Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China.
Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
Food Chem. 2019 Jun 15;283:131-140. doi: 10.1016/j.foodchem.2018.12.121. Epub 2019 Jan 14.
Bananas are a recommended food source to alleviate vitamin A deficiency because they contain a high ratio of provitamin A precursors. The objective of this study was to investigate carotenoid accumulation pattern in banana fruits during postharvest ripening and the mechanisms regulating this process. Ripe banana pulp had an unusually high α-/β-carotene ratio (1.05), and the carotenoid contents increased (p ≤ 0.05) under light and high temperature. We analyzed the sequences, transcript levels, and functions of genes involved in carotenoid synthesis. The high ratio of α-/β-carotene in ripe banana fruit was explained by the high flux to the α-carotene biosynthetic pathway, as reflected by high transcript levels of LCYE, and the weak flux to the β-carotene branch of the biosynthetic pathway due to inactive MaLCYB1.2. High temperature during ripening up-regulated the transcript levels of genes involved in the α- and β-carotene biosynthesis pathways and the activities of their encoded enzymes.
香蕉是推荐的食物来源，可以缓解维生素 A 缺乏症，因为它们含有高比例的维生素 A 前体。本研究的目的是调查香蕉果实在后熟过程中类胡萝卜素的积累模式，以及调节这一过程的机制。成熟的香蕉果肉具有异常高的 α-/β-胡萝卜素比例（1.05），在光照和高温下，类胡萝卜素含量增加（p≤0.05）。我们分析了参与类胡萝卜素合成的基因的序列、转录水平和功能。成熟香蕉果实中高比例的 α-/β-胡萝卜素是由高流量到 α-胡萝卜素生物合成途径解释的，这反映在 LCYE 的高转录水平上，而由于 MaLCYB1.2 失活，β-胡萝卜素分支的通量较弱。成熟过程中的高温上调了参与 α-和 β-胡萝卜素生物合成途径的基因的转录水平及其编码酶的活性。
