To screen environmentally friendly and efficient Cd pollution remediation material, the effects of BC and BF on soil Cd bio-availability and cotton Cd absorption were analyzed under Cd exposure. Besides, the differences in metabolic mechanisms by which biochar (BC) and biofertilizer (BF) affect Cd-contaminated soil and cotton were also analyzed. The results showed that the application of BC and BF increased cotton dry matter accumulation, boll number, and single boll weight, and reduced the Cd content in cotton roots, stems, leaves, and bolls. At harvest, the Cd content in cotton roots in the BC and BF groups reduced by 15.23% and 16.33%, respectively, compared with that in the control. This was attributed to the conversion of carbonate-bound Cd (carbon-Cd) and exchangeable Cd (EX-Cd) by BC and BF into residual Cd (Res-Cd). It should be noted that the soil available Cd (Ava-Cd) content in the BF group was lower than that in the BC group. The metabolomic analysis results showed that for BC vs BF, the relative abundance of differential metabolites Caffeic acid, Xanthurenic acid, and Shikimic acid in soil and cotton roots were up-regulated. Mantel test found that cotton root exudate l-Histinine was correlated with the enrichment of Cd in various organs of cotton. Therefore, the application of BC and BF can alleviate Cd stress by reducing soil Ava-Cd content and cotton's Cd uptake, and BF is superior to BC in reducing Cd content in soil and cotton organs. This study will provide a reference for the development of efficient techniques for the remediation of Cd-polluted alkaline soil, and provide a basis for subsequent metagenomics analysis.

In the present study, the complete mitochondrial genomes of five Peltigera species (Peltigera elisabethae, Peltigera neocanina, Peltigera canina, Peltigera ponojensis, Peltigera neckeri) were sequenced, assembled and compared with relative species. The five mitogenomes were all composed of circular DNA molecules, and their ranged from 58,132 bp to 69,325 bp. The mitochondrial genomes of the five Peltigera species contain 15 protein-coding genes (PCGs), 2 rRNAs, 26–27 tRNAs and an unidentified open reading frame (ORF). The PCG length, AT skew and GC skew varied among the 15 PCGs in the five mitogenomes. Among the 15 PCGs, cox2 had the least K2P genetic distance, indicating that the gene was highly conserved. The synteny analysis revealed that the coding regions were highly conserved in the Peltigera mitochondrial genomes, but gene rearrangement occurred in the intergenic regions. The phylogenetic analysis based on the 14 PCGs showed that the 11 Peltigera species formed well-supported topologies, indicating that the protein-coding genes in the mitochondrial genome may be used as a reliable molecular tool in the study of the phylogenetic relationship of Peltigera.

Lichens are symbiotic associations of algae and fungi. The genetic mechanism of the symbiosis of lichens and the influence of symbiosis on the size and composition of the genomes of symbiotic algae have always been intriguing scientific questions explored by lichenologists. However, there were limited data on lichen genomes. Therefore, we isolated and purified a lichen symbiotic alga to obtain a single strain (Trebouxiophyceae sp. DW1), and then obtained its chloroplast genome information by next-generation sequencing (NGS). The chloroplast genome is 129,447 bp in length, and the GC content is 35.2%. Repetitive sequences with the length of 30–35 bp account for 1.27% of the total chloroplast genome. The simple sequence repeats are all mononucleotide repeats. Codon usage analysis showed that the genome tended to use codon ending in A/U. By comparing the length of different regions of Trebouxiophyceae genomes, we found that the changes in the length of exons, introns, and intergenic sequences affect the size of genomes. Trebouxiophyceae had an unstable chloroplast genome structure, with IRs repeatedly losing during evolution. Phylogenetic analysis showed that Trebouxiophyceae is paraphyletic, and Trebouxiophyceae sp. DW1 is sister to the clade of Koliella longiseta and Pabia signiensis.

Western Tianshan National Nature Reserve in Xinjiang, China stands out for its uniqueness and high biodiversity, including lichens. This study aims to characterize lichen diversity and compare distribution patterns of different life forms, substratum affinities and photobiont types. Surveys were conducted from June to August 2024 using stratified sampling methods at elevation ranging from 1100 m to 3400 m in the study area. Morphological, anatomical and chemical studies revealed 173 lichen species from 24 families and 58 genera, of which 100 species were identified as crustose, 46 as foliose and 27 as fruticose. Among the different habitat groups, strictly saxicolous lichens were dominant with 89 species, followed by corticolous lichens with 44 species and terricolous lichens with 40 species. The total species richness of lichens has a bimodal pattern: one peak appears at a low altitude (1701–2000 m) and the other at a high altitude (2901–3200 m). Among the three substratum categories studied, the species richness of terricolous lichens showed a unimodal relationship with elevation, and the saxicolous lichen had a bimodal pattern. The species richness of corticolous lichens was highest at lower and medium elevations and decreased at higher elevations. With respect to photobiont type, the species richness of cyanolichens showed a unimodal relationship with elevation. Maximum richness occurred at 2700 m, contrary to the chlorolichens, which had a bimodal pattern. Species richness of all three growth forms of lichens showed a bimodal pattern related to elevation. Among the three morphological types, crustose and foliose species richness had their highest values of 38 and 19, respectively, at 1701–2000 m, and fruticose lichens peaked with a maximum of 13 species at 2301–2600 m. The species richness of crustose lichens is lowest between altitudes 2300 and 2600 m, while the lowest species richness of fruticose and foliose lichens occurs at 2001–2300 m and elevations above 2900 m.

Introduction: Lichens are globally distributed symbiotic organisms comprising fungi (mycobionts) and photosynthetic partners (photobionts), with exceptional adaptability to extreme environments. Despite growing interest in lichen symbiosis, chloroplast genome data for photobionts remain scarce, hindering insights into symbiotic coevolution and genomic architecture.Methods: To address this gap, we characterized the chloroplast genome of Chloroidium sp. W5, a photobiont of the lichen Peltigera elisabethae, using next-generation sequencing. The circular genome (190,579 bp) was assembled and annotated using a combination of bioinformatics tools, including GetOrganelle for genome assembly and GeSeq for annotation. We conducted a comprehensive analysis of the genome’s structure, gene content, and repetitive elements. Codon usage patterns were assessed using MEGA 11, and phylogenetic relationships were inferred using maximum likelihood analysis with IQ-tree.Results: The circular genome (190,579 bp) lacks the canonical quadripartite structure (LSC/IR/SSC) and exhibits a strong AT bias (56.1%). Annotation identified 110 functional genes, including 79 protein-coding genes, 28 tRNAs, and 3 rRNAs. Repetitive sequence analysis revealed 5,000 dispersed repeats (2.62% of the genome), predominantly forward and palindromic types, with SSR loci showing a significant A/T preference. Codon usage analysis demonstrated a pronounced bias toward A/U-ending codons (RSCU > 1), suggesting translational adaptation to symbiotic nutrient constraints. Phylogenetic reconstruction robustly placed Chloroidium sp. W5 within the Watanabeales clade (ML = 100), while synteny analysis revealed extensive genomic rearrangements compared to close relatives.Discussion: These findings enrich the chloroplast genome database for lichen photobionts, shedding light on symbiosis-driven genomic plasticity and providing a foundation for studying host-photobiont coevolution and lichen ecological adaptation.