No abstract

Cathaya argyrophylla is an ancient Pinaceae species endemic to China that is listed on the IUCN Red List. Although C. argyrophylla is an ectomycorrhizal plant, the relationship between its rhizospheric soil microbial community and soil properties related to the natural habitat remains unknown. High-throughput sequencing of bacterial 16S rRNA genes and fungal ITS region sequences was used to survey the C. argyrophylla soil community at four natural spatially distributed points in Hunan Province, China, and functional profiles were predicted using PICRUSt2 and FUNGuild. The dominant bacterial phyla included Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi, and the dominant genus was Acidothermus. The dominant fungal phyla were Basidiomycota and Ascomycota, while Russula was the dominant genus. Soil properties were the main factors leading to changes in rhizosphere soil bacterial and fungal communities, with nitrogen being the main driver of changes in soil microbial communities. The metabolic capacities of the microbial communities were predicted to identify differences in their functional profiles, including amino acid transport and metabolism, energy production and conversion, and the presence of fungi, including saprotrophs and symbiotrophs. These findings illuminate the soil microbial ecology of C. argyrophylla, and provide a scientific basis for screening rhizosphere microorganisms that are suitable for vegetation restoration and reconstruction for this important threatened species.

Galium spurium is a farmland weed, with strong stress resistance. However, its chloroplast genome has never been reported. In this study, the complete sequence of the chloroplast genome of G. spurium was characterized, which is a circular molecule, 153,481 bp in length, and with a large single copy region of 84,334 bp, a small single copy region of 17,057 bp, and a pair of inverted repeat regions of 26,045 bp. The whole genome contained 127 genes, including 82 protein-coding genes, 37 transfer RNA genes, and eight ribosomal RNA genes. Phylogenetic analysis shows that it relates closely to G. aparine . This study provides a basis for the further phylogenic study of Galium.

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Soil depth, slope position and different plantations can influence bacterial community composition in Camellia oleifera forests. However, prior studies have focused on the impacts of different depths, slope positions, and forest types on bacterial diversity independently, without comparing their combined impacts. This study aimed to assess variation in soil bacterial community structures according to soil depth and slope position and different forest types in the same plot. The composition of soil bacterial communities was evaluated using high-throughput sequencing of the 16S rRNA gene. Results indicate that the soil organic carbon, humus, and total organic content increased, and the bacterial composition and structure were significantly altered in response to the G. jasminoides + C. oleifera low-yielding forest in comparison to the other three forest types. The highest soil bacteria numbers, Alpha and beta diversity, which improved the soil microecological environment, were associated with the G. jasminoides + C. oleifera forests and not the depth or slope position treatments. The slope position did not have a significant influence on the soil physicochemical and bacterial properties. Structural equation modeling suggested that G. jasminoides + C. oleifera significantly affected the soil bacterial community diversity by mediating the soil pH and NH –N. The effects of forest type on soil bacterial diversity were more important than soil depth and slope position. This specific intercropping system was found to be an effective strategy to improve soil health.

No abstract

Cathaya argyrophylla Chun et Kuang is a severely endangered, tertiary relict plant unique to China whose high physiological sensitivity to the environment, including photosensitivity, is likely closely related to its endangered status; however, the exact mechanism responsible has remained unknown due to the rarity of the plant and the difficulties involved in performing physiological studies on the molecular level. In this study, the chloroplast genomes of six C. argyrophylla populations sampled from different locations in China were characterized and compared. In addition, a gene regulatory network of the polymorphic chloroplast genes responsible for regulating genes found elsewhere in the plant genome was constructed. The result of the genome characterization and comparison showed that the genome characteristics, the gene composition, and the gene sequence of the chloroplast genes varied by location, and the gene regulatory network showed that the differences in growth location may have led to variations in the protein-coding chloroplast gene via various metabolic processes. These findings provide new insights into the relationship between chloroplasts and the sensitive metabolism of C. argyrophylla and provide additional reference materials for the conservation of this endangered plant.

Sedum bulbiferum is a traditional medicinal plant in China, with few reports on its chloroplast genome. In this study, the chloroplast genome of Sedum bulbiferum was characterized, and its phylogenetic position among other closely related species was studied. The results showed that the full length of the chloroplast genome was 150,074 bp, containing a large single-copy (LSC) region and a small single-copy (SSC) region of 81,730 and 16,726 bp, respectively, as well as two inverted repeat regions (IRs) of 25,809 bp like other plants. A total of 128 genes were found, including 83 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic analysis showed that Sedum bulbiferum is closely related to Sedum emarginatum, Sedum alfredii, Sedum tricarpum, Sedum plumbizincicola, and Sedum sarmentosum.