We investigated the influence of Salvia fruticosa colonization by the arbuscular mycorrhizal fungi (AMF) Rhizophagus irregularis on photosynthetic function by using chlorophyll fluorescence imaging analysis to evaluate the light energy use in photosystem II (PSII) of inoculated and non-inoculated plants. We observed that inoculated plants used significantly higher absorbed energy in photochemistry (Φ_PSII) than non-inoculated and exhibited significant lower excess excitation energy (EXC). However, the increased Φ_PSII in inoculated plants did not result in a reduced non-regulated energy loss in PSII (Φ_NO), suggesting the same singlet oxygen (¹O₂) formation between inoculated and non-inoculated plants. The increased Φ_PSII in inoculated plants was due to an increased efficiency of open PSII centers to utilize the absorbed light (Fv’/Fm’) due to a decreased non-photochemical quenching (NPQ) since there was no difference in the fraction of open reaction centers (q_p). The decreased NPQ in inoculated plants resulted in an increased electron-transport rate (ETR) compared to non-inoculated. Yet, inoculated plants exhibited a higher efficiency of the water-splitting complex on the donor side of PSII as revealed by the increased Fv/Fo ratio. A spatial heterogeneity between the leaf tip and the leaf base for the parameters Φ_PSII and Φ_NPQ was observed in both inoculated and non-inoculated plants, reflecting different developmental zones. Overall, our findings suggest that the increased ETR of inoculated S. fruticosa contributes to increased photosynthetic performance, providing growth advantages to inoculated plants by increasing their aboveground biomass, mainly by increasing leaf biomass.

中文翻译：

---

丛枝菌根共生通过改善光系统II光化学作用来增强药用植物丹参中的光合作用。

我们研究的影响丹参紫穗槐定植由丛枝菌根真菌（AMF）Rhizophagus irregularis通过使用叶绿素荧光成像分析，以评估在光系统II（PSII）接种和未接种的植物的光能利用光合功能。我们观察到，接种植物在光化学（_ΦPSII）中使用的吸收能量比未接种植物高，并且显示出显着更低的过量激发能（EXC）。然而，增加的Φ _PSII在接种的植株没有导致在PSII（Φ减小的非管制能量损失_NO），这表明相同的单重态氧（¹ Ò ₂）在已接种植物和未接种植物之间形成。接种植物中_ΦPSII的增加是由于开放的PSII中心利用非光化学猝灭（NPQ）减少所导致的利用吸收光（F v '/ F m '）的效率提高，因为分数没有差异开放式反应中心的数量（q _p）。与未接种植物相比，接种植物中NPQ的降低导致电子传输速率（ETR）的增加。然而，如通过增加的F v / F o比所揭示的，接种的植物在PSII的供体侧表现出更高的水分解复合物效率。参数Φ的叶尖与叶根之间的空间异质性在接种和未接种的植物中均观察到_PSII和_ΦNPQ，反映了不同的发育区。总体而言，我们的发现表明，接种金黄色葡萄球菌的ETR升高有助于光合作用的提高，主要通过增加叶片生物量来增加其地上生物量，从而为接种植物提供生长优势。