Background and aims

White lupin (Lupinus albus) mobilize inaccessible phosphorus (P) by producing cluster root that can secrete carboxylates and enhance the phosphatase activity. Blue lupin (L. angustifolius) and yellow lupin (L. luteus) are classified in the same legume genus as white lupin, this study investigates whether blue and yellow lupins can evoke adaptation strategies under P scarcity.

Methods

For this pot experiment, three lupin species were subjected to -P, + Pi (NaH₂PO₄), and + Po (Phytate) treatments. After two months, we determined biomass and P allocation in lupins, Hedley-P fractions, exudate composition, and bacterial diversity in the rhizosheath under distinct treatments.

Results

The results indicate white lupin accumulated high P content under -P and + Po treatments, while yellow lupin exhibited similar P content under + Po and + Pi treatments. Additionally, white lupin showed higher citrate secretion, ALPase, and PHYase activities under -P condition, as well as increased PHYase and β-Glu activities under + Po treatment. Particularly, the genera Segetibacter, Granulicell, Candidatus_Methylacidiphilum, and Bryobacter, which contributed to phytate activation, were simultaneously present in the rhizosheaths of both white and yellow lupins under + Po treatment.

Conclusion

This study elucidates the multifaceted physiological responses of lupins in adapting to P-deficient and provides novel insight into the role of rhizobacteria in phytate mobilization.

中文翻译：

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不同施磷对 3 种羽扇豆物种生理响应和根瘤菌群落多样性的影响

 背景和目标

白羽扇豆 （Lupinus albus） 通过产生可以分泌羧酸盐并增强磷酸酶活性的簇根来动员难以接近的磷 （P）。蓝羽扇豆 （L. angustifolius） 和黄羽扇豆 （L. luteus） 与白羽扇豆属于同一豆科植物，本研究调查了蓝色和黄色羽扇豆在 P 稀缺下是否能引发适应策略。

 方法

在这个盆栽实验中，对三种羽扇豆进行了 -P、+ Pi （NaH₂PO₄） 和 + Po （植酸盐） 处理。两个月后，我们测定了不同处理下羽扇豆中的生物量和 P 分配、Hedley-P 组分、渗出物组成和根瘤菌中的细菌多样性。

 结果

结果表明，白羽扇豆在 -P 和 + Po 处理下积累了较高的 P 含量，而黄羽扇豆在 + Po 和 + Pi 处理下表现出相似的 P 含量。此外，白色羽扇豆在 -P 条件下表现出更高的柠檬酸盐分泌、ALPase 和 PHYase 活性，在 + Po 处理下 PHYase 和 β-Glu 活性增加。特别是，在+ Po处理下，有助于植酸活化的Segetibacter、Granulicell、Candidatus_Methylacidiphilum和Bryobacter属同时存在于白色和黄色羽扇豆的根鞘中。

 结论

本研究阐明了羽扇豆适应 P 缺陷症的多方面生理反应，并为根际细菌在植酸盐动员中的作用提供了新的见解。