DataSheet_1_Pseudotargeted metabolomics revealed the adaptive mechanism of Draba oreades Schrenk at high altitude.docx

Strong ultraviolet radiation and low temperature environment on Gangshika Mountain, located in the eastern part of the Qilian Mountains in Qinghai Province, can force plants to produce some special secondary metabolites for resisting severe environmental stress. However, the adaptive mechanism of Draba oreades Schrenk at high altitude are still unclear. In the current study, Draba oreades Schrenk from the Gangshika Mountain at altitudes of 3800 m, 4000 m and 4200 m were collected for comprehensive metabolic evaluation using pseudotargeted metabolomics method. Through KEGG pathway enrichment analysis, we found that phenylpropanoid biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism related to the biosynthesis of flavonoids were up-regulated in the high-altitude group, which may enhance the environmental adaptability to strong ultraviolet intensity and low temperature stress in high altitude areas. By TopFc20 distribution diagram, the content of flavonoids gradually increased with the elevation of altitude, mainly including apigenin, luteolin, quercetin, hesperidin, kaempferol and their derivatives. Based on the random forest model, 10 important metabolites were identified as potential biomarkers. L-phenylalanine, L-histidine, naringenin-7-O-Rutinoside-4’-O-glucoside and apigenin related to the flavonoids biosynthesis and plant disease resistance were increased with the elevation of altitude. This study provided important insights for the adaptive mechanism of Draba oreades Schrenk at high altitude by pseudotargeted metabolomics.

位于青海省祁连山东段的岗什卡山地，其强烈的紫外辐射与低温环境可迫使植物产生特殊次生代谢物以抵御严苛的环境胁迫。然而，目前高山葶苈（Draba oreades Schrenk）的高海拔适应机制仍不明晰。本研究采集了岗什卡山地海拔3800 m、4000 m与4200 m处的高山葶苈，采用伪靶向代谢组学（pseudotargeted metabolomics）方法开展全面代谢组分析。通过京都基因与基因组百科全书（KEGG）通路富集分析，本研究发现高海拔组中与黄酮类化合物（flavonoids）生物合成相关的苯丙烷生物合成、苯丙氨酸/酪氨酸/色氨酸生物合成以及苯丙氨酸代谢通路均显著上调，这或可提升植物对高海拔地区强紫外辐射与低温胁迫的环境适应能力。通过TopFc20分布图谱分析，黄酮类化合物的含量随海拔升高逐渐增加，主要包括芹菜素、木犀草素、槲皮素、橙皮苷、山奈酚及其衍生物。基于随机森林模型（random forest model），本研究筛选出10种关键代谢物作为潜在生物标志物。其中，与黄酮类生物合成及植物抗病性相关的L-苯丙氨酸、L-组氨酸、柚皮素-7-O-芸香糖苷-4’-O-葡萄糖苷以及芹菜素，其含量随海拔升高呈上升趋势。本研究通过伪靶向代谢组学技术，为解析高山葶苈的高海拔适应机制提供了重要参考依据。