Abstract：
Numerous phosphorus (P)-acquisition and -utilisation strategies have evolved in plants growing in severely P-impoverished environments. Although these strategies have been well characterised for certain taxa, like Proteaceae, P-poor habitats are characterised by a high biodiversity, and we know little about how species in other families cope with P scarcity. We compared the P-acquisition and leaf P-allocation strategies of Fabaceae and Myrtaceae with those of Proteaceae growing in the same severely P-impoverished habitat. Myrtaceae and Fabaceae exhibited multiple P-acquisition strategies: P-mining by carboxylates or phosphatases, P uptake facilitated by carboxylate-releasing neighbours, and dependence on the elevated soil P availability after fire. Surprisingly, not all species showed high photosynthetic P-use efficiency (PPUE). Highly P-efficient species showed positive correlations between PPUE and the proportion of metabolite P (enzyme substrates), and negative correlations between PPUE and phospholipids (cellular membranes) and nucleic acid P (mostly ribosomal RNA), while we found no correlations in less P-efficient species. Overall, we found that Myrtaceae and Fabaceae used a wider range of strategies than Proteaceae to cope with P scarcity, at both the rhizosphere and leaf level. This knowledge is pivotal to better understand the mechanisms underlying plant survival in severely nutrient-impoverished biodiverse ecosystems.
摘要：
在严重贫磷环境中生长的植物中，已经发展了许多磷（P）获取和利用策略。尽管这些策略对于某些分类单元已经很好地描述了，像Proteaceae，贫民栖息地的特点是生物多样性高，我们对其他家庭的物种如何应对磷短缺知之甚少。我们将豆科和桃金娘科的P获取和叶片P分配策略与在同一严重P贫困的栖息地中生长的Proteaceae的P获取和叶片P分配策略进行了比较。桃金娘科和豆科表现出多种P获取策略：通过羧酸盐或磷酸酶进行P挖掘，释放羧酸盐的邻居促进了磷的吸收，以及对火灾后土壤磷有效性升高的依赖性。令人惊讶的是,并非所有物种都显示出高的光合磷利用效率（PPUE）。高P效率的物种显示PPUE与代谢物P（酶底物）的比例之间呈正相关，PPUE与磷脂（细胞膜）和核酸P（主要是核糖体RNA）之间呈负相关，而我们在磷效率较低的物种中没有发现相关性。总的来说,我们发现，桃金娘科和豆科使用比Proteaceae更广泛的策略来应对磷短缺，在根际和叶水平。这些知识对于更好地了解植物在营养严重匮乏的生物多样性生态系统中生存的机制至关重要。
