Vitamin B₁ is a family of molecules, the most renowned member of which is diphosphorylated thiamine (TDP)—a coenzyme vital for the activity of key enzymes of energy metabolism. Triphosphorylated thiamine derivatives also exist within this family, specifically thiamine triphosphate (TTP) and adenosine thiamine triphosphate (ATTP). They have been investigated primarily in mammalian cells and are thought to act as metabolic messengers but have not received much attention in plants. In this study, we set out to examine for the presence of these triphosphorylated thiamine derivatives in Arabidopsis. We could find TTP in Arabidopsis under standard growth conditions, but we could not detect ATTP. Interestingly, TTP is found primarily in shoot tissue. Drivers of TTP synthesis are light intensity, the proton motive force, as well as TDP content. In plants, TTP accumulates in the organellar powerhouses, the plastids, and mitochondria. Furthermore, in contrast to other B₁ vitamers, there are strong oscillations in tissue levels of TTP levels over diel periods peaking early during the light period. The elevation of TTP levels during the day appears to be coupled to a photosynthesis‐driven process. We propose that TTP may signify TDP sufficiency, particularly in the organellar powerhouses, and discuss our findings in relation to its role.

中文翻译：

---

关于拟南芥中三磷酸硫胺素的性质。

维生素B ₁是分子家族，其中最著名的成员是二磷酸硫胺素（TDP），这是一种对能量代谢关键酶的活性至关重要的辅酶。三磷酸硫胺素衍生物也存在于该家族中，特别是三磷酸硫胺素（TTP）和三磷酸腺苷硫胺素（ATTP）。它们主要在哺乳动物细胞中进行了研究，被认为可以充当代谢信使，但在植物中并未引起太多关注。在这项研究中，我们着手研究拟南芥中是否存在这些三磷酸硫胺素衍生物。在标准生长条件下，我们可以在拟南芥中找到TTP，但无法检测到ATTP。有趣的是，TTP主要存在于芽组织中。TTP合成的驱动因素是光强度，质子动力以及TDP含量。在植物中 TTP积累在细胞器的动力室，质体和线粒体中。此外，与其他B相比_1种维他命，在diel期间的TTP水平在组织中有强烈的振荡，并在光照期达到峰值。白天TTP水平的升高似乎与光合作用驱动的过程有关。我们建议TTP可能表示TDP的充足性，尤其是在细胞器强国中，并讨论我们关于其作用的发现。