Dissecting metabolic puzzles through isotope feeding: a novel amino acid in the biosynthetic pathway of the cruciferous phytoalexins rapalexin A and isocyalexin A
作者:M. Soledade C. Pedras、Estifanos E. Yaya
DOI:10.1039/c2ob27076e
日期:——
Understanding defence pathways of plants is crucial to develop disease-resistant agronomic crops, an important element of sustainable agriculture. For this reason, natural plant defenses such as phytoalexins, involved in protecting plants against microbial pathogens, have enormous biotechnological appeal. Crucifers are economically important plants, with worldwide impact as oilseeds, vegetables of great dietetic value and even nutraceuticals. Notably, the intermediates involved in the biosynthetic pathways of unique cruciferous phytoalexins such as rapalexin A and isocyalexin A remain unknown. Toward this end, using numerous perdeuterated compounds, we have established the potential precursors of these unique phytoalexins and propose for the first time their detailed biosynthetic pathway. This pathway involves a variety of intermediates and a novel amino acid as the central piece of this complex puzzle. This work has set the stage for the discovery of enzymes and genes of the biosynthetic pathway of cruciferous phytoalexins of unique scaffolds.
理解植物的防御途径对于开发抗病农作物至关重要,这是可持续农业的重要组成部分。因此,天然植物防御物质,如植物抗毒素(参与保护植物免受微生物病原体侵害),具有巨大的生物技术吸引力。十字花科植物是具有重要经济价值的植物,在全球范围内作为油料、高营养价值的蔬菜甚至保健品产生影响。值得注意的是,在独特的十字花科植物抗毒素(如芸薹素A和异硫氰酸酯A)的生物合成途径中所涉及的中间体仍未知。为此,我们利用大量氘代化合物确立了这些独特植物抗毒素的可能前体,并首次提出了它们的详细生物合成途径。该途径涉及多种中间体和一种作为这一复杂拼图核心的新型氨基酸。这项工作为发现具有独特骨架的十字花科植物对抗毒素生物合成途径的酶和基因奠定了基础。