Metabolic engineering of ketocarotenoid formation in higher plants
Metabolic engineering of ketocarotenoid formation in higher plants
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DOI：
10.1111/j.1365-313x.2004.02151.x
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发表时间：
2004-08-01
期刊：
影响因子：
7.2
通讯作者：
Fraser, PD
中科院分区：
文献类型：
--
作者：
Ralley, L;Enfissi, EMA;Fraser, PD
虽然高等植物合成类胡萝卜素，但它们不具有形成酮类胡萝卜素的能力。为了产生能够合成酮化和羟基化类胡萝卜素的组合的高等植物，已经将负责胡萝卜素4，4 '加氧酶和3，3'羟化酶的基因转化到番茄和烟草中。基因产物作为多蛋白产生。随后切割的多蛋白，靶向的两种酶的质体和酶的活性已被证明为两种基因产物。代谢物分析表明，在烟草和番茄叶中，β-胡萝卜素及其羟基化中间体形成酮醇化类胡萝卜素。在烟草花的蜜腺组织中，数量增加（10倍）以及成分变化很明显，包括虾青素、角黄素和4-酮玉米黄质的存在。有趣的是，在这个组织中，新形成的类胡萝卜素主要以酯的形式存在。这些数据进行了讨论，在类胡萝卜素的代谢工程和他们的螯合在高等植物组织。
Although higher plants synthesize carotenoids, they do not possess the ability to form ketocarotenoids. In order to generate higher plants capable of synthesizing combinations of ketolated and hydroxylated carotenoids the genes responsible for the carotene 4,4' oxygenase and 3,3' hydroxylase have been transformed into tomato and tobacco. The gene products were produced as a polyprotein. Subsequent cleavage of the polyprotein, targeting of the two enzymes to the plastid and enzyme activities have been shown for both gene products. Metabolite profiling has shown the formation of ketolated carotenoids from beta-carotene and its hydroxylated intermediates in tobacco and tomato leaf. In the nectary tissues of tobacco flowers a quantitative increase (10-fold) as well as compositional changes were evident, including the presence of astaxanthin, canthaxanthin and 4-ketozeaxanthin. Interestingly, in this tissue the newly formed carotenoids resided predominantly as esters. These data are discussed in terms of metabolic engineering of carotenoids and their sequestration in higher plant tissues.