Data from: Seed polyphenols in a diverse tropical plant community

1. Polyphenols are one of the most common groups of secondary metabolites in plants and thought to play a key role in enhancing plant fitness by protecting plants against enemies. Although enemy-inflicted mortality at the seed stage can be an important regulator of plant populations and a key determinant of community structure, few studies have assessed community-level patterns of polyphenol content in seeds. 2. We describe the distribution of the main seed polyphenol groups across 196 plant species on Barro Colorado Island (Panama) and community-level patterns in two aspects of their biological activity (protein precipitation and oxidative capacity). Taking advantage of substantial variation in morphological and ecological traits in the studied plant community, we test for correlations and trade-offs between seed polyphenols and non-chemical plant traits hypothesised to make plant species more or less likely to invest in polyphenol production. 3. The majority of species have polyphenols in their seeds. The incidence and concentrations of polyphenols were related to a set of non-chemical plant traits. Polyphenols were most likely to be present (and where present, to be expressed in high concentrations) in species with large seeds, short seed dormancy times, low investment in mechanical seed defences, high wood density, high leaf mass per area, tough leaves, and slow growth rates. 4. Synthesis: Our study reveals a potential trade-off between chemical and mechanical seed defences and shows that plant species that invest in physical defences at later life stages (high wood density and tough leaves) tend not to invest in physical defences of seeds but instead produce secondary metabolites likely to act as seed defences. Overall, our results conform to predictions from the resource availability hypothesis, which states that species in resource-limited environments (such as slow-growing shade-tolerant tree species) will invest more in defences than fast-growing pioneer species.

1. 多酚（Polyphenols）是植物中最常见的次生代谢产物（secondary metabolites）类群之一，被认为通过抵御天敌以提升植物适合度（plant fitness），发挥关键调控作用。尽管种子阶段（seed stage）遭遇天敌造成的死亡率（enemy-inflicted mortality）可作为调控植物种群（plant populations）、决定群落结构（community structure）的重要因子，但目前针对种子多酚含量的群落水平格局（community-level patterns）的相关研究仍较为匮乏。2. 本数据集收录了巴拿马巴罗科罗拉多岛（Barro Colorado Island）196种植物的主要种子多酚类群（seed polyphenol groups）分布情况，以及其生物活性两方面的群落水平格局：蛋白质沉淀能力（protein precipitation）与氧化能力（oxidative capacity）。研究团队借助该植物群落中丰富的形态与生态性状（morphological and ecological traits）变异，检验种子多酚与非化学植物性状（non-chemical plant traits）间的相关性与权衡（trade-offs）关系，以验证“植物物种是否更倾向于投入多酚生产”的相关假说。3. 绝大多数受试物种的种子中均含有多酚。多酚的检出率与浓度与一系列非化学植物性状显著相关：拥有大种子、短种子休眠期（seed dormancy times）、低种子机械防御（mechanical seed defences）投入、高木材密度（wood density）、高比叶面积（leaf mass per area）、硬叶（tough leaves）以及慢生长速率（slow growth rates）的物种，其种子多酚的检出率更高（若含有多酚，则浓度也普遍处于较高水平）。4. 综合分析结果显示：本研究揭示了种子化学防御与机械防御间潜在的权衡关系，同时发现，在生活史后期投入物理防御的植物物种（如高木材密度、硬叶的物种），往往不会对种子开展物理防御，而是通过产生次生代谢产物来充当种子防御手段。整体而言，本研究结果符合资源可用性假说（resource availability hypothesis）的预测：即资源受限环境中的物种（如生长缓慢的耐阴树种（shade-tolerant tree species）），相较于快速生长的先锋树种（pioneer species），会投入更多资源用于防御。