{"_buckets": {"deposit": "ae519fb4-c123-4e80-8d6f-ab19bf27fc0a"}, "_deposit": {"id": "4690", "owners": [], "pid": {"revision_id": 0, "type": "depid", "value": "4690"}, "status": "published"}, "_oai": {"id": "oai:niigata-u.repo.nii.ac.jp:00004690", "sets": ["455", "564"]}, "item_6_alternative_title_1": {"attribute_name": "その他のタイトル", "attribute_value_mlt": [{"subitem_alternative_title": "イネα-アミラーゼの機能発現に関する研究"}]}, "item_6_biblio_info_6": {"attribute_name": "書誌情報", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2005-09-20", "bibliographicIssueDateType": "Issued"}, "bibliographicPageEnd": "146", "bibliographicPageStart": "1", "bibliographic_titles": [{}]}]}, "item_6_date_granted_51": {"attribute_name": "学位授与年月日", "attribute_value_mlt": [{"subitem_dategranted": "2005-09-20"}]}, "item_6_degree_grantor_49": {"attribute_name": "学位授与機関", "attribute_value_mlt": [{"subitem_degreegrantor": [{"subitem_degreegrantor_name": "新潟大学"}]}]}, "item_6_degree_name_48": {"attribute_name": "学位名", "attribute_value_mlt": [{"subitem_degreename": "博士（農学）"}]}, "item_6_description_4": {"attribute_name": "抄録", "attribute_value_mlt": [{"subitem_description": "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.", "subitem_description_type": "Abstract"}, {"subitem_description": "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.", "subitem_description_type": "Abstract"}]}, "item_6_description_5": {"attribute_name": "内容記述", "attribute_value_mlt": [{"subitem_description": "新大院博（農）甲第63号", "subitem_description_type": "Other"}]}, "item_6_description_53": {"attribute_name": "学位記番号", "attribute_value_mlt": [{"subitem_description": "新大院博（農）甲第63号", "subitem_description_type": "Other"}]}, "item_6_dissertation_number_52": {"attribute_name": "学位授与番号", "attribute_value_mlt": [{"subitem_dissertationnumber": "13101甲第2530号"}]}, "item_6_full_name_3": {"attribute_name": "著者別名", "attribute_value_mlt": [{"nameIdentifiers": [{"nameIdentifier": "48906", "nameIdentifierScheme": "WEKO"}], "names": [{"name": "浅妻, 悟"}]}]}, "item_6_publisher_7": {"attribute_name": "出版者", "attribute_value_mlt": [{"subitem_publisher": "新潟大学大学院自然科学研究科"}]}, "item_6_select_19": {"attribute_name": "著者版フラグ", "attribute_value_mlt": [{"subitem_select_item": "author"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "Asatsuma, Satoru"}], "nameIdentifiers": [{"nameIdentifier": "48905", "nameIdentifierScheme": "WEKO"}]}]}, "item_files": {"attribute_name": "ファイル情報", "attribute_type": "file", "attribute_value_mlt": [{"accessrole": "open_date", "date": [{"dateType": "Available", "dateValue": "2019-08-05"}], "displaytype": "detail", "download_preview_message": "", "file_order": 0, "filename": "13_0033.pdf", "filesize": [{"value": "31.3 MB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_free", "mimetype": "application/pdf", "size": 31300000.0, "url": {"label": "本文", "url": "https://niigata-u.repo.nii.ac.jp/record/4690/files/13_0033.pdf"}, "version_id": "ea5cde59-d998-41f8-bd20-79b88638ca96"}]}, "item_keyword": {"attribute_name": "キーワード", "attribute_value_mlt": [{"subitem_subject": "α-Amylase", "subitem_subject_scheme": "Other"}, {"subitem_subject": "chloroplast", "subitem_subject_scheme": "Other"}, {"subitem_subject": "transgenic plant", "subitem_subject_scheme": "Other"}, {"subitem_subject": "α-アミラーゼ", "subitem_subject_language": "en", "subitem_subject_scheme": "Other"}, {"subitem_subject": "葉緑体", "subitem_subject_language": "en", "subitem_subject_scheme": "Other"}, {"subitem_subject": "トランスジェニック植物", "subitem_subject_language": "en", "subitem_subject_scheme": "Other"}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_resource_type": {"attribute_name": "資源タイプ", "attribute_value_mlt": [{"resourcetype": "thesis", "resourceuri": "http://purl.org/coar/resource_type/c_46ec"}]}, "item_title": "Studies on Functional Expression of α-Amylase in Rice", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "Studies on Functional Expression of α-Amylase in Rice"}, {"subitem_title": "Studies on Functional Expression of α-Amylase in Rice", "subitem_title_language": "en"}]}, "item_type_id": "6", "owner": "1", "path": ["455", "564"], "permalink_uri": "http://hdl.handle.net/10191/1474", "pubdate": {"attribute_name": "公開日", "attribute_value": "2007-04-23"}, "publish_date": "2007-04-23", "publish_status": "0", "recid": "4690", "relation": {}, "relation_version_is_last": true, "title": ["Studies on Functional Expression of α-Amylase in Rice"], "weko_shared_id": 2}