus firma Sieb. et Zucc. (alder) was compared with that of the non-N_2-fixing Morus bombycis Koizumi (Mulberry), which resorbs leaf N. The freezing resistance of leaves of both species was −2°C. Mulberry seedlings lost their photosynthetic ability in mid-October, although the minimum temperature was still above 0°C. Thereafter, their leaves turned yellow and were gradually shed. In contrast, seedlings of the alder maintained their photosynthetic ability until mid-November, when the minimum temperature fell to the freezing resistance limit. Thereafter, their leaves were shed quickly without an autumn tint. The Mulberry resorbed 48.9% of leaf N, whereas the alder resorbed hardly any. These results show that, compared with the Mulberry Tree, the alder extended its growth period for 1 month in return for losing leaf N without resorption. The amount of energy assimilated by the alder in the extended growth period was about six times that required for compensating for the nitrogen loss, if the compensation is dependent only on the Tree's own nitrogen fixation. This surplus energy balance has probably allowed N_2-fixing deciduous Trees to evolve their non-N-resorbing trait.

  • Increase in lodging safety factor of thigmomorphogenically dwarfed shoots of Mulberry Tree
    Physiologia Plantarum, 1991
    Co-Authors: Masaki Tateno
    Abstract:

    The lodging safety factor of mechanically stimulated shoots of Mulberry Tree (Morus bombycis Koidz. cv. Kenmochi) was measured to test the hypothesis that thigmomorphogenic dwarfing increases mechanical stability of plants. The lodging safety factor, an indicator of mechanical stability of erect shoots, has been defined as the ratio of critical lodging load to leaf fresh weight. Two-year-old shoot cuttings of Mulberry Tree were rubbed, brushed, and shaken every day. During the experimental period, the lodging safety factor of the control shoots remained at about 5. while the safety factor of the thigmomorphogenically dwarfed ones was ca 1.6 times larger, which supports the hypothesis. The mechanical stimulation reduced the stem elongation rate, but did not greatly change the partitioning of dry matter between leaves and stem. Therefore, it is concluded that the reduction of stem elongation rate was the main cause of the increase in the lodging safety factor of the stimulated shoots.

Chikako Kuwabara - One of the best experts on this subject based on the ideXlab platform.

  • Endoplasmic reticulum-localized small heat shock protein that accumulates in Mulberry Tree (Morus bombycis Koidz.) during seasonal cold acclimation is responsive to abscisic acid
    Tree physiology, 2010
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Yuri Kanno, Mitsunori Seo, Seizo Fujikawa
    Abstract:

    Summary With seasonal changes, several proteins accumulate in the endoplasmic reticulum (ER)-enriched fraction in the bark of Mulberry Tree (Morus bombycis Koidz.). Results of partial amino acid sequence analysis in our previous study suggested that one of these proteins is the ER-localized small heat shock protein (sHSP), designated 20-kD winteraccumulating protein (WAP20). In the present study, molecular and biochemical properties of WAP20 were investigated in detail. The deduced amino acid sequence of the cDNA has the predicted signal sequence to the ER, retention signal to the ER and two consensus regions conserved in sHSPs. Recombinant WAP20 expressed in Escherichia coli also showed typical biochemical features of sHSPs, including the formation of a high-molecular-mass complex between 200 and 300 kD under native conditions, promotion of the renaturation of chemically denaturated citrate synthase and prevention of heat stress-induced aggregation of the enzyme. Transcript levels of WAP20 in the bark tissue were seasonally changed, showing high expression levels from mid-October to mid-December, and the transcript levels were additionally increased and decreased by cold treatment and warm treatment, respectively. WAP20 transcripts were detected abundantly in bark tissue rather than xylem and winter bud tissues during seasonal cold acclimation. The bark tissue specificity of WAP20 accumulation was also observed by exogenous application of phytohormone abscisic acid (ABA) in de-acclimated twigs, whereas WAP20 transcripts were increased in all of these tissues by heat shock treatment at 37 °C in summer twigs. The results suggest that ABA may be involved in the expression of the WAP20 gene in bark tissue of the Mulberry Tree during seasonal cold acclimation.

  • accumulation of pathogenesis related pr 10 bet v 1 protein homologues in Mulberry morus bombycis koidz Tree during winter
    Plant Cell and Environment, 2004
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    Seasonal evaluation of total soluble protein fractions extracted from cortical parenchyma cells of Mulberry ( Morus bombycis Koidz.) Tree identified a predominant 18 kDa protein that was directly correlated to periods of cold acclimation. The 18 kDa protein, designated as WAP18 ( w inter a ccumulating 18 kDa p roteins) increased from September to December and then gradually decreased until June. The maximum levels of WAP18 were detected in mid-winter, which corresponds to the maximum freeze tolerance in cortical parenchyma cells of Mulberry Tree. Two-dimensional gel electrophoresis confirmed that WAP18 consists of at least three proteins that range between an isoelectric point of 5.0 and 6.0. All three proteins reacted with anti-WAP18 antibodies, thereby suggesting that they represent individual isoforms. Furthermore, N-terminal amino acid sequence analysis demonstrated that all three proteins contain high sequence similarity to each other and high homology to pathogenesis-related (PR) - - 10/Bet v 1 protein families. The purified WAP18 exhibited in vitro cryoprotective activity for the freeze labile L -lactate dehydrogenase (LDH) enzyme. These results suggest that WAP18 may function in the freezing tolerance mechanism of cortical parenchyma cells of Mulberry Tree during winter.

  • Cold Acclimation-Induced WAP27 Localized in Endoplasmic Reticulum in Cortical Parenchyma Cells of Mulberry Tree Was Homologous to Group 3 Late-Embryogenesis Abundant Proteins
    Plant physiology, 2001
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    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 present study, cDNA clones encoding WAP27A and WAP27B were isolated and characterized. The deduced amino acid sequences of WAP27A and WAP27B cDNAs had 12 repeats of an 11-mer amino acid motif that was the common feature of group 3 late-embryogenesis-abundant proteins. Under field conditions, transcripts of WAP27 genes were initially detected in mid-October, reached maximum level from mid-November to mid-December, and then gradually decreased. The transcript levels of WAP27 genes in cortical parenchyma cells harvested in October was drastically induced by cold treatment within a few days, whereas those in cortical parenchyma cells harvested in August were low even by cold treatment for 3 weeks. Immunocytochemical analysis by electron microscopy confirmed that WAP27 was localized specifically in vesicular-form ER and also localized in dehydration-induced multiplex lamellae-form ER. The role of WAP27 in the ER is discussed in relation to acquisition of freezing tolerance of cortical parenchyma cells in Mulberry Tree during winter.

Daisuke Takezawa - One of the best experts on this subject based on the ideXlab platform.

  • Endoplasmic reticulum-localized small heat shock protein that accumulates in Mulberry Tree (Morus bombycis Koidz.) during seasonal cold acclimation is responsive to abscisic acid
    Tree physiology, 2010
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Yuri Kanno, Mitsunori Seo, Seizo Fujikawa
    Abstract:

    Summary With seasonal changes, several proteins accumulate in the endoplasmic reticulum (ER)-enriched fraction in the bark of Mulberry Tree (Morus bombycis Koidz.). Results of partial amino acid sequence analysis in our previous study suggested that one of these proteins is the ER-localized small heat shock protein (sHSP), designated 20-kD winteraccumulating protein (WAP20). In the present study, molecular and biochemical properties of WAP20 were investigated in detail. The deduced amino acid sequence of the cDNA has the predicted signal sequence to the ER, retention signal to the ER and two consensus regions conserved in sHSPs. Recombinant WAP20 expressed in Escherichia coli also showed typical biochemical features of sHSPs, including the formation of a high-molecular-mass complex between 200 and 300 kD under native conditions, promotion of the renaturation of chemically denaturated citrate synthase and prevention of heat stress-induced aggregation of the enzyme. Transcript levels of WAP20 in the bark tissue were seasonally changed, showing high expression levels from mid-October to mid-December, and the transcript levels were additionally increased and decreased by cold treatment and warm treatment, respectively. WAP20 transcripts were detected abundantly in bark tissue rather than xylem and winter bud tissues during seasonal cold acclimation. The bark tissue specificity of WAP20 accumulation was also observed by exogenous application of phytohormone abscisic acid (ABA) in de-acclimated twigs, whereas WAP20 transcripts were increased in all of these tissues by heat shock treatment at 37 °C in summer twigs. The results suggest that ABA may be involved in the expression of the WAP20 gene in bark tissue of the Mulberry Tree during seasonal cold acclimation.

  • accumulation of pathogenesis related pr 10 bet v 1 protein homologues in Mulberry morus bombycis koidz Tree during winter
    Plant Cell and Environment, 2004
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    Seasonal evaluation of total soluble protein fractions extracted from cortical parenchyma cells of Mulberry ( Morus bombycis Koidz.) Tree identified a predominant 18 kDa protein that was directly correlated to periods of cold acclimation. The 18 kDa protein, designated as WAP18 ( w inter a ccumulating 18 kDa p roteins) increased from September to December and then gradually decreased until June. The maximum levels of WAP18 were detected in mid-winter, which corresponds to the maximum freeze tolerance in cortical parenchyma cells of Mulberry Tree. Two-dimensional gel electrophoresis confirmed that WAP18 consists of at least three proteins that range between an isoelectric point of 5.0 and 6.0. All three proteins reacted with anti-WAP18 antibodies, thereby suggesting that they represent individual isoforms. Furthermore, N-terminal amino acid sequence analysis demonstrated that all three proteins contain high sequence similarity to each other and high homology to pathogenesis-related (PR) - - 10/Bet v 1 protein families. The purified WAP18 exhibited in vitro cryoprotective activity for the freeze labile L -lactate dehydrogenase (LDH) enzyme. These results suggest that WAP18 may function in the freezing tolerance mechanism of cortical parenchyma cells of Mulberry Tree during winter.

  • Cold Acclimation-Induced WAP27 Localized in Endoplasmic Reticulum in Cortical Parenchyma Cells of Mulberry Tree Was Homologous to Group 3 Late-Embryogenesis Abundant Proteins
    Plant physiology, 2001
    Co-Authors: Norifumi Ukaji, Chikako Kuwabara, Daisuke Takezawa, Keita Arakawa, Seizo Fujikawa
    Abstract:

    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 present study, cDNA clones encoding WAP27A and WAP27B were isolated and characterized. The deduced amino acid sequences of WAP27A and WAP27B cDNAs had 12 repeats of an 11-mer amino acid motif that was the common feature of group 3 late-embryogenesis-abundant proteins. Under field conditions, transcripts of WAP27 genes were initially detected in mid-October, reached maximum level from mid-November to mid-December, and then gradually decreased. The transcript levels of WAP27 genes in cortical parenchyma cells harvested in October was drastically induced by cold treatment within a few days, whereas those in cortical parenchyma cells harvested in August were low even by cold treatment for 3 weeks. Immunocytochemical analysis by electron microscopy confirmed that WAP27 was localized specifically in vesicular-form ER and also localized in dehydration-induced multiplex lamellae-form ER. The role of WAP27 in the ER is discussed in relation to acquisition of freezing tolerance of cortical parenchyma cells in Mulberry Tree during winter.