Arogenate dehydratases can modulate the levels of phenylacetic acid in Arabidopsis
Arogenate dehydratases can modulate the levels of phenylacetic acid in Arabidopsis
复制标题
芳酸脱水酶可以调节拟南芥中苯乙酸的水平
DOI：
10.1016/j.bbrc.2020.01.041
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发表时间：
2020-03-26
影响因子：
3.1
通讯作者：
Kasahara, Hiroyuki
中科院分区：
文献类型：
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作者：
Aoi, Yuki;Oikawa, Akira;Kasahara, Hiroyuki
苯乙酸（Phenylacetic acid，PAA）是一种广泛存在于植物体内的天然生长素。植物体内的PAA是由苯丙氨酸（Phe）经苯丙酮酸（PPA）合成的，但其合成基因及其调控机制尚不清楚。在这篇文章中，我们表明，芳香酸脱氢酶（ADT）家族，催化arogenate转化为苯丙氨酸，可以调节拟南芥中的PAA的水平。我们发现过表达ADT 4或ADT 5显著增加PAA的量。由于PAA水平的增加，ADT 4 ox和ADT 5 ox植物可以部分恢复由吲哚-3-乙酸（IAA）生物合成抑制剂处理引起的生长素缺陷表型，所述IAA是植物中的主要生长素。相比之下，PAA的水平在adt多重敲除突变体中显著降低。此外，PPA的水平在ADT 4或ADT 5过表达植物中显著增加，但在adt多基因敲除突变体中降低，表明PPA是PAA生物合成的关键中间体。这些结果为拟南芥ADT家族成员通过PPA依赖性途径调节PAA水平提供了证据。(C)2020爱思唯尔公司All rights reserved.
Phenylacetic acid (PAA) is one type of natural auxin and widely exists in plants. Previous biochemical studies demonstrate that PAA in plants is synthesized from phenylalanine (Phe) via phenylpyruvate (PPA), but the PAA biosynthetic genes and its regulation remain unknown. In this article, we show that the AROGENATE DEHYDRATASE (ADT) family, which catalyzes the conversion of arogenate to Phe, can modulate the levels of PAA in Arabidopsis. We found that overexpression of ADT4 or ADT5 remarkably increased the amounts of PAA. Due to an increase in PAA levels, ADT4ox and ADT5ox plants can partially restore the auxin-deficient phenotypes caused by treatments with an inhibitor of the biosynthesis of indole-3-acetic acid (IAA), a main auxin in plants. In contrast, the levels of PAA were significantly reduced in adt multiple knockout mutants. Moreover, the levels of PPA are substantially increased in ADT4 or ADT5 overexpression plants but reduced in adt multiple knockout mutants, suggesting that PPA is a key intermediate of PAA biosynthesis. These results provide an evidence that members of the ADT family of Arabidopsis can modulate PAA level via the PPA-dependent pathway. (C) 2020 Elsevier Inc. All rights reserved.