Over many centuries much effort has been expended on crop improvement, most recently by use of molecular genetic technologies. Although genome sequence information for crop species is not yet available in the public domain, most of the genes of central metabolism have already been cloned and the corresponding transgenic plants generated. Although these plants have often confirmed the hypotheses based on more indirect methodologies, they have also produced unexpected challenges to the metabolic engineer in outlining the enormous flexibility and complexity inherent in plant metabolism. Intriguingly, comparison of transcript and metabolite levels of the TCA cycle revealed strong correlations in expression levels but little coordination in the levels of metabolic intermediates. These factors explain why many attempts to engineer central metabolism have proven unsuccessful to date and suggest that a greater understanding of the regulatory circuits and networks controlling metabolism is required before engineering can become routine. In this article we intend to illustrate these challenges by reviewing attempts to manipulate the central metabolic pathways of Solanaceae (sps.) as well as demonstrating the role for systems biology approaches in metabolic engineering in crops.

中文翻译：

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工程学作物中的中央代谢：学习系统。

多个世纪以来，人们一直在作物改良方面投入大量精力，最近一次是使用分子遗传技术。尽管尚未在公共领域获得农作物物种的基因组序列信息，但大多数中央代谢基因已被克隆，并产生了相应的转基因植物。尽管这些植物通常基于更间接的方法论来证实这些假设，但它们在概述植物代谢固有的巨大灵活性和复杂性方面也给代谢工程师带来了意想不到的挑战。有趣的是，TCA周期的转录本和代谢产物水平的比较显示出表达水平之间的相关性很强，但是代谢中间体的水平却很少协调。这些因素解释了为什么迄今为止尚未进行许多工程化中央代谢的尝试，并表明在工程化成为常规工程之前，需要对控制新陈代谢的调节电路和网络有更深入的了解。在这篇文章中，我们打算通过回顾操纵茄科（sps。）中央代谢途径的尝试以及证明系统生物学方法在作物代谢工程中的作用来说明这些挑战。