Fundo de defesa da citricultura (Fundecitrus), Av. Adhemar P. Barros, Araraquara, São Paulo, Brazil.
Fundo de defesa da citricultura (Fundecitrus), Av. Adhemar P. Barros, Araraquara, São Paulo, Brazil; Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, Ingeniero Fausto Elio s/n, Valencia, Spain.
Food Chem. 2017 Dec 15;237:7-14. doi: 10.1016/j.foodchem.2017.05.076. Epub 2017 May 17.
Blood oranges require low temperature for anthocyanin production. We have investigated the activation of anthocyanin biosynthesis and accumulation in the pulp of Moro blood and Pera blond oranges (Citrus sinensis L. Osbeck) stored at either 4 or 9°C after harvesting. Both temperatures stimulated anthocyanin accumulation in blood but not in blond oranges. Nonetheless, blood orange fruits stored at 9°C reached a darker purple coloration, higher anthocyanin contents and enhanced upregulation of genes from the flavonoid pathway in the pulp and juice than those kept at 4°C. Our results indicated that dihydroflavonol channeling toward anthocyanin production was boosted during the storage at 9°C compared to 4°C, providing more leucoanthocyanidins to enzymes downstream in the pathway. Finally, despite both low temperatures stimulated the expression of key transcription factors likely regulating the pathway, their expression profiles could not explain the differences observed at 9 and 4°C.
血橙的花色苷合成需要低温。我们研究了在收获后分别贮藏于 4℃和 9℃条件下，Moro 血橙和 Pera 脐橙（Citrus sinensis L. Osbeck）果肉中花色苷生物合成和积累的激活情况。这两种温度均能刺激血橙中花色苷的积累，但对脐橙没有影响。尽管如此，在 9℃贮藏的血橙果实颜色更深，花色苷含量更高，且果肉和果汁中类黄酮途径的基因表达上调更为明显，而在 4℃贮藏的果实则不然。我们的结果表明，与 4℃相比，9℃贮藏时二氢黄酮醇向花色苷合成的通道增强，为途径下游的酶提供了更多的无色花青素。最后，尽管低温均能刺激关键转录因子的表达，从而可能调控该途径，但它们的表达模式无法解释在 9℃和 4℃下观察到的差异。
