Broad connections in the Arabidopsis seed metabolic network revealed by metabolite profiling of an amino acid catabolism mutant
Broad connections in the Arabidopsis seed metabolic network revealed by metabolite profiling of an amino acid catabolism mutant
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DOI：
10.1111/j.1365-313x.2009.04083.x
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发表时间：
2010-02-01
期刊：
影响因子：
7.2
通讯作者：
Last, Robert L.
中科院分区：
文献类型：
--
作者：
Gu, Liping;Jones, A. Daniel;Last, Robert L.
拟南芥突变体被鉴定为在种子中20种游离蛋白质氨基酸中有12种增加。由于这些代谢物是由多个看似无关的生物合成网络产生的，因此不可能使用候选基因方法来发现导致这种复杂综合征的酶缺陷。补充代谢物分析显示，种子高蛋氨酸和异戊酰氧基丙基-芥子油苷增加，沿着3-苯甲酰氧基丙基-芥子油苷减少。这些数据导致发现支链氨基酸分解代谢酶异戊酰辅酶A脱氢酶（由基因At 3g 45300或atIVD编码）受损是该代谢综合征的原因。这些结果表明，催化剂在调节种子中支链氨基酸水平方面起着重要作用。ivd 1突变体中受影响的多种代谢物表明存在比以前观察到的更复杂的调节种子氨基酸积累的网络。这种结合靶向和非靶向的代谢物谱分析方法广泛适用于代谢突变体的表征、人类疾病研究和作物种质。
An Arabidopsis thaliana mutant was identified as having increases in 12 of 20 free proteogenic amino acids in seeds. Because these metabolites are produced from multiple, seemingly unrelated biosynthetic networks, it was not possible to use a candidate gene approach to discover the enzyme defect responsible for this complex syndrome. Complementary metabolite profiling analyses revealed increased seed homomethionine and isovaleroyloxypropyl-glucosinolate, along with reduced 3-benzoyloxypropyl-glucosinolate. These data led to the discovery of impaired branched chain amino acid catabolic enzyme isovaleryl-CoA dehydrogenase ( encoded by gene At3g45300 or atIVD) as the cause of this metabolic syndrome. These results indicate that catabolism plays an important role in regulating levels of branched chain amino acids in seeds. The diverse set of metabolites affected in the ivd1 mutants suggests the existence of a more complex network regulating seed amino acid accumulation than previously observed. This combined targeted and non-targeted metabolite profiling approach is broadly applicable to the characterization of metabolic mutants, human disease studies and crop germplasm.