Anthocyanins in tomato

Tomato (Solanum lycopersicum L.) is cultivated all over the world as annual crop in open field and under greenhouse conditions for both fresh consumption and industrial processing. The nutraceutical properties of tomato are mainly related to the antioxidant potential of the fruit, which in turn is due to the presence of a mix of antioxidant bio-molecules like lycopene, ascorbic acid, phenolics, flavonoids and vitamin E. On the other hand, tomato fruits do not normally contain significant concentration of anthocyanins, substances with a well-known nutraceutical value.

The research project carried out in our lab is focused on the study of the synthesis of anthocyanins and other flavonoids in tomato plants with the double aim to characterize the main genetic regulatory factors affecting the biosynthetic pathway in this species and to increase the amount of flavonoids in fruits.

In the first phase of our research, we aimed and succeeded in the identification of the regulatory genes which control the anthocyanin biosynthetic pathway in tomato vegetative tissues and of the specific alleles allowing the activation of the pathway also in the fruit. Result of these studies was also the production of new varieties of Solanum lycopersicum characterized by a purple fruit skin and obtained through conventional breeding. These new varieties were patented and commercialized.

Our experimental activities are now mainly addressed towards the characterization of the physiological mechanisms mediating the activation of the flavonoid biosynthetic pathway and triggered by some environmental factors and abiotic stress conditions. Light and temperature actually represent our major interests due to the conditional phenotypes of the purple fruit lines, mainly affected by high light and low temperatures. Additionally, the influence exerted on the regulation of the biosynthetic pathway by some developmental signals, particularly linked with photomorphogenesis in vegetative tissues and ripening in fruits, will be object of our investigations. Finally, the structure and the composition of the multiprotein MBW transcriptional complex modulating anthocyanin synthesis and accumulation in tomato plants and its interactions with some hormonal signalling pathways will be studied.    

Publications:

• D. L. Zuluaga, S. Gonzali, E. Loreti, C. Pucciariello, E. Degl’Innocenti, L. Guidi, A. Alpi, P. Perata. Arabidopsis thaliana MYB75/PAP1 transcription factor induces anthocyanin production in transgenic tomato plants. Functional Plant Biology 35, 606-618 (2008).
• S. Gonzali, A. Mazzucato, P. Perata. Purple as a tomato: towards high anthocyanin tomatoes. Trends in Plant Science 14, 237-241 (2009).
• G. Povero, S. Gonzali, L. Bassolino, A. Mazzucato, P. Perata. Transcriptional analysis in high-anthocyanin tomatoes reveals synergistical effect of Aft and atv genes. Journal of Plant Physiology 168, 270–279 (2011).
• L. Bassolino, Y. Zhang, H.J. Schoonbeek, C. Kiferle, P. Perata, C. Martin. Accumulation of anthocyanins in tomato skin extends shelf life. New Phytologist 200, 650-655 (2013).
• C. Kiferle, E. Fantini, L. Bassolino, G. Povero, C. Spelt, S. Buti, G. Giuliano, F. Quattrocchio, R. Koes, P. Perata, S. Gonzali: Tomato R2R3-MYB Proteins SlANT1 and SlAN2: Same Protein Activity, Different Roles. PlosOne. doi:10.1371/journal.pone.0136365 (2015).
• S. Colanero, P. Perata, S. Gonzali. The atroviolacea Gene Encodes an R3-MYB Protein Repressing Anthocyanin Synthesis in Tomato Plants. Frontiers in Plant Science 9:830 (2018).
• T. Petric T, C. Kiferle C, P. Perata, S. Gonzali. Optimizing shelf life conditions for anthocyanin-rich tomatoes. PlosOne. doi: 10.1371/journal.pone.0205650 (2018).
• S. Colanero, A. Tagliani, P. Perata, S. Gonzali. Alternative Splicing in the Anthocyanin Fruit Gene Encoding an R2R3 MYB Transcription Factor Affects Anthocyanin Biosynthesis in Tomato Fruits. Plant Communiations 1, 100006 (2020).
• S. Colanero, P. Perata , S. Gonzali. What's behind Purple Tomatoes? Insight into the Mechanisms of Anthocyanin Synthesis in Tomato Fruits. Plant Physiology 182, 1841-1853 (2020).