Calendula officinalis L.is a versatile medicinal plant with numerous applications in various fields. However, its chloroplast genome structure, features, phylogeny, and patterns of evolution and mutation remain largely unexplored. This study examines the chloroplast genome, phylogeny, codon usage bias, and divergence time of C. officinalis, enhancing our understanding of its evolution and adaptation. The chloroplast genome of C. officinalis is a 150,465 bp circular molecule with a G + C content of 37.75% and comprises 131 genes. Phylogenetic analysis revealed a close relationship between C. officinalis, C. arvensis, and Osteospermum ecklonis. A key finding is the similarity in codon usage bias among these species, which, coupled with the divergence time analysis, supports their close phylogenetic proximity. This similarity in codon preference and divergence times underscores a parallel evolutionary adaptation journey for these species, highlighting the intricate interplay between genetic evolution and environmental adaptation in the Asteraceae family. Moreover unique evolutionary features in C. officinalis, possibly associated with certain genes were identified, laying a foundation for future research into the genetic diversity and medicinal value of C. officinalis.
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.
Introduction: Plant mitochondrial genomes (mitogenomes) are known for their structural complexity, particularly within the Orchidaceae. To understand the evolutionary dynamics in the endangered genus Calanthe , this study provides the first complete mitogenome assembly for the endangered species Calanthe sieboldii , a species of horticultural and conservation importance. Methods: A hybrid sequencing approach combining Nanopore long reads and BGI short reads was used for denovo assembly. The genome was annotated, and we performed comparative analyses of repetitive sequences, interorganellar DNA transfer, codon usage, RNA editing, synteny, and phylogeny. Results: The 644,236 bp mitogenome exhibits a highly fragmented architecture, comprising 21 independent circular chromosomes ranging from 19.9 to 48.7 kb. We annotated 39 unique protein-coding genes, 23 tRNA genes, and 3 rRNA genes. The genome is characterized by a high density of repetitive sequences and a massive influx of chloroplast DNA, with mitochondrial–plastid sequences accounting for 12.72% of the total length. Comparative synteny analysis with other orchid species revealed an almost complete loss of gene order, highlighting extreme structural rearrangement. Despite this plasticity, core molecular features, such as codon usage and predicted RNA editing patterns, remain conserved. Phylogenetic analysis robustly placed C. sieboldii within the Orchidaceae. Discussion: This study decodes a complex multichromosomal mitogenome, reinforcing the paradigm of dynamic structural evolution in orchids and providing a vital genomic resource to support conservation efforts and evolutionary research on the Calanthe genus.
Spinal muscular atrophy (SMA) is an autosomal recessive heritable disorder leading to abnormalities and dysfunction of alpha motor neurons, paralysis, and
Calendula officinalis L.is a versatile medicinal plant with numerous applications in various fields. However, its chloroplast genome structure, features, phylogeny, and patterns of evolution and mutation remain largely unexplored. This study examines the chloroplast genome, phylogeny, codon usage bias, and divergence time of C. officinalis, enhancing our understanding of its evolution and adaptation. The chloroplast genome of C. officinalis is a 150,465 bp circular molecule with a G+C content of 37.75% and comprises 131 genes. Phylogenetic analysis revealed a close relationship between C. officinalis, C. arvensis, and Osteospermum ecklonis. A key finding is the similarity in codon usage bias among these species, which, coupled with the divergence time analysis, supports their close phylogenetic proximity. This similarity in codon preference and divergence times underscores a parallel evolutionary adaptation journey for these species, highlighting the intricate interplay between genetic evolution and environmental adaptation in the Asteraceae family.
Solanum pseudocapsicum Linnaeus 1753, a popular indoor potted plant known for its ornamental fruits, had its chloroplast genome sequenced in this study to determine its phylogenetic relationship with other related species and to construct a phylogenetic analysis tree. The research findings are as follows: 1. The chloroplast genome of S. pseudocapsicum comprises a large single-copy (LSC) region of 86,260 base pairs, a small single-copy (SSC) region of 18,325 base pairs, and two inverted repeat (IR) regions, each measuring 25,390 base pairs in length. 2. The G + C content of the entire chloroplast genome is 37.59%, with the highest G + C content found in the IR regions, reaching 43.03%; followed by the LSC region, which has a G + C content of 35.68%; and the lowest in the SSC region, with a G + C content of 31.53%. 3. The genome contains 127 genes, including 82 protein-coding genes, 37 tRNA genes, and 8 rRNA genes, with 18 genes duplicated in the IR regions. 4. Phylogenetic analysis revealed that S. pseudocapsicum, Solanum betaceum, Solanum laciniatum, and Solanum nitidum are genetically closely related and are located on the same branch of the phylogenetic tree, indicating a close relationship among them. This study provides a foundation for the identification, classification, and exploration of genetic diversity within the Solanum genus.