Prunus Pseudocerasus Research Articles

Polyamine oxidase induces flower formation by promoting spermidine and ABA accumulation in cherry (Cerasus pseudocerasus Lindl.)

Polyamines are important small molecules that play a crucial in flower formation in plants. Polyamine oxidases (PAOs) have a significant function in regulating flower development by influencing polyamine homeostasis. Treatment with exogenous Spd resulted in a significant increase in the Spd content in cherry flower buds, which was accompanied by an increase in abscisic acid (ABA) levels and a decrease in gibberellin (GA) levels, as well as a notable rise in the expression of genes associated with flower formation. Polyamine oxidases are essential for maintaining endogenous polyamine homeostasis. Based on the sweet cherry genome and the ‘Manaohong’ cherry transcriptome data, four polyamine metabolism enzyme genes (CpPAO1/2/3/4) were identified. Sequence comparisons of PAO proteins revealed a high degree of sequence similarity between ‘Manaohong’ cherry and sweet cherry, with only a single amino acid variation. Phylogenetic analysis classified CpPAOs into three subclasses. The expression patterns of CpPAOs were significantly tissue-specific, exhibiting higher levels of expression in flowers and young leaves. Exogenous Spd significantly increased the expression abundance of CpPAOs, as well as ABA-related and flower-forming genes. The function of CpPAO2 was subsequently verified through genetic transformation, which demonstrated that the expression levels of ABA synthesis, signal transduction genes, and flower formation genes were substantially elevated in CpPAO2 transgenic lines. These transgenic lines exhibited earlier flowering and a greater number of inflorescences compared to wild type (WT). Yeast single-hybrid and dual-luciferase assays revealed that CpABF5 binds to the promoter of CpSOC1, promoting its expression. Collectively, these results indicated that exogenous Spd increases the content of Spd and Spm while enhancing ABA levels by promoting the transcript level of CpNCEDs in flower buds, thereby facilitating flower formation through the CpABF5-CpSOC1 pathway.

Identifying potential anthocyanin biosynthesis regulator in Chinese cherry by comprehensive genome-wide characterization of the R2R3-MYB transcription factor gene family

BackgroundChinese cherry [Cerasus pseudocerasus (Lindl.) G.Don] (syn. Prunus pseudocerasus Lindl.) is an economically important fruiting cherry species with a diverse range of attractive colors, spanning from the lightest yellow to the darkest black purple. However, the MYB transcription factors involved in anthocyanin biosynthesis underlying fruit color variation in Chinese cherry remain unknown.ResultsIn this study, we characterized the R2R3-MYB gene family of Chinese cherry by genome-wide identification and compared it with those of 10 Rosaceae relatives and Arabidopsis thaliana. A total of 1490 R2R3-MYBs were classified into 43 subfamilies, which included 29 subfamilies containing both Rosaceae MYBs and AtMYBs. One subfamily (S45) contained only Rosaceae MYBs, while three subfamilies (S12, S75, and S77) contained only AtMYBs. The variation in gene numbers within identical subfamilies among different species and the absence of certain subfamilies in some species indicated the species-specific expansion within MYB gene family in Chinese cherry and its relatives. Segmental and tandem duplication events primarily contributed to the expansion of Chinese cherry R2R3-CpMYBs. The duplicated gene pairs underwent purifying selection during evolution after duplication events. Phylogenetic relationships and transcript profiling revealed that CpMYB10 and CpMYB4 are involved in the regulation of anthocyanin biosynthesis in Chinese cherry fruits. Expression patterns, transient overexpression and VIGS results confirmed that CpMYB10 promotes anthocyanin accumulation in the fruit skin, while CpMYB4 acts as a repressor, inhibiting anthocyanin biosynthesis of Chinese cherry.ConclusionsThis study provides a comprehensive and systematic analysis of R2R3-MYB gene family in Chinese cherry and Rosaceae relatives, and identifies two regulators, CpMYB10 and CpMYB4, involved in anthocyanin biosynthesis in Chinese cherry. These results help to develop and utilize the potential functions of anthocyanins in Chinese cherry.

Combined metabolomics and bioactivity assays kernelby-productsof two native Chinese cherry species: The sources of bioactive nutraceutical compounds

Cherry kernels are a by-product of cherries that are usually discarded, leading to waste and pollution. In this study, the chemical composition of 21 batches of cherry kernels from two different cherry species was analyzed using untargeted metabolomics. The in vitro antioxidant activity, cellular antioxidant activity, and antiproliferative activity of these kernel extracts were also determined, and a correlation analysis was conducted between differential compounds and biological activity. A total of 49 differential compounds were screened. The kernels of Prunus tomentosa were found to have significantly higher total phenol, total flavonoid content, and biological activity than those of Prunus pseudocerasus (P < 0.05). Correlation analysis showed that flavonoids had the greatest contribution to biological activity. The study suggests that both species of cherry kernel, particularly Prunus tomentosa, could be a potential source of bioactive compounds that could be used in the pharmaceutical, cosmetic, and food industries.

Haplotype-resolved genome assembly for tetraploid Chinese cherry (Prunus pseudocerasus) offers insights into fruit firmness.

Chinese cherry (Prunus pseudocerasus) holds considerable importance as one of the primary stone fruit crops in China. However, artificially improving its traits and genetic analysis are challenging due to lack of high-quality genomic resources, which mainly result from difficulties associated with resolving its tetraploid and highly heterozygous genome. Herein, we assembled a chromosome-level, haplotype-resolved genome of the cultivar 'Zhuji Duanbing', comprising 993.69Mb assembled into 32 pseudochromosomes using PacBio HiFi, Oxford Nanopore, and Hi-C. Intra-haplotype comparative analyses revealed extensive intra-genomic sequence and expression consistency. Phylogenetic and comparative genomic analyses demonstrated that P. pseudocerasus was a stable autotetraploid species, closely related to wild P. pusilliflora, with the two diverging ~18.34 million years ago. Similar to other Prunus species, P. pseudocerasus underwent a common whole-genome duplication event that occurred ~139.96 million years ago. Because of its low fruit firmness, P. pseudocerasus is unsuitable for long-distance transportation, thereby restricting its rapid development throughout China. At the ripe fruit stage, P. pseudocerasus cv. 'Zhuji Duanbing' was significantly less firm than P. avium cv. 'Heizhenzhu'. The difference in firmness is attributed to the degree of alteration in pectin, cellulose, and hemicellulose contents. In addition, comparative transcriptomic analyses identified GalAK-like and Stv1, two genes involved in pectin biosynthesis, which potentially caused the difference in firmness between 'Zhuji Duanbing' and 'Heizhenzhu'. Transient transformations of PpsGalAK-like and PpsStv1 increase protopectin content and thereby enhance fruit firmness. Our study lays a solid foundation for functional genomic studies and the enhancement of important horticultural traits in Chinese cherries.

Comparative metabolomics profiling highlights unique color variation and bitter taste formation of Chinese cherry fruits

Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don], native to China, is an economically important fruit crop with attractive colors and delicious flavors. However, the specific metabolites present in cherry fruits have remained unknown. Here, we firstly characterized 1439 metabolite components of Chinese cherry fruits, predominantly including amino acids, flavonoids, and phenolic acids. Moreover, we screened ten biomarkers of Chinese cherry accessions by ROC curve analysis. Among 250 flavonoids, 26 structurally unique anthocyanins collectively determined fruit color, with cyanidins playing a dominant role. Differences in accumulated metabolites between anthocyanin and proanthocyanidin pathways were likely responsible for the variation in fruit color, ranging from yellow to black purple. Meanwhile, we found limocitrin-7-O-glucoside, along with eight other compounds, as underlying contributors to bitter off-taste experienced in fruits. This study provides insights into the regulatory network of metabolites involved in color variation and bitterness formation and genetic improvement of Chinese cherry fruits.

The Exploration of Flowering Mechanisms in Cherry Plants

Flowering cherry (Cerasus sp.) are significant spring-blooming trees. However, the short blooming period and the rarity of early and late-flowering varieties limit their use in gardens in northern China. The experiment incorporated annually early-flowering species such as Cerasus discoidea, Cerasus pseudocerasus ‘Introtsa’, Cerasus dielsiana, Cerasus campanulata ‘Youkou’, Cerasus yedoensis ‘Somei-Yoshino’, and Cerasus spachiana f. ascendens, as well as twice-a-year flowering species like Cerasus subhirtella ‘Autumnalis’ and Cerasus subhirtella ‘Accolade’. We observed the timing of natural events and growth measurements for specific plants over a span of two years. This research involved a thorough examination of their ability to withstand cold temperatures, considering their physiological aspects. We examined the levels of nutrients and hormones in the flower buds at various stages of development in plants that bloom yearly and every two years. The findings indicated that C. subhirtella ‘Autumnalis’ is adaptable, offering the lengthiest autumn blooming phase lasting 54 days. The hierarchy of cold tolerance was as follows: C. pseudocerasus ‘Introtsa’ &gt; C. discoidea &gt; Cerasus × subhirtella ‘Autumnalis’ &gt; C. dielsiana &gt; C. ‘Youkou’. Furthermore, the soluble protein content in leaves increased before autumn flower buds’ sprout of twice-a-year flowering varieties but declined in C. yedoensis ‘Somei-Yoshino’ within the same time. We determined that changes in nutrient content significantly contribute to the autumn opening of C. subhirtella ‘Autumnalis’ robust short branch flower buds. During the final phase of flower bud development, the rise in trans-Zeatin-riboside (ZR) and indolacetic acid (IAA) promotes the initiation of the first flowering period in C. subhirtella ‘Autumnalis’ prior to its mandatory hibernation. The occurrence of secondary flowering involves a multifaceted regulatory process. These findings serve as valuable references for delving deeper into the mechanisms governing cherry blossom formation and secondary flowering.

Autotetraploid Origin of Chinese Cherry Revealed by Chromosomal Karyotype and In Situ Hybridization of Seedling Progenies.

Polyploidy is considered a driving force in plant evolution and diversification. Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don], an economically important fruit crop native to China, has evolved at the tetraploid level, with a few pentaploid and hexaploid populations. However, its auto- or allo-polyploid origin remains unclear. To address this issue, we analyzed the ploidy levels and rDNA chromosomal distribution in self- and open-pollinated seedling progenies of tetraploid and hexaploid Chinese cherry. Genomic in situ hybridization (GISH) analysis was conducted to reveal the genomic relationships between Chinese cherry and diploid relatives from the genus Cerasus. Both self- and open-pollinated progenies of tetraploid Chinese cherry exhibited tetraploids, pentaploids, and hexaploids, with tetraploids being the most predominant. In the seedling progenies of hexaploid Chinese cherry, the majority of hexaploids and a few pentaploids were observed. A small number of aneuploids were also observed in the seedling progenies. Chromosome 1, characterized by distinct length characteristics, could be considered the representative chromosome of Chinese cherry. The basic Chinese cherry genome carried two 5S rDNA signals with similar intensity, and polyploids had the expected multiples of this copy number. The 5S rDNA sites were located at the per-centromeric regions of the short arm on chromosomes 4 and 5. Three 45S rDNA sites were detected on chr. 3, 4 and 7 in the haploid complement of Chinese cherry. Tetraploids exhibited 12 signals, while pentaploids and hexaploids showed fewer numbers than expected multiples. Based on the GISH signals, Chinese cherry demonstrated relatively close relationships with C. campanulata and C. conradinae, while being distantly related to another fruiting cherry, C. avium. In combination with the above results, our findings suggested that Chinese cherry likely originated from autotetraploidy.

Comparative physiological and transcriptomic analyses provide insights into fruit softening in Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don

Fruit softening is a complex, genetically programmed and environmentally regulated process, which undergoes biochemical and physiological changes during fruit development. The molecular mechanisms that determine these changes in Chinese cherry [Cerasus peseudocerasus (Lindl.) G.Don] fruits are still unknown. In the present study, fruits of hard-fleshed 'Hongfei' and soft-fleshed 'Pengzhoubai' varieties of Chinese cherry were selected to illustrate the fruit softening at different developmental stages. We analyzed physiological characteristics and transcriptome profiles to identify key cell wall components and candidate genes related to fruit softening and construct the co-expression networks. The dynamic changes of cell wall components (cellulose, hemicellulose, pectin, and lignin), the degrading enzyme activities, and the microstructure were closely related to the fruit firmness during fruit softening. A total of 6,757 and 3,998 differentially expressed genes (DEGs) were screened between stages and varieties, respectively. Comprehensive functional enrichment analysis supported that cell wall metabolism and plant hormone signal transduction pathways were involved in fruit softening. The majority of structural genes were significantly increased with fruit ripening in both varieties, but mainly down-regulated in Hongfei fruits compared with Pengzhoubai, especially DEGs related to cellulose and hemicellulose metabolism. The expression levels of genes involving lignin biosynthesis were decreased with fruit ripening, while mainly up-regulated in Hongfei fruits at red stage. These obvious differences might delay the cell all degrading and loosening, and enhance the cell wall stiffing in Hongfei fruits, which maintained a higher level of fruit firmness than Pengzhoubai. Co-expressed network analysis showed that the key structural genes were correlated with plant hormone signal genes (such as abscisic acid, auxin, and jasmonic acid) and transcription factors (MADS, bHLH, MYB, ERF, NAC, and WRKY). The RNA-seq results were supported using RT-qPCR by 25 selected DEGs that involved in cell wall metabolism, hormone signal pathways and TF genes. These results provide important basis for the molecular mechanism of fruit softening in Chinese cherry.

Phylogeography of 912 Cherry Accessions Insight into Independent Origins of Fruiting Cherries and Domestication Footprints of Cultivated Chinese Cherry (Prunus pseudocerasus Lindl.).

The subgenus Cerasus (Rosaceae) contain numerous fruit trees and ornamentals with high economic values. The origin and genetic divergence among various types of fruiting cherries always remain a perplexing issue. We employed three plastom fragments and ITS sequence matrices derived from 912 cherry accessions to elucidate the phylogeographic structure and genetic relationship among fruiting cherries, as well as the origin and domestication of cultivated Chinese cherry. The integration of haplotype genealogies, Approximate Bayesian computation (ABC) approach and estimation of genetic differentiation within and between different groups and lineages has facilitated the resolution of several previously unresolved questions. Firstly, distant phylogenetic relationships between Cerasus and Microcerasus accessions, as indicated by both nuclear and chloroplast data, suggested independent origins and evolution for these two taxa. Moreover, two distinct geographic origin centers (Europe and China) have been confirmed, with significant phylogeographic signals and high genetic differentiation observed between cherries from these regions. This may be attributed to long-term geographic isolation caused by Himalaya-Hengduan Mountains. Our phylogeographic analyses and ABC analysis suggested that cherries inhabiting in China may have undergone multiple hybridization events during the glacial refugia of the eastern edge and southern Himalaya-Hengduan Mountains, followed by rapid radiation throughout their current habitats during interglacial period. The discrepancy between nuclear and chloroplast data may be attributed to hybridization events and incomplete lineage sorting. Furthermore, we speculated that the domesticated Chinese cherries were derived from wild accessions in Longmenshan Fault Zones approximately 2600 years ago. We have also traced the domestication processes and dispersal routes of cultivated Chinese cherries.

Improvement of Postharvest Fruit Quality of Two Popular Chinese Cherry (Prunus pseudocerasus) Cultivars by Biological and Chemical Preservatives

Improvement of Postharvest Fruit Quality of Two Popular Chinese Cherry (Prunus pseudocerasus) Cultivars by Biological and Chemical Preservatives

First report of Colletotrichum godetiae causing anthracnose fruit rot on Prunus pseudocerasus in Zhejiang province, China.

Prunus pseudocerasus (L.) G. Don is an economically important crop, with 8,420 hm2 of harvested area and 35,000 tons in 2020 (https://www.fao.org/faostat/zh/#data/QCL), and is one of the favorite fruits among consumers. A severe fruit rot disease of P. pseudocerasus cultivar "HeiZhenZhu" was observed in an orchard in Pujiang county (119°42'E, 29°21'N), Zhejiang province in April 2022. Sixty-three plants from a survey of about 200 plants showed anthracnose symptoms, with a disease incidence of more than 30%. Ten diseased fruits were collected from eight different trees. The naturally affected fruits during color changing stage showed initial light brown necrotic lesions, later, the lesions were depressed, and dark brown, the fruits were rotten, and pink conidial masses were produced (Fig. 1 A-F). Conidia were transferred using a sterilized needle into sterile water, diluted to approx. 10 conidia/µL, and spread onto potato dextrose agar (PDA) (Thermo Scientific™) (containing cephalosporin 50 µg/mL). After 24 h, single colonies were transferred, and six single-spore isolates were obtained from different plants. When the strains were grown at 26°C for 7 days, the colonies on PDA were flat with entire margin, surface medium gray-green to white, reverse salmon, light gray-green to white (Fig. 1 G). The conidia of the representative strain YTTJ-JHGS5 were unicellular, hyaline, smooth-walled, cylindrical to fusiform with one end round and one end acute, or both acute ends, 14.4 to 18.9 µm (mean = 16.4 ± 0.9 µm, n = 30) × 4.4 to 5.8 µm (mean = 5.1 ± 0.3 µm, n = 30) (Fig. 1 I). Conidiogenous cells were hyaline, smooth-walled, cylindrical to clavate, 6.5-16.8 µm × 2.6-5.3 µm (n = 30), opening 1.1-2.0 µm (Fig. 1 H). Appressoria were single, light brown to medium brown, elliptical or irregular in shape, the outline entire or undulate, 9.2 to 12.1 µm (mean = 9.2 ± 1.1 µm, n = 30) × 4.6 to 6.7 µm (mean = 5.6 ± 0.4 µm, n = 30) (Fig. 1 J). The morphological characteristics of YTTJ-JHGS5 were consistent with the Colletotrichum acutatum species complex (Damm et al. 2012). To further identify the species, the internal transcribed spacer (ITS), actin (ACT), beta-tubulin (TUB), chitin synthase (CHS-1), calmodulin (CAL) and glyceraldehyde-3-phosphate dehydrogenase (GPD) genes were sequenced (Weir et al. 2012; O'Donnell et al. 2000). The thirty-six sequences had been deposited in GenBank (ITS: ON155427-ON155432; ACT: ON191542-ON191547; CAL: ON191548-ON191553; CHS-1: ON167522-ON167527; GPD: ON191554-ON191559; TUB2: ON191560-ON191565, respectively). A BLAST search of these sequences (ITS, ACT, CHS-1, GPD, and TUB2) showed 99% identity with the sequences of ex-holotype C. godetiae CBS133.44 (ITS: JQ948402; ACT: JQ949723; CHS-1: JQ949063; GPD: JQ948733; TUB2: JQ950053) (Damm et al. 2012); the sequences of CAL genes of these strains showed 99% identity with the sequence of C. godetiae VV-087 (CAL: MK416001) (Varjas et al. 2020). The Bayes phylogenesis showed that six strains and C. godetiae CBS133.44 were clustered in a robust branch (Bayesian posterior probability = 1). Based on the morphological characteristics and phylogenesis, these strains were identified as C. godetiae. To fulfill Koch's postulates, in April 2022, live plant pathogenicity tests were performed in the field, and color-changing-stage fruits of five-year-old trees were disinfected with 75% alcohol and air-dried for 10 min to volatilize excess alcohol. A conidial suspension (50 mL of 1 × 106 conidia/mL) was sprayed on fifteen fruits for each plant, fifteen fruits sprayed with sterilized water served as control. The experiment was repeated four times, each repeat contained ten trees. The daily average temperature and daily average RH in the orchard were 22°C and 67%, respectively. After 6 days, the fruit surfaces were depressed, dark brown, later, the lesions were expanded, and pink conidial masses were observed (Fig. 1, L). Control fruits remain healthy (Fig. 1, K). C. godetiae was re-isolated from the lesions of inoculated fruits. C. godetiae has been reported on Ceanothus sp., Fragaria × ananassa and so on worldwide (Farr and Rossman 2022), in addition, C. fructicola infected cherry (Zhao et al. 2022). To our knowledge, this is the first report of C. godetiae causing anthracnose fruit rot on Prunus pseudocerasus in China. This disease occurs mainly on immature fruits and leads to yield loss in the field, therefore it is necessary to take preventive measures in advance.

Integrated Transcriptome and Metabolome Analyses Provide Insights into the Coloring Mechanism of Dark-red and Yellow Fruits in Chinese Cherry [Cerasus pseudocerasus (Lindl.) G. Don

Chinese cherry [Cerasus pseudocerasus (Lindl.) G. Don] is an important fruit tree from China that has excellent ornamental, economic, and nutritional values with various colors. The dark-red or red coloration of fruit, an attractive trait for consumers, is determined by anthocyanin pigmentation. In this study, the coloring patterns during fruit development in dark-red and yellow Chinese cherry fruits were firstly illustrated by integrated transcriptome and widely-targeted metabolome analyses. Anthocyanin accumulation in dark-red fruits was significantly higher compared with yellow fruits from the color conversion period, being positively correlated to the color ratio. Based on transcriptome analysis, eight structural genes (CpCHS, CpCHI, CpF3H, CpF3'H, CpDFR, CpANS, CpUFGT, and CpGST) were significantly upregulated in dark-red fruits from the color conversion period, especially CpANS, CpUFGT, and CpGST. On contrary, the expression level of CpLAR were considerably higher in yellow fruits than in dark-red fruits, especially at the early stage. Eight regulatory genes (CpMYB4, CpMYB10, CpMYB20, CpMYB306, bHLH1, CpNAC10, CpERF106, and CpbZIP4) were also identified as determinants of fruit color in Chinese cherry. Liquid chromatography-tandem mass spectrometry identified 33 and 3 differential expressed metabolites related to anthocyanins and procyanidins between mature dark-red and yellow fruits. Cyanidin-3-O-rutinoside was the predominant anthocyanin compound in both fruits, while it was 6.23-fold higher in dark-red than in yellow fruits. More accumulated flavanol and procyanidin contents resulted in less anthocyanin content in flavonoid pathway in yellow fruits due to the higher expression level of CpLAR. These findings can help understand the coloring mechanism of dark-red and yellow fruits in Chinese cherry, and provide genetic basis for breeding new cultivars.

Inheritance analysis of fruit-related traits in Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don] breeding progenies

• Heredity variation and inheritance tendency were analyzed for eighteen fruit-related traits of F 1 population derived from 'Hongfei' × 'Pujianghonghua' of Chinese cherry for two years. • Significant levels of transgressive heterosis were observed for total soluble solid, anthocyanin content and fruit stalk length, whereas negative heterosis detected in fruit weight and size. • The fruit-related traits were most likely controlled by two pairs of major genes, which exerted both additive effects and dominant effects. • The heritability of major gene controlling maturity date and fruit development period was high, while that of major genes controlling fruit quality traits was low. Chinese cherry [ Cerasus pseudocerasus (Lindl.) G.Don] is one of the important stone fruits in China. To explore the heredity variation of fruit-related traits, we investigated 18 fruit-related traits of the F 1 segregating population around 700 individuals derived from 'Hongfei' × 'Pujianghonghua' of Chinese cherry for two years. The mixed major gene and polygene inheritance model method was also evaluated for their fitness in relating to the traits. The results showed that the main fruit traits had different degrees of variation, with the coefficient of variation ranging from 4.76 to 26.71% (72.23% for anthocyanin content) in 2021, and from 4.71 to 21.57% in 2022. Significant levels of transgressive heterosis were observed for fruit stalk length, total soluble solid and anthocyanin content, whereas negative heterosis was detected in fruit weight and size. The most suitable genetic model for fruit maturity date and fruit development period was 2MG-ADI and 2MG-AD, respectively, and the heritability of major gene was greater than 90%. The optimal genetic model for ten fruit size and flavor related traits was 2MG-AD or 2MG-EA, which were controlled by two pairs of major genes with additive-dominant effect or equal-additive effect, with the major gene heritability being less than 45%. The additive effects of the fruit-related traits were mostly positive, while the dominant effects were mainly negative. These results provide a theoretical basis for quantitative trait locus (QTL) mapping and marker-assisted breeding of fruit-related traits in Chinese cherry.

Cross-Talk between Transcriptome Analysis and Dynamic Changes of Carbohydrates Identifies Stage-Specific Genes during the Flower Bud Differentiation Process of Chinese Cherry (Prunus pseudocerasus L.)

Flower bud differentiation is crucial to reproductive success in plants. In the present study, RNA-Seq and nutrients quantification were used to identify the stage-specific genes for flower bud differentiation with buds which characterize the marked change during flower bud formation from a widely grown Chinese cherry (Prunus pseudocerasus L.) cultivar 'Manaohong'. A KEGG enrichment analysis revealed that the sugar metabolism pathways dynamically changed. The gradually decreasing trend in the contents of total sugar, soluble sugar and protein implies that the differentiation was an energy-consuming process. Changes in the contents of D-glucose and sorbitol were conformed with the gene expression trends of bglX and SORD, respectively, which at least partially reflects a key role of the two substances in the transition from physiological to morphological differentiation. Further, the WRKY and SBP families were also significantly differentially expressed during the vegetative-to-reproductive transition. In addition, floral meristem identity genes, e.g., AP1, AP3, PI, AGL6, SEP1, LFY, and UFO demonstrate involvement in the specification of the petal and stamen primordia, and FPF1 might promote the onset of morphological differentiation. Conclusively, the available evidence justifies the involvement of sugar metabolism in the flower bud differentiation of Chinese cherry, and the uncovered candidate genes are beneficial to further elucidate flower bud differentiation in cherries.

Overexpression of CpADC from Chinese Cherry (Cerasus pseudocerasus Lindl. ‘Manaohong’) Promotes the Ability of Response to Drought in Arabidopsis thaliana

Polyamines (PA) play an important role in the growth, development and stress resistance of plants, and arginine decarboxylase (ADC) is one of the key enzymes in the biosynthetic pathway of polyamines. Previously, the transcriptional regulation of the 'Manaohong' cherry under the shelter covering was carried out, and the PA synthase-related genes, particularly the ADC gene, were differentially expressed as exposure to drought stress. However, the mechanisms of how ADC is involved in the response of cherry to abiotic stress (especially drought stress) are still unknown. In the present work, the full-length coding sequence of this gene was isolated and named CpADC. Bioinformatics analysis indicated that the coding sequence of CpADC was 2529 bp in length. Cluster analysis showed that CpADC had the highest homologies with those of sweet cherry (Prunus avium, XP_021806331) and peach (Prunus persica, XP_007200307). Subcellular localization detected that the CpADC was localized in the plant nucleus. The qPCR quantification showed that CpADC was differentially expressed in roots, stems, leaves, flower buds, flowers, and fruits at different periods. Drought stress treatments were applied to both wild-type (WT) and transgenic Arabidopsis lines, and relevant physiological indicators were measured, and the results showed that the putrescine content of transgenic Arabidopsis was higher than that of WT under high-temperature treatment. The results showed that the MDA content of WT was consistently higher than that of transgenic plants and that the degree of stress in WT was more severe than in transgenic Arabidopsis, indicating that transgenic CpADC was able to enhance the stress resistance of the plants. Both the transgenic and WT plants had significantly higher levels of proline in their leaves after the stress treatment than before, but the WT plant had lower levels of proline than that of transgenic Arabidopsis in both cases. This shows that the accumulation of proline in the transgenic plants was higher than that in the wild type under drought and high and low-temperature stress, suggesting that the transgenic plants are more stress tolerant than the WT. Taken together, our results reveal that, under drought stress, the increase in both expressions of CpADC gene and Put (putrescine) accumulation regulates the activity of ADC, the content of MDA and Pro to enhance the drought resistance of Arabidopsis thaliana.

Accurate Chromosome Identification in the Prunus Subgenus Cerasus (Prunus pseudocerasus) and its Relatives by Oligo-FISH.

A precise, rapid and straightforward approach to chromosome identification is fundamental for cytogenetics studies. However, the identification of individual chromosomes was not previously possible for Chinese cherry or other Prunus species due to the small size and similar morphology of their chromosomes. To address this issue, we designed a pool of oligonucleotides distributed across specific pseudochromosome regions of Chinese cherry. This oligonucleotide pool was amplified through multiplex PCR with specific internal primers to produce probes that could recognize specific chromosomes. External primers modified with red and green fluorescence tags could produce unique signal barcoding patterns to identify each chromosome concomitantly. The same oligonucleotide pool could also discriminate all chromosomes in other Prunus species. Additionally, the 5S/45S rDNA probes and the oligo pool were applied in two sequential rounds of fluorescence in situ hybridization (FISH) localized to chromosomes and showed different distribution patterns among Prunus species. At the same time, comparative karyotype analysis revealed high conservation among P. pseudocerasus, P. avium, and P. persica. Together, these findings establish this oligonucleotide pool as the most effective tool for chromosome identification and the analysis of genome organization and evolution in the genus Prunus.

Intercropping with the potential cadmium hyperaccumulator Solanum photeinocarpum, and its post‐grafting generations, decrease cadmium uptake and promote growth of cherry

AbstractCadmium (Cd)‐contaminated soil has affected the fruit production safety. To decrease the Cd accumulation in the fruits, the effects of intercropping with the potential Cd‐hyperaccumulator Solanum photeinocarpum and its post‐grafting generations on the Cd uptake in cherry (Cerasus pseudocerasus) were studied by the pot experiments. Intercropping increased the biomass of cherry seedlings to some extent, and decreased the biomass of S. photeinocarpum and its post‐grafting generations. Intercropping decreased the Cd contents in cherry seedlings, and increased the Cd contents in S. photeinocarpum and its post‐grafting generations. Compared with their respective monoculture, intercropping decreased the shoot Cd content in cherry seedlings by 31.37%–60.70%, and increased the shoot Cd contents in S. photeinocarpum its post‐grafting generations by 18.50%–28.76%. In addition, intercropping also decreased the root‐to‐shoot Cd translocations in both plant species, and decreased the Cd content in the branches and fruits of fruiting cherry trees and the Cd extractions of S. photeinocarpum and its post‐grafting generations. Therefore, intercropping with S. photeinocarpum and its post‐grafting generations can be used to reduce Cd accumulation in cherry for fruit production safety.

Optimizing Nitrogen, Phosphorus, and Potassium Fertilization Rates for Fruit Performance of Chinese Cherry (Prunus pseudocerasus Lindl.)

ABSTRACT Attempts had been made to optimize nitrogen (N), phosphorus (P) and potassium (K) fertilization rates for increased fruit performance of Chinese cherry (Prunus pseudocerasus Lindl.). This study was conducted using a randomized block design (RBD) consisting of three factors and four levels, totaling to 14 treatments with each treatment repeated in triplicate. The results illustrated that the fertilization application increased the trunk, leaf, crown and new shoot growth, however, the optimal combination of N, P, and K (NPK) fertilization for growth varied among different parts of the young tree. Moreover, the fruit weight and size, internal quality, and fruit set rate (FSR) were positively affected by fertilization. Specifically, the no. 12 treatment (0.3 kg N + 0.4 kg P + 0.2 kg K) contained the optimal NPK combination for enhanced fruit size and cherry fruit set. Similarly, although the treatment is not the maximum of NPK concentration, the no. 12 treatment for mean daily values of Pn (MDVP) and the NPK concentration in leaf was significantly higher compared to other treatments. Additionally, Pearson’s correlation analysis suggests that the FSR was positively and significantly correlated with fruit weight (FW), fruit vertical diameter (FVD) and the soluble sugars (SS) in fruit. In general, the no. 12 treatment was the optimal NPK fertilization rates for young tree growth, fruit quality of Chinese cherry (Prunus pseudocerasus Lindl.) in the Karst region of southwest China.

Antidepressant effects of cherry leaf decoction on a chronic unpredictable mild stress rat model based on the Glu/GABA-Gln metabolic loop.

Cherry leaves (Prunus pseudocerasus Lindl. [Rosaceae]), a traditional Chinese herbal medicine, can regulate the factors closely related to depression including inflammatory cytokines, oxidative stress and blood glucose level. However, the antidepressant effects of cherry leaves and underlying neuromodulatory mechanisms remain relatively have not been elucidated explicitly. The present study investigated the antidepressant effects of cherry leaf decoction (CLD). The underlying neuromodulatory mechanism was explored by examining the glutamate (Glu)/γ-aminobutyric acid (GABA)-glutamine (Gln) metabolic loop. The chronic unpredictable mild stress (CUMS) rodent model was used in this study. The main flavonoids components of CLD were identified using high-performance liquid chromatography (HPLC). The antidepressant effects of CLD were assessed throughout behavioural tests including the bodyweight, sucrose preference test (SPT), forced swimming test (FPT) and tail suspension test (TST). Moreover, The baseline levels of serum adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were quantified. The expression of proteins integrally involved in the Glu/GABA-Gln metabolic loop were observed and quantified by Western blotting, reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. This study found that CLD ameliorated depressive-like behaviours induced by CUMS. The increase of serum ACTH and CORT baseline levels induced by CUMS was also reversed after CLD intervention. Furthermore, CUMS reduced the expression of GAD65, GAD67, GLT-1, GS and GABAA and increased NMDAR1 levels in the rat hippocampus, which was normalized by CLD treatment. The findings demonstrated that CLD could ameliorate the depression-like behaviours induced by CUMS, potentially through the inhibition of hypothalamic-pituitary-adrenal (HPA) axis hyperactivity and the regulation of Glu/GABA-Gln metabolic loop.

Identification of Bacillus species causing bacterial leaf spot of peach in China

AbstractPeach (Prunus persica L.) is an economically important fruit and is cultivated widely in the world. Bacterial leaf spot (BLS) is a major disease limiting the yield of peach in most peach‐producing areas worldwide. To identify the pathogen causing bacterial leaf spot, evaluate its pathogenicity, and explore its host range, the diseased leaves were collected. Phylogenetic analysis of the partial 16S rRNA genes showed that the five isolates belong to the Bacillus cereus species complex. Three of the five isolates were identified as B. cereus, with the remaining isolates being B. thuringiensis and B. pacificus, based on multilocus sequence analysis (16S rDNA, adk, ccpA, ftsA, glpT, pyrE, recF, and sucC) and biochemical characteristics. All five isolates were pathogenic on Prunus persica as well as on Cerasus pseudocerasus, but none of the isolates was pathogenic on C. humilis, plum (Prunus salicina), or Armeniaca vulgaris. To our knowledge, this is the first report on the occurrence of B. cereus species complex as causal agents of BLS of peach, which will benefit the development of future control measures.