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Accession number;00A0464800
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| Title;Pathway of Chlorophyll Degradation in Yellowing Radish(Raphanus sativus L.) Cotyledons. |
| Author;
AKIYAMA YU
(Yamaguchi Univ., Fac. of Agric.)
TAKAHASHI CHINATSU
(Yamaguchi Univ., Fac. of Agric.)
YAMAUCHI NAOKI
(Yamaguchi Univ., Fac. of Agric.)
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Journal Title;Journal of the Japanese Society for Food Science and Technology
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Journal Code:F0895A
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ISSN:1341-027X
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VOL.47;NO.4;PAGE.296-301(2000)
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| Figure&Table&Reference;FIG.5, REF.25 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Changes in chlorophyll(Chl) contents, Chl derivatives and Chl degrading enzyme activities in radish(Raphanus sativus L.) cotyledons were studied to clarify the pathway of Chl degradation with senescence. Radish cotyledons turned yellow appreciably with senescence after 3 days of the storage at 25.DEG.C.. Chls a and b contents in cotyledons decreased greatly with yellowing during storage. Chlorophyllide(Chlide) a decreased strongly with yellowing after a temporary increase on day 2 of the storage at 25.DEG.C., whereas 132-hydroxychlorophyll a(Chl a-1) decreased gradually. In the reaction mixture containing the cotyledon extract, Chlide a increased greatly on 3hr of the reaction and then decreased slightly during the reaction. An unknown substance was formed during the reaction and its absorption maximum was similar to that of Chlide a. Chlorophyllase activity increased on day 2 of the storage at 25.DEG.C. and then decreased with yellowing of cotyledons. Chl degrading peroxidase activity increased markedly on day 4 of the storage at 25.DEG.C.. In addition, Chl oxidase activity increased gradually with yellowing of cotyledons. We suggest that Chl degradation in radish cotyledons depends on the Chl-Chlide pathway and the Chl a-Chl a-1 pathway, and that the Chl a-Chl a-1 pathway involved in both Chl degrading peroxidase and Chl oxidase could play more important role of the yellowing of cotyledons that the Chl-Chlide pathway. (author abst.) |
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