Arabidopsis Phosphoglycerate Dehydrogenase1 of the Phosphoserine Pathway Is Essential for Development and Required for Ammonium Assimilation and Tryptophan Biosynthesis
Arabidopsis Phosphoglycerate Dehydrogenase1 of the Phosphoserine Pathway Is Essential for Development and Required for Ammonium Assimilation and Tryptophan Biosynthesis
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DOI：
10.1105/tpc.113.118992
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发表时间：
2013-12-01
期刊：
影响因子：
11.6
通讯作者：
Krueger, Stephan
中科院分区：
文献类型：
--
作者：
Benstein, Ruben Maximilian;Ludewig, Katja;Krueger, Stephan
在植物中，两个独立的丝氨酸生物合成途径，光呼吸和糖酵解磷酸丝氨酸（PS）途径，已被假定。虽然光呼吸途径的特点是很好的，很少的信息是在植物中的PS途径的功能。在这里，我们提出了一个详细的表征磷酸甘油酸脱氢酶（PGDH）的组成部分，在拟南芥的PS途径。所有PGDH定位于质体，并具有相似的动力学性质，但它们对丝氨酸反馈抑制的敏感性不同。此外，对pgdh1和磷酸丝氨酸磷酸酶突变体的分析揭示了胚胎致死表型，并且PGDH 1沉默系的生长受到抑制。PGDH1沉默线生长在环境和高CO2条件下的代谢分析表明PS生物合成和铵同化之间的直接联系。此外，我们获得了PS和色氨酸生物合成之间相互关联的几条证据，因为PGDH 1和磷酸丝氨酸氨基转移酶1的表达受色氨酸生物合成的两种激活剂MYB 51和MYB 34的调节。此外，在PGDH 1沉默的植物中，葡聚糖衍生的硫代葡萄糖苷和生长素的浓度降低。从本质上讲，我们的研究结果提供了证据PS生物合成的植物发育和代谢的重要功能。
In plants, two independent serine biosynthetic pathways, the photorespiratory and glycolytic phosphoserine (PS) pathways, have been postulated. Although the photorespiratory pathway is well characterized, little information is available on the function of the PS pathway in plants. Here, we present a detailed characterization of phosphoglycerate dehydrogenases (PGDHs) as components of the PS pathway in Arabidopsis thaliana. All PGDHs localize to plastids and possess similar kinetic properties, but they differ with respect to their sensitivity to serine feedback inhibition. Furthermore, analysis of pgdh1 and phosphoserine phosphatase mutants revealed an embryo-lethal phenotype and PGDH1-silenced lines were inhibited in growth. Metabolic analyses of PGDH1-silenced lines grown under ambient and high CO2 conditions indicate a direct link between PS biosynthesis and ammonium assimilation. In addition, we obtained several lines of evidence for an interconnection between PS and tryptophan biosynthesis, because the expression of PGDH1 and PHOSPHOSERINE AMINOTRANSFERASE1 is regulated by MYB51 and MYB34, two activators of tryptophan biosynthesis. Moreover, the concentration of tryptophan-derived glucosinolates and auxin were reduced in PGDH1-silenced plants. In essence, our results provide evidence for a vital function of PS biosynthesis for plant development and metabolism.