Metabolite shift in Medicago truncatula occurs in phosphorus deprivation
Metabolite shift in Medicago truncatula occurs in phosphorus deprivation
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DOI：
10.1093/jxb/erab559
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发表时间：
2022-03-09
影响因子：
6.9
通讯作者：
Dickstein, Rebecca
中科院分区：
文献类型：
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作者：
Dokwal, Dhiraj;Cocuron, Jean-Christophe;Dickstein, Rebecca
共生固氮需要豆科寄主和根瘤菌之间成功的相互作用，这种相互作用发生在称为根瘤的特殊器官中。固氮豆科植物对磷的需要量高于矿质氮上生长的豆科植物，苜蓿是在分子水平上研究缺磷效应的重要模式植物。因此，进行了一项研究，以解决空气栽培和经受4周磷胁迫的M. truncatula代谢物水平的变化。首先，基于gc - ms的非靶向代谢组学最初揭示了结节代谢谱的变化，氨基酸和糖的水平增加，有机酸的数量下降。随后，采用LC-MS/MS对这些化合物进行定量，包括整个植物的磷酸化代谢物。我们的研究结果表明，磷叶片中有机酸和磷酸化化合物的水平急剧下降，磷根和根瘤的水平略有下降。此外，缺磷处理使全株糖和氨基酸含量升高。这些发现提供了证据，证明M. truncatula的固氮是通过与碳和磷代谢平行的N反馈机制介导的。截断紫花苜蓿在磷剥夺过程中发生代谢变化，叶片中有机酸和磷酸化代谢物急剧下降，全株糖和氨基酸增加。
Symbiotic nitrogen (N) fixation entails successful interaction between legume hosts and rhizobia that occur in specialized organs called nodules. N-fixing legumes have a higher demand for phosphorus (P) than legumes grown on mineral N. Medicago truncatula is an important model plant for characterization of effects of P deficiency at the molecular level. Hence, a study was carried out to address the alteration in metabolite levels of M. truncatula grown aeroponically and subjected to 4 weeks of P stress. First, GC-MS-based untargeted metabolomics initially revealed changes in the metabolic profile of nodules, with increased levels of amino acids and sugars and a decline in amounts of organic acids. Subsequently, LC-MS/MS was used to quantify these compounds including phosphorylated metabolites in the whole plant. Our results showed a drastic reduction in levels of organic acids and phosphorylated compounds in -P leaves, with a moderate reduction in -P roots and nodules. Additionally, sugars and amino acids were elevated in the whole plant under P deprivation. These findings provide evidence that N fixation in M. truncatula is mediated through a N feedback mechanism that in parallel is related to carbon and P metabolism.Medicago truncatulaundergoes a metabolic shift in phosphorus deprivation, with a drastic decline in organic acids and phosphorylated metabolites in leaves and an increase in sugars and amino acids in the whole plant.