1. NYC4, the rice ortholog of Arabidopsis THF1, is involved in the degradation of chlorophyll - protein complexes during leaf senescence.
- Author
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Yamatani, Hiroshi, Sato, Yutaka, Masuda, Yu, Kato, Yusuke, Morita, Ryouhei, Fukunaga, Kenji, Nagamura, Yoshiaki, Nishimura, Minoru, Sakamoto, Wataru, Tanaka, Ayumi, and Kusaba, Makoto
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ARABIDOPSIS ,LEAF aging ,CHLOROPHYLL ,PLANT translocation ,RICE ,MICROARRAY technology ,PHENOTYPES - Abstract
Yellowing/chlorophyll breakdown is a prominent phenomenon in leaf senescence, and is associated with the degradation of chlorophyll - protein complexes. From a rice mutant population generated by ionizing radiation, we isolated nyc4-1, a stay-green mutant with a defect in chlorophyll breakdown during leaf senescence. Using gene mapping, nyc4-1 was found to be linked to two chromosomal regions. We extracted Os07g0558500 as a candidate for NYC4 via gene expression microarray analysis, and concluded from further evidence that disruption of the gene by a translocation-related event causes the nyc4 phenotype. Os07g0558500 is thought to be the ortholog of THF1 in Arabidopsis thaliana. The thf1 mutant leaves show variegation in a light intensity-dependent manner. Surprisingly, the F
v / Fm value remained high in nyc4-1 during the dark incubation, suggesting that photosystem II retained its function. Western blot analysis revealed that, in nyc4-1, the PSII core subunits D1 and D2 were significantly retained during leaf senescence in comparison with wild-type and other non-functional stay-green mutants, including sgr-2, a mutant of the key regulator of chlorophyll degradation SGR. The role of NYC4 in degradation of chlorophyll and chlorophyll - protein complexes during leaf senescence is discussed. [ABSTRACT FROM AUTHOR]- Published
- 2013
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