The Transcript and Metabolite Networks Affected by the Two Clades of Arabidopsis Glucosinolate Biosynthesis Regulators
The Transcript and Metabolite Networks Affected by the Two Clades of Arabidopsis Glucosinolate Biosynthesis Regulators
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DOI：
10.1104/pp.108.124784
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发表时间：
2008-12-01
期刊：
影响因子：
7.4
通讯作者：
Aharoni, Asaph
中科院分区：
文献类型：
--
作者：
Malitsky, Sergey;Blum, Eyal;Aharoni, Asaph
本研究综合运用转录组学和代谢组学的相关数据，研究了拟南芥（Arabidopsis thaliana）中硫代葡萄糖苷（GS）生物合成的调控及其与初级代谢途径的相互作用。我们用于分析的遗传材料是过表达调节脂肪族和吲哚GS生物合成途径（分别为AG和IG）的两个基因分支（ALTERED TRYPTOPHAN REGULATION 1 [ATR 1]样和MYB 28样）的转基因植物。我们发现，这些调节剂的活性不限于GS生物合成周围的代谢空间，但与初级代谢的更远的代谢网络紧密相连。这表明，与我们在这里研究的调节因子相似，控制次级代谢途径的其他因子也可能控制中枢代谢的核心途径。相对广泛的观点，转录本和代谢物改变过表达的不同因素的转基因植物强调GS代谢的新链接到其他代谢途径，包括茉莉酸，叶酸，苯甲酸，和各种苯丙素。它还揭示了在为GS生物合成提供前体的代谢途径的“远端”网络中的转录和代谢枢纽，并且ATR 1样进化枝基因的过表达对吲哚化合物的代谢具有比先前描述的更广泛的影响。虽然之前已经提出了在拟南芥中产生GS的甲硫氨酸和色氨酸途径之间的相互的、负的串扰，但是我们现在表明它不限于AG和IG，而是包括另外的代谢物，例如植物抗毒素camalexin。结合转基因株系的基因表达相关性分析，我们提出了一个模型，说明GS生物合成调节因子是如何维持代谢网络平衡的。ATR 1/MYB 34可能是两个进化枝基因活性之间的重要调节因子。虽然它在下游基因靶点方面与ATR 1样进化枝成员非常相似，但它的表达与MYB 28样进化枝成员的表达高度相关。最后，我们使用这里获得的独特的转基因植物来表明，与IG相比，AG可能是烟粉虱的更有效的威慑。对昆虫行为的影响提出了一个重要的问题，为未来的调查功能方面，我们最初的发现，这表明丰富的表达的MYB 28样进化枝基因在拟南芥叶的远轴域。
In this study, transcriptomics and metabolomics data were integrated in order to examine the regulation of glucosinolate (GS) biosynthesis in Arabidopsis (Arabidopsis thaliana) and its interface with pathways of primary metabolism. Our genetic material for analyses were transgenic plants overexpressing members of two clades of genes (ALTERED TRYPTOPHAN REGULATION1 [ATR1]-like and MYB28-like) that regulate the aliphatic and indole GS biosynthetic pathways (AGs and IGs, respectively). We show that activity of these regulators is not restricted to the metabolic space surrounding GS biosynthesis but is tightly linked to more distal metabolic networks of primary metabolism. This suggests that with similarity to the regulators we have investigated here, other factors controlling pathways of secondary metabolism might also control core pathways of central metabolism. The relatively broad view of transcripts and metabolites altered in transgenic plants overexpressing the different factors underlined novel links of GS metabolism to additional metabolic pathways, including those of jasmonic acid, folate, benzoic acid, and various phenylpropanoids. It also revealed transcriptional and metabolic hubs in the "distal'' network of metabolic pathways supplying precursors to GSbiosynthesis and that overexpression of the ATR1-like clade genes has a muchbroader effect on the metabolism of indolic compounds than described previously. While the reciprocal, negative cross talk between the methionine and tryptophan pathways that generate GSs in Arabidopsis has been suggested previously, we now show that it is not restricted to AGs and IGs but includes additional metabolites, such as the phytoalexin camalexin. Combining the profiling data of transgenic lines with gene expression correlation analysis allowed us to propose a model ofhowthe balance in the metabolic network is maintained by the GS biosynthesis regulators. It appears that ATR1/MYB34 is an important mediator between the gene activities of the two clades. While it is very similar to the ATR1-like clade members in terms of downstream gene targets, its expression is highly correlated with that of the MYB28-like clade members. Finally, we used the unique transgenic plants obtained here to show that AGs are likely more potent deterrents of the whitefly Bemisia tabaci compared with IGs. The influence on insect behavior raises an important question for future investigation of the functional aspect of our initial finding, which pointed to enriched expression of the MYB28-like clade genes in the abaxial domain of the Arabidopsis leaf.