To evaluate phylogenetic patterns of the distribution and evolution of plant secondary metabolites (PSMs), we selected 8 classes of PSMs and mapped them onto an updated phylogenetic tree including 437 families of seed plants. Significant phylogenetic signal was detected in 17 of the 18 tested seed plant clades for at least one of the 8 PSM classes using the D statistic. Phylogenetic signal, nevertheless, indicated weak clustering of PSMs compared to a random distribution across all seed plants. The observed signal suggests strong diversifying selection during seed plant evolution and/or relatively weak evolutionary constraints on the evolution of PSMs. In the survey of the current phylogenetic distributions of PSM, we found that multiple origins of PSM biosynthesis due to external selective forces for diverse genetic pathways may have played important roles. In contrast, a single origin of PSM seems rather uncommon. The distribution patterns for PSMs observed in this study may also be useful in the search for natural compounds for medicinal purposes.

中文翻译：

---

系统发育模式表明种子植物“生命之树”中次生代谢物频繁出现多个起源


为了评估植物次生代谢物（PSM）的分布和进化的系统发育模式，我们选择了 8 类 PSM，并将它们映射到包括 437 个种子植物科的更新的系统发育树上。使用 D 统计量，在 18 个测试的种子植物进化枝中的 17 个中检测到 8 个 PSM 类别中的至少一个的显着系统发育信号。然而，系统发育信号表明，与所有种子植物中的随机分布相比，PSM 的聚类较弱。观察到的信号表明种子植物进化过程中存在强烈的多样化选择和/或 PSM 进化的相对较弱的进化限制。在对当前 PSM 系统发育分布的调查中，我们发现，由于不同遗传途径的外部选择力，PSM 生物合成的多个起源可能发挥了重要作用。相比之下，PSM 的单一起源似乎相当罕见。本研究中观察到的 PSM 分布模式也可能有助于寻找药用天然化合物。