Abstract：
Agriophyllum squarrosum (L.) Moq., a pioneer plant endemic to the temperate deserts of Asia, could be domesticated into an ideal crop with outstanding ecological and medicinal characteristics. A previous study showed differential organic acid accumulation between two in situ altitudinal ecotypes. To verify whether this accumulation was determined by environmental or genetic factors, we conducted organic acid targeted metabolic profiling among 14 populations of A. squarrosum collected from regions with different altitudes based on a common garden experiment. Results showed that the most abundant organic acid in A. squarrosum was citric acid (96.03%, 2322.90 μg g-1). Association analysis with in situ environmental variables showed that salicylic acid content was positively correlated with altitudinal gradient. Considering the enrichment of salicylic acid and protocatechualdehyde in high-altitude populations based on the common garden experiment, and the high expression of their biosynthesis relative genes (i.e., PAL and C4H) in the in situ high-altitude ecotype, we propose that organic acid accumulation could be involved in local adaptation to high altitudes. This study not only addresses the molecular basis of local adaptation involving the accumulation of organic acids in the desert plant A. squarrosum but also provides a method to screen wild germplasms to mitigate the impact of global climate change.
摘要：
苦参草（L.)Moq。,亚洲温带沙漠特有的先锋植物，可以驯化成具有突出生态和药用特性的理想作物。先前的研究表明，两种原位海拔生态型之间的有机酸积累存在差异。为了验证这种积累是由环境因素还是遗传因素决定的，我们在一个普通的花园实验基础上,对从不同海拔高度地区采集的14个squarrosum种群进行了有机酸靶向代谢分析.结果表明,水曲柳中含量最高的有机酸是柠檬酸(96.03%,2322.90μgg-1)。与原位环境变量的关联分析表明，水杨酸含量与海拔梯度呈正相关。基于普通园林实验，考虑到高海拔人群中水杨酸和原儿茶醛的富集，以及它们的生物合成相关基因的高表达(即，PAL和C4H）在原位高海拔生态型中，我们认为有机酸的积累可能与当地对高海拔地区的适应有关。这项研究不仅解决了涉及荒漠植物A.squarrosum中有机酸积累的局部适应的分子基础，而且还提供了一种筛选野生种质资源的方法，以减轻全球气候变化的影响。
