Silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers.
Silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers.
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DOI：
10.1186/1471-2229-7-11
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发表时间：
2007-03-02
影响因子：
5.3
通讯作者：
Giuliano, Giovanni
中科院分区：
文献类型：
--
作者：
Diretto, Gianfranco;Welsch, Ralf;Tavazza, Raffaela;Mourgues, Fabienne;Pizzichini, Daniele;Beyer, Peter;Giuliano, Giovanni
-胡萝卜素是维生素a的主要膳食前体，马铃薯块茎含有低水平的类胡萝卜素，主要由叶黄素（在- β分支中）和紫黄素（在- β分支中）组成。这些类胡萝卜素都没有维生素A原活性。我们之前的研究表明，对β分支的第一步LCY-e的结节特异性沉默，将代谢通量重定向到β - β -类胡萝卜素，使总类胡萝卜素增加2.5倍，β -胡萝卜素增加14倍。在这项工作中，我们沉默了块茎中的非血红素β -胡萝卜素羟化酶CHY1和CHY2。实时RT-PCR测量证实了这两个基因的结核特异性沉默。CHY沉默块茎的类胡萝卜素含量比LCY-e沉默块茎变化更大，β -胡萝卜素含量增加了38倍，总类胡萝卜素含量增加了4.5倍。这些变化伴随着β -胡萝卜素羟基化的直接产物玉米黄质的减少，但下游的叶黄素、紫黄素和新黄质却没有减少。内源基因表达的变化与LCY-e沉默块茎的变化广泛且部分重叠：CrtISO、LCY-b和ZEP在两种情况下都被诱导，表明它们可能响应单个类胡萝卜素物种之间的平衡。与番茄红素的epsilon环化一起，β -胡萝卜素羟基化是马铃薯块茎中胡萝卜素生成的另一个调控步骤。这些数据与在块茎中高度表达的CHY2在控制这一步骤中的普遍作用一致。不同工程策略的结合对块茎类胡萝卜素含量的控制具有良好的前景。
Beta-carotene is the main dietary precursor of vitamin A. Potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein (in the beta-epsilon branch) and violaxanthin (in the beta-beta branch). None of these carotenoids have provitamin A activity. We have previously shown that tuber-specific silencing of the first step in the epsilon-beta branch, LCY-e, redirects metabolic flux towards beta-beta carotenoids, increases total carotenoids up to 2.5-fold and beta-carotene up to 14-fold. In this work, we silenced the non-heme beta-carotene hydroxylases CHY1 and CHY2 in the tuber. Real Time RT-PCR measurements confirmed the tuber-specific silencing of both genes . CHY silenced tubers showed more dramatic changes in carotenoid content than LCY-e silenced tubers, with beta-carotene increasing up to 38-fold and total carotenoids up to 4.5-fold. These changes were accompanied by a decrease in the immediate product of beta-carotene hydroxylation, zeaxanthin, but not of the downstream xanthophylls, viola- and neoxanthin. Changes in endogenous gene expression were extensive and partially overlapping with those of LCY-e silenced tubers: CrtISO, LCY-b and ZEP were induced in both cases, indicating that they may respond to the balance between individual carotenoid species. Together with epsilon-cyclization of lycopene, beta-carotene hydroxylation is another regulatory step in potato tuber carotenogenesis. The data are consistent with a prevalent role of CHY2, which is highly expressed in tubers, in the control of this step. Combination of different engineering strategies holds good promise for the manipulation of tuber carotenoid content.
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影响因子：
8.4
作者：
Morris, Wayne L.;Ducreux, Laurence J. M.;Taylor, Mark A.
通讯作者：
Taylor, Mark A.
影响因子：
3.5
作者：
Fiore, Alessia;Dall'Osto, Luca;Giuliano, Giovanni
通讯作者：
Giuliano, Giovanni
土豆块状类胡萝卜素的代谢工程通过七叶烯酸酯环化酶的块茎特异性沉默。
影响因子：
5.3
作者：
Diretto, Gianfranco;Tavazza, Raffaela;Welsch, Ralf;Pizzichini, Daniele;Mourgues, Fabienne;Papacchioli, Velia;Beyer, Peter;Giuliano, Giovanni
通讯作者：
Giuliano, Giovanni
DOI：
10.1073/pnas.190177497
发表时间：
2000-09-26
影响因子：
11.1
作者：
Ronen, G;Carmel-Goren, L;Hirschberg, J
通讯作者：
Hirschberg, J
影响因子：
1.9
作者：
Nesterenko, S;Sink, KC
通讯作者：
Sink, KC