Summary of Research Project Results Under the JSPS FY2000
"Research for the future Program"

1.Research Institution The University of Tokyo
2.Research Area Life Science
3.Research Field Mechanisms of Plant Responses to Environment and Application to Biotechnology
4.Term of Project FY1996〜FY2000
5.Project Number 96L00601
6.Title of Project Signal Transduction from Perception of Environmental Stimuli to Responses in Plants

7.Projetct Leader
Name Institution,Department Title of Position
Noriaki KONDO The University of Tokyo, Graduate School of Science Professor

8.Core Members

Names Institution,Department Title of Position
Makoto Matsuoka Nagoya University, BioScience Center Professor

9.Cooperating Researchers

Names Institution,Department Title of Position
Akira NAGATANI Kyoto University, Graduate School of Science Professor
Takao KONDO Nagoya University, Graduate School of Science Professor
Shuichi YANAGISAWA The University of Tokyo, Graduate School of Arts and Sciences Assistant Professor

10.Summary of Research Results

(1) The transcript level of photolyase, which restores the DNA damage caused by UV-B radiation, was enhanced by UV-B radiation, especially 300nm. This result suggests that the induction of photolyase in plants may be mediated by some photoreceptor specific for UV-B. (2) The structure of hys1 gene, which is induced by dark condition and promotes the senescence of green leaves, was analyzed. (3) A novel transcription factor DF1, which combines with cis-element of a GTPase gene, was obtained. (4) Some mutants of Arabidopsis, which become early senescent, have short hypocotyls in the dark, or are highly sensitive to blue and red light, were isolated. A novel cytochrome P450 gene and a novel nuclear protein gene were found as genes causing these mutations. (5) It was found that a transcription-activating factor CIP4, which interacts with a photomorphogenesis-relating protein COP1, is involved in hypocotylhypocotyls elongation. (6) A gene, of which expression in host plants is intensively suppressed by Rhizobium inoculation, was introduced into white clover, to examine the effect on formation of root nodule. (7) A novel Nod factor, which is produced by leguminous bacteria of Lotus japonicus and induces intensively root nodule, was found. (8) It was found that a homeodomain protein NTH15HD suppresses the transcription of an enzyme involved in gibberellin biosynthesis by combining with the cis-element of the enzyme gene. (9) In dormant axillary bud, some genes induced by ABA application, expressed during seed maturation, or mediating transduction of ABA signal were found. (10) In the research on the molecular mechanism of circadian clock in cyanobacteria, new information on phosphorylation of KaiC protein was obtained. A gene homologous to phytochrome, which is involved in phase shift of circadian clock, was found. SasR gene, which is involved in amplification of circadian oscillation, was successfully cloned.

11.Key Words

(1)UV-B photoreceptor、(2)Senescence of green leaves、(3)GTPase
(4)CytochromeP450、(5)COP1、(6)Nod factor
(7)Homeodomain protein、(8)ABA signal transduction、(9)Kai protein