Panara Francesco, Passeri Valentina, Lopez Loredana, Porceddu Andrea, Calderini Ornella, Paolocci Francesco
Trisaia Research Center, Italian National Agency for New Technologies Energy and Sustainable Economic Development, (ENEA), 75026 Rotondella, MT, Italy.
Institute of Biosciences and Bioresources, Consiglio Nazionale delle Ricerche, 06128 Perugia, PG, Italy.
Plants (Basel). 2022 May 16;11(10):1318. doi: 10.3390/plants11101318.
Flavonoids are essential compounds widespread in plants and exert many functions such as defence, definition of organ colour and protection against stresses. In , flavonoid biosynthesis and accumulation is finely regulated in terms of tissue specificity and induction by external factors, such as cold and other stresses. Among flavonoids, anthocyanin precursors are synthesised in the cytoplasm, transported to the tonoplast, then imported into the vacuole for further modifications and storage. In the present work, we functionally characterised MtrGSTF7, a phi-class glutathione S-transferase involved in anthocyanin transport to the tonoplast. The mutant completely lost the ability to accumulate anthocyanins in leaves both under control and anthocyanin inductive conditions. On the contrary, this mutant showed an increase in the levels of soluble proanthocyanidins (Pas) in their seeds with respect to the wild type. By complementation and expression data analysis, we showed that, differently from and similarly to , transport of anthocyanin and proanthocyanidins is likely carried out by different GSTs belonging to the phi-class. Such functional diversification likely results from the plant need to finely tune the accumulation of diverse classes of flavonoids according to the target organs and developmental stages.
黄酮类化合物是植物中广泛存在的重要化合物，具有多种功能，如防御、器官颜色的界定以及抵御胁迫等。在植物中，黄酮类化合物的生物合成和积累在组织特异性以及外部因素（如寒冷和其他胁迫）诱导方面受到精细调控。在黄酮类化合物中，花青素前体在细胞质中合成，转运至液泡膜，然后导入液泡进行进一步修饰和储存。在本研究中，我们对MtrGSTF7进行了功能表征，它是一种参与花青素向液泡膜转运的phi类谷胱甘肽S-转移酶。该突变体在对照和花青素诱导条件下，叶片中完全丧失了积累花青素的能力。相反，与野生型相比，该突变体种子中可溶性原花青素（PAs）水平有所增加。通过互补和表达数据分析，我们表明，与其他情况不同且与某些情况相似，花青素和原花青素的转运可能由属于phi类的不同谷胱甘肽S-转移酶进行。这种功能多样化可能源于植物根据目标器官和发育阶段精细调节不同类黄酮积累的需求。
