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ID 21456
本文ファイル
著者
Nakagawa, Ayami
Sakamoto, Saori
Morikawa, Hiromichi
キーワード
Arabidopsis (Arabidopsis thaliana)
plant growth and development
purine metabolism
senescence
xanthine dehydrogenase
NDC
生物科学・一般生物学
抄録(英)
Xanthine dehydrogenase (XDH) is a ubiquitous enzyme involved in purine metabolism which catalyzes the oxidation of hypoxanthine and xanthine to uric acid. Although the essential role of XDH is well documented in the nitrogen-fixing nodules of leguminous plants, the physiological importance of this enzyme remains uncertain in non-leguminous species such as Arabidopsis. To evaluate the impact of an XDH deficiency on whole-plant physiology and development in Arabidopsis, RNA interference (RNAi) was used to generate transgenic lines of this species in which AtXDH1 and AtXDH2, the two paralogous genes for XDH in this plant, were silenced simultaneously. The nearly complete reduction in the total XDH protein levels caused by this gene silencing resulted in the dramatic overaccumulation of xanthine and a retarded growth phenotype in which fruit development and seed fertility were also affected. A less severe silencing of XDH did not cause these growth abnormalities. The impaired growth phenotype was mimicked by treating wild-type plants with the XDH inhibitor allopurinol, and was reversed in the RNAi transgenic lines by exogenous supplementation of uric acid. Inactivation of XDH is also associated with precocious senescence in mature leaves displaying accelerated chlorophyll breakdown and by the early induction of senescence-related genes and enzyme markers. In contrast, the XDH protein levels increase with the aging of the wild-type leaves, supporting the physiological relevance of the function of this enzyme in leaf senescence. Our current results thus indicate that XDH functions in various aspects of plant growth and development.
掲載誌名
Plant and Cell Physiology
48巻
10号
開始ページ
1484
終了ページ
1495
出版年月日
2007-10
出版者
Oxford University Press
ISSN
0032-0781
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
author
権利情報
Copyright(c) 2007 Oxford University Press
関連情報URL(IsVersionOf)
http://dx.doi.org/10.1093/pcp/pcm119
部局名
理学研究科