Arogenate Dehydratase Isoforms Differentially Regulate Anthocyanin Biosynthesis in Arabidopsis thaliana
Arogenate Dehydratase Isoforms Differentially Regulate Anthocyanin Biosynthesis in Arabidopsis thaliana
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芳酸脱水酶亚型差异调节拟南芥花青素生物合成
DOI：
10.1016/j.molp.2016.09.010
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发表时间：
2016-12-05
期刊：
影响因子：
27.5
通讯作者：
Huang, Jirong
中科院分区：
文献类型：
--
作者：
Chen, Qingbo;Man, Cong;Huang, Jirong
花色苷是一类由L-苯丙氨酸（Phe）衍生的黄酮类化合物，在植物抗逆和植物与昆虫的相互作用中发挥重要作用。虽然花色素苷生物合成途径及其调控机制已被广泛研究，但苯丙氨酸供应水平是否影响花色素苷生物合成仍不清楚。本文研究了arogenate转化为Phe的关键酶arogenate转化酶（ADT）在蔗糖诱导的拟南芥花色素苷合成中的作用。遗传分析表明，所有六个ADT异构体的功能冗余的花青素苷的生物合成，但有差异的贡献。ADT 2对花青素积累的贡献最大，其次是ADT 1和ADT 3，以及ADT 4-ADT 6。我们发现，花青苷含量与苯丙氨酸和蔗糖诱导的ADT转录水平呈正相关。因此，在培养基中添加苯丙氨酸可以显著提高野生型植株的花青素含量，并挽救adt 1-adt 3双突变体的花青素积累表型。此外，过表达ADT 4的转基因植物，其似乎比过表达ADT 2对Phe不太敏感，过量积累Phe并产生升高水平的花青素。综上所述，我们的研究结果表明，苯丙氨酸的水平是一个重要的调控因素，维持花青素苷的生物合成。
Anthocyanins, a group of L-phenylalanine (Phe)-derived flavonoids, have been demonstrated to play important roles in plant stress resistance and interactions between plants and insects. Although the anthocyanin biosynthetic pathway and its regulatory mechanisms have been extensively studied, it remains unclear whether the level of Phe supply affects anthocyanin biosynthesis. Here, we investigated the roles of arogenate dehydratases (ADTs), the key enzymes that catalyze the conversion of arogenate into Phe, in sucrose-induced anthocyanin biosynthesis in Arabidopsis. Genetic analysis showed that all six ADT isoforms function redundantly in anthocyanin biosynthesis but have differential contributions. ADT2 contributes the most to anthocyanin accumulation, followed by ADT1 and ADT3, and ADT4-ADT6. We found that anthocyanin content is positively correlated with the levels of Phe and sucrose-induced ADT transcripts in seedlings. Consistently, addition of Phe to the medium could dramatically increase anthocyanin content in the wild-type plants and rescue the phenotype of the adt1 adt3 double mutant regarding the anthocyanin accumulation. Moreover, transgenic plants overexpressing ADT4, which appears to be less sensitive to Phe than overexpression of ADT2, hyperaccumulate Phe and produce elevated level of anthocyanins. Taken together, our results suggest that the level of Phe is an important regulatory factor for sustaining anthocyanin biosynthesis.