Received April 1, 2003
Accepted July 2, 2003
Disruption of the AtREV3 Gene Causes Hypersensitivity to Ultraviolet B Light
and 
-Rays in Arabidopsis: Implication of the Presence of a Translesion Synthesis
Mechanism in Plants
Ayako Sakamoto 1*, Vo Thi Thuong Lan 2, Yoshihiro Hase 1, Naoya Shikazono 1, Tsukasa Matsunaga 3, and Atsushi Tanaka 1
1
Department of Ion-Beam-Applied Biology, Japan Atomic Energy Research Institute, Takasaki
370-1292, Japan
2
Department of Ion-Beam-Applied Biology, Japan Atomic Energy Research Institute, Takasaki
370-1292, Japan; Department of Biology, Hanoi University of Science, Hanoi,
Vietnam
3
Faculty of Pharmaceutical Science, Kanazawa University, Kanazawa, Ishikawa 920-0934,
Japan
* To whom correspondence should be addressed. E-mail: sakamoto{at}taka.jaeri.go.jp.
To investigate UV light response mechanisms in higher plants, we isolated a UV light-sensitive
mutant, rev3-1, in Arabidopsis. The root growth of rev3-1 was inhibited
after UV-B irradiation under both light and dark conditions. We found that chromosome
1 of rev3-1 was broken at a minimum of three points, causing chromosome
inversion and translocation. A gene disrupted by this rearrangement encoded the catalytic
subunit of DNA polymerase 
(AtREV3), which is thought to be involved
in translesion synthesis. The rev3-1 seedlings also were sensitive to 
-rays
and mitomycin C, which are known to inhibit DNA replication. Incorporation of bromodeoxyuridine
after UV-B irradiation was less in rev3-1 than in the wild type. These results
indicate that UV light-damaged DNA interrupted DNA replication in the rev3-1
mutant, leading to the inhibition of cell division and root elongation.
