Riboswitch-mediated inducible expression of an astaxanthin biosynthetic operon in plastids.
Riboswitch-mediated inducible expression of an astaxanthin biosynthetic operon in plastids.
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核糖开关介导的虾青素生物合成操纵子在质体中的诱导表达。
DOI：
10.1093/plphys/kiab428
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发表时间：
2022-01-20
期刊：
影响因子：
7.4
通讯作者：
Bock R
中科院分区：
文献类型：
--
作者：
Agrawal S;Karcher D;Ruf S;Erban A;Hertle AP;Kopka J;Bock R
虾青素（3，3 ′-dihydroxy-β，β-carotene-4，4 ′-dione）是一种高价值的类胡萝卜素，是自然界中最有效的抗氧化剂之一。除了在鱼类养殖中的大规模使用外，该色素还可用作食品补充剂和化妆品中的活性成分，以及用于治疗与活性氧有关的疾病的药物。通过核和质体工程，已经将虾青素合成的生化途径引入种子植物中，这些种子植物不天然合成这种色素。最高的积累率已达到转质体植物，但大量生产的虾青素导致严重的生长迟缓。是什么限制了虾青素的积累水平，是什么导致了突变表型是未知的。在这里，我们解决了这些问题，使虾青素合成烟草（烟草）质体诱导的合成核糖开关。我们表明，已经在未诱导的状态下，虾青素积累到类似的高水平，在transplastomic植物表达的途径组成。重要的是，诱导型植物表现出野生型样的生长特性，核糖开关诱导导致虾青素积累的进一步增加。我们的数据表明，与组成型虾青素合成的突变体表型是由于大量的代谢物周转，并表明，虾青素的积累是有限的隔离能力的质体。合成的虾青素操纵子在质体中的诱导表达阐明了组成型途径表达的生长表型，并提供了对类胡萝卜素生物合成瓶颈的见解。
The high-value carotenoid astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione) is one of the most potent antioxidants in nature. In addition to its large-scale use in fish farming, the pigment has applications as a food supplement and an active ingredient in cosmetics and in pharmaceuticals for the treatment of diseases linked to reactive oxygen species. The biochemical pathway for astaxanthin synthesis has been introduced into seed plants, which do not naturally synthesize this pigment, by nuclear and plastid engineering. The highest accumulation rates have been achieved in transplastomic plants, but massive production of astaxanthin has resulted in severe growth retardation. What limits astaxanthin accumulation levels and what causes the mutant phenotype is unknown. Here, we addressed these questions by making astaxanthin synthesis in tobacco (Nicotiana tabacum) plastids inducible by a synthetic riboswitch. We show that, already in the uninduced state, astaxanthin accumulates to similarly high levels as in transplastomic plants expressing the pathway constitutively. Importantly, the inducible plants displayed wild-type–like growth properties and riboswitch induction resulted in a further increase in astaxanthin accumulation. Our data suggest that the mutant phenotype associated with constitutive astaxanthin synthesis is due to massive metabolite turnover, and indicate that astaxanthin accumulation is limited by the sequestration capacity of the plastid. Inducible expression of a synthetic astaxanthin operon in plastids alleviates the growth phenotype of constitutive pathway expression and provides insights into carotenoid biosynthesis bottlenecks.
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影响因子：
14.9
作者：
Emadpour M;Karcher D;Bock R
通讯作者：
Bock R
影响因子：
7.2
作者：
Chaimovitsh, David;Abu-Abied, Mohamad;Sadot, Einat
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Sadot, Einat
影响因子：
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作者：
Enfissi, EMA;Fraser, PD;Bramley, PM
通讯作者：
Bramley, PM
影响因子：
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作者：
Agrawal, Shreya;Karcher, Daniel;Bock, Ralph
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影响因子：
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作者：
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通讯作者：
Bock, Ralph