Hong Gaojie, Wang Jie, Zhang Yong, Hochstetter Danielle, Zhang Shuping, Pan Yue, Shi Yunlong, Xu Ping, Wang Yuefei
Department of Tea Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Department of Tea Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Plant Physiol Biochem. 2014 May;78:49-52. doi: 10.1016/j.plaphy.2014.02.017. Epub 2014 Mar 3.
Tea (Camellia sinensis L.) is a crop with both commercial and medicinal value with remarkably high polyphenol content in the form of catechins. To understand the molecular regulation of catechin biosynthesis in tea, we treated the tea plants with darkness. We used qRT-PCR to validate the expression of genes involved in catechin biosynthesis. It indicated that dark treatment displayed different effects on the genes participating in tea flavonoid (FL) pathway. The early genes of FL biosynthesis pathway, CHSI, F3H and DFR, remained at steady expression levels when treated by darkness. It is noteworthy that the expression level of LAR increased and the level of ANS decreased under dark conditions. The vanillin assay showed that the dark-treated plants contained lower levels of total catechins than those grown under normal conditions. The HPLC analysis further demonstrated the changes in biosynthesis of catechins under these conditions. In accordance with the gene expression pattern, the content of epicatechins (ECs) declined and that of catechins (Cs) was elevated in response to the darkness. Our study uncovered the molecular mechanisms and biochemical changes of shading in tea cultivation.
茶树（Camellia sinensis L.）是一种具有商业和药用价值的作物，其儿茶素形式的多酚含量极高。为了了解茶树中儿茶素生物合成的分子调控机制，我们对茶树进行了黑暗处理。我们使用qRT-PCR验证了参与儿茶素生物合成的基因的表达。结果表明，黑暗处理对参与茶叶黄酮（FL）途径的基因表现出不同的影响。FL生物合成途径的早期基因CHSI、F3H和DFR在黑暗处理时保持稳定的表达水平。值得注意的是，在黑暗条件下，LAR的表达水平升高而ANS的水平降低。香草醛测定表明，黑暗处理的植株总儿茶素含量低于正常生长条件下的植株。HPLC分析进一步证明了这些条件下儿茶素生物合成的变化。根据基因表达模式，表儿茶素（ECs）的含量下降，而儿茶素（Cs）的含量因黑暗处理而升高。我们的研究揭示了茶树栽培中遮荫的分子机制和生化变化。
