Fantini Elio, Daddiego Loretta, Facella Paolo, Perrella Giorgio, Bianco Linda, Fasano Carlo, Alagna Fiammetta, Savoia Michele Antonio, Rigano Daniela, Sirignano Carmina, Scafati Orazio Taglialatela, Pacifico Severina, Piccolella Simona, Lopez Loredana, Panara Francesco
Trisaia Research Center, ENEA, S.S. 106 Ionica - Km 419+500, 75026, Rotondella, MT, Italy.
Department of Biosciences, University of Milan, Via Celoria 26, 20133, Milan, Italy.
Planta. 2025 May 24;262(1):5. doi: 10.1007/s00425-025-04719-9.
This study showed that MYC2 transcriptionally regulates valuable metabolites in Taraxacum spp. through direct interaction with specific target gene promoters. The Russian dandelion (Taraxacum kok-saghyz) represents a promising alternative species, capable of producing several high-added-value compounds, including natural rubber. Nevertheless, further enhancements are required for its optimal utilization by the industry. Here, we explored the role of the bHLH transcription factor TksMYC2, homolog of AtMYC2, in the regulation of the biosynthesis of specialized metabolites and free fatty acids and in the control of natural rubber production. Metabolic analyses of Taraxacum kok-saghyz plants showed that the overexpression of TksMYC2 significantly affected the accumulation of metabolites in roots and leaves, such as sesquiterpene lactones, phenylpropanoids, and free fatty acids. Moreover, overexpressing plants presented a significant increase in natural rubber production in both Taraxacum kok-saghyz and its related species Taraxacum brevicorniculatum. The direct interaction of TksMYC2 with the regulatory regions of cis-prenyltransferase 2 (CPT2), small rubber particle proteins (SRPP1, SRPP3, and SRPP4), involved in the biosynthesis of natural rubber, and with the germacrene A oxidase (GAO), involved in the biosynthesis of sesquiterpenes, was demonstrated by chromatin immunoprecipitation coupled with quantitative PCR. Additionally, these genes were highly induced in the lines overexpressing TksMYC2. Our findings suggest that TksMYC2 and its downstream components may be valid targets for breeding programmes to increase the production of valuable metabolites, including natural rubber.
本研究表明，MYC2通过与特定靶基因启动子直接相互作用，对蒲公英属植物中的重要代谢产物进行转录调控。俄罗斯蒲公英（Taraxacum kok-saghyz）是一种很有前景的替代物种，能够产生多种高附加值化合物，包括天然橡胶。然而，为了实现该产业对其的最佳利用，仍需要进一步改良。在此，我们探究了bHLH转录因子TksMYC2（AtMYC2的同源物）在调控特殊代谢产物和游离脂肪酸生物合成以及天然橡胶生产控制中的作用。对俄罗斯蒲公英植株的代谢分析表明，TksMYC2的过表达显著影响了根和叶中代谢产物的积累，如倍半萜内酯、苯丙烷类化合物和游离脂肪酸。此外，过表达植株的天然橡胶产量在俄罗斯蒲公英及其近缘物种短角蒲公英中均显著增加。染色质免疫沉淀结合定量PCR证明，TksMYC2与参与天然橡胶生物合成的顺式异戊烯基转移酶2（CPT2）、小橡胶粒子蛋白（SRPP1、SRPP3和SRPP4）的调控区域以及参与倍半萜生物合成的杜松烯A氧化酶（GAO）直接相互作用。此外，这些基因在过表达TksMYC2的株系中被高度诱导。我们的研究结果表明，TksMYC2及其下游组分可能是育种计划中增加包括天然橡胶在内的重要代谢产物产量的有效靶点。
