Changes in root traits and rhizosphere microbiome are important ways to optimize plant phosphorus (P) efficiency and promote multifunctionality in intercropping. However, whether and how synthetic microbial communities isolated from polyculture systems can facilitate plant growth and P uptake are still largely unknown. A field experiment was first carried out to assess the rice yield and P uptake in the rice/soybean intercropping systems, and a synthetic microbial community (SynCom) isolated from intercropped rice was then constructed to elucidate the potential mechanisms of growth-promoting effects on rice growth and P uptake in a series of pot experiments. Our results showed that the yield and P uptake of intercropped rice were lower than those of rice grown in monoculture. However, bacterial networks in the rice rhizosphere were more stable in polyculture, exhibiting more hub nodes and greater modularity compared to the rice monoculture. A bacterial synthetic community (SynCom) composed of four bacterial strains (Variovorax paradoxus, Novosphingobium subterraneum, Hydrogenophaga pseudoflava, Acidovorax sp.) significantly enhanced the biomass and P uptake of potted rice plants. These growth-promoting effects are underpinned by multiple pathways, including the direct activation of soil available P, increased root surface area and root tip number, reduced root diameter, and promotion of root-to-shoot P translocation through up-regulation of Pi transporter genes (OsPht1;1, OsPht1;2, OsPht1;4, OsPht1;6). This study highlights the potential of harnessing synthetic microbial communities to enhance nutrient acquisition and improve crop production.

Intercropping has the potential to improve phosphorus (P) uptake and crop growth, but the potential benefits and relative contributions of root morphology and arbuscular mycorrhizal fungi (AMF) colonization are largely unknown for the intercropping of rice and soybean under dry cultivation. Both field and pot experiments were conducted with dry-cultivated rice (Oryza sativa L.) and soybean (Glycine max L. Merr.) grown alone or intercropped under two P levels. Two root separation modes between rice and soybean were employed to explore the contribution of AMF association and root plasticity on P uptake in intercrops. The results showed that rice/soybean intercropping resulted in a notable increase in the total biomass and yield compared to monoculture in the field. In the potted experiment, compared to the plastic root separation treatment (PS), the no root separation treatment (NS) increased the total biomass and P uptake by 9.4% and 19.9%, irrespective of the P levels. This was primarily attributable to a considerable enhancement in biomass and phosphorus uptake in soybean by 40.4% and 49.7%, which offset a slight decline in the rice of NS compared to PS by 26.8% and 18.0%, respectively. The results of random forest analysis indicate that the P uptake by the dominant species, soybean, was mainly contributed by root morphology, while rice was more dependent on AMF colonization in the intercropping system. Therefore, dry-cultivated rice/soybean intercropping enhances P uptake and productivity by leveraging complementary belowground strategies, with soybean benefiting primarily from root morphological adjustments and rice relying more on arbuscular mycorrhizal fungi colonization.

Arbuscular mycorrhizal fungi (AMF) engage in complex interactions with plants and both aboveground (AG) and belowground (BG) herbivores, collectively shaping plant fitness, defense strategies, and AM fungal community assembly. A central question within these interactions concerns the role of nutrients. Growing evidence suggests that nutrients acquired by AMF not only enhance plant growth but also support both resistance- and tolerance-based defense strategies. Nutrient-derived primary and secondary metabolites exert systemically asymmetric effects on AG and BG herbivores through the plant’s metabolic network. These changes can trigger cascading responses in plants and herbivores, altering their performance in concert with abiotic and biotic factors such as plant and herbivore identity, feeding mode, arrival sequence, and damage intensity. Despite recent progress, significant gaps remain in understanding how AMF-mediated nutrients are distributed across ecological compartments and organisms within complex food webs. Moving forward, integrating nutrient flux analyses with mechanistic models will be crucial for predicting interaction outcomes under global change drivers such as elevated atmospheric CO₂ and nutrient enrichment.

Apocynum venetum and Apocynum pictum are two important medicinal plants of the same genus but distinct species; their flavonoid and phenylpropanoid constituents are closely related to their medicinal value. Untargeted metabolomics was used to compare the flavonoid- and phenylpropanoid-related differential metabolites of roots, stems, and leaves in the two species at the seedling, growth, and mature stages. In total, 568, 560, and 530 differential metabolites were annotated in roots, stems, and leaves, respectively, of which 39 were related to the flavonoid and phenylpropanoid pathways. KEGG enrichment analysis showed that flavonoid and phenylpropanoid biosynthesis were enriched in leaves and flavone and flavonol biosynthesis in stems. Among the annotated metabolites, flavone/flavonol-type compounds (Quercetin and Luteolin) and phenylpropanoid compounds (Sinapic acid, Sinapyl alcohol, Caffeic acid, 5-caffeoylshikimic acid) differed markedly between species and among tissues, whereas flavanones and their derivatives, the flavanonol Taxifolin (Level 2) and naringenin-O-dihexoside (Level 3), were enriched in A. pictum. Overall, species, tissue, and growth stage jointly influence the accumulation of flavonoid- and phenylpropanoid-related metabolites in Apocynum, providing a basis for germplasm evaluation, medicinal-material identification, and the rational utilization of different tissues.