RESUMEN
The use of halophytes in conjunction with arbuscular mycorrhizal (AM) fungi has been found to enhance the removal efficacy of heavy metals and salts in heavy metals contaminated saline soil. The mechanisms of AM fungi on promoting halophyte growth and regulating metabolism remain unclear. In this study, combinations of 0 g kg-1 NaCl and 3 mg kg-1 Cd (S0Cd3), 6 g kg-1 NaCl and 3 mg kg-1 Cd (S6Cd3), and 12 g kg-1 NaCl and 3 mg kg-1 Cd (S12Cd3) were employed to explore the impact of Funneliformis mosseae on the growth and metabolism of Suaeda salsa. The results showed that AM fungi increased the biomass and the P, K+, Ca2+, and Mg2+ accumulations, reduced the Cd and Na+ concentrations in S0Cd3 and S6Cd3, and increased the Cd concentrations in S12Cd3. AM fungi inoculation reduced the Cd and Na+ transfer factors and increased the Cd and Na+ accumulations in S6Cd3. The metabolomics of S6Cd3 showed that AM fungi upregulated the expression of 5-hydroxy-L-tryptophan and 3-indoleacid acid in tryptophan metabolism, potentially acting as crucial antioxidants enabling plants to actively cope with abiotic stresses. AM fungi upregulated the expression of arbutin in glycolysis process, enhancing the plants' osmoregulation capacity. AM fungi upregulated the expression of 2-hydroxycinnamic acid in phenylalanine metabolism and dopaquinone in tyrosine metabolism. These two metabolites help effectively remove reactive oxygen species. Correspondingly, AM fungi decreased MDA content and increased soluble sugar content. These results indicate that AM fungi improve the stress resistance of S. salsa by increasing nutrient uptake and regulating physiological and metabolic changes.
Asunto(s)
Aminoácidos , Cadmio , Chenopodiaceae , Glucólisis , Micorrizas , Reguladores del Crecimiento de las Plantas , Micorrizas/fisiología , Micorrizas/metabolismo , Cadmio/metabolismo , Cadmio/toxicidad , Chenopodiaceae/metabolismo , Chenopodiaceae/microbiología , Chenopodiaceae/efectos de los fármacos , Reguladores del Crecimiento de las Plantas/metabolismo , Aminoácidos/metabolismo , Estrés Salino , Plantas Tolerantes a la Sal/metabolismo , Plantas Tolerantes a la Sal/microbiología , HongosRESUMEN
Rare earth elements (REEs) have been widely used in traditional and high-tech fields, and high doses of REEs are considered a risk to the ecosystem. Although the influence of arbuscular mycorrhizal fungi (AMF) in promoting host resistance to heavy metal (HM) stress has been well documented, the molecular mechanism by which AMF symbiosis enhances plant tolerance to REEs is still unclear. A pot experiment was conducted to investigate the molecular mechanism by which the AMF Claroideoglomus etunicatum promotes maize (Zea mays) seedling tolerance to lanthanum (La) stress (100 mg·kg-1 La). C. etunicatum symbiosis significantly improved maize seedling growth, P and La uptake and photosynthesis. Transcriptome, proteome, and metabolome analyses performed alone and together revealed that differentially expressed genes (DEGs) related to auxin /indole-3-acetic acid (AUX/IAA) and the DEGs and differentially expressed proteins (DEPs) related to ATP-binding cassette (ABC) transporters, natural resistance-associated macrophage proteins (Nramp6), vacuoles and vesicles were upregulated. In contrast, photosynthesis-related DEGs and DEPs were downregulated, and 1-phosphatidyl-1D-myo-inositol 3-phosphate (PI(3)P) was more abundant under C. etunicatum symbiosis. C. etunicatum symbiosis can promote plant growth by increasing P uptake, regulating plant hormone signal transduction, photosynthesis and glycerophospholipid metabolism pathways and enhancing La transport and compartmentalization in vacuoles and vesicles. The results provide new insights into the promotion of plant REE tolerance by AMF symbiosis and the possibility of utilizing AMF-maize interactions in REE phytoremediation and recycling.
RESUMEN
Alkaline lakes are a special type of extreme saline-alkali ecosystem, and the dominant plants store a large number of microbial resources with salinity-tolerant or growth-promoting properties in the littoral zones. In this study, high-throughput sequencing technology and molecular ecological networks were used to analyze the bacteria and fungi from different rhizocompartments of three dominant plants along the salinity gradient in the littoral zones of Sunit Alkali Lake. The study found that fungal communities were more tolerant of environmental abiotic stress, and salinity was not the main environmental factor affecting the composition of microbial communities. Mantel test analysis revealed that SOC (soil organic carbon) was the primary environmental factor affecting the rhizosphere bacterial community as well as the rhizosphere endophyte bacteria and fungi, while CO32- (carbonate ions) had a greater impact on the rhizosphere fungal communities. In addition, keystones identified through the associated molecular network play an important role in helping plants resist saline-alkali environments. There were significant differences in the metabolic pathways of microorganisms from different rhizocompartments predicted by the PICRUSt2 database, which may help to understand how microorganisms resist environmental stress. This study is of great importance for understanding the salt environments around alkaline lakes and excavating potential microbial resources.
Asunto(s)
Lagos , Microbiota , Carbono , Suelo , Microbiología del Suelo , Plantas , Bacterias , Rizosfera , Hongos , ÁlcalisRESUMEN
Lake littoral zones can also be regarded as another extremely hypersaline environment due to hypersaline properties of salt lakes. In this study, high-throughput sequencing technique was used to analyze bacteria and fungi from different rhizocompartments (rhizosphere and endosphere) of four dominant plants along the salinity gradient in the littoral zones of Ejinur Salt Lake. The study found that microbial α-diversity did not increase with the decrease of salinity, indicating that salinity was not the main factor on the effect of microbial diversity. Distance-based redundancy analysis and regression analysis were used to further reveal the relationship between microorganisms from different rhizocompartments and plant species and soil physicochemical properties. Bacteria and fungi in the rhizosphere and endosphere were the most significantly affected by SO4 2-, SOC, HCO3 -, and SOC, respectively. Correlation network analysis revealed the potential role of microorganisms in different root compartments on the regulation of salt stress through synergistic and antagonistic interactions. LEfSe analysis further indicated that dominant microbial taxa in different rhizocompartments had a positive response to plants, such as Marinobacter, Palleronia, Arthrobacter, and Penicillium. This study was of great significance and practical value for understanding salt environments around salt lakes to excavate the potential microbial resources.