1990 Fiscal Year Final Research Report Summary
Isolation and Characterization of a Novel UV Photoreceptor P_<290>
| Project/Area Number |
63480015
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | Kobe University |
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Principal Investigator |
HASHIMOTO Tohru Fact. of Sci. Dept. of Biol. Professor, 理学部, 教授 (60087616)
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| Co-Investigator(Kenkyū-buntansha) |
YATSUHASHI Hiroko Fact. of Edu. Dept. of Biol. Asoc. Prof., 教育学部, 助教授 (60182359)
SHICHIJO Chizuko Fact. of Sci. Dept. of Biol. Technician, 理学部, 教務職員 (70226132)
UEMURA Matsuo Fact. of Sci. Dept. of Biol. Lecturer, 理学部, 助手 (00213398)
MORIMOTO Naoaki Fact. of Sci. Dept. of Biol. Lecturer, 理学部, 助手 (30174452)
TSURUMI Seiji Grad. School of Sci. & Tech. Lecturer, 自然科学研究科, 助手 (80144608)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Chromosaponin I, II / Pea / Sorghum / Rhodotorula minuta / Anthocyanin / UV-B Photoreceptor |
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| Research Abstract |
Candidates of the UV-B photoreceptors were extracted from etiolated seedings of peas (Pisum sativum L. Cvs. Alaska and Progress No. 9), broad bean (Vicia faba L.) and sorghum (Sorghum bicolor Moench). Of the one from Alaska pea the structure was proposed as 22-O-[3-hydroxy-2-methyl-4-pyronyl]-soyaponin I, based on the findings of UV spectroscopy, nuclear magnetic resonance and mass spectrometries and others. Because of the presence of a UV-absorbing moiety, 3-hydroxy-2-methyl-4-pyrone, in addition to soyasaponin I, it was named chromosaponin I. The one from sorghum was different, and was named chromosaponin II. A careful extraction from Alaska pea with a buffer, gel permeation chromatography and gel-electrophoresis suggested that in plant cells it occurs mostly as a protein conjugate of about 53 kilodaltons. In a pea plant it occurs most abundantly in the apical hook and the root tip, where cell differentiation takes place most actively.
Whether the chromosaponin I protein conjugate is biologically functional was not clarified in this study, because we failed in inducing anthocyanin synthesis in carrot protoplasts, on which the antibody of this protein conjugate had originally been planned to test whether or not it inhibits UV-B action. Now we are attempting an alternative to use an in vitro transcription system.
In addition to the above-stated results we obtained the following findings :
1. UV-B photoreceptor(s) is different from DNA or RNA, judging from action spectra for amplification of phytochrome-mediated anthocyanin synthesis and for inhibition of anthocyanin synthesis induced by UV-B and red light in sorghum.
2. UV-B induces rapid changes in constituents of cell wall and plasma membrane of the yeast, Rhodotorula minuta.
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