Carotenoid Isomerase Is Key Determinant of Petal Color of Calendula officinalis*
Carotenoid Isomerase Is Key Determinant of Petal Color of Calendula officinalis*
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类胡萝卜素异构酶是金盏花花瓣颜色的关键决定因素*
DOI：
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发表时间：
2011
影响因子：
4.8
通讯作者：
A. Ohmiya
中科院分区：
文献类型：
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作者：
S. Kishimoto;A. Ohmiya
背景：红色的5-顺式类胡萝卜素积累在橙子的花瓣中，而不是黄色的花瓣中。结果：在橙子花瓣中的CRTISO缺乏异构酶活性。结论：CRTISO活性是决定菊花花瓣颜色的关键因素。意义：CoCRTISO的462位Cys-His-His和450位Gly对异构酶活性很重要。金盏花（Calendula officinalis）的橙子花瓣积累红色类胡萝卜素，其C-5或C-5′位具有顺式构型（5-cis-类胡萝卜素）。我们推测，橙色花的拟南芥是一个类胡萝卜素异构酶（crtiso）的功能丧失突变体，损害顺式到反式5-顺式-类胡萝卜素的转换。我们比较了橙子和黄花拟南芥CRTISO的序列和酶活性。四种类型的CRTISO表达在菊花花瓣。其中一个基因（CoCRTISO 1）的推导氨基酸序列在橙子和黄花拟南芥中不同，而其他三个CRTISOs的序列在这些植物中是相同的。CoCRTISO同源物的酶活性分析表明，CoCRTISO 1-Y，这是在黄色花瓣中表达，类胡萝卜素从顺式到反式构型的转换，而CoCRTISO 1-ORa和1-ORb，这是在橙子花瓣中表达，没有表现出任何活性的顺式类胡萝卜素，我们测试。此外，通过橙子和黄色系杂交获得的F2后代的CoCRTISO 1基因型与花瓣颜色紧密连锁。这些数据表明，CoCRTISO 1是5-顺式-类胡萝卜素的积累在菊花花瓣的关键调节器。定点突变表明，CoCRTISO 1-ORa中462-464位Cys-His-His的缺失和CoCRTISO 1-ORb中450位Gly-to-Glu氨基酸的取代完全消除了酶活性，表明这些氨基酸残基对CRTISO的酶活性很重要。
Background: Reddish 5-cis-carotenoids accumulate in the orange but not yellow petals of calendula. Results: A CRTISO in orange petals of calendula lacks an isomerase activity. Conclusion: CRTISO activity is a key factor in determining calendula petal color. Significance: Cys-His-His at position 462 and Gly at position 450 of CoCRTISO are important for the isomerase activity. Orange petals of calendula (Calendula officinalis) accumulate red carotenoids with the cis-configuration at the C-5 or C-5′ position (5-cis-carotenoids). We speculated that the orange-flowered calendula is a carotenoid isomerase (crtiso) loss-of-function mutant that impairs the cis-to-trans conversion of 5-cis-carotenoids. We compared the sequences and enzyme activities of CRTISO from orange- and yellow-flowered calendulas. Four types of CRTISO were expressed in calendula petals. The deduced amino acid sequence of one of these genes (CoCRTISO1) was different between orange- and yellow-flowered calendulas, whereas the sequences of the other three CRTISOs were identical between these plants. Analysis of the enzymatic activities of the CoCRTISO homologs showed that CoCRTISO1-Y, which was expressed in yellow petals, converted carotenoids from the cis-to-trans-configuration, whereas both CoCRTISO1-ORa and 1-ORb, which were expressed in orange petals, showed no activity with any of the cis-carotenoids we tested. Moreover, the CoCRTISO1 genotypes of the F2 progeny obtained by crossing orange and yellow lines linked closely to petal color. These data indicate that CoCRTISO1 is a key regulator of the accumulation of 5-cis-carotenoids in calendula petals. Site-directed mutagenesis showed that the deletion of Cys-His-His at positions 462–464 in CoCRTISO1-ORa and a Gly-to-Glu amino acid substitution at position 450 in CoCRTISO1-ORb abolished enzyme activity completely, indicating that these amino acid residues are important for the enzymatic activity of CRTISO.
影响因子：
3.5
作者：
HO, SN;HUNT, HD;PEASE, LR
通讯作者：
PEASE, LR
影响因子：
6.9
作者：
Matthews, PD;Luo, RB;Wurtzel, ET
通讯作者：
Wurtzel, ET