精華區beta BOTANY_91 關於我們 聯絡資訊
PHYTON 討論會公告 ---------------------------------------------------------------------- 時間: 18:00-21:00 3-Mar-1999 地點: 圖書館討論室346 主持人: 徐捷 性質: 討論會簡述, 論文--光合作用 題目: Analysis of the chlorophyll biosynthetic system in a chlorophyll b-less barley mutent 作者: Arkadii B. Rudoi & Rostislav A. Shcherbakov 關鍵字: biosynthetic enzymes, chlorophyll, chlorophyllide, pigment formation, protochlorophyllide 來源: Photosynthisis Research 58:71-80, 1998 參考閱讀:(a)認何有關chlorophyll biosynthesis的文章(課本上的) (b)(不勉強)Robert J. Porra, Photochemistry and Photobiology, 1997, 65(3):492-516 (其中的圖....) 附注: (a)第一次總是比較匆忙 所以公告的時間略晚 下次應會改進 (b)摘要來不及翻譯 就照抄了.... (c)以後的公告格式大概就是這樣.... (d)我們大約在17:50於圖書館三樓集合 (e)未竟事宜以後再公布 摘要: The chlorophyll b-less barley (Hordeum vulgare L.) mutant chlorina 2807 allelic to the well-known barle mutant chlorina f2 was studied. 5-Aminolevulinic acid at saturating concentration (40 mM) was introduced into postetiolated leaves of the mutant and its wild type, and the protochlorophylide accumulation in the dark was measured. It was found that the activity of the enzyme system transforming 5-aminolevulinic acid into protochlorophyllide was the same in both types of plants. The activity of esterifying enzymes that catalyze attachment of phytol to chlorophyllide was analyzed by in filtration of exogenous chlorophyllides a and b into etiolated leaves. The reaction was shown to have close rates in the mutant and wild-type plants. In very early stages of greening of etiolated leaves,when the apoproteins of the light-harvesting complexes are not yet formed, appearance of chlorophyll b were conversion in any stage of greening. On the other hand, in the mutant as well as in the wild type an active reverse conversion of chlorophyll b into chlorophyll a was possible. It is concluded that (a) in the mutant chlorina 2807 the ability of the biosynthe to transform 5-aminolevulinic acid to chlorophyll a is fully preserved, (b) in the mutant the enzymes converting chlorophyll a into chlorophyll b are most likely absent or damaged, (c) the conversion of chlorophyll a into chlorophyll b and the reverse conversion of chlorophyll b into chlorophyll a are performed by different enzymes. -- ▓▓▓◣ ▓ ▓ ▓ ▓ ▓▓▓▓ ◢▓▓◣ ▓ ▓ ▓  ▓ ▓ ▓ ▓ ▓ ▓ ▓ ▓ ▓▓ ▓ ▓▓▓◤ ▓▓▓▓   ▓ ▓ ▓ ▓ ▓ ▓ ▓ ▓ ▓ ▓   ▓ ▓ ▓ ▓ ▓ ▓▓ ▓ ▓ ▓   ▓ ▓ ◥▓▓◤ ▓ ▓ -- ※ 發信站: 批踢踢實業坊(ptt.twbbs.org) ◆ From: pc17.cc.ntu.edu