UV-B-Induced CPD Photolyase Gene Expression is Regulated by UVR8-Dependent and -Independent Pathways in Arabidopsis.
Plants have evolved various mechanisms that protect against the harmful effects of UV-B radiation (280-315 nm) on growth and development. Cyclobutane pyrimidine dimer (CPD) photolyase, the repair enzyme for UV-B-induced CPDs, is essential for protecting cells from UV-B radiation. Expression of the CPD photolyase gene (PHR) is controlled by light with various wavelengths including UV-B, but the mechanisms of this regulation remain poorly understood. In this study, we investigated the regulation of PHR expression by light with various wavelengths, in particular low-fluence UV-B radiation (280 nm, 0.2 µmol m(-2) s(-1)), in Arabidopsis thaliana seedlings grown under light-dark cycles for 7 d and then adapted to the dark for 3 d. Low-fluence UV-B radiation induced CPDs but not reactive oxygen species. AtPHR expression was effectively induced by UV-B, UV-A (375 nm) and blue light. Expression induced by UV-A and blue light was predominantly regulated by the cryptochrome-dependent pathway, whereas phytochromes A and B played a minor but noticeable role. Expression induced by UV-B was predominantly regulated by the UVR8-dependent pathway. AtPHR expression was also mediated by a UVR8-independent pathway, which is correlated with CPD accumulation induced by UV-B radiation. These results indicate that Arabidopsis has evolved diverse mechanisms to regulate CPD photolyase expression by multiple photoreceptor signaling pathways, including UVR8-dependent and -independent pathways, as protection against harmful effects of UV-B radiation.
Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577 Japan.
Nan
N
Li
Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577 Japan.
Mika
M
Teranishi
Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577 Japan.
Hiroko
H
Yamaguchi
Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan PRESTO, JST, Saitama, 332-0012 Japan.
Tomonao
T
Matsushita
Division of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810 Japan.
Masaaki K
MK
Watahiki
Institute for Chemical Research, Kyoto University, Uji, 611-0011 Japan.
Tomohiko
T
Tsuge
Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Shao-Shan
SS
Li
Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577 Japan j-hidema@m.tohoku.ac.jp.
Jun
J
Hidema
D017360:Arabidopsis / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D015398:Signal Transduction / Q000528:radiation effects; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C525052:Uvr8 protein, Arabidopsis; D004255:Deoxyribodipyrimidine Photo-Lyase
Arabidopsis; CPD photolyase; Cryptochrome; Cyclobutane pyrimidine dimer (CPD); Gene expression; UVR8