Journal of Agricultural and Food Chemistry, Nov 24, 2008
Steroidal glycoalkaloids are naturally occurring, secondary plant metabolites that are found in f... more Steroidal glycoalkaloids are naturally occurring, secondary plant metabolites that are found in foods, including potatoes and tomatoes. Their content in plants is controlled by both genetic and environmental factors. Glycoalkaloid profiles can be passed to progenies during breeding and hybridization of wild and cultivated potatoes designed to develop improved potatoes. The most common potato, Solanum tuberosum, contains primarily the glycoalkaloids, R-solanine and R-chaconine. However, wild-type potatoes being used for breeding new varieties contain other, less common glycoalkaloids. Because glycoalkaloid composition is a major criterion for the release of new potato cultivars, we used HPLC, TLC, GC, and GC/MS to determine their nature and content in several Solanum species widely used in potato breeding and hybridization programs. Solanum tuberosum, as well as S. andigena and S. stenotomum, contained R-solanine and R-chaconine. S. canasense was found to contain only dehydrocommersonine. S. acaule contained R-tomatine and demissine. S. juzepczukii and S. curtilobum contained demissine and two previously unidentified glycoalkaloids. We characterized them as demissidine-glucose/rhamnose (1/1 ratio) and demissidine-galactose/ glucose/rhamnose (1/1/1 ratio), tentatively named dihydro-1-chaconine and dihydrosolanine, respectively. We found extensive variability in the glycoalkaloid profiles in the tested potato varieties. The possible significance of these findings for plant breeding and food safety is discussed.
The effects of mineral salts on plantlet formation were investigated in tobacco anther culture pa... more The effects of mineral salts on plantlet formation were investigated in tobacco anther culture paying special attention to Nat EDTA, a component of FeEDTA. Removal of mineral salts other than FeEDTA from the basal medium had little influence on plantlet formation. While, removal of FeEDTA arrested plantlet formation severely, but did not affect the induction of embryogenic pollen grains. Moreover, very few plantlets were obtained from anthers transferred to FeEDTA-free medium after 3 weeks of culture. From these results, it is concluded that FeEDTA plays the most important role in the development from embryoid to green plantlet. Plantlet formation was almost completely arrested on NaZEDTA-free medium. In contrast, plantlet formation on ferrous sulphate free (NaZEDTA) medium was comparable to that on basal medium. Also, the highest frequency of plantlet formation was obtained at the same concentration (2x10-4M) for both FeEDTA and NaZ EDTA. These results suggest that the effects of FeEDTA on the plantlet formation in tobacco anther culture refer to the function of NaZEDTA itself. FeEDTA is considered to be one of the most important complements among mineral salts in tobacco anther culture. In the present paper, the effect of each mineral salt on plantlet formation is investigated in tobacco anther culture paying special attention to Na2EDTA which is a component of FeEDTA stock solution.
Soil salinity is one of the main obstacles to increasing rice production. Since rice (Oryza sativ... more Soil salinity is one of the main obstacles to increasing rice production. Since rice (Oryza sativa) is rated as an especially salt sensitive crop (Mass and Hoffman 1977; Shannon et al. 1998), most of the modern high-yielding rice cultivars perform poorly in saline environments. In addition, as saline soils are usually waterlogged, it is not feasible to grow crops other than rice in such areas (Gregorio and Senadhira 1995). The rice germplasm has genetic variability for salt tolerance (Xie et al. 2000), and two traditional Oryza sativa spp. indica cultivars, Pokkali and Nona Bokra, possess salt tolerance sufficiently high for rice breeding programs (Akbar et al. 1985; Gregorio and Senadhira 1993). Anther culture is a useful technique to produce lines with desirable combinations of required traits. It has been well integrated into rice breeding programs especially in Japan and China, where a number of high yielding, disease resistant and better quality rice cultivars have been selected from microspore derived plants (Loo and Xu 1991). However, indica cultivars respond poorly to in vitro techniques (Abe and Futsuhara 1986; Hartke and Lörz 1989), and in consequence the practical production of haploids from anther or microspore culture in rice breeding is limited to Oryza sativa spp. japonica
The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a major limitation o... more The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a major limitation of photosynthetic CO 2 assimilation in C 3 plants. In order to find useful Rubisco for improvement of photosynthesis in rice under elevated CO 2 , we analyzed the catalytic turnover rate (k cat) of Rubisco in Poaceae including C 3 alpine plants, C 3 cold-resistant plants and C 4 plants. Rubisco in these plants showed 1.1-to 2.8-fold higher k cat than that in rice. However, the most of high k cat Rubisco also showed a higher km for CO 2 (Kc) than that of rice, indicating that increase in k cat led to decrease in the affinity for CO 2. Rubisco in Festuca ovina, Phleum pratense and Sorghum bicolor showed relatively high k cat to Kc. Although the k cat of Rubisco in F. ovina and P. pratense was not so high (1.5-1.6 fold relative to rice), the Kc was comparable to that in rice and the amino acid sequence of RbcL shared higher identity to that in rice than that in S. bicolor. By contrast, Rubisco of S. bicolor showed considerably high k cat (2.5-fold relative to rice), which is considered to be the most important factor for improvement of photosynthesis. In our estimation, the expression of high k cat Rubisco of F. ovina and S. bicolor in rice could significantly enhance CO 2 assimilation at Ci of 50 Pa, the level assumed to be reached by the middle of this century.
The purpose of this study was to investigate the effects of 2,4-D, 6-furfurylamino purine (kineti... more The purpose of this study was to investigate the effects of 2,4-D, 6-furfurylamino purine (kinetin), and abscisic acid (ABA) on the response of cultured immature wheat (Triticum aestivum L.) embryos, by evaluating direct germination, callus growth, shoot regeneration and its development. The reduction of 2, 4-D concentration or the addition of kinetin to callus induction media promoted direct germination of cultured embryos, whereas the addition of ABA suppressed it extremely. Callus growth was promoted by reducing 2, 4-D concentration or by adding ABA at lower concentrations, though these alterations did not affect the frequency of callus formation. Concentrations of 2, 4-D in callus induction media did not affect the frequency of subsequent shoot regeneration from calli; however, the regenerated shoots developed rapidly when calli were induced at lower 2, 4-D. The addition of kinetin or ABA significantly improved the shoot-forming ability of callus cultures, especially in less responsive cultivars. Cont.: control.
Two hexaploid somatic hybrids, DA12-3 (2n = 68) and DA28 (2n = 74), derived from cell fusion betw... more Two hexaploid somatic hybrids, DA12-3 (2n = 68) and DA28 (2n = 74), derived from cell fusion between dihaploid Solanum acaule and tetraploid Solanum tuberosum, were crossed with S. tuberosum. Two BC1 families, DA12T and DA28T, were generated, each containing 25 plants. Although the average of somatic chromosome numbers fitted hypothetical numbers assuming equal separation, considerable variation was found: 2n = 54-62 in DA12T and 2n = 58-65 in DA28T. Fifty-two of 80 RFLP single-copy probes generated 108 marker bands specific for S. acaule, by which BC1 progeny were analyzed. The segregation of marker bands from at least 44 probes was explained by two alleles per locus, which had to be heterozygous in dihaploid S. acaule and maintained in homozygous condition in homoeologous chromosomes of tetraploid S. acaule. On average, 73.7% of the chromosomes derived from S. acaule were detected as recombinants, suggesting that frequent homoeologous recombination occurred between S. acaule and S. tuberosum chromosomes. Therefore, S. acaule germplasm can be effectively transferred to the cultivated potato gene pool through backcrossing hexaploid somatic hybrids with S. tuberosum. In both BC1 families, S. acaule chromosomes 3, 4, 6, and 11 were detected as recombinants with higher frequencies (84-98%) than those of chromosomes 9 and 10 (60 and 58%, respectively), suggesting that chromosomal differentiation exists between S. acaule genomes.Key words: hexaploid somatic hybrids, Solanum acaule, homoeologous recombination, RFLP markers.
Effects of colchicine pretreatment of cold-preserved spikes on the increase in ratio of diploidiz... more Effects of colchicine pretreatment of cold-preserved spikes on the increase in ratio of diploidized fertile regenerants in anther culture of rice were studied. After 10 days of storage at 10C, cut ends of the spikes including uninucleate pollen grains were dipped into colchicine solution at the same temperature. When the spikes were treated with 0.8% colchicine solution for 3 days, more than 50% of the regenerants, obtained in subsequent anther culture, were fertile.
Journal of Agricultural and Food Chemistry, Nov 24, 2008
Steroidal glycoalkaloids are naturally occurring, secondary plant metabolites that are found in f... more Steroidal glycoalkaloids are naturally occurring, secondary plant metabolites that are found in foods, including potatoes and tomatoes. Their content in plants is controlled by both genetic and environmental factors. Glycoalkaloid profiles can be passed to progenies during breeding and hybridization of wild and cultivated potatoes designed to develop improved potatoes. The most common potato, Solanum tuberosum, contains primarily the glycoalkaloids, R-solanine and R-chaconine. However, wild-type potatoes being used for breeding new varieties contain other, less common glycoalkaloids. Because glycoalkaloid composition is a major criterion for the release of new potato cultivars, we used HPLC, TLC, GC, and GC/MS to determine their nature and content in several Solanum species widely used in potato breeding and hybridization programs. Solanum tuberosum, as well as S. andigena and S. stenotomum, contained R-solanine and R-chaconine. S. canasense was found to contain only dehydrocommersonine. S. acaule contained R-tomatine and demissine. S. juzepczukii and S. curtilobum contained demissine and two previously unidentified glycoalkaloids. We characterized them as demissidine-glucose/rhamnose (1/1 ratio) and demissidine-galactose/ glucose/rhamnose (1/1/1 ratio), tentatively named dihydro-1-chaconine and dihydrosolanine, respectively. We found extensive variability in the glycoalkaloid profiles in the tested potato varieties. The possible significance of these findings for plant breeding and food safety is discussed.
The effects of mineral salts on plantlet formation were investigated in tobacco anther culture pa... more The effects of mineral salts on plantlet formation were investigated in tobacco anther culture paying special attention to Nat EDTA, a component of FeEDTA. Removal of mineral salts other than FeEDTA from the basal medium had little influence on plantlet formation. While, removal of FeEDTA arrested plantlet formation severely, but did not affect the induction of embryogenic pollen grains. Moreover, very few plantlets were obtained from anthers transferred to FeEDTA-free medium after 3 weeks of culture. From these results, it is concluded that FeEDTA plays the most important role in the development from embryoid to green plantlet. Plantlet formation was almost completely arrested on NaZEDTA-free medium. In contrast, plantlet formation on ferrous sulphate free (NaZEDTA) medium was comparable to that on basal medium. Also, the highest frequency of plantlet formation was obtained at the same concentration (2x10-4M) for both FeEDTA and NaZ EDTA. These results suggest that the effects of FeEDTA on the plantlet formation in tobacco anther culture refer to the function of NaZEDTA itself. FeEDTA is considered to be one of the most important complements among mineral salts in tobacco anther culture. In the present paper, the effect of each mineral salt on plantlet formation is investigated in tobacco anther culture paying special attention to Na2EDTA which is a component of FeEDTA stock solution.
Soil salinity is one of the main obstacles to increasing rice production. Since rice (Oryza sativ... more Soil salinity is one of the main obstacles to increasing rice production. Since rice (Oryza sativa) is rated as an especially salt sensitive crop (Mass and Hoffman 1977; Shannon et al. 1998), most of the modern high-yielding rice cultivars perform poorly in saline environments. In addition, as saline soils are usually waterlogged, it is not feasible to grow crops other than rice in such areas (Gregorio and Senadhira 1995). The rice germplasm has genetic variability for salt tolerance (Xie et al. 2000), and two traditional Oryza sativa spp. indica cultivars, Pokkali and Nona Bokra, possess salt tolerance sufficiently high for rice breeding programs (Akbar et al. 1985; Gregorio and Senadhira 1993). Anther culture is a useful technique to produce lines with desirable combinations of required traits. It has been well integrated into rice breeding programs especially in Japan and China, where a number of high yielding, disease resistant and better quality rice cultivars have been selected from microspore derived plants (Loo and Xu 1991). However, indica cultivars respond poorly to in vitro techniques (Abe and Futsuhara 1986; Hartke and Lörz 1989), and in consequence the practical production of haploids from anther or microspore culture in rice breeding is limited to Oryza sativa spp. japonica
The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a major limitation o... more The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a major limitation of photosynthetic CO 2 assimilation in C 3 plants. In order to find useful Rubisco for improvement of photosynthesis in rice under elevated CO 2 , we analyzed the catalytic turnover rate (k cat) of Rubisco in Poaceae including C 3 alpine plants, C 3 cold-resistant plants and C 4 plants. Rubisco in these plants showed 1.1-to 2.8-fold higher k cat than that in rice. However, the most of high k cat Rubisco also showed a higher km for CO 2 (Kc) than that of rice, indicating that increase in k cat led to decrease in the affinity for CO 2. Rubisco in Festuca ovina, Phleum pratense and Sorghum bicolor showed relatively high k cat to Kc. Although the k cat of Rubisco in F. ovina and P. pratense was not so high (1.5-1.6 fold relative to rice), the Kc was comparable to that in rice and the amino acid sequence of RbcL shared higher identity to that in rice than that in S. bicolor. By contrast, Rubisco of S. bicolor showed considerably high k cat (2.5-fold relative to rice), which is considered to be the most important factor for improvement of photosynthesis. In our estimation, the expression of high k cat Rubisco of F. ovina and S. bicolor in rice could significantly enhance CO 2 assimilation at Ci of 50 Pa, the level assumed to be reached by the middle of this century.
The purpose of this study was to investigate the effects of 2,4-D, 6-furfurylamino purine (kineti... more The purpose of this study was to investigate the effects of 2,4-D, 6-furfurylamino purine (kinetin), and abscisic acid (ABA) on the response of cultured immature wheat (Triticum aestivum L.) embryos, by evaluating direct germination, callus growth, shoot regeneration and its development. The reduction of 2, 4-D concentration or the addition of kinetin to callus induction media promoted direct germination of cultured embryos, whereas the addition of ABA suppressed it extremely. Callus growth was promoted by reducing 2, 4-D concentration or by adding ABA at lower concentrations, though these alterations did not affect the frequency of callus formation. Concentrations of 2, 4-D in callus induction media did not affect the frequency of subsequent shoot regeneration from calli; however, the regenerated shoots developed rapidly when calli were induced at lower 2, 4-D. The addition of kinetin or ABA significantly improved the shoot-forming ability of callus cultures, especially in less responsive cultivars. Cont.: control.
Two hexaploid somatic hybrids, DA12-3 (2n = 68) and DA28 (2n = 74), derived from cell fusion betw... more Two hexaploid somatic hybrids, DA12-3 (2n = 68) and DA28 (2n = 74), derived from cell fusion between dihaploid Solanum acaule and tetraploid Solanum tuberosum, were crossed with S. tuberosum. Two BC1 families, DA12T and DA28T, were generated, each containing 25 plants. Although the average of somatic chromosome numbers fitted hypothetical numbers assuming equal separation, considerable variation was found: 2n = 54-62 in DA12T and 2n = 58-65 in DA28T. Fifty-two of 80 RFLP single-copy probes generated 108 marker bands specific for S. acaule, by which BC1 progeny were analyzed. The segregation of marker bands from at least 44 probes was explained by two alleles per locus, which had to be heterozygous in dihaploid S. acaule and maintained in homozygous condition in homoeologous chromosomes of tetraploid S. acaule. On average, 73.7% of the chromosomes derived from S. acaule were detected as recombinants, suggesting that frequent homoeologous recombination occurred between S. acaule and S. tuberosum chromosomes. Therefore, S. acaule germplasm can be effectively transferred to the cultivated potato gene pool through backcrossing hexaploid somatic hybrids with S. tuberosum. In both BC1 families, S. acaule chromosomes 3, 4, 6, and 11 were detected as recombinants with higher frequencies (84-98%) than those of chromosomes 9 and 10 (60 and 58%, respectively), suggesting that chromosomal differentiation exists between S. acaule genomes.Key words: hexaploid somatic hybrids, Solanum acaule, homoeologous recombination, RFLP markers.
Effects of colchicine pretreatment of cold-preserved spikes on the increase in ratio of diploidiz... more Effects of colchicine pretreatment of cold-preserved spikes on the increase in ratio of diploidized fertile regenerants in anther culture of rice were studied. After 10 days of storage at 10C, cut ends of the spikes including uninucleate pollen grains were dipped into colchicine solution at the same temperature. When the spikes were treated with 0.8% colchicine solution for 3 days, more than 50% of the regenerants, obtained in subsequent anther culture, were fertile.
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Papers by Shuji Misoo