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Akira Sugiura - One of the best experts on this subject based on the ideXlab platform.
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Influence of Low Temperature before Flowering on the Occurrence of Unreduced Pollen in Japanese Persimmon (Diospyros kaki Thunb.)
HortScience, 2005Co-Authors: A. Yamada, Ryutaro Tao, Akira SugiuraAbstract:The efficacy of ploidy breeding using unreduced pollen in Japanese Persimmon (Diospyros kaki Thunb.) is not high because of the low frequency of unreduced pollen in most cultivars. This study was conducted in 2002 and 2003 to determine if the exposure to a low temperature before flowering could enhance the unreduced pollen formation in five cultivars of Japanese Persimmon including two cultivars that barely produce unreduced pollen under the field condition. The results showed that low-temperature treatment (4 °C for 48 hours) increased the occurrence of unreduced pollen at 15 to 17 and 17 to 18 days after the end of the low-temperature treatment in 2002 and 2003, respectively, in all five cultivars tested. Naturally occurring temperatures below 5 °C in the field also ap- peared to enhance the unreduced pollen formation in the cultivars that naturally produce unreduced pollen in the field. Most plant genera contain species with different ploidy levels and ploidy can even vary within a species. Change of ploidy often brings about acquisition of some horticulturally beneficial traits such as seedlessness, large fruit, polyploid vigor and thicker branches with short internodes (Sanford, 1983). Manipulation of ploidy, therefore, has been considered to be one of the most effective breeding techniques. Japanese Persimmon (Diospyros kaki Thunb.) is a polyploid fruit tree species that has been cultivated for over ten centuries in Japan. Namikawa and Higashi (1928) first reported that Japanese Persimmon is a hexa- ploid (2n = 6x = 90) plant. Later, Zhuang et al. (1990) found that a few seedless cultivars are nonaploid (2n = 9x = 135) in contrast to the hexaploidy of most seeded cultivars. Since no dodecaploid Persimmons have been found in nature, the nonaploid cultivars are considered to arise from spontaneous crossing between reduced (n) and unreduced (2n) gametes. In fact, Sugiura et al. (2000) demonstrated the occurrence of unreduced giant pollen grains in several monoecious Japanese Persimmon cultivars and artificially produced nonaploid seedlings by crossing sorted giant pollen grains with a hexaploid female cultivar. Although this technique seems to be very promising for breeding nonaploid seedless cultivars of Japanese Persimmon, the efficacy of obtain- ing nonaploid plants was very low, and only about 3% of the seeds obtained had embryos that could be rescued by in vitro culture. Furthermore, the low incidence of giant pol- len makes it difficult to use this technique in breeding programs. Both genetic and environmental factors affect unreduced pollen formation. Specific genotypes produce a larger number of unre- duced pollen grains in several plant species such as lily (Lilium spp.; van Tuyl and Stekelenburg, 1988), alfalfa (Medicago sativa; Calderini and Mariani, 1997), Lotus tenuis (Negri and Lemmi, 1998), and genus Vaccinium (Lyrene et al, 2003). A low or high temperature may stimulate the production of unreduced gametes. A low temperature stimulated the formation of unreduced pollen in Mexican lime (Citrus aurantifolia; Iwamasa and Iwasaki, 1963), mulberry (Morus spp.; Seki, 1956), and Dasy- pyrum villosum (Stefani and colonna, 1996). By contrast, a high temperature increased the frequency of unreduced pollen formation in perennial ryegrass (Lolium perenne; Den Nijis and Stephenson, 1988), Lotus tenuis (Negri and Lemmi, 1998), and lily (van Tuyl and Stekelenburg, 1988). If the percentage of unreduced pollen formation could be increased by changing environmental factors before flowering, unre- duced pollen could be more efficiently used for ploidy manipulation in Japanese Persimmon. As the first step towards this goal, this study was conducted to determine if a low temperature before flowering could increase the formation of unreduced pollen in several cultivars of Japanese Persimmon.
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transformation of Japanese Persimmon diospyros kaki thunb with apple cdna encoding nadp dependent sorbitol 6 phosphate dehydrogenase
Plant Science, 2001Co-Authors: Mei Gao, Keisuke Miura, Ryutaro Tao, Abhaya M. Dandekar, Akira SugiuraAbstract:Abstract Japanese Persimmon ( Diospyros kaki Thunb. cv Jiro) was transformed with apple ( Malus x domestica Borkh.) cDNA encoding NADP-dependent sorbitol-6-phosphate dehydrogenase (S6PDH) by an Agrobacterium -mediated leaf-disc transformation system. Integration and expression of the transgene were confirmed by genomic DNA blot and immunoblot analyses. Sorbitol accumulation in five of six transgenic plants obtained was confirmed by GC-MS. The amount of sorbitol in the leaves of transgenic plants varied from 14.5 to 61.5 μmol g −1 fr wt −1 . Sorbitol was not found in leaves of non-transformed ‘Jiro’ or the line PS7 that produced S6PDH protein with no S6PDH activity. Eventually, two transformed lines producing high (PS1) and medium (PS6) amounts of sorbitol, one control transformed line (PS7), and non-transformed ‘Jiro’ were selected and evaluated for salt-stress tolerance. Under NaCl stress, the activity of photosystem II in leaves was determined in terms of the ratio of the variable (Fv) to the maximum (Fm) fluorescence of chlorophyll. The rate of decline in Fv/Fm under NaCl stress was lower in PS1 than the other three lines, suggesting that PS1 is more tolerant to NaCl stress than the other three lines. The factors that caused enhanced salt stress tolerance in PS1 are discussed in relation to sorbitol biosynthesis and its growth.
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factors affecting rooting of Japanese Persimmon hardwood cuttings
Journal of The Japanese Society for Horticultural Science, 2001Co-Authors: Takuya Tetsumura, Ryutaro Tao, Akira SugiuraAbstract:The factors influencing rooting of hardwood cuttings from two cvs. of Japanese Persimmon (Diospyros kaki Thunb.), Jiro and Nishimurawase, were studied. After the tops of micropropagated trees were removed, suckers sprouted from the roots. A quarter of the cuttings made from these basal suckers rooted. Half of the cuttings, whose basal part had been etiolated by mounding with rice husks, initiated roots. Some of the etiolated suckers which had already rooted within the mounds were easily established in a bottom-heated medium after being separated from the mother plants. Cuttings from the one-year-old shoots of micropropagated or conventionally grafted trees did not root. There was no significant difference in the rooting percentage between 'Jiro' and 'Nishimurawase' cuttings. In comparison with the control, soaking the base in 25 ppm IBA for 24 hr or dipping in 3000 ppm IBA for 5 sec did not improve the rooting percentage. Imbedding the cuttings in a rooting mixture from late-January to late-March had no effect on the rooting percentage. Almost all rooted cuttings grew well and became established. Before the rooting treatment, adventitious root primordia at various differentiation stages were found in the basal region of mounded suckers, in which a well-developed periderm and few sclerenchymatous cells were present. Root primordia were not observed in the bases of unmounded suckers or their mid-sections. The unmounded suckers had a discontinuous sclerenchymatous ring and their cuttings rooted to some degree, whereas the mid-sections of suckers had a well-developed, continuous sclerenchymatous ring and their cuttings scarcely rooted.
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identification of molecular markers linked to the trait of natural astringency loss of Japanese Persimmon diospyros kaki fruit
Journal of the American Society for Horticultural Science, 2001Co-Authors: Shinya Kanzaki, Akira Sugiura, Keizo Yonemori, Akihiko Sato, Masahiko YamadaAbstract:ADDITIONAL INDEX WORDS. AFLP, bulked segregant analysis, astringency, RFLP marker ABSTRACT. Japanese Persimmon (Diospyros kaki Thunb.) cultivars are classified into four types depending upon the nature of astringency loss of the fruit. Among them, the pollination-constant and nonastringent (PCNA) type is the most desirable for fresh fruit consumption due to the trait of stable loss of astringency on the tree with fruit development. Lack of tannin accumulation is the main cause of natural astringency loss in PCNA-type fruit, and is qualitatively inherited. The PCNA trait is recessive to the non-PCNA trait. In this study, we investigated amplified fragment length polymor- phism (AFLP) markers for the trait of natural astringency loss of PCNA-type fruit using bulked segregant analysis (BSA) for efficient selection of PCNA type plants in a breeding population. A total of 128 primer combinations were tested and one AFLP marker was found to be linked to the dominant allele controlling the trait for astringency. This marker, EACC/ MCTA-400, was absent in all of the PCNA-type plants tested, whereas it was present in about half of the non-PCNA-type plants tested. However, RFLP analysis using this marker enabled the detection of the other dominant allele, and all PCNA-type plants could be distinguished from the non-PCNA-type plants. Application of this marker system will be useful for the selection of PCNA-type plants in Persimmon breeding.
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Some Factors Affecting the Rooting of Softwood Cuttings of Japanese Persimmon
Engei Gakkai zasshi, 2001Co-Authors: Takuya Tetsumura, Ryutaro Tao, Akira SugiuraAbstract:The factors influencing rooting of softwood cuttings of two cultivars, 'Jiro' and 'Nishimurawase', of Japanese Persimmon (Diospyros kaki Thunb.) were studied. The cuttings from the root suckers of micropropagated trees rooted best, followed by those from the shoots of micropropagated trees and grafted trees in that order. Except for the cuttings from grafted trees, the shorter the cuttings, the higher the rooting percentage. When planted in late June, the single bud, leafy cuttings (leaf-bud cuttings) taken from the root suckers and treated with indole-3-butyric acid (IBA), 70% or more rooted well. When planted in late July or late August, however, less than 40% of the leaf-bud cuttings rooted. Comparable cuttings without IBA treatment scarcely rooted when planted in late June, and did not root at all when planted in late July or late August. There was no significant difference in the rooting capacity between the two cultivars. Almost all leaf-bud cuttings from the root suckers survived during the experimental period (60 days), although those from the shoots of grafted trees died gradually ; none of the 25-cm cuttings from the root suckers survived 25 days after planting. The vascular cambium at the base of leaf-bud cuttings from the root suckers began to divide actively soon after planting. Callus formed in the phloem and cortex of the cut surface and developed extensively. However, active cell division was not observed at the bases of leaf-bud cuttings from the shoots of grafted trees nor 25-cm cuttings from the root suckers. Initial cells of the adventitious root produced in the vascular cambium of the leaf-bud cuttings from the root suckers were first observed 20 days after planting ; they developed to roots and emerged 30 days after planting.
Ryutaro Tao - One of the best experts on this subject based on the ideXlab platform.
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Sexual polyploidization of Japanese Persimmon by utilizing unreduced egg
Acta Horticulturae, 2007Co-Authors: A. Yamada, Ryutaro TaoAbstract:We analyzed the ploidy levels of seedlings of several Japanese Persimmon (Diospyros kaki) cultivars to investigate the possible occurrence of unreduced eggs in this fruit species. Among the five cultivars tested, 'Fujiwaragosho' produced seedlings whose ploidy levels were more than hexaploid, mainly nonaploid or dodecaploid, at a very high frequency. Since these seedlings were obtained from the seeds that developed normally and contained fully-developed endosperm, it is suggested that unreduced embryo sac may have not been involved in the occurrence of seedlings with ploidy variation observed in this study. If unreduced embryo sac had formed and fertilized with reduced pollen, abnormal endosperm development could have been observed. The ploidy variation in seedlings of 'Fujiwaragosho' could have been induced by abnormal embryo sac formation or abnormal embryo development that occurred during embryo sac formation or early embryo development, respectively. The possible use of 'Fujiwaragosho' as a mother plant for sexual polyploidization breeding in Persimmon was discussed.
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High frequency sexual polyploidisation observed in hexaploid Japanese Persimmon (Diospyros kaki) ‘Fujiwaragosho’
The Journal of Horticultural Science and Biotechnology, 2006Co-Authors: A. Yamada, Ryutaro TaoAbstract:SummaryWe analysed ploidy levels in Japanese Persimmon (Diospyros kaki) to investigate the possible occurrence of unreduced eggs in this fruit species. Among the five cultivars tested, ‘Fujiwaragosho’ produced a very high frequency of embryos whose ploidy levels were more than hexaploid. These embryos were mainly nonaploid or dodecaploid, while the ploidy levels of the endosperms of the seeds from which the embryos derived were mainly normal nonaploid. A few seeds contained octadecaploid endosperms with hexaploid, nonaploid or dodecaploid embryos. Octadecaploidy in the endosperm and dodecaploidy in the embryo, in a seed, indicated that the unreduced embryo sac might have been involved in the formation of seedlings, with ploidy variation in some cases. However, there was no such indication in most cases because the ploidy level of most endosperms was the normal nonaploid. These results suggest that several modifications, including incomplete meiosis of megaspore mother cells or extra mitotic divisions duri...
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Influence of Low Temperature before Flowering on the Occurrence of Unreduced Pollen in Japanese Persimmon (Diospyros kaki Thunb.)
HortScience, 2005Co-Authors: A. Yamada, Ryutaro Tao, Akira SugiuraAbstract:The efficacy of ploidy breeding using unreduced pollen in Japanese Persimmon (Diospyros kaki Thunb.) is not high because of the low frequency of unreduced pollen in most cultivars. This study was conducted in 2002 and 2003 to determine if the exposure to a low temperature before flowering could enhance the unreduced pollen formation in five cultivars of Japanese Persimmon including two cultivars that barely produce unreduced pollen under the field condition. The results showed that low-temperature treatment (4 °C for 48 hours) increased the occurrence of unreduced pollen at 15 to 17 and 17 to 18 days after the end of the low-temperature treatment in 2002 and 2003, respectively, in all five cultivars tested. Naturally occurring temperatures below 5 °C in the field also ap- peared to enhance the unreduced pollen formation in the cultivars that naturally produce unreduced pollen in the field. Most plant genera contain species with different ploidy levels and ploidy can even vary within a species. Change of ploidy often brings about acquisition of some horticulturally beneficial traits such as seedlessness, large fruit, polyploid vigor and thicker branches with short internodes (Sanford, 1983). Manipulation of ploidy, therefore, has been considered to be one of the most effective breeding techniques. Japanese Persimmon (Diospyros kaki Thunb.) is a polyploid fruit tree species that has been cultivated for over ten centuries in Japan. Namikawa and Higashi (1928) first reported that Japanese Persimmon is a hexa- ploid (2n = 6x = 90) plant. Later, Zhuang et al. (1990) found that a few seedless cultivars are nonaploid (2n = 9x = 135) in contrast to the hexaploidy of most seeded cultivars. Since no dodecaploid Persimmons have been found in nature, the nonaploid cultivars are considered to arise from spontaneous crossing between reduced (n) and unreduced (2n) gametes. In fact, Sugiura et al. (2000) demonstrated the occurrence of unreduced giant pollen grains in several monoecious Japanese Persimmon cultivars and artificially produced nonaploid seedlings by crossing sorted giant pollen grains with a hexaploid female cultivar. Although this technique seems to be very promising for breeding nonaploid seedless cultivars of Japanese Persimmon, the efficacy of obtain- ing nonaploid plants was very low, and only about 3% of the seeds obtained had embryos that could be rescued by in vitro culture. Furthermore, the low incidence of giant pol- len makes it difficult to use this technique in breeding programs. Both genetic and environmental factors affect unreduced pollen formation. Specific genotypes produce a larger number of unre- duced pollen grains in several plant species such as lily (Lilium spp.; van Tuyl and Stekelenburg, 1988), alfalfa (Medicago sativa; Calderini and Mariani, 1997), Lotus tenuis (Negri and Lemmi, 1998), and genus Vaccinium (Lyrene et al, 2003). A low or high temperature may stimulate the production of unreduced gametes. A low temperature stimulated the formation of unreduced pollen in Mexican lime (Citrus aurantifolia; Iwamasa and Iwasaki, 1963), mulberry (Morus spp.; Seki, 1956), and Dasy- pyrum villosum (Stefani and colonna, 1996). By contrast, a high temperature increased the frequency of unreduced pollen formation in perennial ryegrass (Lolium perenne; Den Nijis and Stephenson, 1988), Lotus tenuis (Negri and Lemmi, 1998), and lily (van Tuyl and Stekelenburg, 1988). If the percentage of unreduced pollen formation could be increased by changing environmental factors before flowering, unre- duced pollen could be more efficiently used for ploidy manipulation in Japanese Persimmon. As the first step towards this goal, this study was conducted to determine if a low temperature before flowering could increase the formation of unreduced pollen in several cultivars of Japanese Persimmon.
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Engineered sorbitol accumulation induces dwarfism in Japanese Persimmon.
Journal of plant physiology, 2004Co-Authors: Michihito Deguchi, Mei Gao, Ryutaro Tao, Takuya Tetsumura, Yoshiko Koshita, Shohei Yamaki, Yoshinori KanayamaAbstract:A cDNA encoding sorbitol-6-phosphate dehydrogenase (S6PDH), which is a key enzyme in sorbitol biosynthesis in Rosaceae, was introduced into the Japanese Persimmon (Diospyros kaki) to increase the environmental stress tolerance. Resultant transformants exhibited salt-tolerance with dwarfing phenotypes. Therefore, we studied two transgenic lines to understand the physiological mechanism of this dwarfism: lines PS1 and PS6 accumulated high and moderate levels of sorbitol, respectively. The average length of shoots was significantly shorter as compared with the wild-type in line PS1, while no such decrease was observed in line PS6. The myo-inositol and glucose 6-phosphate (G6P) contents were measured in the transgenic lines because previous work with tobacco transformed with S6PDH had suggested that growth inhibition was due to depletion of these metabolites. Although the myo-inositol content was decreased in PS1 plants, the decrease was much smaller than that observed in transgenic tobacco that accumulates sorbitol. The G6P contents were the same in PS1 plants and phenotypically normal PS6 plants. The level of indole-3-acetic acid (IAA), which affects stem elongation, in line PS1 was similar to the levels in the other lines. A decrease in gibberellin (GA) content generally induces dwarfism in plants. However, GA was not decreased in PS1 plants compared with wild-type or control plants. Therefore, we focused on sorbitol accumulation as the most remarkable feature of PS1 plants. As one possibility, the observed growth inhibition was likely caused by an osmotic imbalance between the cytosol and vacuole.
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transformation of Japanese Persimmon diospyros kaki thunb with apple cdna encoding nadp dependent sorbitol 6 phosphate dehydrogenase
Plant Science, 2001Co-Authors: Mei Gao, Keisuke Miura, Ryutaro Tao, Abhaya M. Dandekar, Akira SugiuraAbstract:Abstract Japanese Persimmon ( Diospyros kaki Thunb. cv Jiro) was transformed with apple ( Malus x domestica Borkh.) cDNA encoding NADP-dependent sorbitol-6-phosphate dehydrogenase (S6PDH) by an Agrobacterium -mediated leaf-disc transformation system. Integration and expression of the transgene were confirmed by genomic DNA blot and immunoblot analyses. Sorbitol accumulation in five of six transgenic plants obtained was confirmed by GC-MS. The amount of sorbitol in the leaves of transgenic plants varied from 14.5 to 61.5 μmol g −1 fr wt −1 . Sorbitol was not found in leaves of non-transformed ‘Jiro’ or the line PS7 that produced S6PDH protein with no S6PDH activity. Eventually, two transformed lines producing high (PS1) and medium (PS6) amounts of sorbitol, one control transformed line (PS7), and non-transformed ‘Jiro’ were selected and evaluated for salt-stress tolerance. Under NaCl stress, the activity of photosystem II in leaves was determined in terms of the ratio of the variable (Fv) to the maximum (Fm) fluorescence of chlorophyll. The rate of decline in Fv/Fm under NaCl stress was lower in PS1 than the other three lines, suggesting that PS1 is more tolerant to NaCl stress than the other three lines. The factors that caused enhanced salt stress tolerance in PS1 are discussed in relation to sorbitol biosynthesis and its growth.
Mei Gao - One of the best experts on this subject based on the ideXlab platform.
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Engineered sorbitol accumulation induces dwarfism in Japanese Persimmon.
Journal of plant physiology, 2004Co-Authors: Michihito Deguchi, Mei Gao, Ryutaro Tao, Takuya Tetsumura, Yoshiko Koshita, Shohei Yamaki, Yoshinori KanayamaAbstract:A cDNA encoding sorbitol-6-phosphate dehydrogenase (S6PDH), which is a key enzyme in sorbitol biosynthesis in Rosaceae, was introduced into the Japanese Persimmon (Diospyros kaki) to increase the environmental stress tolerance. Resultant transformants exhibited salt-tolerance with dwarfing phenotypes. Therefore, we studied two transgenic lines to understand the physiological mechanism of this dwarfism: lines PS1 and PS6 accumulated high and moderate levels of sorbitol, respectively. The average length of shoots was significantly shorter as compared with the wild-type in line PS1, while no such decrease was observed in line PS6. The myo-inositol and glucose 6-phosphate (G6P) contents were measured in the transgenic lines because previous work with tobacco transformed with S6PDH had suggested that growth inhibition was due to depletion of these metabolites. Although the myo-inositol content was decreased in PS1 plants, the decrease was much smaller than that observed in transgenic tobacco that accumulates sorbitol. The G6P contents were the same in PS1 plants and phenotypically normal PS6 plants. The level of indole-3-acetic acid (IAA), which affects stem elongation, in line PS1 was similar to the levels in the other lines. A decrease in gibberellin (GA) content generally induces dwarfism in plants. However, GA was not decreased in PS1 plants compared with wild-type or control plants. Therefore, we focused on sorbitol accumulation as the most remarkable feature of PS1 plants. As one possibility, the observed growth inhibition was likely caused by an osmotic imbalance between the cytosol and vacuole.
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transformation of Japanese Persimmon diospyros kaki thunb with apple cdna encoding nadp dependent sorbitol 6 phosphate dehydrogenase
Plant Science, 2001Co-Authors: Mei Gao, Keisuke Miura, Ryutaro Tao, Abhaya M. Dandekar, Akira SugiuraAbstract:Abstract Japanese Persimmon ( Diospyros kaki Thunb. cv Jiro) was transformed with apple ( Malus x domestica Borkh.) cDNA encoding NADP-dependent sorbitol-6-phosphate dehydrogenase (S6PDH) by an Agrobacterium -mediated leaf-disc transformation system. Integration and expression of the transgene were confirmed by genomic DNA blot and immunoblot analyses. Sorbitol accumulation in five of six transgenic plants obtained was confirmed by GC-MS. The amount of sorbitol in the leaves of transgenic plants varied from 14.5 to 61.5 μmol g −1 fr wt −1 . Sorbitol was not found in leaves of non-transformed ‘Jiro’ or the line PS7 that produced S6PDH protein with no S6PDH activity. Eventually, two transformed lines producing high (PS1) and medium (PS6) amounts of sorbitol, one control transformed line (PS7), and non-transformed ‘Jiro’ were selected and evaluated for salt-stress tolerance. Under NaCl stress, the activity of photosystem II in leaves was determined in terms of the ratio of the variable (Fv) to the maximum (Fm) fluorescence of chlorophyll. The rate of decline in Fv/Fm under NaCl stress was lower in PS1 than the other three lines, suggesting that PS1 is more tolerant to NaCl stress than the other three lines. The factors that caused enhanced salt stress tolerance in PS1 are discussed in relation to sorbitol biosynthesis and its growth.
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Transformation of Japanese Persimmon (Diospyros kaki Thunb.) with a bacterial gene for choline oxidase
Molecular Breeding, 2000Co-Authors: Mei Gao, Norio Murata, Akira Sugiura, Atsushi Sakamoto, Keisuke Miura, Ryutaro TaoAbstract:This report describes the first successful genetic engineering of tolerance to salt in an agriculturally important species of woody plants by Agrobacterium-mediated transformation with the codA gene of Arthrobacter globiformis. This gene encodes choline oxidase, which catalyzes the oxidation of choline to glycinebetaine. The binary plasmid vector pGC95.091, containing a kanamycin-resistance gene (nptII), a gene for β-glucuronidase (gusA) and the codA gene in its T-DNA region, was used with a disarmed strain of Agrobacterium tumefaciens, EHA101, to transform Japanese Persimmon (Diospyros kaki Thunb. `Jiro') by the leaf disk transformation method. The pRS95.101 plasmid that included only nptII and gusA in the T-DNA region was used as a control. We selected eight transgenic lines with one or two copies of the T-DNA after transformation with pGC95.091 (PC lines) and three lines after transformation with pRS95.101 (PR lines). The eight PC lines produced choline oxidase and glycinebetaine whereas neither was found in untransformed `Jiro' and in the control PR lines. Transgenic plants grew normally, resembling wild-type plants both in vitro and ex vitro. The activity of photosystem II in leaves of the transgenic Japanese Persimmon plants under NaCl stress was determined in terms of the ratio of the variable (Fv) to the maximum (Fm) fluorescence of chlorophyll (Fv/Fm). The rate of decline in (Fv/Fm under NaCl stress was lower in the PC lines than in the control PR lines. These results demonstrated that genetic engineering of Japanese Persimmon, which allowed it to accumulate glycinebetaine, enhanced the tolerance to salt stress of this plant.
Takuya Tetsumura - One of the best experts on this subject based on the ideXlab platform.
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Growth and production of adult Japanese Persimmon (Diospyros kaki) trees grafted onto dwarfing rootstocks
Scientia Horticulturae, 2015Co-Authors: Takuya Tetsumura, S. Ishimura, T. Hidaka, Emiko Hirano, Hiroharu Uchida, Yusuke Kai, Shirou Kuroki, Yoshinori Uchida, Chitose HonshoAbstract:Abstract The field performance of adult ‘Fuyu’ and ‘Hiratanenashi’ Japanese Persimmon ( Diospyros kaki Thunb.) trees grafted onto D. kaki seedlings (S), Rootstock-a (R-a), and MKR1, as well as own-rooted trees, which were planted in February 2003, was investigated. The height of trees grafted onto MKR1 did not increase after 2010, although the other trees grew vigorously. All trees increased annually in number of shoots, but this was not the case for mean shoot length. Trees grafted onto MKR1 continued to increase in number of flowers and percentage of flower-bearing shoots, whereas the number of flowers and percentage of flower-bearing shoots did not increase each year in most of the other trees examined. The fruit yield per tree did not markedly differ between rootstocks except for in ‘Hiratanenashi’ on S. However, the yield efficiencies of the trees grafted onto MKR1 were the highest in total, even when the tree was over 10 years old. There were no consistent trends in fruit quality between rootstocks, except for fruit weight in ‘Fuyu’, where the trees grafted onto R-a produced lighter fruit. The shelf life of ‘Fuyu’ fruit grafted onto MKR1 was not different from that of the trees grafted on the other rootstocks. These results indicated that trees grafted onto MKR1 produced normal, commercial fruit. Although the mechanism by which MKR1 causes dwarfing in Persimmon trees remains unknown, these results allow us to conclude that MKR1 is a practical dwarfing rootstock for easy-to-manage orchard system of Japanese Persimmon.
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MKR1 dwarfing rootstock promotes formation of floral primordia of Japanese Persimmon 'Hiratane-nashi'
Acta Horticulturae, 2013Co-Authors: S. Ishimura, T. Hidaka, Chitose Honsho, E. Hirano, Takuya TetsumuraAbstract:We observed floral and leaf bud primordia in the buds of Japanese Persimmon ‘Hiratane-nashi’ (Diospyros kaki Thunb.) grafted on several types of rootstocks by using a digital microscope. Seedling stocks and own-rooted trees increased number of leaf bud primordia in the buds, and the buds on these trees continued to grow till the beginning of September. In contrast, after the middle of June, the buds of MKR1 trees almost stopped growing, and floral primordia in the buds increased until late July. The developmental stages of floral and leaf bud primordia stopped after July 15 and August 4, respectively. There were no correlations between longitudinal diameter and number of floral primordia in seedling stocks and own-rooted trees. However, a positive correlation in MKR1 trees and a negative correlation in “Rootstock a” trees were found. These phenomena were considered that the decrease in activity of apical meristems in the axillary buds on MKR1 trees induced the occurrence of flower initiation whereas the increase on the other trees led undifferentiated primordia to leaf bud. Hence, larger buds of seedling stocks, own-rooted trees and “Rootstock a” trees did not always contain more floral primordia.
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Engineered sorbitol accumulation induces dwarfism in Japanese Persimmon.
Journal of plant physiology, 2004Co-Authors: Michihito Deguchi, Mei Gao, Ryutaro Tao, Takuya Tetsumura, Yoshiko Koshita, Shohei Yamaki, Yoshinori KanayamaAbstract:A cDNA encoding sorbitol-6-phosphate dehydrogenase (S6PDH), which is a key enzyme in sorbitol biosynthesis in Rosaceae, was introduced into the Japanese Persimmon (Diospyros kaki) to increase the environmental stress tolerance. Resultant transformants exhibited salt-tolerance with dwarfing phenotypes. Therefore, we studied two transgenic lines to understand the physiological mechanism of this dwarfism: lines PS1 and PS6 accumulated high and moderate levels of sorbitol, respectively. The average length of shoots was significantly shorter as compared with the wild-type in line PS1, while no such decrease was observed in line PS6. The myo-inositol and glucose 6-phosphate (G6P) contents were measured in the transgenic lines because previous work with tobacco transformed with S6PDH had suggested that growth inhibition was due to depletion of these metabolites. Although the myo-inositol content was decreased in PS1 plants, the decrease was much smaller than that observed in transgenic tobacco that accumulates sorbitol. The G6P contents were the same in PS1 plants and phenotypically normal PS6 plants. The level of indole-3-acetic acid (IAA), which affects stem elongation, in line PS1 was similar to the levels in the other lines. A decrease in gibberellin (GA) content generally induces dwarfism in plants. However, GA was not decreased in PS1 plants compared with wild-type or control plants. Therefore, we focused on sorbitol accumulation as the most remarkable feature of PS1 plants. As one possibility, the observed growth inhibition was likely caused by an osmotic imbalance between the cytosol and vacuole.
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Comparative Field Performance of Mature Japanese Persimmon Trees Grafted on Seedling Rootstocks vs. Micropropagated Ones
Engei Gakkai zasshi, 2004Co-Authors: Takuya Tetsumura, Yoshiro Koyanagi, Sosuke Ito, Tsuyoshi Habu, Koshiro KawaseAbstract:The growth of micropropagated (M) Japanese Persimmon (Diospyros kakl Thunb. cv. Nishimura wase) trees from the 8th to llth year after planting was compared with that of trees grafted on seedlings (G) in the orchard. The M trees grew more vigorously than did the G trees; the differences in tree canopy and trunk cross-sectional area between the M and G trees increased annually. The percentage of shoots with male flowers in the total number of shoots in the M trees was lower than that in the G trees., although the difference was not significant. The percentage of shoots with female flowers in the total number of shoots in the M trees was the same as that in the G trees. Although the yield per tree of M trees was larger than that of G trees, there was no significant difference between the G and M trees in the yield efficiency (yield per canopy volume). These results suggest that micropropagation caused reinvigoration, but not true rejuvenation. M trees showed uniform growth, flowering and fruiting.
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factors affecting rooting of Japanese Persimmon hardwood cuttings
Journal of The Japanese Society for Horticultural Science, 2001Co-Authors: Takuya Tetsumura, Ryutaro Tao, Akira SugiuraAbstract:The factors influencing rooting of hardwood cuttings from two cvs. of Japanese Persimmon (Diospyros kaki Thunb.), Jiro and Nishimurawase, were studied. After the tops of micropropagated trees were removed, suckers sprouted from the roots. A quarter of the cuttings made from these basal suckers rooted. Half of the cuttings, whose basal part had been etiolated by mounding with rice husks, initiated roots. Some of the etiolated suckers which had already rooted within the mounds were easily established in a bottom-heated medium after being separated from the mother plants. Cuttings from the one-year-old shoots of micropropagated or conventionally grafted trees did not root. There was no significant difference in the rooting percentage between 'Jiro' and 'Nishimurawase' cuttings. In comparison with the control, soaking the base in 25 ppm IBA for 24 hr or dipping in 3000 ppm IBA for 5 sec did not improve the rooting percentage. Imbedding the cuttings in a rooting mixture from late-January to late-March had no effect on the rooting percentage. Almost all rooted cuttings grew well and became established. Before the rooting treatment, adventitious root primordia at various differentiation stages were found in the basal region of mounded suckers, in which a well-developed periderm and few sclerenchymatous cells were present. Root primordia were not observed in the bases of unmounded suckers or their mid-sections. The unmounded suckers had a discontinuous sclerenchymatous ring and their cuttings rooted to some degree, whereas the mid-sections of suckers had a well-developed, continuous sclerenchymatous ring and their cuttings scarcely rooted.
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effect of sugars on rooting of shoots of Japanese Persimmon propagated in vitro
Plant Biotechnology, 1999Co-Authors: Hiroshi KagamiAbstract:The effect of different concentrations of sucrose, glucose and fructose on in vitro rooting of shoots of Japanese Persimmon that had been induced from selected rootstocks was studied. When the shoots of Japanese Persimmon strain “No.3” were cultured on autoclaved half-strength Murashige and Skoog medium (MS medium) containing 0.2M fructose, roots were induced in 94% of the shoots after 45 days of culture whereas only 30% of rooting was obtained on media containing the same concentration of sucrose or glucose. However, filter-sterilized fructose had no stimulative effect on rooting. The autoclaved medium containing 0.2M fructose showed consistently high percentages of rooting (80%<) of the shoots for 9 rootstock strains tested, whereas only 3 strains responded to the culture on medium containing 0.1M sucrose following 250mg/l IBA pretreatment.
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Effect of Sugars on Rooting of Shoots of Japanese Persimmon Propagated in vitro
Plant Biotechnology, 1999Co-Authors: Hiroshi KagamiAbstract:The effect of different concentrations of sucrose, glucose and fructose on in vitro rooting of shoots of Japanese Persimmon that had been induced from selected rootstocks was studied. When the shoots of Japanese Persimmon strain “No.3” were cultured on autoclaved half-strength Murashige and Skoog medium (MS medium) containing 0.2M fructose, roots were induced in 94% of the shoots after 45 days of culture whereas only 30% of rooting was obtained on media containing the same concentration of sucrose or glucose. However, filter-sterilized fructose had no stimulative effect on rooting. The autoclaved medium containing 0.2M fructose showed consistently high percentages of rooting (80%
