Rice NPH1 homologues, OsNPH1a and OsNPH1b, are differently photoregulated.

The members of nonphototropic hypocotyl 1 (NPH1) family of genes in plants are considered to be the blue-light photoreceptors for phototropism. We isolated and characterized two NPH1 homologues from rice named as OsNPH1a and OsNPH1b. The predicted proteins of both OsNPH1 genes include LOV (LOV1 and LOV2) and protein kinase domains which are typically conserved regions in all the members of NPH1 family. Comparison of OsNPH1 apoproteins with those from other plant species revealed a close homology of OsNPHla with Arabidopsis, maize and oat NPH1, while the OsNPH1b appeared to be more closer to the recently found Arabidopsis NPL1. These structural homologies indicate that NPH1 homologues can be grouped into two classes namely "NPH1 type" and "NPL1 type". Northern blot analysis showed that OsNPH1a was strongly expressed in coleoptiles, whereas OsNPH1b was highly expressed in leaves of dark-grown rice seedlings. When the dark-grown seedlings were transferred to the continuous white light, the abundance of the OsNPH1a transcript in coleoptiles rapidly declined to the minimum levels, whereas the OsNPH1b transcript level in leaves gradually increased. These results lead us to conclude that expression of OsNPH1a and OsNPH1b is differently photoregulated in different tissues of rice seedlings.

[1]  J. Christie,et al.  LOV (light, oxygen, or voltage) domains of the blue-light photoreceptor phototropin (nph1): binding sites for the chromophore flavin mononucleotide. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[2]  T. Kanegae,et al.  A phytochrome from the fern Adiantum with features of the putative photoreceptor NPH1. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[3]  P Reymond,et al.  Arabidopsis NPH1: a flavoprotein with the properties of a photoreceptor for phototropism. , 1998, Science.

[4]  P. Oeller,et al.  Arabidopsis NPH1: a protein kinase with a putative redox-sensing domain. , 1997, Science.

[5]  I. Zhulin,et al.  PAS domain S-boxes in Archaea, Bacteria and sensors for oxygen and redox. , 1997, Trends in biochemical sciences.

[6]  Thomas L. Madden,et al.  Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. , 1997, Nucleic acids research.

[7]  J. Mullet,et al.  The Sorghum Photoperiod Sensitivity Gene, Ma3, Encodes a Phytochrome B , 1997, Plant physiology.

[8]  E. Schäfer,et al.  Photoperception and signalling of induction reactions by different phytochromes , 1996 .

[9]  T. Shinomura,et al.  Action spectra for phytochrome A- and B-specific photoinduction of seed germination in Arabidopsis thaliana. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[10]  H. Hirochika,et al.  Retrotransposons of rice involved in mutations induced by tissue culture. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[11]  K. Shimamoto,et al.  The Molecular Biology of Rice , 1995, Science.

[12]  M. Yano,et al.  Conservation of Duplicated Segments between Rice Chromosome 11 and 12 , 1995 .

[13]  E. Liscum,et al.  Mutations in the NPH1 locus of Arabidopsis disrupt the perception of phototropic stimuli. , 1995, The Plant cell.

[14]  P. Reymond,et al.  Blue light activates a specific protein kinase in higher plants. , 1992, Plant physiology.

[15]  M. Iino.  Phototropism : mechanisms and ecological implications , 1990 .

[16]  S. Kay,et al.  The sequence of the rice phytochrome gene. , 1989, Nucleic acids research.

[17]  S. Kay,et al.  The rice phytochrome gene: structure, autoregulated expression, and binding of GT-1 to a conserved site in the 5' upstream region. , 1989, The Plant cell.

[18]  D. Lipman,et al.  Improved tools for biological sequence comparison. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[19]  M. Daly,et al.  MAPMAKER: an interactive computer package for constructing primary genetic linkage maps of experimental and natural populations. , 1987, Genomics.

[20]  D. Lipman,et al.  Rapid and sensitive protein similarity searches. , 1985, Science.

[21]  M. Kimura,et al.  The neutral theory of molecular evolution. , 1983, Scientific American.

[22]  P. Quail,et al.  Autoregulatory control of translatable phytochrome mRNA levels. , 1983, Proceedings of the National Academy of Sciences of the United States of America.

[23]  W. F. Thompson,et al.  Rapid isolation of high molecular weight plant DNA. , 1980, Nucleic acids research.

[24]  C. Darwin.  Power of Movement in Plants , 1880 .

[25]  S. Lin,et al.  A high-density rice genetic linkage map with 2275 markers using a single F2 population. , 1998, Genetics.

[26]  M. Matsuoka.  Classification and Characterization of cDNA That Encodes the Light-Harvesting Chlorophyll a/b Binding Protein of Photosystem II from Rice , 1990 .

[27]  D. D. Kosambi.  The estimation of map distances from recombination values. , 1943 .