Phosphorus (P) is a finite and pivotal resource in determining plant yield. Intercropping with legumes is frequently proposed to improve P nutrition in many crops such as wheat, and the greater yield and P uptake observed are mostly attributed to legumes' root exudation of organic acids and phosphatases, which modify rhizosphere chemistry. The same rhizosphere modification drives the selection of specific bacterial communities by providing carbon sources such as organic acids and other metabolites. This study aimed to further understand the influence of P bioavailability on bacterial community selection and whether this can be extended to other crops through intercropping. Pea, lupin and wheat were grown as intercrops and as sole crops at four levels of P availability. This was achieved by using a low-P soil from the long-term experiment at Rothamsted Research, amended with available and low-available forms of P. After 62 days of growth, 16S rRNA gene amplicon sequencing was performed from rhizosphere samples, and acid and alkaline phosphomonoesterase (PME) activity was measured. The plant species was the main factor determining the structure of the bacterial community followed by P availability. When P was unavailable or depleted, legume monoculture as well as intercropping, was associated with reduced bacterial species richness and diversity, which was partly explained by an increased relative abundance of , and spp. The complexity and interconnections of the bacterial community were increased in intercropping when P was unavailable as was alkaline PME activity, while the acid PME activity was more affected by the plant. In conclusion, wheat intercropping can generate a more complex and interconnected root-associated bacterial community, which can potentially contribute to the facilitation of P uptake.

中文翻译：

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磷的可用性驱动豆科小麦间作对原核群落相互作用的影响

磷 (P) 是决定植物产量的有限且关键的资源。经常提出与豆科植物间作以改善小麦等许多作物的磷营养，观察到的更高的产量和磷吸收主要归因于豆科植物根部分泌的有机酸和磷酸酶，它们改变了根际化学。相同的根际修饰通过提供有机酸和其他代谢物等碳源来驱动特定细菌群落的选择。本研究旨在进一步了解磷生物利用率对细菌群落选择的影响，以及是否可以通过间作将其推广到其他作物。豌豆、羽扇豆和小麦在四种可用磷水平下作为间作作物和单一作物种植。这是通过使用洛桑研究中心长期实验的低磷土壤并用可用和低可用磷形式进行修正来实现的。生长 62 天后，对根际样品进行 16S rRNA 基因扩增子测序，并用酸并测量碱性磷酸单酯酶（PME）活性。植物种类是决定细菌群落结构的主要因素，其次是磷的有效性。当磷不可用或耗尽时，豆科植物单一栽培以及间作与细菌物种丰富度和多样性降低有关，部分原因是 、 和 spp 的相对丰度增加。当磷不可用时，间作细菌群落的复杂性和相互联系增加，碱性 PME 活性也增加，而酸性 PME 活性更容易受到植物的影响。总之，小麦间作可以产生更复杂和相互关联的根部相关细菌群落，这可能有助于促进磷的吸收。