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Studies on Functional Expression of α-Amylase in Rice
http://hdl.handle.net/10191/1474
http://hdl.handle.net/10191/1474512e514a-e17d-4a2d-aa7b-51e8a9422229
| 名前 / ファイル | ライセンス | アクション |
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本文 (31.3 MB)
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| Item type | 学位論文 / Thesis or Dissertation(1) | |||||
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| 公開日 | 2007-04-23 | |||||
| タイトル | ||||||
| タイトル | Studies on Functional Expression of α-Amylase in Rice | |||||
| タイトル | ||||||
| タイトル | Studies on Functional Expression of α-Amylase in Rice | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | α-Amylase | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | chloroplast | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | transgenic plant | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | α-アミラーゼ | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | 葉緑体 | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | トランスジェニック植物 | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_46ec | |||||
| 資源タイプ | thesis | |||||
| その他のタイトル | ||||||
| その他のタイトル | イネα-アミラーゼの機能発現に関する研究 | |||||
| 著者 |
Asatsuma, Satoru
× Asatsuma, Satoru |
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| 著者別名 | ||||||
| 識別子Scheme | WEKO | |||||
| 識別子 | 48906 | |||||
| 姓名 | 浅妻, 悟 | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The aim of this reserch is clarify details of funtional expression of α-amylase in rice. Studies of suspension-cultured cell system provided evidences that phosphate is a potent stimulator for α-amylase secretion and starch degradation. Studies of transgenic rice plants with suppressed expression or overexpression of α-amylase showed that α-amylase is involved in degradation of plastidial starch in living cells. These results indecate that there exist multi-subcellular localization of α-amylase encoded by single gene in rice. Furthermore, α-amylase I-1 fused with green fluorescence protein was targeted into the plastids in bombarded onion epidermal cells, indicating that rice α-amylase I-1 molecule contains a plastid targeting signal common to both rice and onion cells. The cotents are follows. Novel Regulatory Factor for α-Amylase Secretion and Stach Degradation in Rice Cell Culture Effects of phosphate on the Ca2+ uptake and the sucrose-controlled secretion of α-amylase molecules in cultured cells were investigated, Phosphate markedly stimulated Ca2+ uptake into rice cells, particulary at the outer cell layer of the cell cluster. Phosphate at 10 mM was found to increse the synthesis and extracelluar liberaton of α-amylase II-4 molecules in the sucrose-supplemented cells. The distribution pattern of enzyme in rice cell clusters induced by phosphate was similar to that of Ca2+ uptake, Phosphate did not increase the level of mRNA of α-amylase II-4, indicating that phosphate stimulates the translation and posttranslational secretory processes of α-amylase II-4 molecules in the presence of sucrose. Furthermore, phosphate enhanced both the Ca2+ uptake and α-amylase II-4 synthesis in the microsomes. These results strongly suggested that the ratio of phosphate to sugar is important for regulating the Ca2+ uptake, and that phosphate and sugar precisely coordinate the Ca2+-mediated synthesis and extracelluar liberation of α-amylase II-4 molecules in rice cells. In addition, phosphate reduced the starch content in rice cells, same as the sugar-starved cells. The results may indicate that α-amylase plays a role for degrading starch in living cells. Involment of α-Amylase in Starch Degradation in Rice Plastids To determine role of α-amylase isoform I-1 in the degradation of starch in rice leaf chloroplasts, I renerated a series of transgenic rice plants with suppressed expression of α-amylase I-1. In the lines with suppressed expression or overexpression of α-amylase I-1 at both mRNA and protein levels, seed germinaton and seedling growth were markedly delayed in comparison with those in the wild-type plants. | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Houever, the growth retardation was overcome by supplementation of sugars. Interestingly, a significant increse of starch accumulation in the young leaf tissues was observed under a sugar-supplemented condition. In contrast, the starch content of leaves was reduced in the plants overexpressinf α-amylase i-1. In immunocytochemicalanalysis with specific anti-α-amylase I-1 antiserum, immuno-gold particles deposited in the choroplasts and estracellular space in young leaf cells. I further examined the expression and targeting of α-amylase I-1 fused with the green fluorescent protein in re-differentiated green cells, and showed that the fluorescence of expressed fusion protein co-localized with the chlorophyll autofluorescence in the transgenic cells. In addition, mature protein species of α-amylase I-1 bearing an oligosaccharide side chain were detected in the isolated chloroplasts. Based on these results, I concluded that α-amylase I-1 targets the chloroplasts through the ER-Golgi system and plays a significant role in the starch degradation in rice leaves. Overexpression of α-Amylase affects Starch accumulation in Ripening Seeds of Rice To determine physiological function of α-amylase isoform II-4, I generated a series transgenic rice plants with overexpression of α-amylase II-4. In the line with overexpression of α-amylase II-4 at both the mRNA and protein levels, the ability of seed germination and seedling growth was unaltered. Unlike α-amylase I-1, starch accumulation in leaf tissues overexpressing α-amylase II-4 was scarcely changed. However, the seeds produced in the transgenic rice plants exhibited an abnormal accumulation of starch, as well as that in rice overexpressing α-amylase I-1. Based on these in endosperm of ripening seed and controls accumulation of reserve stach in rice. | |||||
| 内容記述 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 新大院博（農）甲第63号 | |||||
| 書誌情報 | p. 1-146, 発行日 2005-09-20 | |||||
| 出版者 | ||||||
| 出版者 | 新潟大学大学院自然科学研究科 | |||||
| 著者版フラグ | ||||||
| 値 | author | |||||
| 学位名 | ||||||
| 学位名 | 博士（農学） | |||||
| 学位授与機関 | ||||||
| 学位授与機関名 | 新潟大学 | |||||
| 学位授与年月日 | ||||||
| 学位授与年月日 | 2005-09-20 | |||||
| 学位授与番号 | ||||||
| 学位授与番号 | 13101甲第2530号 | |||||
| 学位記番号 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 新大院博（農）甲第63号 | |||||
