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The properties of nanopipettes largely rely on the materials introduced onto their inner walls, which allow for a vast extension of their sensing capabilities. The challenge of simultaneously enhancing the sensitivity and selectivity of nanopipettes for pH sensing remains, hindering their practical applications. Herein, we report insulin-modified nanopipettes with excellent pH response performances, which were prepared by introducing insulin onto their inner walls via a two-step reaction involving silanization and amidation. The pH response intensity based on ion current rectification was significantly enhanced by approximately 4.29 times when utilizing insulin-modified nanopipettes compared with bare ones, demonstrating a linear response within the pH range of 2.50 to 7.80. In addition, insulin-modified nanopipettes featured good reversibility and selectivity. The modification processes were monitored using the I-V curves, and the relevant mechanisms were discussed. The effects of solution pH and insulin concentration on the modification results were investigated to achieve optimal insulin introduction. This study showed that the pH response behavior of nanopipettes can be greatly improved by introducing versatile molecules onto the inner walls, thereby contributing to the development and utilization of pH-responsive nanopipettes. [ABSTRACT FROM AUTHOR]

The article discusses research on whole genome sequencing of Mesorhizobium strains isolated from native legumes growing in two distant Low Arctic sites to understand the population genomics of rhizobia from northern Canada. The study measured the phylogenetic and average nucleotide identity of bacterial strains and analyzed legume nodulation and symbiotic nitrogen fixation on their chromosome. It describes the growth characteristics, taxonomy, genomic structures of three Mesorhizobium strains.

Cerasus serrulata (Rosaceae) is an important flowering cherry resource which is valuable for developing new cultivars of flowering cherries. It is broadly distributed and possesses abundant variations. In this study, phylogeographic analysis was conducted to reveal the evolutionary history to better understand the genetic diversity and genetic structure of C. serrulata so as to provide more accurate molecular insights into better conservation and utilization of the germplasm resources. A total of 327 individuals from 18 wild populations were collected. Three chloroplast DNA (cpDNA) fragments (matK, trnD‐E, and trnS‐G) and the nuclear internal transcribed spacer (ITS) were utilized. The results showed a high genetic diversity at both species level and population level of C. serrulata. High genetic differentiation and the existence of the phylogeographic structure were detected. No significant expansion events were discovered. Two geographic lineages were inferred. One was confined to the Qinling Mountains and the Taihang Mountains. The other was from the Wuling Mountains to the Jiangnan Hilly Regions and then went northeast to the coast of Asia. In addition, some taxonomic treatments of the C. serrulata complex are discussed and reconsidered. Conservation and utilization strategies of wild C. serrulata germplasm resources were recommended. [ABSTRACT FROM AUTHOR]

Cerasus dielsiana (Rosaceae) is one of the most characteristic wild flowering cherry species endemic to subtropical China, with high conservation value from ornamental, economic, and ecological perspectives. To verify its spatial genetic structure and phylogeographic history, evaluation of nuclear (ITS) sequence variation in 203 individuals from 25 wild populations across its natural distribution ranges was conducted. High levels of ribotypes and nuclear diversity (Hd = 0.879 ± 0.012, π = 3.56 ± 0.16) were detected at the species level. Spatial analysis of molecular variation (SAMOVA), median-joining network and phylogenetic Neighbour-joining tree assigned the populations into four genetically distinct groups. Meanwhile, high levels of genetic differentiation among populations and strong phylogeographic patterns (Nst = 0.837 > Gst = 0.585; P < 0.05) were revealed based on the analysis of molecular variance (AMOVA). Results of neutrality tests, mismatch distribution analyses, Mantel test, barrier analyses, together with ecological niche modelling (ENM) simulation and BEAST analysis suggest a long-term demographic history (95% HPD: 3.64–8.83 Mya) of C. dielsiana, and at least three potential in situ glacial refugia as well as recent demographic expansion in eastern region have been detected. Collectively, we highlight that the combined effect of natural selection and random genetic drift under complex topography and palaeoclimatic oscillations since the Last Glacial Maximum (LGM) in subtropical China might have been the main driver to the species' allopatric differentiation. Scientific conservation and sustainable utilization for wild C. dielsiana germplasm resources were subsequently proposed. [ABSTRACT FROM AUTHOR]

Keteleeria davidiana (Bertrand) Beissner 1891 (Pinaceae) is a rare tertiary relict plant endemic to China. However, since the main morphological characteristics used for identifying K. davidiana are variable, some taxonomic treatments within the species are still controversial. Here a complete chloroplast genome of K. davidiana representing a special genotype was assembled, which could provide more information for the taxonomic study of this species. The assembled genome was 117,642 bp in length with a large single-copy (LSC) region (74,825 bp), a small single-copy (SSC) region (40,247 bp), and two incomplete inverted repeats (IRs) regions (1285 bp each). In total, 118 genes were predicted, including 4 rRNAs, 34 tRNAs, and 80 protein-coding genes. The overall GC content of the assembled genome was 38.5%. Phylogenetic analysis showed that different accessions of K. davidiana formed a clade with relatively low support (bootstrap value = 71), which indicated a high level of sequences variation within the species. [ABSTRACT FROM AUTHOR]

Tectaria (Tectariaceae) is one of the most confusing fern genera in terms of its circumscription and phylogeny. Since its original description, a number of genera had been moved into or related with this genus, while others had been segregated from it. Tectaria is also among the largest fern genera, comprising 150–210 mostly tropical species. Previous molecular studies have been far from comprehensive (sampling no more than 76 accessions from 52 species), limited in geographic scope (mainly restricted to Asia), and based exclusively on plastid markers. In the present study, DNA sequences of eight plastid and one nuclear marker of 360 accessions representing ca. 130 species of Tectaria , ca. 36 species of six non- Tectaria genera in Tectariaceae, 12 species of Davalliaceae, Oleandraceae, and Polypodiaceae, and 13 species of Lomariopsidaceae were used to infer a phylogeny with maximum likelihood, Bayesian inference, and maximum parsimony approaches. Our major results include: (1) the most recently proposed circumscription of Tectaria is strongly supported as monophyletic; (2) the genera Lenda , Microbrochis , Phlebiogonium , and Sagenia , sampled here for the first time, are resolved as part of Tectaria ; (3) four superclades representing early splits in Tectaria are identified, with the Old World species being sister to the New World species; (4) 12 well-supported major clades in Tectaria are revealed, differing from one another in molecular, morphological, and geographical features; (5) evolution of 13 morphological characters is inferred in a phylogenetic context and morphological synapomorphies of various clades are identified; and in particular (6) free venation in Tectaria is inferred to be repeatedly derived from anastomosing venation, an evolutionary phenomenon not documented previously in vascular plants in a phylogenetic context based on both plastid and nuclear evidence. [ABSTRACT FROM AUTHOR]

The diverse and pantropical genus Ctenitis , in the Dryopteridaceae, has been largely ignored in phylogenetic studies until now. In this study, we fill in this gap by reconstructing the first comprehensive phylogeny of the genus including 53 species currently recognized in the genus Ctenitis , among which seven species formerly were assigned to the genus Pseudotectaria and one to Heterogonium . Special emphasis was given to the sampling of species occurring in the African-Indian Ocean region. The presented results include reconstruction of a biogeographic scenario based on estimated divergence times and ancestral area reconstruction. Our findings confirm the inclusion, within Ctenitis , of the Indian Ocean species formerly placed in Pseudotectaria and Heterogonium . The crown group divergence was estimated to date back to the Oligocene or Early Miocene. The biogeographical scenario indicates an initial divergence of the Asian-Pacific ranges and the neotropical ranges, and a subsequent colonization of the Afro-Madagascan region by a lineage with neotropical ancestors. The Afro-Madagascan lineage splits into a lineage endemic to the Mascarene islands and a lineage occurring in Madagascar, the Comoros and Africa. The range expansion towards Africa and Madagascar was estimated to date back to the late Miocene, whereas the estimated ages for the onset of the diversification of the Mascarene diversity is consistent with the ages of these young, volcanic islands. The absence of any extant species of Ctenitis with a multi-continental distribution range and the rarity of inter-island dispersal and speciation in the Indian Ocean region suggest a limited contribution of long distance dispersal to the biogeographical history of this fern genus, versus a high contribution of local speciation. [ABSTRACT FROM AUTHOR]