The use of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of heavy metal cadmium (Cd) and for enhancing plant growth in Cd-polluted soil is widely recognized as an effective approach. This study aimed to isolate Cd-resistant bacteria with plant growth-promoting (PGP) traits from the rhizosphere of vegetables subjected to metal contamination and to investigate the mechanisms associated with Cd adsorption as well as its impact on Cd uptake in lettuce. Six Cd-resistant bacterial strains were isolated from rhizosphere soil, among which the R27 strain exhibited the highest tolerance to Cd (minimum inhibitory concentration of 2000 mg/L) along with PGP traits, including phosphate solubilization (385.11 mg/L), the production of indole-3-acetic acid (IAA) (35.92 mg/L), and siderophore production (3.34 mg/L). Through a range of physiological, biochemical, and molecular assessments, the R27 strain was classified as Bacillus siamensis. This strain demonstrated notable efficiency in removing Cd²⁺ from the growth medium, achieving an efficacy of 80.1%. This removal was facilitated by cell surface adsorption through functional groups such as O–H, C=O, –CO–NH–, and C–O, alongside intracellular Cd accumulation, as evidenced by SEM, TEM, EDX, and FTIR analyses. Pot culture experiments indicated that R27 significantly promoted lettuce seedling growth and helped plants tolerate Cd stress, with the underlying mechanisms likely involving increased antioxidant activities for scavenging reactive oxygen species (ROS) induced by Cd stress, and reduced Cd²⁺ levels in lettuce seedlings to mitigate Cd²⁺ toxicity. These physiological changes were further supported by the down-regulation of genes associated with cadmium transport, including IRT1, Nramp1, HMA2, HMA4, ZIP4, and ZIP12, as well as the significantly reduced root bio-concentration factor (BCF) and translocation factor (TF). In summary, the R27 strain offers considerable potential in the bioremediation of Cd-polluted soils and can serve as a bio-fertilizer to enhance plant growth.

The siliciclastic rocks in the Xishanyao (XSY) and Toutunhe (TTH) formations recorded the Middle Jurassic palaeogeographic evolution processes of the Bogda Mountains. To explore their provenance, the geochronological, geochemical, and petrological characteristics of the Middle Jurassic sandstones from the west Bogda area are analyzed in this study. The detrital grains of sandstones are generally poorly to moderately sorted and subangular to subrounded. Low to moderate CIA* (chemical index of alteration), PIA (plagioclase index of alteration), CIW (chemical index of weathering) and relatively high ICV (index of compositional variability) values indicate the overall low to moderate weathering intensity, low sediment recycling, and abundant first-cycle siliciclastics supply. The abundant acid volcanic lithic fragments and element contents/ratios of the sandstones indicate source areas dominated by felsic rocks. The detrital zircon U-Pb age spectrum of the lower XSY Formation is dominated by a single Carboniferous age group. Multiple Palaeozoic zircon U-Pb age groups exist in the middle-upper XSY Formation. The TTH Formation has a typical age of late Middle Jurassic. Combined with the sedimentological characteristics, it reveals that (1) the Eastern Bogda Mountains (EBM) were the only provenance for the lower XSY Formation; (2) both the Yemaquan arc and the EBM provided detritus for the middle XSY Formation; (3) the Yemaquan arc became a minor provenance for the TTH and upper XSY formations. Middle Jurassic palaeogeographic evolution in the EBM is inferred as follows: (1) during the deposition of the lower XSY Formation, the EBM suffered a rapid uplift and became an obvious positive relief; (2) the palaeorelief became high in the Yemaquan arc area and low in the EBM during the deposition of the middle XSY Formation; (3) the Yemaquan arc was considerably eroded, which caused the palaeotopography to decline sharply during the deposition of the upper XSY Formation; (4) the EBM uplifted again during the TTH Formation period, accompanied by volcanic activities at ~165Ma.

The Qianjiadian uranium deposit is a typical interstratified oxidized zone sandstone-hosted uranium deposit hosted in the Upper Cretaceous Yaojia Formation of the southern Songliao Basin. Despite its significance, little research has been conducted on the relationship between trace elements, REEs, and uranium mineralization in this deposit. This study presents new geochemical data from sandstones in the oxidation, transition, and reduction zones. The sandstones in the transition zone are highly enriched in U and moderately enriched in Mo, Cd, and V compared to those in the oxidation and reduction zones. They are also weakly enriched in Co, Ni, and Zn. The oxidation and transition zone sandstones have higher ∑LREE and ∑HREE contents than those in the reduction zone. However, the oxidation zone sandstones are characterized by LREE enrichment and flat HRRE distribution, while the transition zone sandstones show HRRE enrichment and flat LREE distribution. These trace element and REE differentiation characteristics within each subzone are closely related to the geological process of interstratified oxygenation. Oxygenated uranium-bearing fluids from southwestern provenance areas carried multiple trace elements and REEs and infiltrated along the oxidation sandstones to reach the Yaojia Formation’s transition zone. During this process, a certain amount of Mo, V, Cd, and LREE from the oxygenated ore-forming fluids was precipitated by Fe-Mn hydroxide adsorption or calcite and siderite cementation. Meanwhile, about 20.33% of preexisting U in the oxidation zone sandstones was continuously extracted and entered into the oxygenated ore-forming fluids. In the transition zone, where dissolved oxygen was exhausted and hydrocarbons were continuously injected, U, Mo, Cd, V, Co, Ni, Zn, and REEs were unloaded and precipitated as uranium minerals, sulfide minerals, or carbonate minerals. The enrichment of Mo, Cd, V, and HREEs in the sandstones can serve as new prospecting indicators for the Qianjiadian uranium deposit.

The shale of Cambrian Niutitang Formation is one of the most important shale gas reservoirs in the Middle Yangtze region, South China. Nanopores are important reservoir spaces for shale gas. The study of pore characteristics and its formation controlling factors is of great significance for the exploration and development of shale gas in the Niutitang Formation. In this study, two drilling core samples and two profile samples were investigated. The laser Raman, X-ray diffraction analysis, FE-SEM, and low-pressure N₂ and CO₂ adsorption methods are used to study the geochemical and mineral compositions of the shales, and the nanopore characteristics and its formation controlling factors of the shales are discussed. Results show that the shales have the following features: (1) rich in organic matter (OM) and the total organic carbon (TOC) contents ranging from 2.65 to 11.33%, with an average value of 6.81%. (2) The main mineral components of these shales are quartz, feldspar, clay minerals, calcite, and a small amount of pyrite. (3) The samples from the center of the Middle Yangtze region (EY1 well and BGP profile) have a higher maturity value ( %) relatively to the samples from the south of the Middle Yangtze region (XD1 well and JF profile), where the is 2.8%. (4) The maximum N₂ adsorption capacity of the four groups of shale samples ranges from 5.090 to 27.333 cm³/g, with an average value of 15.571 cm³/g, while the maximum CO₂ adsorption capacity ranges from 2.686 to 5.567 cm³/g, with an average value of 3.776 cm³/g. The higher maturity leads to the EY1 well having the lowest average maximum N₂ adsorption capacity, while most of the OM pores in the EY1 well and BGP profile samples are smaller than 10 nm in diameter. The tectonic uplift leads to the profile samples having more meso-macropores than the core samples. The dissolution pores and granular mineral support are the key factors for the better pore structure of the high-evolution stage Niutitang Formation shale.

Longya Lily (Lilium brownii var. viridulum) bulb rot, a devastating soil-borne disease caused by Fusarium oxysporum f. sp. lilii (Fol L1-1), severely compromises yield and quality of this economically significant crop. In this study, strain R12 was isolated from the rhizosphere soil of asymptomatic Longya lily plants and identified as Bacillus velezensis. The strain significantly disrupted the spore germination and hyphal morphology of Fol L1-1. In pot experiments, R12 not only effectively suppressed disease development but also promoted plant growth, a trait potentially linked to its indole-3-acetic acid (IAA) production capacity. Genomic analysis revealed a 4,015,523 bp circular chromosome (46.42% GC content) harboring gene clusters for the synthesis of diverse secondary metabolites, including surfactin, fengycin, difficidin, and bacillibactin. These findings highlight the potential of B. velezensis R12 as a biocontrol agent and provide insights into its mechanisms for suppressing phytopathogens and promoting plant growth.