Angiosperm-wide analysis of fruit and ovary evolution aided by a new nuclear phylogeny supports association of the same ovary type with both dry and fleshy fruits.

Fruit functions in seed protection and dispersal and belongs to many dry and fleshy types, yet their evolutionary pattern remains unclear in part due to uncertainties in the phylogenetic relationships among several orders and families. Thus we used nuclear genes of 502 angiosperm species representing 231 families to reconstruct a well supported phylogeny, with resolved relationships for orders and families with previously uncertain placements. Using this phylogeny as a framework, molecular dating supports a Triassic origin of the crown angiosperms, followed by the emergence of most orders in the Jurassic and Cretaceous and their rise to ecological dominance during the Cretaceous Terrestrial Revolution. The robust phylogeny allowed an examination of the evolutionary pattern of fruit and ovary types, revealing a trend of parallel carpel fusions during early diversifications in eudicots, monocots, and magnoliids. Moreover, taxa in the same order or family with the same ovary type can develop either dry or fleshy fruits with strong correlations between specific types of dry and fleshy fruits; such associations of ovary, dry and fleshy fruits define several ovary-fruit "modules" each found in multiple families. One of the frequent modules has an ovary containing multiple ovules, capsules and berries, and another with an ovary having one or two ovules, achenes (or other single-seeded dry fruits) and drupes. This new perspective of relationships among fruit types highlights the closeness of specific dry and fleshy fruit types, such as capsule and berry, that develop from the same ovary type and belong to the same module relative to dry and fleshy fruits of other modules (such as achenes and drupes). Further analyses of gene families containing known genes for ovary and fruit development identified phylogenetic nodes with multiple gene duplications, supporting a possible role of whole-genome duplications, in combination with climate changes and animal behaviors, in angiosperm fruit and ovary diversification.

Complete chloroplast genomes of Rubus species (Rosaceae) and comparative analysis within the genus.

BACKGROUND: Rubus is the largest genus of the family Rosaceae and is valued as medicinal, edible, and ornamental plants. Here, we sequenced and assembled eight chloroplast (cp) genomes of Rubus from the Dabie Mountains in Central China. Fifty-one Rubus species were comparatively analyzed for the cp genomes including the eight newly discovered genomes and forty-three previously reported in GenBank database (NCBI). RESULTS: The eight newly obtained cp genomes had the same quadripartite structure as the other cp genomes in Rubus. The length of the eight plastomes ranged from 155,546 bp to 156,321 bp with similar GC content (37.0 to 37.3%). The results indicated 133-134 genes were annotated for the Rubus plastomes, which contained 88 or 89 protein coding genes (PCGs), 37 transfer RNA genes (tRNAs), and eight ribosomal RNA genes (rRNAs). Among them, 16 (or 18) of the genes were duplicated in the IR region. Structural comparative analysis results showed that the gene content and order were relatively preserved. Nucleotide variability analysis identified nine hotspot regions for genomic divergence and multiple simple sequences repeats (SSRs), which may be used as markers for genetic diversity and phylogenetic analysis. Phylogenetic relationships were highly supported within the family Rosaceae, as evidenced by sub-clade taxa cp genome sequences. CONCLUSION: Thus, the whole plastome may be used as a super-marker in phylogenetic studies of this genus.

Metabolite analysis reveals flavonoids accumulation during flower development in Rhododendron pulchrum sweet (Ericaceae).

The azalea (Rhododendron simsii Planch.) is an important ornamental woody plant with various medicinal properties due to its phytochemical compositions and components. However little information on the metabolite variation during flower development in Rhododendron has been provided. In our study, a comparative analysis of the flavonoid profile was performed in Rhododendron pulchrum sweet at three stages of flower development, bud (stage 1), partially open flower (stage 2), and full bloom (stage 3). A total of 199 flavonoids, including flavone, flavonol, flavone C-glycosides, flavanone, anthocyanin, and isoflavone were identified. In hierarchical clustering analysis (HCA) and principal component analysis (PCA), the accumulation of flavonoids displayed a clear development stage variation. During flower development, 78 differential accumulated metabolites (DAMs) were identified, and most were enriched to higher levels at the full bloom stage. A total of 11 DAMs including flavone (chrysin, chrysoeriol O-glucuronic acid, and chrysoeriol O-hexosyl-O-pentoside), isoflavone (biochanin A), and flavonol (3,7-di-O-methyl quercetin and isorhamnetin) were significantly altered at three stages. In particular, 3,7-di-O-methyl quercetin was the top increased metabolite during flower development. Furthermore, integrative analyses of metabolomic and transcriptomic were conducted, revealing that the contents of isoflavone, biochanin A, glycitin, and prunetin were correlated with the expression of 2-hydroxyisoflavanone dehydratase (HIDH), which provide insight into the regulatory mechanism that controls isoflavone biosynthesis in R. pulchrum. This study will provide a new reference for increasing desired metabolites effectively by more accurate or appropriate genetic engineering strategies.

Melanoserispenghuana (Lactucinae, Cichorieae, Asteraceae), a new species from North-central Yunnan, China.

In this paper, we describe a new species, Melanoserispenghuana, from Mt. Jiaozi Xueshan located in North-central Yunnan, China. Despite its morphological similarities to M.likiangensis, M.penghuana exhibits distinct differences in leaf texture, shape of terminal lobes, indumentum of leaves, peduncles, and involucres, as well as the length of the achenes. Additionally, the conservation status of this species is classified as Vulnerable through data analysis from two field surveys.

Characterization of the complete chloroplast genome sequence of Limnophila sessiliflora Blume 1826 (Plantaginaceae).

Limnophila sessiliflora Blume 1826 is a perennial amphibious herb with ornamental and water purification value that is widespread in temperate and tropical Asia. In the present study, we sequenced, assembled, and annotated the complete chloroplast (cp) genome of L. sessiliflora. It is 152,395 bp in length, with a typical quadripartite structure, comprising a pair of inverted repeat regions (IRs; 25,545 bp), a large single-copy region (LSC; 83,163 bp), and a small single-copy (SSC; 18,142 bp) region. The whole cp genome contained 135 genes, including 89 protein-coding genes (PCGs), 38 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. The maximum-likelihood (ML) phylogenetic analysis indicated that L. sessiliflora was closely related to the genera Bacopa and Scoparia in the tribe Gratioleae of Plantaginaceae. This cp genome provides a valuable genetic resource for phylogenetic study.

Climate Change Potentially Leads to Habitat Expansion and Increases the Invasion Risk of Hydrocharis (Hydrocharitaceae).

Climate change is a crucial factor impacting the geographical distribution of plants and potentially increases the risk of invasion for certain species, especially for aquatic plants dispersed by water flow. Here, we combined six algorithms provided by the biomod2 platform to predict the changes in global climate-suitable areas for five species of Hydrocharis (Hydrocharitaceae) (H. chevalieri, H. dubia, H. laevigata, H. morsus-ranae, and H. spongia) under two current and future carbon emission scenarios. Our results show that H. dubia, H. morsus-ranae, and H. laevigata had a wide range of suitable areas and a high risk of invasion, while H. chevalieri and H. spongia had relatively narrow suitable areas. In the future climate scenario, the species of Hydrocharis may gain a wider habitat area, with Northern Hemisphere species showing a trend of migration to higher latitudes and the change in tropical species being more complex. The high-carbon-emission scenario led to greater changes in the habitat area of Hydrocharis. Therefore, we recommend strengthening the monitoring and reporting of high-risk species and taking effective measures to control the invasion of Hydrocharis species.

Complete chloroplast genome sequence of Rhododendronmariesii and comparative genomics of related species in the family Ericaeae.

Rhododendronmariesii Hemsley et Wilson, 1907, a typical member of the family Ericaeae, possesses valuable medicinal and horticultural properties. In this research, the complete chloroplast (cp) genome of R.mariesii was sequenced and assembled, which proved to be a typical quadripartite structure with the length of 203,480 bp. In particular, the lengths of the large single copy region (LSC), small single copy region (SSC), and inverted repeat regions (IR) were 113,715 bp, 7,953 bp, and 40,918 bp, respectively. Among the 151 unique genes, 98 were protein-coding genes, 8 were tRNA genes, and 45 were rRNA genes. The structural characteristics of the R.mariesiicp genome was similar to other angiosperms. Leucine was the most representative amino acid, while cysteine was the lowest representative. Totally, 30 codons showed obvious codon usage bias, and most were A/U-ending codons. Six highly variable regions were observed, such as trnK-pafI and atpE-rpoB, which could serve as potential markers for future barcoding and phylogenetic research of R.mariesii species. Coding regions were more conserved than non-coding regions. Expansion and contraction in the IR region might be the main length variation in R.mariesii and related Ericaeae species. Maximum-likelihood (ML) phylogenetic analysis revealed that R.mariesii was relatively closed to the R.simsii Planchon, 1853 and R.pulchrum Sweet,1831. This research will supply rich genetic resource for R.mariesii and related species of the Ericaeae.

Small RNA sequencing provides insights into molecular mechanism of flower development in Rhododendron pulchrum Sweet.

Rhododendron pulchrum sweet, a member of the Ericaceae family possessing valuable horticultural properties, is widely distributed in the temperate regions. Though serving as bioindicator of metal pollution, the molecular mechanism regulating flowering in R. pulchrum is very limited. Illumina sequencing was performed to identify critical miRNAs in the synthesis of flavonoids at different developmental stages. Totally, 722 miRNAs belonging to 104 families were screened, and 84 novel mature miRNA sequences were predicted. The miR166, miR156, and miR167-1 families were dominant. In particular, 126 miRNAs were significantly differentially expressed among four different flowering stages. Totally, 593 genes were differentially regulated by miRNAs during the flower development process, which were mostly involved in "metabolic pathways", "plant hormone signal transduction", and "mitosis and regulation of biosynthetic processes". In pigment biosynthesis and signal transduction processes, gra-miR750 significantly regulated the expression of flavonoid 3',5'-hydroxylase; aof-miR171a, aof-miR171b, aof-miR171c, cas-miR171a-3p, and cas-miR171c-3p could regulate the expression of DELLA protein; aof-miR390, aof-miR396b, ath-miR3932b-5p, cas-miR171a-3p, aof-miR171a, and aof-miR171b regulated BAK1 expression. This research showed great potentials for genetic improvement of flower color traits for R. pulchrum and other Rhododendron species.

The complete chloroplast genome sequence of Callitriche palustris (Plantaginaceae).

Callitriche palustris L. is an annual aquatic or marsh plant, wide spread in temperate regions throughout the world. In present study, we sequenced, assembled and annotated the complete chloroplast (cp) genome of C. palustris. The length of C. palustris complete cp genome was 150,138 bp, with a typical quadripartite structure comprising a pair of inverted repeat regions (IRs; 25,667 bp), a large single copy region (LSC; 81,432 bp) and a small single copy region (SSC; 17,372 bp). The whole cp genome contained 134 genes, including 89 protein-coding genes (PCGs), 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. The maximum likelihood (ML) phylogenetic analysis indicated that C. palustris was a member of Plantaginaceae, but the relationships between subfamilies and tribes need more samplings. This cp genome would provide a valuable genetic resource for C. palustris' phylogenetic study.

The complete chloroplast genome sequence of China Lindera praecox (Lauraceae) and intra-species diversity.

Lindera praecox is a signature composition in the broadleaved deciduous forest of East China and Japan. Presently, the complete chloroplast (cp) genome of this species was sequenced, assembled, and annotated. It is 152,818 bp in length and encodes 85 protein-coding genes, 36 transfer RNA (tRNA) genes and eight ribosomal RNA (rRNA) genes. The phylogenetic analysis indicated intraspecific varieties within L. praecox species collected in China and Japan. This chloroplast genome sequencing offers genetic background for resources conservation and phylogenetic studies.

The complete chloroplast genome sequence of Sinojackia huangmeiensis (Styracaceae).

Sinojackia huangmeiensis J. W. Ge & X. H. Yao is a member of the genus Sinojackia endemic to central and east China. Here we assembled and annotated the complete chloroplast (cp) genome. It is 158,758 bp in length and encodes 84 protein-coding genes, 37 transfer RNA (tRNA) genes and eight ribosomal RNA (rRNA) genes. The Maximum likelihood phylogenetic analysis confirm that S. huangmeiensis is a closely related but another different species to S. sarcocarpa.

Complete chloroplast genome sequence and phylogenetic analysis of Magnolia pilocarpa, a highly ornamental species endemic in central China.

Magnolia pilocarpa Z. Z. Zhao et Z. W. Xie is a species with high horticultural and medicinal value, which found only in Dabie Mountain of central China. In this study, we sequenced, assembled and annotated the complete chloroplast (cp) genome of M. pilocarpa. The length of M. pilocarpa complete cp genome was 160,104 bp, with a typical quadripartite structure comprising a pair of inverted repeat regions (IRs; 26,591 bp), a large single copy region (LSC; 88,110 bp) and a small single copy region (SSC; 18,812 bp). The whole cp genome contained 129 unique genes, including 79 protein-coding genes (PCGs), 30 transfer RNA (tRNA) genes and four ribosomal RNA (rRNA) genes. The maximum-likelihood (ML) phylogenetic analysis indicated that M. pilocarpa was relatively closed to the M. denudata. This chloroplast genome would provide a valuable genetic resource for M. pilocarpa.

The complete chloroplast genome sequence of Anogeissus acuminata (combretaceae).

Anogeissus acuminata (Roxburgh ex Candolle) Guillemin et al. is an Endangered and dominant species of deciduous forests distributed in the Mekong valley of southwest China and adjacent Indo-China Peninsula. Here we assembled and annotated the complete chloroplast (cp) genome. It is 159,993 bp in length and encodes 84 protein-coding genes, 37 transfer RNA (tRNA) genes and eight ribosomal RNA (rRNA) genes. This chloroplast genome sequencing offers genetic background for conservation and phylogenetic studies.

The complete chloroplast genome sequence of Brainea insignis (Blechnaceae).

Brainea insignis (Hooker) J. Smith, a member of Blechnaceae, is a rare and endangered species in tropical Asia. Here we assembled and annotated the complete chloroplast (cp) genome. It is 149,730 bp in length and encodes 88 protein-coding genes, 36 transfer RNA (tRNA) genes and eight ribosomal RNA (rRNA) genes. This chloroplast genome sequencing offers a useful resource for future conservation genetics and phylogenetic studies.

The complete chloroplast genome sequence of Melica scabrosa (Poaceae).

Melica scabrosa Trin. is an important forage grass of Poaceae, wildly distributed in the Northeast Asia to Qinghai-Xizang Plateau. The complete chloroplast genome sequence of M. scabrosa was obtained by de novo assembly using whole genome sequence data. The chloroplast genome is 134,889 bp in length, containing 80,560 bp in a large single copy (LSC), 12,706 bp in a small single copy (SSC) and 20,810 bp in a pair of inverted repeats (IRs). A total of 129 genes including 83 protein-coding genes and 38 structural RNA genes were identified. Phylogenetic analysis represented close relationship among Melica species. This chloroplast genome sequencing offers a useful resource for future genetics and phylogenetic studies.