Molecular characterization of PSEUDO RESPONSE REGULATOR family in Rosaceae and function of PbPRR59a and PbPRR59b in flowering regulation.

BACKGROUND: PSEUDO RESPONSE REGULATOR (PRR) genes are essential components of circadian clock, playing vital roles in multiple processes including plant growth, flowering and stress response. Nonetheless, little is known about the evolution and function of PRR family in Rosaceae species. RESULTS: In this study, a total of 43 PRR genes in seven Rosaceae species were identified through comprehensive analysis. The evolutionary relationships were analyzed with phylogenetic tree, duplication events and synteny. PRR genes were classified into three groups (PRR1, PRR5/9, PRR3/7). The expansion of PRR family was mainly derived from dispersed and whole-genome duplication events. Purifying selection was the major force for PRR family evolution. Synteny analysis indicated the existence of multiple orthologous PRR gene pairs between pear and other Rosaceae species. Moreover, the conserved motifs of eight PbPRR proteins supported the phylogenetic relationship. PRR genes showed diverse expression pattern in various tissues of pear (Pyrus bretschneideri). Transcript analysis under 12-h light/ dark cycle and constant light conditions revealed that PRR genes exhibited distinct rhythmic oscillations in pear. PbPRR59a and PbPRR59b highly homologous to AtPRR5 and AtPRR9 were cloned for further functional verification. PbPRR59a and PbPRR59b proteins were localized in the nucleus. The ectopic overexpression of PbPRR59a and PbPRR59b significantly delayed flowering in Arabidopsis transgenic plants by repress the expression of AtGI, AtCO and AtFT under long-day conditions. CONCLUSIONS: These results provide information for exploring the evolution of PRR genes in plants, and contribute to the subsequent functional studies of PRR genes in pear and other Rosaceae species.

Chromosome-level genome assembly of a cliff plant Taihangia rupestris var. ciliata provides insights into its adaptation and demographic history.

BACKGROUND: Cliffs are recognized as one of the most challenging environments for plants, characterized by harsh conditions such as drought, infertile soil, and steep terrain. However, they surprisingly host ancient and diverse plant communities and play a crucial role in protecting biodiversity. The Taihang Mountains, which act as a natural boundary in eastern China, support a rich variety of plant species, including many unique to cliff habitats. However, it is little known how cliff plants adapt to harsh habitats and the demographic history in this region. RESULTS: To better understand the demographic history and adaptation of cliff plants in this area, we analyzed the chromosome-level genome of a representative cliff plant, T. rupestris var. ciliata, which has a genome size of 769.5 Mb, with a scaffold N50 of 104.92 Mb. The rapid expansion of transposable elements may have contributed to the increasing genome and its ability to adapt to unique and challenging cliff habitats. Comparative analysis of the genome evolution between Taihangia and non-cliff plants in Rosaceae revealed a significant expansion of gene families associated with oxidative phosphorylation, which is likely a response to the abiotic stresses faced by cliff plants. This expansion may explain the long-term adaptation of Taihangia to harsh cliff environments. The effective population size of the two varieties has continuously decreased due to climatic fluctuations during the Quaternary period. Furthermore, significant differences in gene expression between the two varieties may explain the varied leaf phenotypes and adaptations to harsh conditions in different natural distributions. CONCLUSION: Our study highlights the extraordinary adaptation of T. rupestris var. ciliata, shedding light on the evolution of cliff plants worldwide.

Transcriptome and metabolome profiling reveal the effects of hormones on current-year shoot growth in Chinese 'Cuiguan' pear grafted onto vigorous rootstock 'Duli' and dwarf rootstock 'Quince A'.

BACKGROUND: Dwarf rootstocks have important practical significance for high-density planting in pear orchards. The shoots of 'Cuiguan' grafted onto the dwarf rootstock were shorter than those grafted onto the vigorous rootstock. However, the mechanism of shorter shoot formation is not clear. RESULTS: In this study, the current-year shoot transcriptomes and phytohormone contents of 'CG‒QA' ('Cuiguan' was grafted onto 'Quince A', and 'Hardy' was used as interstock) and 'CG‒DL' ('Cuiguan' was grafted onto 'Duli', and 'Hardy' was used as interstock) were compared. The transcriptome results showed that a total of 452 differentially expressed genes (DEGs) were identified, including 248 downregulated genes and 204 upregulated genes; the plant hormone signal transduction and zeatin biosynthesis pathways were significantly enriched in the top 20 KEGG enrichment terms. Abscisic acid (ABA) was the most abundant hormone in 'CG‒QA' and 'CG‒DL'; auxin and cytokinin (CTK) were the most diverse hormones; additionally, the contents of ABA, auxin, and CTK in 'CG‒DL' were higher than those in 'CG‒QA', while the fresh shoot of 'CG‒QA' accumulated more gibberellin (GA) and salicylic acid (SA). Metabolome and transcriptome co-analysis identified three key hormone-related DEGs, of which two (Aldehyde dehydrogenase gene ALDH3F1 and YUCCA2) were upregulated and one (Cytokinin oxidase/dehydrogenase gene CKX3) was downregulated. CONCLUSIONS: Based on the results of transcriptomic and metabolomic analysis, we found that auxin and CTK mainly regulated the shoot differences of 'CG-QA' and 'CG-DL', and other hormones such as ABA, GA, and SA synergistically regulated this process. Three hormone-related genes ALDH3F1, YUCCA2, and CKX3 were the key genes contributing to the difference in shoot growth between 'CG-QA' and 'CG-DL' pear. This research provides new insight into the molecular mechanism underlying shoot shortening after grafted onto dwarf rootstocks.

Plastid genome and its phylogenetic implications of Asiatic Spiraea (Rosaceae).

BACKGROUND: Spiraea L. is a genus comprising approximately 90 species that are distributed throughout the northern temperate regions. China is recognized as the center of species diversity for this genus, hosting more than 70 species, including 47 endemic species. While Spiraea is well-known for its ornamental value, its taxonomic and phylogenetic studies have been insufficient. RESULTS: In this study, we conducted sequencing and assembly of the plastid genomes (plastomes) of 34 Asiatic Spiraea accessions (representing 27 Asiatic Spiraea species) from China and neighboring regions. The Spiraea plastid genome exhibits typical quadripartite structures and encodes 113-114 genes, including 78-79 protein-coding genes (PCGs), 30 tRNA genes, and 4 rRNA genes. Linear regression analysis revealed a significant correlation between genome size and the length of the SC region. By the sliding windows method, we identified several hypervariable hotspots within the Spiraea plastome, all of which were localized in the SC regions. Our phylogenomic analysis successfully established a robust phylogenetic framework for Spiraea, but it did not support the current defined section boundaries. Additionally, we discovered that the genus underwent diversification after the Early Oligocene (~ 30 Ma), followed by a rapid speciation process during the Pliocene and Pleistocene periods. CONCLUSIONS: The plastomes of Spiraea provided us invaluable insights into its phylogenetic relationships and evolutionary history. In conjunction with plastome data, further investigations utilizing other genomes, such as the nuclear genome, are urgently needed to enhance our understanding of the evolutionary history of this genus.

Introduction of a diverse genetic background of Pyrus into Malus through intergeneric hybridization.

Wide hybridizations across species and genera have been employed to enhance agriculturally important traits in crops. Within the tribe Maleae of the Rosaceae family, different genera and species exhibit several traits useful for increasing diversity and gene pool through hybridization. This study aimed to develop and characterize intergeneric hybrid individuals between Malus and Pyrus. Through seed germination, shoot multiplication, and rooting in vitro, acclimatized seedlings showing vegetative growth on their own roots were obtained from crosses of Malus × domestica pollinated by Pyrus communis, P. bretschneideri, and the Pyrus interspecific hybrid (P. communis × P. pyrifolia). Comparative analysis of leaf morphology, flow cytometry, and molecular genotyping confirmed the hybrid status of the individuals. Genome-wide genotyping revealed that all the hybrid individuals inherited genomic fragments symmetrically from the Malus and Pyrus parents. To the best of our knowledge, this is the first report on the development of intergeneric hybrid seedlings between Malus × domestica and P. bretschneideri. Furthermore, the Pyrus interspecific hybrid individual served as a bridge plant for introducing the genetic background of P. pyrifolia into Malus × domestica. The results of this study provided a crucial foundation for breeding through intergeneric hybridization between Malus and Pyrus, facilitating the incorporation of valuable traits from diverse gene pools.

Ecofriendly Controlled-Release Insecticide Carrier: pH-/Temperature-Responsive Rosin-Derived Hydrogels for Avermectin Delivery against Mythimna separata (Walker).

The exploration of environmentally friendly, less toxic, sustained-release insecticide is increasing with the growing demand for food to meet the requirements of the expanding population. As a sustained-release carrier, the unique, environmentally friendly intelligent responsive hydrogel system is an important factor in improving the efficiency of insecticide utilization and accurate release. In this study, we developed a facile approach for incorporating the natural compound rosin (dehydroabietic acid, DA) and zinc ions (Zn2+) into a poly(N-isopropylacrylamide) (PNIPAM) hydrogel network to construct a controlled-release hydrogel carrier (DA-PNIPAM-Zn2+). Then, the model insecticide avermectin (AVM) was encapsulated in the carrier at a drug loading rate of 36.32% to form AVM@DA-PNIPAM-Zn2+. Surprisingly, the smart controlled carrier exhibited environmental responsiveness, strongly enhanced mechanical properties, self-healing ability, hydrophobicity, and photostability to ensure a balance between environmental friendliness and the precision of the drug release. The release experiments showed that the carboxyl and amide groups in the polymer chains alter the intermolecular forces within the hydrogel meshes and ingredient diffusion by changing temperatures (25 and 40 °C) and pH values (5.8, 7.4, and 8.5), leading to different release behaviors. The insecticidal activity of the AVM@DA-PNIPAM-Zn2+ against oriental armyworms was good, with an effective minimum toxicity toward aquatic animals. Therefore, AVM@DA-PNIPAM-Zn2+ is an effective drug delivery system against oriental armyworms. We anticipate that this ecofriendly, sustainable, smart-response carrier may broaden the utilization rosin and its possible applications in the agricultural sector.

Plant kleptomaniacs: geographical genetic patterns in the amphi-apomictic Rubus ser. Glandulosi (Rosaceae) reveal complex reticulate evolution of Eurasian brambles.

BACKGROUND AND AIMS: Rubus ser. Glandulosi provides a unique model of geographical parthenogenesis on a homoploid (2n = 4x) level. We aim to characterize evolutionary and phylogeographical patterns in this taxon and shed light on the geographical differentiation of apomicts and sexuals. Ultimately, we aim to evaluate the importance of phylogeography in the formation of geographical parthenogenesis. METHODS: Rubus ser. Glandulosi was sampled across its Eurasian range together with other co-occurring Rubus taxa (587 individuals in total). Double-digest restriction site-associated DNA sequencing (ddRADseq) and modelling of suitable climate were used for evolutionary inferences. KEY RESULTS: Six ancestral species were identified that contributed to the contemporary gene pool of R. ser. Glandulosi. Sexuals were introgressed from Rubus dolichocarpus and Rubus moschus in West Asia and from Rubus ulmifolius agg., Rubus canescens and Rubus incanescens in Europe, whereas apomicts were characterized by alleles of Rubus subsect. Rubus. Gene flow between sexuals and apomicts was also detected, as was occasional hybridization with other taxa. CONCLUSIONS: We hypothesize that sexuals survived the last glacial period in several large southern refugia, whereas apomicts were mostly restricted to southern France, whence they quickly recolonized Central and Western Europe. The secondary contact of sexuals and apomicts was probably the principal factor that established geographical parthenogenesis in R. ser. Glandulosi. Sexual populations are not impoverished in genetic diversity along their borderline with apomicts, and maladaptive population genetic processes probably did not shape the geographical patterns.

Comparing RT-PCR of Individual Samples with High-Throughput Sequencing of Pooled Plant Samples for Field-Level Surveillance of Viruses in Blackberry and Wild Rubus.

Blackberry production is increasing in the Southeastern United States with the availability of new cultivars. In addition to high production costs, growers are challenged by virus diseases. Blackberry yellow vein disease (BYVD) significantly limits blackberry production. BYVD is associated with the crinivirus blackberry yellow vein-associated virus in mixed infections with other viruses. The specific disease etiology and ecological factors underlying BYVD are not well understood and rely on the effective diagnosis of several viruses involved in the complex. In 2021, we collected samples from blackberry plants showing BYVD symptoms, asymptomatic blackberry plants, and wild Rosaceae spp. from nine farms across South Carolina, for a total of 372 individual plant samples. RNA from individual samples was isolated and pooled into sample groups (i.e., symptomatic, asymptomatic, and wild) from each farm for a total of 24 pooled samples. We sequenced the pooled RNA using Illumina and analyzed sequence profiles using the Virtool bioinformatics application. We also tested each plant for six viruses by reverse transcriptase PCR or reverse transcriptase quantitative PCR and compared plant (PCR)-level and field (high-throughput sequencing [HTS])-level data. Virtool detected 17 known viruses in the pooled samples, including 11 blackberry viruses. PCR testing was mostly consistent with HTS, with some notable disagreements for specific viruses. Our study demonstrates that HTS could be used as an efficient tool to detect viruses in bulked samples in blackberry fields, although limitations to using HTS for field-level surveillance are also discussed here.

Comprehensive Evolutionary Analysis of the SMXL Gene Family in Rosaceae: Further Insights into Its Origin, Expansion, Diversification, and Role in Regulating Pear Branching.

SMXL genes constitute a conserved gene family that is ubiquitous in angiosperms and involved in regulating various plant processes, including branching, leaf elongation, and anthocyanin biosynthesis, but little is known about their molecular functions in pear branching. Here, we performed genome-wide identification and investigation of the SMXL genes in 16 angiosperms and analyzed their phylogenetics, structural features, conserved motifs, and expression patterns. In total, 121 SMXLs genes were identified and were classified into four groups. The number of non-redundant SMXL genes in each species varied from 3 (Amborella trichopoda Baill.) to 18 (Glycine max Merr.) and revealed clear gene expansion events over evolutionary history. All the SMXL genes showed conserved structures, containing no more than two introns. Three-dimensional protein structure prediction revealed distinct structures between but similar structures within groups. A quantitative real-time PCR analysis revealed different expressions of 10 SMXL genes from pear branching induced by fruit-thinning treatment. Overall, our study provides a comprehensive investigation of SMXL genes in the Rosaceae family, especially pear. The results offer a reference for understanding the evolutionary history of SMXL genes and provide excellent candidates for studying fruit tree branching regulation, and in facilitating pear pruning and planting strategies.

Antidepressant-like Effects of Chinese Quince (Chaenomeles sinensis) Fruit Based on In Vivo and Molecular Docking Studies.

In this study, we examined the potential antidepressant-like effects of Chinese quince fruit extract (Chaenomeles sinensis fruit extract, CSFE) in an in vivo model induced by repeated injection of corticosterone (CORT)-induced depression. HPLC analysis determined that chlorogenic acid (CGA), neo-chlorogenic acid (neo-CGA), and rutin (RT) compounds were major constituents in CSFE. Male ICR mice (5 weeks old) were orally administered various doses (30, 100, and 300 mg/kg) of CSFE and selegiline (10 mg/kg), a monoamine oxidase B (MAO-B) inhibitor, as a positive control following daily intraperitoneal injections of CORT (40 mg/kg) for 21 days. In our results, mice treated with CSFE exhibited significant improvements in depressive-like behaviors induced by CORT. This was evidenced by reduced immobility times in the tail suspension test and forced swim test, as well as increased step-through latency times in the passive avoidance test. Indeed, mice treated with CSFE also exhibited a significant decrease in anxiety-like behaviors as measured by the elevated plus maze test. Moreover, molecular docking analysis indicated that CGA and neo-CGA from CSFE had stronger binding to the active site of MAO-B. Our results indicate that CSFE has potential antidepressant effects in a mouse model of repeated injections of CORT-induced depression.

Pulp or Peel? Comparative Analysis of the Phytochemical Content and Selected Cosmetic-Related Properties of Annona cherimola L., Diospyros kaki Thumb., Cydonia oblonga Mill. and Fortunella margarita Swingle Pulp and Peel Extracts.

Fruit peels might be a valuable source of active ingredients for cosmetics, leading to more sustainable usage of plant by-products. The aim of the study was to evaluate the phytochemical content and selected biological properties of hydroglycolic extracts from peels and pulps of Annona cherimola, Diospyros kaki, Cydonia oblonga, and Fortunella margarita as potential cosmetic ingredients. Peel and pulp extracts were compared for their antiradical activity (using DPPH and ABTS radical scavenging assays), skin-lightening potential (tyrosinase inhibitory assay), sun protection factor (SPF), and cytotoxicity toward human fibroblast, keratinocyte, and melanoma cell lines. The total content of polyphenols and/or flavonoids was significantly higher in peel than in pulp extracts, and the composition of particular active compounds was also markedly different. The HPLC-MS fingerprinting revealed the presence of catechin, epicatechin and rutoside in the peel of D. kaki, whereas kaempferol glucoside and procyanidin A were present only in the pulp. In A. cherimola, catechin, epicatechin and rutoside were identified only in the peel of the fruit, whereas procyanidins were traced only in the pulp extracts. Quercetin and luteolinidin were found to be characteristic compounds of F. margarita peel extract. Naringenin and hesperidin were found only in the pulp of F. margarita. The most significant compositional variety between the peel and pulp extracts was observed for C. oblonga: Peel extracts contained a higher number of active components (e.g., vicenin-2, kaempferol rutinoside, or kaempferol galactoside) than pulp extract. The radical scavenging potential of peel extracts was higher than of the pulp extracts. D. kaki and F. margarita peel and pulp extracts inhibited mushroom and murine tyrosinases at comparable levels. The C. oblonga pulp extract was a more potent mushroom tyrosinase inhibitor than the peel extract. Peel extract of A. cherimola inhibited mushroom tyrosinase but activated the murine enzyme. F. margarita pulp and peel extracts showed the highest in vitro SPF. A. cherimola, D. kaki, and F. margarita extracts were not cytotoxic for fibroblasts and keratinocytes up to a concentration of 2% (v/v) and the peel extracts were cytotoxic for A375 melanoma cells. To summarize, peel extracts from all analyzed fruit showed comparable or better cosmetic-related properties than pulp extracts and might be considered multifunctional active ingredients of skin lightening, anti-aging, and protective cosmetics.

Recent Advances in Polysaccharides from Chaenomeles speciosa (Sweet) Nakai.: Extraction, Purification, Structural Characteristics, Health Benefits, and Applications.

This article systematically reviews the extraction and purification methods, structural characteristics, structure-activity relationship, and health benefits of C. speciosa polysaccharides, and their potential application in food, medicine, functional products, and feed, in order to provide a useful reference for future research. Chaenomeles speciosa (Sweet) Nakai. has attracted the attention of health consumers and medical researchers as a traditional Chinese medicine with edible, medicinal, and nutritional benefits. According to this study, C. speciosa polysaccharides have significant health benefits, such as anti-diaetic, anti-inflammatory and analgesic, anti-tumor, and immunomodulatory effects. Researchers determined the molecular weight, structural characteristics, and monosaccharide composition and ratio of C. speciosa polysaccharides by water extraction and alcohol precipitation. This study will lay a solid foundation for further optimization of the extraction process of C. speciosa polysaccharides and the development of their products. As an active ingredient with high value, C. speciosa polysaccharides are worthy of further study and full development. C. speciosa polysaccharides should be further explored in the future, to innovate their extraction methods, enrich their types and biological activities, and lay a solid foundation for further research and development of products containing polysaccharides that are beneficial to the human body.

Exploring the potential of phenolic and antioxidant compounds in new Rosaceae fruits.

BACKGROUND: Rosaceae fruits have been used in traditional medicine for the prevention and treatment of diseases. However, these fruits have not extensively been studied regarding their phenolic composition. Thus, this research focuses on the determination of phenolic compounds by high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry, flavan-3-ols by high-performance liquid chromatography with fluorescence detection, and the antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power of the fruits of five species of genera Crataegus and Sorbus (Rosaceae). RESULTS: We found a total of 71 phenolic compounds from which 30 were identified in these berries for the first time. Crataegus monogyna and Crataegus laciniata revealed higher total phenolic and flavan-3-ol contents than the other species and the highest antioxidant activities. CONCLUSIONS: Therefore, the fruits evaluated have demonstrated to be important sources of bioactive compounds with huge potential for being used in nutraceutical or food scopes. Additional studies could be needed to evaluate the influence of the different production areas on the phenolic content. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of fertilizer application on the growth of Stranvaesia davidiana D. seedlings.

Wild plants represent a potential source of urban landscape trees. Stranvaesia davidiana Dcne. is a member of the Stranvaesia Lindl. Genus, which belongs to family Rosaceae Juss. It has great ornamental value. It can contribute to urban color foliage and fruit species. However, the most effective fertilizer application strategy required for its cultivation is unknown. Therefore, we conducted an orthogonal experiment to investigate the fertilizer type and level (pure nitrogen) using ten experimental groups, including an untreated control group. Pot experiments were used to determine the growth indices of seedlings, including plant height, basal diameter, and chlorophyll content post-fertilizer treatment. This study explored the most appropriate fertiler application model for the growth of S. davidiana seedlings. The results revealed that enhanced seedling growth depended on the type and amount of fertilizer used, and their interaction. Fertilizer application increased the plant height by 2.67 cm to 12.26 cm, basal diameter by 0.39 cm to 0.75 cm, and chlorophyll content by 5.66 to 19.86. Among the different types of fertilizer, organic fertilizer increased the plant height by 0.42 cm to 9.59 cm and basal diameter by 0.01 cm to 0.05 cm, compared with the control group. Organic fertilizer had the maximum effect on seedling growth, especially at medium levels. The total growth of basal diameter and chlorophyll content was 1.58 ± 0.04 cm and 39.53 ± 2.37, respectively. Basal diameter is the most critical index in seedling reproduction . The study results suggest that the application of 4.06 g of organic fertilizer per plant was the most effective, and served as a basis for further field trials.

Identification of self-incompatibility alleles in Quince (Cydonia oblonga Mill.).

The Quince (Cydonia oblonga Mill.), typically known for its self-compatibility, surprisingly presents a degree of self-incompatibility. This research focused on exploring the diversity within the self-incompatibility gene locus (S) in various C. oblonga genotypes. Through meticulous DNA sequencing, the study sought to unearth potential novel S alleles. In the process of genotyping the S gene across multiple quince genotypes, not only were the previously documented S1 and S2 alleles identified, but this investigation also uncovered two previously unrecognized alleles, termed S4 and S5. These alleles, particularly S4, emerged as the most prevalent among the tested genotypes. To corroborate the findings derived from DNA sequencing, the study employed pollen tube growth germination assays. These assays elucidated a higher pollen germination rate in the Ardabil2 genotype in contrast to Behta. Additionally, the study involved assessing pollen tube growth in both Ardabil2 and Behta through cross-pollination techniques, meticulously tracking the development of pollen tubes at various stages. Remarkably, the outcomes demonstrated that the Behta genotype possesses self-incompatibility, whereas the Ardabil2 genotype showcases a notable degree of self-compatibility. This groundbreaking discovery of new S alleles in quince not only affirms the species' self-compatibility but also sheds light on the complexities of allelic diversity and its impact on self-incompatibility. Such insights are invaluable for enhancing the yield of quince orchards through strategic breeding programs.

Relative contributions of taxonomic and functional diversity to the assembly of plant communities hosting endemic Dianthus species in a mountain steppe.

Plant community assembly is the outcome of long-term evolutionary events (evident as taxonomic diversity; TD) and immediate adaptive fitness (functional diversity; FD); a balance expected to shift in favour of FD in 'harsh' habitats under intense selection pressures. We compared TD and FD responses along climatic and edaphic gradients for communities of two species (Dianthus pseudocrinitus and D. polylepis) endemic to the montane steppes of the Khorassan-Kopet Dagh floristic province, NE Iran. 75 plots at 15 sites were used to relate TD and FD to environmental gradients. In general, greater TD was associated with variation in soil factors (potassium, lime, organic matter contents), whereas FD was constrained by aridity (drought adaptation). Crucially, even plant communities hosting different subspecies of D. polylepis responded differently to aridity: D. polylepis subsp. binaludensis communities included a variety of broadly stress-tolerant taxa with no clear environmental response, but TD of D. polylepis subsp. polylepis communities was directly related to precipitation, with consistently low FD reflecting a few highly specialized stress-tolerators. Integrating taxonomic and functional diversity metrics is essential to understand the communities hosting even extremely closely related taxa, which respond idiosyncratically to climate and soil gradients.

Chromosome-scale genome assembly and annotation of Cotoneaster glaucophyllus.

Cotoneaster glaucophyllus is a semi-evergreen plant that blossoms in late summer, producing dense, attractive, fragrant white flowers with significant ornamental and ecological value. Here, a chromosome-scale genome assembly was obtained by integrating PacBio and Illumina sequencing data with the aid of Hi-C technology. The genome assembly was 563.3 Mb in length, with contig N50 and scaffold N50 values of ~6 Mb and ~31 Mb, respectively. Most (95.59%) of the sequences were anchored onto 17 pseudochromosomes (538.4 Mb). We predicted 35,856 protein-coding genes, 1,401 miRNAs, 655 tRNAs, 425 rRNAs, and 795 snRNAs. The functions of 34,967 genes (97.52%) were predicted. The availability of this chromosome-level genome will provide valuable resources for molecular studies of this species, facilitating future research on speciation, functional genomics, and comparative genomics within the Rosaceae family.

Revealing the structural changes of lignin in Chinese quince (Chaenomeles sinensis) fruit as it matures.

Chinese quince fruits (Chaenomeles sinensis) contain substantial amounts of lignin; however, the exact structure of lignin remains to be investigated. In this study, milled wood lignins (Milled wood lignin (MWL)-1, MWL-2, MWL-3, MWL-4, MWL-5, and MWL-6) were extracted from fruits harvested once a month from May to October 2019 to investigate their structural evolution during fruit growth. The samples were characterized via High-performance anion exchange chromatography (HPAEC), Fourier transform-infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), thermogravimetric (TGA), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and NMR (2D-heteronuclear single quantum coherence (HSQC) and 31P). The MWL samples in all fruit growth stages were GS-type lignin and lignin core undergoing minimal alterations during fruit development. The predominant linkage in the lignin structure was ß-O-4', followed by ß-ß' and ß-5'. Galactose and glucose were the main monosaccharides associated with MWL. In MWL-6, the lignin exhibited the highest homogeneity and thermal stability. As the fruit matured, a gradual increase in the ß-O-4' proportion and the ratio of S/G was observed. The results provide comprehensive characterization of the cell wall lignin of quince fruit as it matures. This study could inspire innovative applications of quince fruit lignin and provide the optimal harvest time for lignin utilization.

PbRbohH/J mediates ROS generation to regulate the growth of pollen tube in pear.

Respiratory burst oxidase homolog (Rboh) family genes play crucial functions in development and growth. However, comprehensive and systematic investigation of Rboh family members in Rosaceae and their specific functions during pear pollen development are still limited. In the study, 63 Rboh genes were identified from eight Rosaceae genomes (Malus domestica, Pyrus bretschneideri, Pyrus communis, Prunus persica, Rubus occidentalis, Fragaria vesca, Prunus mume and Prunus avium) and divided into seven main subfamilies (I-VII) according to phylogenetic and structural features. Different modes of gene duplication led to the expansion of Rboh family, with purifying selection playing a vital role in the evolution of Rboh genes. In addition, RNA sequencing and qRT-PCR results indicated that PbRbohH and PbRbohJ were specifically high-expressed in pear pollen. Subsequently, subcellular localization revealed that PbRbohH/J distributed at the plasma membrane. Furthermore, by pharmacological analysis and antisense oligodeoxynucleotide assay, PbRbohH/J were demonstrated to mediate the formation of reactive oxygen species (ROS) to manage pollen tube growth. In conclusion, our results provide useful insights into the functions, expression patterns, evolutionary history of the Rboh genes in pear and other Rosaceae species.

Modified Chinese quince oligomeric proanthocyanidin protects deep-frying oil quality by inhibiting oxidation.

Chinese quince (Chaenomeles sinensis) fruit is an underutilized resource, rich in proanthocyanidins with antioxidant ability but poor lipid solubility. In this study, a novel modified oligomeric proanthocyanidin (MOPA) was prepared, which exhibited favorable lipid solubility (354.52 mg/100 g). It showed higher radical scavenging abilities than commercial antioxidant-BHA (butylated hydroxyanisole), both at 0.4-0.5 mg/mL. The addition of MOPA (0.04 %wt.) significantly increased the oxidative stability index of the soybean oil from 5.52 to 8.03 h, which was slightly lower than that of BHA (8.35 h). Analysis of the physicochemical properties and composition of oil during deep-frying showed that MOPA demonstrated significant antioxidant effects and effectively restricted the oil oxidation. This inhibition also delays the formation of heterocyclic amines (HAs) in fried food, thereby reducing the migration of HAs from food to deep-frying oil. Therefore, MOPA is a promising novel liposoluble antioxidant for protecting the quality of deep-frying oil.