Comparative proteomics of a lycopene-accumulating mutant reveals the important role of oxidative stress on carotenogenesis in sweet orange (Citrus sinensis [L.] osbeck)
Comparative proteomics of a lycopene-accumulating mutant reveals the important role of oxidative stress on carotenogenesis in sweet orange (Citrus sinensis [L.] osbeck)
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番茄红素积累突变体的比较蛋白质组学揭示了氧化应激对甜橙（Citrus sinensis [L.] osbeck）胡萝卜素生成的重要作用
DOI：
10.1002/pmic.200900092
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发表时间：
2009-12-01
期刊：
影响因子：
3.4
通讯作者：
Deng, Xiuxin
中科院分区：
文献类型：
--
作者：
Pan, Zhiyong;Liu, Qing;Deng, Xiuxin
自然甜橙子（Citrus sinenesis [L.] Osbeck）突变体'红安柳'由于在果肉中积累番茄红素而具有很高的利用价值。本研究采用双向电泳结合MALDI-TOF-TOF MS技术，分析了红安柳果肉与野生型果肉在4个成熟期的蛋白质组变化。在鉴定的74个差异表达蛋白中，大多数蛋白质与胁迫反应、碳水化合物/能量代谢和调控、蛋白质命运、修饰和降解有关。特别是，六种抗氧化酶的表达水平被改变的突变;和各自的酶活性的测定表明，在'红安六'的氧化应激水平的增强，这意味着氧化应激对胡萝卜素的调控作用。这一结论进一步证实了我们的观察，处理果肉与叔丁基过氧化氢（活性氧祖）诱导番茄红素积累的'红安柳'。基因表达分析表明，番茄红素合成上游基因在‘红安柳’和野生型番茄中均在汁囊中表达上调，而在节膜中表达下调。结果表明，转录后调控在胡萝卜素合成中起重要作用，因为番茄红素在'红安柳'中被诱导而不是WT。这一结果还表明，柑橘汁囊和切段膜中胡萝卜素的生成可能受不同机制的调控。
A spontaneous sweet orange (Citrus sinenesis [L.] Osbeck) mutant 'Hong Anliu' is of high value due to lycopene accumulation in the pulp. In this study, we analyzed the proteomic alterations in the pulp of 'Hong Anliu' versus its wild type (WT) at four maturing stages by using 2-DE combined with MALDI-TOF-TOF MS. Among the 74 differentially expressed proteins identified, the majority are predicted to be involved in stress response, carbohydrate/energy metabolism and regulation, or protein fate, modification and degradation. Particularly, expression levels of six anti-oxidative enzymes were altered by the mutation; and assays of their respective enzymatic activities indicated an enhanced level of oxidative stress in 'Hong Anliu', implying a regulatory role of oxidative stress on carotenogenesis. This conclusion was further confirmed by our observation that treatment of fruit pulps with tert-butylhydroperoxide (a ROS progenitor) induced lycopene accumulation in 'Hong Anliu' only. Gene expression showed that genes, predicted to function upstream of lycopene biosynthesis were generally upregulated in juice sacs, but downregulated in segment membranes in both 'Hong Anliu' and its WT. The result suggests an important role of post-transcriptional regulation on carotenogenesis since lycopene was induced in 'Hong Anliu' but not WT. The result also implies that carotenogenesis in juice sacs and segment membranes of citrus fruits may be regulated by different mechanisms.