Complete Genome Sequence of Pantoea ananatis Strain LCFJ-001 Isolated from Bacterial Wilt Mulberry.

A Pantoea ananatis strain, named LCFJ-001 (GDMCC: 1.6101), was isolated for the first time from bacterial wilt-diseased roots of mulberry (Morus atropurpurea) in the western part of the Guangxi Zhuang Autonomous Region, China. Moreover, through Koch's postulates, it was proven that LCFJ-001 can cause mulberry wilt, which is one of the pathogens of mulberry bacterial wilt. Here, we report a complete, annotated genome sequence of P. ananatis LCFJ-001. The entire genome sequence of P. ananatis strain LCFJ-001 was a 4,499,350 bp circular chromosome with 53.50% GC content. In total, 3,521 genes were annotated, of which 3,418 were assigned protein-coding genes. In addition, 22 ribosomal RNAs and 81 transfer RNAs were identified. The presented resource will help explore the pathogenetic mechanisms of mulberry wilt disease caused by the genus Pantoea.

Characterization of the Complete Mitochondrial Genome Sequences of Three Croakers (Perciformes, Sciaenidae) and Novel Insights into the Phylogenetics.

The three croakers (Nibea coibor, Protonibea diacanthus and Argyrosomus amoyensis, Perciformes, Sciaenidae) are important commercial species inhabiting the Eastern Indian Ocean and Western Pacific. Molecular data employed in previous research on phylogenetic reconstruction have not been adequate and complete, and systematic and comprehensive phylogenetic relationships for these fish are unresolved. We sequenced the complete mitochondrial genomes of the three croakers using next-generation sequencing for the first time. We analyzed the composition and phylogenies between 19 species in the family Sciaenidae using the mitochondrial protein coding sequences of 204 species in the Series Eupercaria. We present the characterization of the complete mitochondrial genome sequences of the three croakers. Gene arrangement and distribution of the three croakers are canonically identical and consistent with other vertebrates. We found that the family Sciaenidae is an independent branch that is isolated from the order Perciformes and does not belong to any extant classification. Therefore, this family is expected to belong to a new classification at the order level and needs further analysis. The evolution of Sciaenidae has lagged far behind the Perciformes differentiation. This study presents a novel insight into the phylogenetics of the family Sciaenidae from the order Perciformes and facilitates additional studies on the evolution and phylogeny of Series Eupercaria.

Resource and Environmental Pressures on the Transformation of Planting Industry in Arid Oasis.

Controlling environmental pollutant discharge and water resource demand is crucial for the sustainable development of agriculture and rural areas in arid oases. Taking Ganzhou, an arid oasis in Northwest China, as an example, we established an analysis framework for the relationship between the planting industry transformation and the resource and environmental pressures, from 2011 to 2020, through the methods of inventory, coefficient and quota accounting. The results showed that the planting scale of crops in oases has continuously expanded, with a structural dominance of corn seed production. Pollutant discharge showed a "Z"-type evolution trend, and the demand for water consumption continued to increase. The transformation of the planting industry and pollutant discharge showed coupled trade-offs and a synergetic alternating fluctuations coupling relationship, which was highly co-evolutionary with the demand for water resources. Crop planting exhibited four spatial patterns, namely the mixed planting area of grain and cash crops grown in mountain areas (GCPA), suburban scale vegetable planting (SVPA), planting of seed production corn (MSPA), and the compound planting area of grain crops, oil crops, vegetables, and other characteristic crops (CMPA). MSPA and SVPA had the highest total and average volume per unit area, respectively. The planting industry transformation and evolution of resource and environment pressures are closely related to changes in national strategies, regional agricultural policies, and environmental regulations. Therefore, studying their relationships provides a scientific basis for the formulation of suitable countermeasures, according to the development stage of a region.

The ties of brotherhood between japonica and indica rice for regional adaptation.

Selection of beneficial genomic variants was crucial for regional adaptation of crops during domestication, but the underlying genomic basis remains largely unexplored. Here we report a genome-wide selective-sweep analysis of 655 japonica and 1,205 indica accessions selected from 2,673 landraces through principal component analysis to identify 5,636 non-synonymous single nucleotide polymorphisms (SNPs) fixed in at least one subspecies. We classified these SNPs into three groups, jiS (japonica- and indica-selected), jS (japonica-selected only), and iS (indica-selected only), and documented evidence for selection acting on these groups, their relation to yield-related traits, such as heading date, and their practical value in cropping area prediction. We also demonstrated the role of a jiS-SNP-containing gene in temperature adaptability. Our study informs genes underpinning adaptation that may shape Green Super Rice and proposes a time-saving, cost-reducing selection strategy of genomic breeding, sweep-SNP-guided selection, for developing regionally-adapted heterosis.

FishPIE: A universal phylogenetically informative exon markers set for ray-finned fishes.

Understanding the evolutionary history of the highly diverse ray-finned fishes has been challenging, and the development of more universal primers for phylogenetic analyses may help overcoming these challenges. We developed FishPIE, a nested PCR primer set of 82 phylogenetically informative exon markers, and tested it on 203 species from 31 orders of Actinopterygii. We combined orthologous sequences of the FishPIE markers obtained from published genomes and transcriptomes and constructed the phylogeny of 710 species belonging to 190 families and 60 orders. The resulting phylogenies had topologies comparable to previous phylogenomic studies. We demonstrated that the FishPIE markers could address phylogenetic questions across broad taxonomic levels. By incorporating the newly sequenced taxa, we were able to shed new light on the phylogeny of the highly diverse Cypriniformes. Thus, FishPIE holds great promise for generating genetic data for broad taxonomic groups and accelerating our understanding of the fish tree of life.

A complete sequence of mitochondrial genome of Neolamarckia cadamba and its use for systematic analysis.

Neolamarckia cadamba is an important tropical and subtropical tree for timber industry in southern China and is also a medicinal plant because of the secondary product cadambine. N. cadamba belongs to Rubiaceae family and its taxonomic relationships with other species are not fully evaluated based on genome sequences. Here, we report the complete sequences of mitochondrial genome of N. cadamba, which is 414,980 bp in length and successfully assembled in two genome circles (109,836 bp and 305,144 bp). The mtDNA harbors 83 genes in total, including 40 protein-coding genes (PCGs), 31 transfer RNA genes, 6 ribosomal RNA genes, and 6 other genes. The base composition of the whole genome is estimated as 27.26% for base A, 22.63% for C, 22.53% for G, and 27.56% for T, with the A + T content of 54.82% (54.45% in the small circle and 54.79% in the large circle). Repetitive sequences account for ~ 0.14% of the whole genome. A maximum likelihood (ML) tree based on DNA sequences of 24 PCGs supports that N. cadamba belongs to order Gentianales. A ML tree based on rps3 gene of 60 species in family Rubiaceae shows that N. cadamba is more related to Cephalanthus accidentalis and Hymenodictyon parvifolium and belongs to the Cinchonoideae subfamily. The result indicates that N. cadamba is genetically distant from the species and genera of Rubiaceae in systematic position. As the first sequence of mitochondrial genome of N. cadamba, it will provide a useful resource to investigate genetic variation and develop molecular markers for genetic breeding in the future.

Comparison of mitochondrial genome and development of specific PCR primers for identifying two scuticociliates, Pseudocohnilembus persalinus and Uronema marinum.

BACKGROUND: Pseudocohnilembus persalinus and Uronema marinum (Ciliophora, Scuticociliatia), as parasitic scuticociliatid ciliates, were isolated from Scophthalmus maximus and Takifugu rubripes, respectively, in our previous studies. These ciliates are morphologically very similar; hence, it is difficult to identify specific scuticociliate species using traditional classification methods for performing taxonomic research and disease control studies. METHODS: We annotated the mitochondrial genomes of these two scuticociliates on the basis of previous sequencing, including analyses of nucleotide composition, codon usage, Ka/Ks, and p-distance. We also compared the nucleotide and amino acid similarity of the mitochondrial genomes of P. persalinus, U. marinum, and other 12 related ciliates, and a phylogenetic tree was constructed using 16 common genes. We chose the nad4 and nad7 genes to design specific PCR primers for identification. RESULTS: P. persalinus and U. marinum were found to have a close evolutionary relationship. Although codon preferences were similar, differences were observed in the usage of codons such as CGA, CGC, and GTC. Both Ka/Ks and p-distance were less than 1. Except for yejR, ymf57, ymf67, and ymf75, the amino acid sequence similarity between P. persalinus and U. marinum was greater than 50%. CONCLUSIONS: The mitochondrial genomes of P. persalinus and U. marinum were thoroughly compared to provide a reference for disease prevention and control. The specific PCR primers enabled us to identify P. persalinus and U. marinum rapidly and accurately at the molecular level, thus providing a basis for classification and identification.

Complete chloroplast genome sequence of Amomum villosum and comparative analysis with other Zingiberaceae plants.

Objective: Amomum villosum (AV) is an herb whose dried fruit has been extensively used in modern medicine to treat digestive system diseases such as dysentery, vomiting and abdominal pain. This paper aims to supplement chloroplast (cp) genomic resources and to be used in phylogenetic studies and identification of AV related plants. Methods: High-throughput sequencing technology was used to determine the complete sequence of the AV cp genome, and the sequence was then compared with three related species. Results: The genome size of AV we obtained was 163,968 bp with an obvious tetrad structure. The AV cp genome was observed to contain 125 unique genes and 81 simple sequence repeat (SSRs) had been determined and the majority of which were adenine-thymine (AT)-rich. Comparative analysis of genome sequence of four ginger plants showed that the atpF, clpP and rpl32 genes are potential markers for identifying Amomum species. Phylogenetic analysis suggested that AV was closely related to A. kravanh and A. compactum. Conclusion: These results have brought useful genetic resources for further identification researches, DNA barcoding, resolving taxonomy and understanding the evolutionary mode of Zingiberaceae cp genome.

Mitochondrial genome of Parasinilabeo longicorpus provides insights into the phylogeny of Labeoninae.

Parasinilabeo longicorpus is an endemic species living in the karst regions of South China. In the present study, we firstly performed the complete mitogenome sequence of P. longicorpus (Cyprinidae: Labeoninae). Results showed that the mitogenome was 16,596 bp in length and contained 37 genes (i.e. 13 protein-coding, 22 transfer RNA, and two ribosomal RNA genes) and a single control region. The genetic arrangement and distribution of the mitogenome were consistent with that of other vertebrates. Phylogenetic analysis of the protein-coding genes indicated that Labeoninae species could be divided into three branches. Parasinilabeo longicorpus showed close evolutionary relationship with P. assimilis. This study should help to improve our understanding of the mitogenomes and phylogenetics of Labeoninae, and provide a foundation for further taxonomic, systematic, and genetic studies.

Identification, expression, and phylogenetic analyses of terpenoid biosynthesis-related genes in secondary xylem of loblolly pine (Pinus taeda L.) based on transcriptome analyses.

Loblolly pine (Pinus taeda L.) is one of the most important species for oleoresin (a mixture of terpenoids) in South China. The high oleoresin content of loblolly pine is associated with resistance to bark beetles and other economic benefits. In this study, we conducted transcriptome analyses of loblolly pine secondary xylem to gain insight into the genes involved in terpenoid biosynthesis. A total of 372 unigenes were identified as being critical for oleoresin production, including genes for ATP-binding cassette (ABC) transporters, the cytochrome P450 (CYP) protein family, and terpenoid backbone biosynthesis enzymes. Six key genes involved in terpenoid biosynthetic pathways were selected for multiple sequence alignment, conserved motif prediction, and phylogenetic and expression profile analyses. The protein sequences of all six genes exhibited a higher degree of sequence conservation, and upstream genes were relatively more conserved than downstream genes in terpenoid biosynthetic pathways. The N-terminal regions of these sequences were less conserved than the C-terminal ends, as the N-terminals were quite diverse in both length and composition. The phylogenetic analyses revealed that most genes originated from gene duplication after species divergence, and partial genes exhibited incomplete lineage sorting. In addition, the expression profile analyses showed that all six genes exhibited high expression levels during the high-oleoresin-yielding phase.

The complete chloroplast genome sequence of Cunninghamia lanceolata.

We determined the complete chloroplast genome sequence of Cunninghamia lanceolata (GenBank accession: NC_021437.1) in this study. The total length of the chloroplast genome is 135 334 bp. The GC content is 35%. A total of 119 genes are successfully annotated, including 35 tRNA (20 tRNA species), 3 rRNA (3 rRNA species) and 81 protein-coding genes (81 PCG species). Twelve protein-coding genes (rps16, ycf3, rpoC1, atpF, rps12, ndhB, rpl2, rpl16, petD, petB, ndhA, rps15) contain one or two introns. A maximum likelihood phylogenetic analysis showed that this newly characterized Cunninghamia lanceolata chloroplast genome will provide essential data for further study on phylogenetic resolution, biodiversity for the genus Cunninghamia and Taxodiacea.

The complete chloroplast genome of Gnetum montanum and sequence analysis.

The complete chloroplast sequence of Gnetum montanum (GenBank accession number: NC_021438.1) was determined and characterized in this study. The size of the chloroplast genome of Gnetum montanum is 115 019 bp. Including a large single copy (LSC) region of 66 697 bp and a small single copy (SSC) region of 9494 bp separated by a pair of identical inverted repeat regions (IRs) of 19 414 bp each. A total of 108 genes that were successfully annotated contains 65 protein-coding genes, 40 tRNA genes and 3 rRNA genes. The GC content of the chloroplast genome of Gnetum montanum is 38.16%. Twelve genes contain one introns.