Aims

Salt stress presents a significant impediment to crop growth and development. However, the effects of indigenous arbuscular mycorrhizal fungi (AMF) and the addition of exogenous AMF on soybean growth strategies under salt stress remain poorly understood. The purpose of this study was to examine the impact of different AMF sources on soybean growth strategies under salt stress conditions.

Methods

In this study, we established three different salt stress gradients (1, 2, and 4 g NaCl kg⁻¹ soil) along with two AMF treatments (indigenous AMF and added exogenous AMF) to evaluate soybean growth parameters, enzymes, and soil indicators.

Results

Under salt stress, exogenous AMF significantly increased mycorrhizal colonization in soybean, resulting in a notable enhancement in phosphorus (P) and potassium (K) concentration while reducing nitrogen (N) absorption. Additionally, the addition of exogenous AMF demonstrated the capacity to enhance soybean salt tolerance by lowering soybean sodium (Na) and malondialdehyde (MDA) content, catalase (CAT) activity, and increasing K⁺/Na⁺ ratio and acid phosphatase (A-Pase) activity. In contrast, in the indigenous AMF treatment, rhizosphere A-Pase activity in soybean exhibited predominantly positive correlations with each trait, and the K⁺/Na⁺ ratio relied more on mycorrhizal colonization and CAT activity. Soybean biomass was influenced both directly and indirectly, with the K⁺/Na⁺ ratio serving as a crucial pivot in the indirect pathway.

Conclusions

The addition of exogenous AMF can enhance soybean salt tolerance by regulating nutrient and sodium absorption, enzyme activity, and MDA content. Meanwhile, indigenous AMF promotes salt tolerance in soybeans by global regulating trait associations.

中文翻译：

---

丛枝菌根真菌对大豆响应盐胁迫生长策略的影响

 目标

盐胁迫严重阻碍作物生长和发育。然而，本土丛枝菌根真菌（AMF）和添加外源 AMF 对盐胁迫下大豆生长策略的影响仍知之甚少。本研究的目的是探讨不同 AMF 来源对盐胁迫条件下大豆生长策略的影响。

 方法

在本研究中，我们建立了三种不同的盐胁迫梯度（1、2和4 g NaCl kg ^-1土壤）以及两种AMF处理（本土AMF和添加外源AMF）来评估大豆生长参数、酶和土壤指标。

 结果

在盐胁迫下，外源AMF显着增加了大豆的菌根定植，导致磷（P）和钾（K）浓度显着增加，同时减少了氮（N）吸收。此外，添加外源AMF可以通过降低大豆钠（Na）和丙二醛（MDA）含量、过氧化氢酶（CAT）活性、增加K ⁺ /Na ⁺比值和酸性磷酸酶（A-Pase）来增强大豆耐盐性。 ） 活动。相比之下，在本土AMF处理中，大豆根际A-Pase活性与每个性状呈显着正相关，并且K ⁺ /Na ⁺比率更依赖于菌根定植和CAT活性。大豆生物量受到直接和间接影响，其中 K ⁺ /Na ⁺比率是间接途径中的关键枢纽。

 结论

添加外源AMF可以通过调节养分和钠的吸收、酶活性和MDA含量来增强大豆的耐盐性。同时，本土 AMF 通过全球调节性状关联来促进大豆的耐盐性。