Lei Zhentian, Watson Bonnie S, Huhman David, Yang Dong Sik, Sumner Lloyd W
University of Missouri Metabolomics Center, Columbia, MO, United States.
Department of Biochemistry, University of Missouri, Columbia, MO, United States.
Front Plant Sci. 2019 Jul 3;10:850. doi: 10.3389/fpls.2019.00850. eCollection 2019.
A total of 1,622 samples representing 201 ecotypes were analyzed using ultrahigh pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) to ascertain saponin profiles in different ecotypes and to provide data for a genome-wide association study and subsequent line selection for saponin biosynthesis. These ecotypes originated from 14 different Mediterranean countries, i.e., Algeria, Cyprus, France, Greece, Israel, Italy, Jordan, Libya, Morocco, Portugal, Spain, Syria, Tunisia, and Turkey. The results revealed significant differences in the saponin content among the ecotypes. European ecotypes generally contained higher saponin content than African ecotypes ( < 0.0001). This suggests that ecotypes modulate their secondary metabolism to adapt to their environments. Significant differences in saponin accumulation were also observed between the aerial and the root tissues of the same ecotypes ( < 0.0001). While some saponins were found to be present in both the aerial and root tissues, zanhic acid glycosides were found predominantly in the aerial tissues. Bayogenin and hederagenin glycosides were found mostly in roots. The differential spatially resolved accumulation of saponins suggests that saponins in the aerial and root tissues play different roles in plant fitness. Aerial saponins such as zanhic glycosides may act as animal feeding deterrent and root saponins may protect against soil microbes.
共对代表201种生态型的1622个样本进行了超高压液相色谱-质谱联用（UHPLC-MS）分析，以确定不同生态型中的皂苷谱，并为全基因组关联研究及随后的皂苷生物合成品系选择提供数据。这些生态型源自14个不同的地中海国家，即阿尔及利亚、塞浦路斯、法国、希腊、以色列、意大利、约旦、利比亚、摩洛哥、葡萄牙、西班牙、叙利亚、突尼斯和土耳其。结果显示，各生态型之间的皂苷含量存在显著差异。欧洲生态型的皂苷含量普遍高于非洲生态型（<0.0001）。这表明生态型会调节其次生代谢以适应环境。在同一生态型的地上组织和根组织之间也观察到皂苷积累的显著差异（<0.0001）。虽然在地上组织和根组织中都发现了一些皂苷，但扎尼酸糖苷主要存在于地上组织中。贝萼配基和常春藤皂苷元糖苷大多存在于根中。皂苷在空间上的差异积累表明，地上组织和根组织中的皂苷在植物适应性方面发挥着不同作用。地上皂苷如扎尼糖苷可能起到阻止动物取食的作用，而根皂苷可能抵御土壤微生物。
