Huang Xiuzheng, Liu Lei, Qiang Xiaojing, Meng Yuanfa, Li Zhiyong, Huang Fan
Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot 100081, China.
Plants (Basel). 2024 Feb 29;13(5):700. doi: 10.3390/plants13050700.
The petals of ssp. and . ssp. are purple and yellow, respectively. Free hybridization between . ssp. and . ssp. has created hybrids with various flower colors in nature. Moreover, the flower colors of alfalfa are closely correlated with yield, nutritional quality, stress tolerance and other agronomic characteristics. To elucidate the underlying mechanisms of flower color formation in . ssp. and . ssp. , we conducted an integrative analysis of the transcriptome and metabolome of alfalfa with three different petal colors (purple, yellow and cream). The metabolic profiles suggested that anthocyanins and carotenoids are the crucial pigments in purple and yellow flowers, respectively. A quantitative exploration of the anthocyanin and carotenoid components indicated that the accumulations of cyanidin, delphinidin, peonidin, malvidin, pelargonidin and petunidin derivatives are significantly higher in purple flowers than in cream flowers. In addition, the content of carotenes (phytoene, α-carotene and β-carotene) and xanthophylls (α-cryptoxanthin, lutein, β-cryptoxanthin, zeaxanthin, antheraxanthin and violaxanthin derivatives) was markedly higher in yellow flowers than in cream flowers. Furthermore, we found that delphinidin-3,5-O-diglucoside and lutein were the predominant pigments accumulated in purple and yellow flowers, respectively. The transcriptomic results revealed that twenty-five upregulated structural genes (one , three , twelve , two , one , one , one and four ) are involved in the accumulation of anthocyanins in purple flowers, and nine structural genes (two , one , two , two , one and one ) exert an effect on the carotenoid biosynthesis pathway in yellow flowers. The findings of this study reveal the underlying mechanisms of anthocyanin and carotenoid biosynthesis in alfalfa with three classic flower colors.
[该物种的亚种]和[另一物种的亚种]的花瓣分别为紫色和黄色。[某一物种的亚种]和[另一物种的亚种]之间的自由杂交在自然界中产生了具有各种花色的杂种。此外，苜蓿的花色与产量、营养品质、抗逆性和其他农艺性状密切相关。为了阐明[某一物种的亚种]和[另一物种的亚种]花色形成的潜在机制，我们对三种不同花瓣颜色（紫色、黄色和米色）的苜蓿进行了转录组和代谢组的综合分析。代谢谱表明，花青素和类胡萝卜素分别是紫色和黄色花朵中的关键色素。对花青素和类胡萝卜素成分的定量研究表明，矢车菊素、飞燕草素、芍药色素、锦葵色素、天竺葵色素和矮牵牛色素衍生物在紫色花朵中的积累显著高于米色花朵。此外，黄色花朵中类胡萝卜素（八氢番茄红素、α-胡萝卜素和β-胡萝卜素）和叶黄素（α-隐黄质、叶黄素、β-隐黄质、玉米黄质、花药黄质和紫黄质衍生物）的含量明显高于米色花朵。此外，我们发现飞燕草素-3,5-O-二葡萄糖苷和叶黄素分别是紫色和黄色花朵中积累的主要色素。转录组结果显示，25个上调的结构基因（1个[基因名称1]、3个[基因名称2]、12个[基因名称3]、2个[基因名称4]、1个[基因名称5]、1个[基因名称6]、1个[基因名称7]和4个[基因名称8]）参与了紫色花朵中花青素的积累，9个结构基因（2个[基因名称9]、1个[基因名称10]、2个[基因名称11]、2个[基因名称12]、1个[基因名称13]和1个[基因名称14]）对黄色花朵中的类胡萝卜素生物合成途径有影响。本研究结果揭示了三种经典花色苜蓿中花青素和类胡萝卜素生物合成的潜在机制。
