Partitioning of sulfur between primary and secondary metabolism

硫是植物中的一种基本营养物质，存在于一系列必需的初级代谢物以及许多次生化合物中。由于其化学特性，主要代谢物中的硫通常以硫醇或硫化物的形式被还原，而次要化合物中的硫通常以有机硫酸盐的形式被氧化。我们在拟南芥中鉴定了4种不同亚型的腺苷5‘-磷酸硫酸盐(APS)激酶，它们是完成生命周期和合成硫代葡萄糖苷等硫酸盐次生产物所必需的。然而，我们的分析没有回答几个重要的问题：(I)APS激酶的氧化还原调节在控制S初级和次级代谢分配中的作用是什么(II.)为什么APS激酶亚型APK2单独不能维持拟南芥的生长，以及(Iii)APS激酶在不产生硫代葡萄糖苷的植物物种中的重要性是什么？这项建议解决了这些问题，以便对植物硫代谢的控制获得更详细和更一般的见解。

Sulfur is an essential nutrient in plants, present in a range of essential primary metabolites as well as in numerous secondary compounds. Due to its chemistry, sulfur in the primary metabolites is usually incorporated in a reduced form as a thiol or sulfide, whereas the secondary compounds contain often oxidized sulfur as organic sulfate. We have characterized 4 isoforms of the enzyme adenosine 5´-phosphosulfate (APS) kinase in Arabidopsis as being essential for completion of the life cycle and for synthesis of sulfated secondary products, such as glucosinolates. Our analyses however left several important questions unanswered: (i.) What is the role of redox regulation of APS kinase for control of partitioning of S between primary and secondary metabolism (ii.) Why is APS kinase isoform APK2 alone not capable to sustain growth of Arabidopsis, and (iii.) What is the importance of APS kinase in plant species not producing glucosinolates? This proposal addresses these questions in order to obtain more detailed and more general insights into control of plant sulfur metabolism.