Os01g0227100

Please input one-sentence summary here. nyc1 is a recessive mutant in rice and it canretain green leaves during senescence.

Annotated Information

Function

Please input function information here. The symbol of the gene “Os01g0227100” is NYC1. nyc1 is a recessive mutant in rice, nyc1 was isolated as a stay-green mutant in the paddy field. nyc1 remains green until just before death in natural senescence and does not show yellowing.In nyc1, most light-harvesting complex II（LHCII ）members are selectively retained during senescence, in contrast with the wild type. nyc1retains granal structure during senescence.

1.Inhibition of LHCP Degradation in nyc1.

In wild-type senescent leaves, the abundance of these protein complexes was reduced remarkably at 5 DDI；In nyc1, the abundances of chlorophyll abinding proteins, LHCP dimer (whose major component is LHCI), PSI reaction center complex, and CP43/47 were reduced to similar levels as in the wild type at 5 and 7 DDI, but the LHCP trimer and monomer were apparent even at 7 DDI. 

2.Inhibition of Degradation of Pigments Strongly Bound to LHCP in nyc1. By 8 DDI, the amounts of most photosynthetic pigments exceptb-carotene were significantly reduced in the wild type. In nyc1, the degradation of not only chlorophyllaand chlorophyllbbut also neoxanthin and lutein was apparently inhibited.

3. the degradation of chlorophyll b was severely inhibited and light-harvesting complex II was selectively retained during senescence, resulting in the retention of thylakoid grana even at a late stage of senescence.

4.The protein encoded by NYC1 is necessary for catalyzing the first step of chlorophyll b degradation. Analysis of the nyc1 mutant, which shows the stay-green phenotype, revealed that chlorophyll b degradation is required for the degradation of light-harvesting complex II and thylakoid grana in leaf senescence.

Expression

Please input expression information here. nyc1 was located between cleaved-amplified polymorphic sequence (CAPS) markers P0443E07.24 and P0452F10.5. Five genes were predicted in this≈40-kb region. One of them seems to encode encodes a protein with 504 amino acids belonging to the SDR family.The amino acid sequence of NYC1 contains all important amino acid residues conserved in the classical SDR family, including a dinucleotide binding motif (TGXXXGXG) and a catalytic site (YXXXK). NYC1 has an Arg at key position 15 (180th amino acid) and another at key position 37 (202nd amino acid). Sequence analysis of the nyc1-1 allele revealed a single base pair change, a G-to-A substitution, at the first exon/first intron junction, which may prevent splicing of the first intron and result in the early termination of translation.

Evolution

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Labs working on this gene

Please input related labs here. Graduate School of Agricultural and Life Sciences, University of Tokyo. Institute of Low-Temperature Science, Hokkaido University. Institute of Radiation Breeding, National Institute of Agrobiological Sciences. Chugoku National Agricultural Research Center for WesternRegion, National Agriculture and Bio-oriented Research Organization.

References

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[1] Yutaka Sato1,+, Ryouhei Morita2, Susumu Katsuma1, Minoru Nishimura2, Ayumi Tanaka3 and Makoto Kusaba1,4,*(2009)Rice NON-YELLOW COLORING1 Is Involved in Light-Harvesting Complex II and Grana Degradation during Leaf Senescence.The Plant Journal.57:121-130.

[2]Makoto Kusaba,a,1Hisashi Ito,b Ryouhei Morita,cShuichi Iida,dYutaka Sato,aMasaru Fujimoto,aShinji Kawasaki,eRyouichi Tanaka,bHirohiko Hirochika,eMinoru Nishimura,cand Ayumi Tanakab(2007)Two short-chain dehydrogenase/reductases, NON-YELLOW COLORING 1 and NYC1-LIKE, are required for chlorophyll b and light-harvesting complex II degradation during senescence in rice.The Plant Cell.19: 1362–1375.