L-DOPA, also known as Levodopa or L-3,4-dihydroxyphenylalanine, is a non-standard amino acid, and the gold standard drug for the treatment for Parkinson's Disease (PD). Recently, a gene encoding the enzyme that is responsible for its synthesis, as a precursor of the coloured pigment group betalains, was identified in beetroot, BvCYP76AD6. We have engineered tomato fruit enriched in L-DOPA through overexpression of BvCYP76AD6 in a fruit specific manner. Analysis of the transgenic fruit revealed the feasibility of accumulating L-DOPA in a non-naturally betalain-producing plant. Fruit accumulating L-DOPA also showed major effects on the fruit metabolome. Some of these changes included elevation of amino acids levels, changes in the levels of intermediates of the TCA and glycolysis pathways and reductions in the levels of phenolic compounds and nitrogen-containing specialised metabolites. Furthermore, we were able to increase the L-DOPA levels further by elevating the expression of the metabolic master regulator, MYB12, specifically in tomato fruit, together with BvCYP76AD6. Our study elucidated new roles for L-DOPA in plants, because it impacted fruit quality parameters including antioxidant capacity and firmness. The L-DOPA levels achieved in tomato fruit were comparable to the levels in other non-seed organs of L-DOPA - accumulating plants, offering an opportunity to develop new biological sources of L-DOPA by widening the repertoire of L-DOPA accumulating plants. These tomato fruit could be used as an alternative source of this important pharmaceutical.

L-DOPA，也称为左旋多巴或L-3,4-二羟基苯丙氨酸，是一种非标准氨基酸，是治疗帕金森病（PD）的金标准药物。最近，在甜菜根BvCYP76AD6中发现了一种编码负责其合成的酶的基因，它是有色色素组甜菜碱的前体。我们通过BvCYP76AD6的过表达设计了富含 L-DOPA 的番茄果实以水果特定的方式。对转基因果实的分析揭示了在非天然甜菜碱生产植物中积累 L-DOPA 的可行性。积累 L-DOPA 的果实也显示出对果实代谢组的主要影响。其中一些变化包括氨基酸水平的升高、TCA 中间体水平和糖酵解途径的变化以及酚类化合物和含氮特殊代谢物水平的降低。此外，我们能够通过提高代谢主调节因子MYB12的表达，特别是在番茄果实中的表达，与BvCYP76AD6一起进一步增加 L-DOPA 水平. 我们的研究阐明了 L-DOPA 在植物中的新作用，因为它会影响水果质量参数，包括抗氧化能力和硬度。番茄果实中的 L-DOPA 水平与 L-DOPA 积累植物的其他非种子器官中的水平相当，这为通过扩大 L-DOPA 积累植物的库来开发新的 L-DOPA 生物来源提供了机会. 这些番茄果实可以用作这种重要药物的替代来源。