Tillage practices can directly affect soil quality, influencing soil properties, crop growth, and soil microbial community characteristics. However, the influence of long-term tillage practices on the rhizosphere bacterial community in lime concretion black soil remains largely unknown. In this study, the effects of nine-year rotary tillage (RT), no-tillage (NT), subsoiling tillage (ST), and plow tillage (PT) on soil chemical properties, microbial community structure, and correlations between bacterial communities and soil properties in the maize rhizosphere were investigated. The results revealed that the maize yield in ST and PT was higher by 10.61% and 10.26% than that in RT and by 10.25% and 9.90% than that in NT, respectively. The soil organic matter (SOM) and total nitrogen (TN) contents in NT and ST were significantly higher than those in RT and PT, whereas the available phosphorus (AP) content in ST and PT was significantly higher than that in NT and RT. The diversity and richness of the soil bacterial communities exhibited a trend of NT > RT > PT > ST. The principal component analysis revealed that the soil bacterial community differed among treatments. Linear discriminant analysis effect size (LEfSe) analysis demonstrated that Proteobacteria, Armatimonadetes, Verrucomicrobia, and Chloroflexi could serve as crucial biomarkers. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) results revealed that genes involved in carbon, lipid, and xenobiotic metabolism were enriched under ST and PT, whereas those involved in nitrogen and carbon fixation were enriched under NT. Besides, Proteobacteria, Verrucomicrobia, and Armatimonadetes were positively associated with AP levels and negatively associated with pH; however, Acidobacteria, Bacteroidetes, and Planctomycetes exhibited an opposite trend. Overall, ST and PT improved the soil properties and environmental suitability by increasing the bacterial keystone taxa; thus, these practices improved crop yield. These findings could enhance our understanding of the rhizosphere functional microbial community in lime concretion black soil for winter wheat–summer maize double-cropping system.

Talaromyces purpurogenus, an endophytic fungus, exhibits beneficial effects on plants during plant–fungus interactions. However, the molecular mechanisms underlying plants’ responses to T. purpurogenus under low-phosphorous (P) stress are not fully understood. In this study, we investigated the transcriptomic changes in maize with low-P-sensitive (31778) and -tolerant (CCM454) genotypes under low-P stress and its symbiotic interaction with T. purpurogenus. Its colonization enhanced plant growth and facilitated P uptake, particularly in 31778. Transcriptome sequencing revealed that 135 DEGs from CCM454 and 389 from 31778 were identified, and that only 6 DEGs were common. This suggested that CCM454 and 31778 exhibited distinct molecular responses to T. purpurogenus inoculation. GO and KEGG analysis revealed that DEGs in 31778 were associated with nicotianamine biosynthesis, organic acid metabolic process, inorganic anion transport, biosynthesis of various secondary metabolites and nitrogen metabolism. In CCM454, DEGs were associated with anthocyanin biosynthesis, diterpenoid biosynthesis and metabolic process. After T. purpurogenus inoculation, the genes associated with phosphate transporter, phosphatase, peroxidase and high-affinity nitrate transporter were upregulated in 31778, whereas AP2-EREBP-transcription factors were detected at significantly higher levels in CCM454. This study provided insights on the molecular mechanisms underlying plant–endophytic fungus symbiosis and low-P stress in maize with low-P-sensitive and -tolerant genotypes.

Lodging causes a reduction in wheat (Triticum aestivum L.) yield and quality. A shorter plant height (PH) can reduce the incidence of lodging. The overuse of nitrogen promotes excessive vegetative growth, leads to taller plants, and increases lodging risk. Here, we utilized genome-wide association studies (GWASs) to explore the genetic basis of PH and the nitrogen effect index (NEI), a parameter to estimate the responses of PH under varying nitrogen conditions, using 21,201 SNP markers from the Illumina Wheat 90K SNP array. A total of 191 wheat varieties from Yellow and Huai Valley regions of China, as well as other global regions, were analyzed across two growing seasons under four nitrogen treatments, namely N₀ (0 kg/ha), N₁₅₀ (150 kg/ha), N₂₁₀ (210 kg/ha), and N₂₇₀ (270 kg/ha). GWAS results showed that 30 genetic markers were associated with PH, explaining phenotypic variance from 5.92% to 13.69%. Additionally, nine significant loci were associated with the NEI. Notably, markers on chromosomes 1A and 6B were linked to both PH and the NEI, which were insensitive to low- and high-nitrogen fertilizers. In addition, the PH of the three cultivars (Zhoumai16, Zhoumai13, and Bima1) showed little variation in four nitrogen fertilizer levels. This study identified key genetic markers associated with wheat PH and the NEI, providing insights for optimizing nitrogen use in wheat breeding.