The tomato mutation nxd1 reveals a gene necessary for neoxanthin biosynthesis and demonstrates that violaxanthin is a sufficient precursor for abscisic acid biosynthesis
The tomato mutation nxd1 reveals a gene necessary for neoxanthin biosynthesis and demonstrates that violaxanthin is a sufficient precursor for abscisic acid biosynthesis
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DOI：
10.1111/tpj.12451
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发表时间：
2014-04-01
期刊：
影响因子：
7.2
通讯作者：
Hirschberg, Joseph
中科院分区：
文献类型：
--
作者：
Neuman, Hadar;Galpaz, Navot;Hirschberg, Joseph
类胡萝卜素色素是植物生命不可缺少的。它们在质体中合成，在质体中提供光合作用的基本功能。类胡萝卜素是合成独脚金内酯植物激素（由 β-胡萝卜素制成）和脱落酸（ABA）（由某些叶黄素产生）的前体。尽管我们对类胡萝卜素生物合成途径的理解取得了重大进展，但叶黄素新黄质的合成仍然未知。我们在这里报告了番茄（Solanum lycopersicum）突变体新黄质缺陷1（nxd1）的分离，该突变体缺乏新黄质，以及番茄和拟南芥中新黄质合成所需基因的克隆。 nxd1 基因座编码一个功能未知的基因，该基因在所有高等植物中都是保守的。 NXD1 的活性是必需的，但不能单独支持新黄质的合成。缺乏新黄质并不会显着降低番茄植株在耕地条件下的适应性，也不会损害 ABA 的合成，这表明番茄中的紫黄质是体内产生 ABA 的充分前体。
Carotenoid pigments are indispensable for plant life. They are synthesized within plastids where they provide essential functions in photosynthesis. Carotenoids serve as precursors for the synthesis of the strigolactone phytohormones, which are made from beta-carotene, and of abscisic acid (ABA), which is produced from certain xanthophylls. Despite the significant progress that has been made in our understanding of the carotenoid biosynthesis pathway, the synthesis of the xanthophyll neoxanthin has remained unknown. We report here on the isolation of a tomato (Solanum lycopersicum) mutant, neoxanthin-deficient 1 (nxd1), which lacks neoxanthin, and on the cloning of a gene that is necessary for neoxanthin synthesis in both tomato and Arabidopsis. The locus nxd1 encodes a gene of unknown function that is conserved in all higher plants. The activity of NXD1 is essential but cannot solely support neoxanthin synthesis. Lack of neoxanthin does not significantly reduce the fitness of tomato plants in cultivated field conditions and does not impair the synthesis of ABA, suggesting that in tomato violaxanthin is a sufficient precursor for ABA production in vivo.