Picrorhiza kurrooa is an endangered herb known to produce the medicinally important picrosides through isoprenoid pathway. The present work showed the functionality of WRKY motifs (TGAC cis-acting elements) present in the promoters of regulatory genes 3-hydroxy-3-methylglutaryl coenzyme A reductase (Pkhmgr) and 1-deoxy-d-xylulose-5-phosphate synthase (Pkdxs) of the picrosides biosynthetic pathway by electrophoretic mobility shift assay. Also, the two WRKY genes, PkdWRKY and PksWRKY, were characterized and found to contain double and single characteristic WRKY domains, respectively along with a zinc-finger motif in each domain. Expression analysis revealed that PkdWRKY and PksWRKY exhibited a positive and negative correlation, respectively, with picrosides content under the environment of light and in different tissues. Functional evaluation in yeast showed DNA binding ability of both PksWRKY and PkdWRKY; however, only PkdWRKY exhibited transcriptional activation ability. Transient overexpression of PkdWRKY and PksWRKY in tobacco modulated the expression of selected native genes of tobacco involved in MVA and MEP pathway suggesting functionality of PkdWRKY and PksWRKY in planta. Collectively, data suggested that PkdWRKY and PksWRKY might be positive and negative regulators, respectively in the picrosides biosynthetic pathway.

中文翻译：

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两个光响应性WRKY基因与濒危药用Picrorhiza kurrooa Royle ex Benth中的苦味苷含量呈正相关和负相关。

Picrorhiza kurrooa是一种濒临灭绝的草药，已知会通过类异戊二烯途径产生具有重要医学意义的苦味苷。目前的工作表明，在调节基因3-羟基-3-甲基戊二酰辅酶A还原酶（Pkhmgr）和1-脱氧-d-木酮糖-5-磷酸合酶（）的启动子中存在WRKY基序（TGAC顺式作用元件）的功能。 Pkdxs）通过电泳迁移率移动分析法确定了苦味素的生物合成途径。此外，两个WRKY基因PkdWRKY和PksWRKY的特征在于，发现它们分别包含两个和单个特征性WRKY域，每个域中都带有一个锌指基序。表达分析表明，PkdWRKY和PksWRKY在光环境下和在不同组织中分别与苦味素含量呈正相关和负相关。酵母中的功能评估显示了PksWRKY和PkdWRKY的DNA结合能力。但是，只有PkdWRKY表现出转录激活能力。烟草中PkdWRKY和PksWRKY的瞬时过表达调节了参与MVA和MEP途径的烟草中选定天然基因的表达，提示植物中PkdWRKY和PksWRKY的功能。总体而言，数据表明PkdWRKY和PksWRKY可能分别在苦瓜类生物合成途径中是正调节剂和负调节剂。