PROTOHEME TURNOVER AND CHLOROPHYLL SYNTHESIS IN GREENING BARLEY TISSUE
PROTOHEME TURNOVER AND CHLOROPHYLL SYNTHESIS IN GREENING BARLEY TISSUE
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DOI：
10.1104/pp.55.3.485
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发表时间：
1975-01-01
期刊：
影响因子：
7.4
通讯作者：
JONES, OTG
中科院分区：
文献类型：
--
作者：
CASTELFRANCO, PA;JONES, OTG
将14 C标记的前体喂入黄化大麦叶(Hordeum vulgareL.var.Proctor)的研究产生了具有相似特异性放射性的叶绿素和原血红素。这些发现表明： (a) 在没有净合成的情况下，原血红素似乎会快速周转； (b) 两种色素可能源自单一 5-氨基乙酰丙酸池； (c) 谷氨酸-1-14C的有效利用和甘氨酸-2-14C的相对较差的利用表明5-氨基乙酰丙酸可能是通过5-氨基乙酰丙酸合成酶（琥珀酰辅酶A-甘氨酸琥珀酰转移酶）以外的途径合成的，与之前发表的工作一致； (d) 在允许叶绿素快速积累的条件下，原血红素周转似乎更快； (e) 差异光谱表明线粒体细胞色素对大麦叶中总血红素的贡献相对较小。这些发现是根据有关光合生物四吡咯调节的现有知识进行讨论的。
Studies in which14C-labeled precursors were fed to etiolated barley leaves (Hordeum vulgareL. var. Proctor) yielded chlorophyll and protoheme having similar specific radioactivities. These findings indicate: (a) there appears to be a rapid turnover of protoheme in the absence of net synthesis; (b) both pigments probably originate from a single 5-aminolevulinic acid pool; (c) the efficient utilization of glutamate-1-14C and the relatively poor utilization of glycine-2-14C suggest that 5-aminolevulinic acid is probably synthesized by a pathway other than 5-aminolevulinic acid synthetase (succinyl CoA-glycine succinyltransferase) in agreement with previously published work; (d) protoheme turnover appears to be faster under conditions which allow for rapid chlorophyll accumulation; (e) difference spectra indicate that mitochondrial cytochromes make a relatively minor contribution to the total heme in barley leaves. These findings are discussed in the light of current knowledge about tetrapyrrole regulation in photosynthetic organisms.