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The rice Os11g0523800 was Similar to Phytochrome B.Rice phytochrome is the feeling of the red / far-red light receptors only.Rice only three phytochrome genes, PHYA, PHYB and PHYC. Hd3a expression inhibition PhyB mediated inhibition of rice is long-day flowering main reason.

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PhyA phytochrome-mediated regulation of rice Hd1 florigen Hd3a expression and critical day length. Hd3a expression inhibition PhyB mediated inhibition of rice is long-day flowering main reason. First overexpression Hd1, under short-day conditions is needed to delay flowering in rice phyB participation, indicating light regulation Hd1 Hd3a transcription regulation; secondly, just to extend the length of a single day can reduce Hd3a expression, and the extent corresponding to the length of day; last , in the presence of light conditions, Hd1 Hd1 protein levels in plants overexpressing not changed. These results also show that the expression of phyB-mediated inhibition of rice Hd3a molecular mechanisms critical day length is an integral component[1] These findings indicate that phytochromes contribute to multiple steps in the control of internode elongation, such as the expression of the GA biosynthesis gene OsGA3ox2, ACO1 expression, and the onset of internode elongation.[2] PhyB total leaf area and by controlling the density of stomata of rice drought tolerance, phyB reason drought, double the total area and lower leaf transpiration per unit area of the blade itself lead to a decrease in water loss[3] Phytochrome GA oxidase inhibiting the expression of genes GA20ox. Rice seedlings, phytochrome-mediated inhibition of the biosynthesis of GA, and cryptochrome cry1 activity involved in the induction of GA inactivation, the accumulation of these independent role in reducing the levels of active gibberellin light. With the results of different studies dicots, independent and coordinated regulation of active gibberellin content of rice in different light receptor pathway.[4]


We have isolated phytochrome B (phyB) and phyC mutants from rice (Oryza sativa) and have produced all combinations of double mutants. Seedlings of phyB and phyB phyC mutants exhibited a partial loss of sensitivity to continuous red light (Rc) but still showed significant deetiolation responses. The responses to Rc were completely canceled in phyA phyB double mutants. These results indicate that phyA and phyB act in a highly redundant manner to control deetiolation under Rc. Under continuous far-red light (FRc), phyA mutants showed partially impaired deetiolation, and phyA phyC double mutants showed no significant residual phytochrome responses, indicating that not only phyA but also phyC is involved in the photoperception of FRc in rice. Interestingly, the phyB phyC double mutant displayed clear R/FR reversibility in the pulse irradiation experiments, indicating that both phyA and phyB can mediate the low-fluence response for gene expression. Rice is a short-day plant, and we found that mutation in either phyB or phyC caused moderate early flowering under the long-day photoperiod, while monogenic phyA mutation had little effect on the flowering time. The phyA mutation, however, in combination with phyB or phyC mutation caused dramatic early flowering.[5]


Phytochromes are believed to be solely responsible for red and far-red light perception, but this has never been definitively tested. To directly address this hypothesis, a phytochrome triple mutant (phyAphyBphyC) was generated in rice (Oryza sativa L. cv. Nipponbare) and its responses to red and far-red light were monitored. Since rice only has three phytochrome genes (PHYA, PHYB and PHYC), this mutant is completely lacking any phytochrome. Rice seedlings grown in the dark develop long coleoptiles while undergoing regular circumnutation. The phytochrome triple mutants also show this characteristic skotomorphogenesis, even under continuous red or far-red light. The morphology of the triple mutant seedlings grown under red or far-red light appears completely the same as etiolated seedlings, and they show no expression of the light-induced genes. This is direct evidence demonstrating that phytochromes are the sole photoreceptors for perceiving red and far-red light, at least during rice seedling establishment. Furthermore, the shape of the triple mutant plants was dramatically altered. Most remarkably, triple mutants extend their internodes even during the vegetative growth stage, which is a time during which wild-type rice plants never elongate their internodes. The triple mutants also flowered very early under long day conditions and set very few seeds due to incomplete male sterility. These data indicate that phytochromes play an important role in maximizing photosynthetic abilities during the vegetative growth stage in rice.[6]

Labs working on this gene

  • Graduate School of Frontier Sciences, University of Tokyo, 5–1–5 Kashiwanoha, Kashiwa 277–8561, Japan

(A.O.); and Functional Plant Research Unit, National Institute of Agrobiological Sciences, 2–1–2 Kannondai, Tsukuba 305–8602, Japan (A.O., H.I., K.I.-K., M.T., T.I.)

  • Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305–8602, Japan

(M.I., S.K., M.T.); and RIKEN Plant Science Center, Yokohama, Kanagawa 230–0045, Japan (A.H., S.Y.)

  • College of Life Sciences, Shandong Normal University,250014 Jinan, People’s Republic of China
  • Photobiology and Photosynthesis Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8602 Japan
  • RIKEN Plant Science Center, Yokohama, Kanagawa, 230-0045 Japan
  • Genome Resource Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8602 Japan
  • Department of Plant Physiology, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
  • Hitachi Central Research Laboratory, Hatoyama, Saitama 350-0395, Japan

Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang 790–784, Korea,

  • Crop Biotech Institute, Kyung Hee University, Yongin 446–701, Korea, and
  • Department of Plant Systems Biotech, Kyung Hee University, Yongin 446–701, Korea


  1. Asami Osugi;Hironori Itoh;Kyoko Ikeda-Kawakatsu;Makoto Takano;Takeshi Izawa.Molecular dissection of the roles of phytochrome in photoperiodic flowering in rice Plant Physiology, 2011, 157(3): 1128-1137.
  2. Masao Iwamoto;Seiichiro Kiyota;Atsushi Hanada;Shinjiro Yamaguchi;Makoto Takano.The Multiple Contributions of Phytochromes to the Control of Internode Elongation in Rice Plant Physiology, 2011, 157(3): 1187-1195.
  3. Jing Liu;Fang Zhang;Jinjun Zhou;Fan Chen;Baoshan Wang;Xianzhi Xie.Phytochrome B control of total leaf area and stomatal density affects drought tolerance in rice.Plant Molecular Biology, 2012, 78(3): 289-300.
  4. Fumiaki Hirose;Noritoshi Inagaki;Atsushi Hanada;Shinjiro Yamaguchi;Yuji Kamiya;Akio Miyao;Hirohiko Hirochika;Makoto Takano. Cryptochrome and Phytochrome Cooperatively but Independently Reduce Active Gibberellin Content in Rice Seedlings under Light Irradiation. Plant and Cell Physiology, 2012, 53(9): 1570-1582.
  5. Makoto Takano;Noritoshi Inagaki;Xianzhi Xie;Natsu Yuzurihara;Fukiko Hihara;Toru Ishizuka;Masahiro Yano;Minoru Nishimura;Akio Miyao;Hirohiko Hirochika;Tomoko Shinomura.Distinct and Cooperative Functions of Phytochromes A, B, and C in the Control of Deetiolation and Flowering in Rice.The Plant Cell, 2005, 17(12): 3311-3325.
  6. Makoto Takano;Noritoshi Inagaki;Xianzhi Xie;Seiichiro Kiyota;Akiko Baba-Kasai;Takanari Tanabata;Tomoko Shinomura. Phytochromes are the sole photoreceptors for perceiving red/far-red light in rice.Proceedings of the National Academy of Sciences, 2009, 106(34): 14705-14710.

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