ODORANT1 regulates fragrance biosynthesis in petunia flowers
ODORANT1 regulates fragrance biosynthesis in petunia flowers
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DOI：
10.1105/tpc.104.028837
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发表时间：
2005-05-01
期刊：
影响因子：
11.6
通讯作者：
Schuurink, RC
中科院分区：
文献类型：
--
作者：
Verdonk, JC;Haring, MA;Schuurink, RC
花香对植物繁殖很重要，因为它能吸引传粉者到性器官。因此，挥发性物质的释放通常与传粉者的觅食活动有关。在矮牵牛中，挥发性苯并呋喃决定花的香气。虽然苯型生物合成的途径已被鉴定，但涉及的酶还不太清楚。生产和排放如何监管尚不清楚。通过有针对性的转录组分析，我们确定ODORANT 1（ODO 1），R2 R3型MYB家族的成员，作为一个候选人的挥发性benzoline在矮牵牛品种W115（米切尔）花的调节。这些花只有在傍晚和夜晚才有香味。ODO 1的转录水平在挥发性排放开始前增加，当挥发性排放下降时下降。在转基因P. hybrida Mitchell植物中下调ODO 1通过减少来自莽草酸途径的前体的合成而强烈降低挥发性苯类化合物水平。通过抑制ODO 1表达，该途径中几个基因的转录水平降低。此外，ODO 1可以激活5-烯醇-乙酰莽草酸-3-磷酸合酶基因的启动子。花色素，这是从相同的莽草酸前体提供，没有受到影响，因为颜色和气味的生物合成发生在不同的发育阶段。我们的研究确定ODO 1作为花香生物合成的关键调节因子。
Floral scent is important to plant reproduction because it attracts pollinators to the sexual organs. Therefore, volatile emission is usually tuned to the foraging activity of the pollinators. In Petunia hybrida, volatile benzenoids determine the floral aroma. Although the pathways for benzenoid biosynthesis have been characterized, the enzymes involved are less well understood. How production and emission are regulated is unknown. By targeted transcriptome analyses, we identified ODORANT1 (ODO1), a member of the R2R3-type MYB family, as a candidate for the regulation of volatile benzenoids in Petunia hybrida cv W115 (Mitchell) flowers. These flowers are only fragrant in the evening and at night. Transcript levels of ODO1 increased before the onset of volatile emission and decreased when volatile emission declined. Downregulation of ODO1 in transgenic P. hybrida Mitchell plants strongly reduced volatile benzenoid levels through decreased synthesis of precursors from the shikimate pathway. The transcript levels of several genes in this pathway were reduced by suppression of ODO1 expression. Moreover, ODO1 could activate the promoter of the 5-enol-pyruvylshikimate-3-phosphate synthase gene. Flower pigmentation, which is furnished from the same shikimate precursors, was not influenced because color and scent biosynthesis occur at different developmental stages. Our studies identify ODO1 as a key regulator of floral scent biosynthesis.