Lan Xiaozhong, Quan Hong, Xia Xinli, Yin Weilun, Zheng Weilie
College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.
TAAHC-SWU Medicinal Plant Joint R&D Centre, Agricultural and Animal Husbandry College, Tibet University, Nyingchi of Tibet, People's Republic of China.
Biotechnol Appl Biochem. 2016 May;63(3):419-26. doi: 10.1002/bab.1376. Epub 2015 Nov 5.
Mirabilis himalaica is an endangered medicinal plant species in the Tibetan Plateau. The two genes respectively encoding chalcone synthase (MhCHS) and chalcone isomerase (MhCHI) were isolated and characterized from M. himalaica. The sequence analysis revealed that the two genes were similar with their corresponding homologous genes in other plants. The tissue profiles showed that both MhCHS and MhCHI had higher expression levels in roots than in stems and leaves. Transgenic hairy root cultures respectively with overexpressing MhCHS and MhCHI were established. The genomic PCR detection confirmed the authority of transgenic hairy root lines, in which either MhCHS or MhCHI expression levels were much higher than that in non-transgenic hairy root line. Finally, the HPLC detection results demonstrated that the rotenoid contents in MhCHS/MhCHI-transformed hairy root lines were enhanced. This study provided two candidate genes that could be used to genetic engineering rotenoid biosynthesis in M. himalaica and an alternative method to produce rotenoid using transgenic hairy root cultures.
喜马拉雅紫茉莉是青藏高原上一种濒危的药用植物物种。从喜马拉雅紫茉莉中分离并鉴定了分别编码查尔酮合酶（MhCHS）和查尔酮异构酶（MhCHI）的两个基因。序列分析表明，这两个基因与其在其他植物中的相应同源基因相似。组织表达谱显示，MhCHS和MhCHI在根中的表达水平均高于茎和叶。分别建立了过表达MhCHS和MhCHI的转基因毛状根培养物。基因组PCR检测证实了转基因毛状根系的可靠性，其中MhCHS或MhCHI的表达水平均远高于非转基因毛状根系。最后，HPLC检测结果表明，MhCHS/MhCHI转化的毛状根系中鱼藤酮类化合物含量增加。本研究提供了两个可用于喜马拉雅紫茉莉鱼藤酮类化合物生物合成基因工程的候选基因，以及一种利用转基因毛状根培养物生产鱼藤酮类化合物的替代方法。
