Regulation of anthocyanin biosynthesis involved in the formation of marginal picotee petals in Petunia
Regulation of anthocyanin biosynthesis involved in the formation of marginal picotee petals in Petunia
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DOI：
10.1016/j.plantsci.2005.12.003
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发表时间：
2006-04-01
期刊：
影响因子：
5.2
通讯作者：
Nakayama, M
中科院分区：
文献类型：
--
作者：
Saito, R;Fukuta, N;Nakayama, M
边缘皮可蒂是一种花的颜色，其特征是花瓣的顶部和基部区域颜色不同。为了深入了解色素积累导致的内源模式形成的分子机制，我们分析了矮牵牛花冠不同部位花青素相关化合物以及参与花青素生物合成的6个基因的转录水平。两种不同的机制抑制花青素苷的生物合成提出了不同的着色模式的品种。在仅在花的中心显示强烈着色的品种的花冠的白色边缘中，催化肉桂酸衍生物转化为类黄酮的查耳酮合酶的表达被抑制，肉桂酸衍生物积累，而其他酶的表达水平相似，表明类黄酮生物合成的减少与花冠边缘无色素区的形成有关。对于具有相反对比模式的花瓣，黄酮醇和黄酮醇合酶转录物的水平在白色区域中特别高，而直接参与花色素苷生物合成的其他基因的转录物水平在白色和有色区域之间相似，这表明通过增强黄酮醇合酶的表达而增强黄酮醇生物合成至少部分地导致花色素苷水平的降低，在栽培品种中形成无色素的区域，显示白色花冠中心。(c)2005爱思唯尔爱尔兰有限公司保留所有权利。
Marginal picotee is a floral coloration characterized by differently colored apical and basal zones in the petals. To gain insights into the molecular mechanisms underlying endogenous pattern formation due to pigment accumulation, we analyzed the levels of anthocyanin-related compounds as well as transcripts of six genes involved in anthocyanin biosynthesis in different parts of corolla in Petunia hybrida. Two distinct mechanisms for repression of anthocyanin biosynthesis are proposed in cultivars showing different coloration patterns. In the white margin of the corolla of a cultivar showing strong coloration only in the center of the flower, expression of chalcone synthase, which catalyzes the conversion of cinnamic acid derivatives into flavonoids, was repressed and cinnamic acid derivatives were accumulated, while the expression levels of other enzymes were similar, suggesting that reduction in flavonoid biosynthesis by repression of chalcone synthase is involved in the formation of unpigmented zones in the corolla margins. As for petals bearing the reverse contrast pattern, the levels of flavonol and flavonol synthase transcripts were particularly high in the white regions, while the transcript levels of other genes directly involved in anthocyanin biosynthesis were similar between the white and colored regions, suggesting that enhancement of flavonol biosynthesis by enhanced expression of flavonol synthase is at least in part responsible for reduction in anthocyanin level and formation of unpigmented zones in a cultivar showing white corolla centers. (c) 2005 Elsevier Ireland Ltd. All rights reserved.