Genetic dissection of the tissue-specific roles of type III effectors and phytotoxins in the pathogenicity of Pseudomonas syringae pv. syringae to cherry.

When compared with other phylogroups (PGs) of the Pseudomonas syringae species complex, P. syringae pv. syringae (Pss) strains within PG2 have a reduced repertoire of type III effectors (T3Es) but produce several phytotoxins. Effectors within the cherry pathogen Pss 9644 were grouped based on their frequency in strains from Prunus as the conserved effector locus (CEL) common to most P. syringae pathogens; a core of effectors common to PG2; a set of PRUNUS effectors common to cherry pathogens; and a FLEXIBLE set of T3Es. Pss 9644 also contains gene clusters for biosynthesis of toxins syringomycin, syringopeptin and syringolin A. After confirmation of virulence gene expression, mutants with a sequential series of T3E and toxin deletions were pathogenicity tested on wood, leaves and fruits of sweet cherry (Prunus avium) and leaves of ornamental cherry (Prunus incisa). The toxins had a key role in disease development in fruits but were less important in leaves and wood. An effectorless mutant retained some pathogenicity to fruit but not wood or leaves. Striking redundancy was observed amongst effector groups. The CEL effectors have important roles during the early stages of leaf infection and possibly acted synergistically with toxins in all tissues. Deletion of separate groups of T3Es had more effect in P. incisa than in P. avium. Mixed inocula were used to complement the toxin mutations in trans and indicated that strain mixtures may be important in the field. Our results highlight the niche-specific role of toxins in P. avium tissues and the complexity of effector redundancy in the pathogen Pss 9644.

Chinese cherry CpMYB44-CpSPDS2 module regulates spermidine content and florescence in tobacco.

The flower bud differentiation plays a crucial role in cherry yield and quality. In a preliminary study, we revealed the promotion of spermidine (Spd) in bud differentiation and quality. However, the molecular mechanism underlying Spd regulating cherry bud differentiation remains unclear. To address this research gap, we cloned CpSPDS2, a gene that encodes Spd synthase and is highly expressed in whole flowers and pistils of the Chinese cherry (cv. 'Manaohong'). Furthermore, an overexpression vector with this gene was constructed to transform tobacco plants. The findings demonstrated that transgenic lines exhibited higher Spd content, an earlier flowering time by 6 d, and more lateral buds and flowers than wild-type lines. Additionally, yeast one-hybrid assays and two-luciferase experiments confirmed that the R2R3-MYB transcription factor (CpMYB44) directly binds to and activates the CpSPDS2 promoter transcription. It is indicated that CpMYB44 promotes Spd accumulation via regulating CpSPDS2 expression, thus accelerating the flower growth. This research provides a basis for resolving the molecular mechanism of CpSPDS2 involved in cherry bud differentiation.

Mutations overlying the miR172 target site of TOE-type genes are prime candidate variants for the double-flower trait in mei.

Mutations affecting flower shape in many plants have been favored by human selection, and various fruit trees are also grown for ornamental purposes. Mei (Prunus mume) is a dual purpose tree originated in China well known in the Western world for its generous early blooms, often bearing double flowers. Building on the knowledge of its genomic location, a candidate gene approach was used to identify a 49 bp deletion encompassing the miR172 target site of the euAP2 gene pmTOE (PmuVar_Ch1_3490) as a prime variant linked to flower doubleness. Searching within a large dataset of genome sequencing data from Eastern germplasm collections demonstrated a tight variant-trait association, further confirmed in a panel of commercial and non-commercial varieties available in Italy. Moreover, two SNP mutations in the miR172 target site of pmPET (PmuVar_Ch1_1333) were identified in some double flower accessions. The mei orthologue of PETALOSA genes already found responsible for the phenotype in other plants suggests that independent variants may have been selected throughout mei domestication history.

Comparative genomics of N-acetyl-5-methoxytryptamine members in four Prunus species with insights into bud dormancy and abiotic stress responses in Prunus avium.

KEY MESSAGE: This study provides novel insights into the evolution, diversification, and functions of melatonin biosynthesis genes in Prunus species, highlighting their potential role in regulating bud dormancy and abiotic stresses. The biosynthesis of melatonin (MEL) in plants is primarily governed by enzymatic reactions involving key enzymes such as serotonin N-acetyltransferase (SNAT), tryptamine 5-hydroxylase (T5H), N-acetylserotonin methyltransferase (ASMT) and tryptophan decarboxylase (TDC). In this study, we analyzed Melatonin genes in four Prunus species such as Prunus avium (Pavi), Prunus pusilliflora (Ppus), Prunus serulata (Pser), and Prunus persica (Pper) based on comparative genomics approach. Among the four Prunus species, a total of 29 TDCs, 998 T5Hs, 16 SNATs, and 115 ASMTs within the genome of four Prunus genomes. A thorough investigation of melatonin-related genes was carried out using systematic biological methods and comparative genomics. Through phylogenetic analysis, orthologous clusters, Go enrichment, syntenic relationship, and gene duplication analysis, we discovered both similarities and variations in Melatonin genes among these Prunus species. Additionally, our study revealed the existence of unique subgroup members in the Melatonin genes of these species, which were distinct from those found in Arabidopsis genes. Furthermore, the transcriptomic expression analysis revealed the potential significance of melatonin genes in bud dormancy regulation and abiotic stresses. Our extensive results offer valuable perspectives on the evolutionary patterns, intricate expansion, and functions of PavMEL genes. Given their promising attributes, PavTDCs, PavT5H, PavNAT, and three PavASMT genes warrant in-depth exploration as prime candidates for manipulating dormancy in sweet cherry. This was done to lay the foundation for future explorations into the structural and functional aspects of these factors in Prunus species. This study offers significant insights into the functions of ASMT, SNAT, T5H, and TDC genes and sheds light on their roles in Prunus avium. Moreover, it established a robust foundation for further exploration functional characterization of melatonin genes in fruit species.

Effects of almond (Armeniaca Sibirica L. Lam) polysaccharides on gut microbiota and anti-inflammatory effects on LPS-induced RAW264.7 cells.

The aim of this study was to investigate the prebiotic properties of the almond polysaccharide AP-1 on intestinal microorganisms by using an in vitro fecal fermentation method and its anti-inflammatory effect on lipopolysaccharide (LPS)-induced RAW264.7 cells. The results showed that during the in vitro fermentation of AP-1, the pH value of the fermentation broth decreased obviously, while the concentration of short-chain fatty acids (SCFAs) increased significantly, especially acetic acid and butyric acid. In genus level, the number of Clostridium and Megamonas increased markedly in the AP-1 group after 24 h of fermentation. After 48 h of fermentation, there was a noticeable increase in the number of beneficial genera Lactobacillaceae and Bifidobacteriaceae, and a considerable decrease in the number of pro-inflammatory genera. In addition, we found that AP-1 had no toxic effect on RAW264.7 cells. In the LPS-induced inflammation model of RAW264.7 cells, AP-1 could effectively inhibit the release of NO, regulate the level of reactive oxides (ROS), and effectively down-regulate the mRNA expression of TNF-α, IL-1ß, IL-6 and iNOS. In conclusion, the almond polysaccharide AP-1 may be a functional active substance aimed at promoting intestinal health and exerting anti-inflammatory effects.

Molecular characterization and evolutionary relationships of DOFs in four cherry species and functional analysis in sweet cherry.

The DOF (DNA binding with one finger) has multiple functions in plants. However, it has received little attention in the research field of cherries. In this study, the evolutionary relationship and molecular characterization of DOF in four cherry species were analyzed, revealing its expression pattern in sweet cherry. There are 23 members in Prunus avium cv. 'Tieton', 88 in Prunus cerasus, 53 in Cerasus × yedoensis, and 27 in Cerasus serrulata. Most of these genes are intron-less or non-intron, with a conserved C2-C2 domain. Due to heterozygosity and chromosomal ploidy, whole-genome duplication (WGD) events occur to varying degrees, and DOF genes are contracted during evolution. Furthermore, these genes are affected by purifying selection pressure. Under low-temperature treatment, the expression of PavDOF2 and PavDOF18 were significantly up-regulated, while that of PavDOF16 is significantly down-regulated. The expression of PavDOF9, PavDOF12, PavDOF14, PavDOF16, PavDOF17, PavDOF18, and PavDOF19 exhibits an increasing trend during flower development and varies during sweet cherry fruit development. PavDOF1, PavDOF8, PavDOF9, and PavDOF15 are localized in the nucleus but is not transcriptionally active. The findings systemically demonstrate the molecular characteristics of DOF in different cherry varieties, providing a basis for further research on the functions of these genes.

Allelic variation of PmCBF03 contributes to the altitude and temperature adaptability in Japanese apricot (Prunus mume Sieb. et Zucc.).

Japanese apricot is an important subtropical deciduous fruit tree in China, widely distributed in different altitude areas. How does it adapt to the different temperature environments in these areas? In this study, we identified a low-temperature transcription factor PmCBF03 on chromosome 7 through adaptive analysis of populations at different altitudes, which has an early termination single nucleotide polymorphism mutation. There were two different types of variation, PmCBF03A type in high-altitude areas and PmCBF03T type in low-altitude areas. PmCBF03A gene increased the survival rate, Fv/Fm values, antioxidant enzyme activity, and expression levels of antioxidant enzyme genes, and reducing electrolyte leakage and accumulation of reactive oxygen species in transgenic Arabidopsis under low temperature and freezing stress. Simultaneously, PmCBF03A gene promoted the dormancy of transgenic Arabidopsis seeds than wild-type. Biochemical analysis demonstrated that PmCBF03A directly bound to the DRE/CRT element in the promoters of the PmCOR413, PmDAM6 and PmABI5 genes, promoting their transcription and enhanced the cold resistance and dormancy of the overexpressing PmCBF03A lines. While PmCBF03T gene is unable to bind to the promoters of PmDAM6 and PmABI5 genes, leading to early release of dormancy to adapt to the problem of insufficient chilling requirement in low-altitude areas.

Fruits of Wild-Grown Shrubs for Health Nutrition.

Cultivated fruits and berries, such as raspberries, strawberries, black currants, cherries, blueberries, are generally recognized sources of antioxidants, vitamins, minerals, and other substances beneficial to human health and well-being. However, there are also wild berries and fruits that are of undoubted interest as food products having valuable medicinal properties due to the presence of phenolic compounds, antioxidants, and vitamins. These fruits have a great potential to be used in functional food making. The present review is dedicated to fruits of wild-grown shrubs Bird cherry (Prunus padus L.), Rowan berry (Sorbus aucuparia L.), Guelder rose (Viburnum opulus L.), Black elderberry (Sambucus nigra L.), and Barberry (Berberis vulgaris L.) The chemical compositions of these wild berries are described as well as their effects on the improvement of human health proved by clinical trials and epidemiological studies. The possibilities of using the fruits of wild-grown shrubs in the preparation of functional foods and examples of their implementation for the manufacturing of dairy, bakery and meat products are considered.

[Exploration of cross-cultivar group characteristics of a new cultivar of Prunus mume 'Zhizhang Guhong Chongcui'].

'Zhizhang Guhong Chongcui' is a new cultivar of Prunus mume with cross-cultivar group characteristics. It has typical characteristics of cinnabar purple cultivar group and green calyx cultivar group. It has green calyx, white flower, and light purple xylem, but the mechanism remains unclear. In order to clarify the causes of its cross-cultivar group traits, the color phenotype, anthocyanin content and the expression levels of genes related to anthocyanin synthesis pathway of 'Zhizhang Guhong Chongcui', 'Yuxi Zhusha' and 'Yuxi Bian Lü'e' were determined. It was found that the red degree of petals, sepals and fresh xylem in branches was positively correlated with the total anthocyanin content. MYBɑ1, MYB1, and bHLH3 were the key transcription factor genes that affected the redness of the three cultivars of flowers and xylem. The transcription factors further promoted the high expression of structural genes F3'H, DFR, ANS and UFGT, thereby promoting the production of red traits. Combined with phenotype, anthocyanin content and qRT-PCR results, it was speculated that the white color of petals of 'Zhizhang Guhong Chongcui' were derived from the high expression of FLS, F3'5'H, LAR and ANR genes in other branches of cyanidin synthesis pathway, and the low expression of GST gene. The green color of sepals might be originated from the relatively low expression of F3'H, DFR and ANS genes. The red color of xylem might be derived from the high expression of ANS and UFGT genes. This study made a preliminary explanation for the characteristics of the cross-cultivar group of 'Zhizhang Guhong Chongcui', and provided a reference for molecular breeding of flower color and xylem color of Prunus mume.

Plant height variation and genetic diversity between Prunus ledebouriana (Schlecht.) YY Yao and Prunus tenella Batsch based on using SSR markers in East Kazakhstan.

Background: Genetic differences between isolated endemic populations of plant species and those with widely known twin species are relevant for conserving the biological diversity of our planet's flora. Prunus ledebouriana (Schlecht.) YY Yao is an endangered and endemic species of shrub almond from central Asia. Few studies have explored this species, which is closely related and morphologically similar to the well-known Prunus tenella Batsch. In this article, we present a comparative analysis of studies of three P. ledebouriana populations and one close population of P. tenella in Eastern Kazakhstan in order to determine the particular geographic mutual replacement of the two species. Methods: The populations were collected from different ecological niches, including one steppe population near Ust-Kamenogorsk (P. tenella) and three populations (P. ledebouriana) in the mountainous area. Estimation of plant height using a t-test suggested a statistically significant difference between the populations and the two species (P < 0.0001). DNA simple sequence repeat (SSR) markers were applied to study the two species' genetic diversity and population structure. Results: A total of 19 polymorphic SSR loci were analyzed, and the results showed that the population collected in mountainous areas had a lower variation level than steppe populations. The highest level of Nei's genetic diversity index was demonstrated in the 4-UK population (0.622) of P. tenella. The lowest was recorded in population 3-KA (0.461) of P. ledebouriana, collected at the highest altitude of the four populations (2,086 meters above sea level). The total genetic variation of P. ledebouriana was distributed 73% within populations and 27% between populations. STRUCTURE results showed that two morphologically similar species diverged starting at step K = 3, with limited population mixing. The results confirmed the morphological and genetic differences between P. tenella and P. ledebouriana and described the level of genetic variation for P. ledebouriana. The study's results proved that the steppe zone and mountain altitude factor between P. tenella and isolated mountain samples of P. ledebouriana.

Exploring the potential of high-resolution LC-MS in combination with ion mobility separation and surrogate minimal depth for enhanced almond origin authentication.

Almonds (Prunus dulcisMill.) are consumed worldwide and their geographical origin plays a crucial role in determining their market value. In the present study, a total of 250 almond reference samples from six countries (Australia, Spain, Iran, Italy, Morocco, and the USA) were non-polar extracted and analyzed by UPLC-ESI-IM-qToF-MS. Four harvest periods, more than 30 different varieties, including both sweet and bitter almonds, were considered in the method development. Principal component analysis showed that there are three groups of samples with similarities: Australia/USA, Spain/Italy and Iran/Morocco. For origin determination, a random forest achieved an accuracy of 88.8 %. Misclassifications occurred mainly between almonds from the USA and Australia, due to similar varieties and similar external influences such as climate conditions. Metabolites relevant for classification were selected using Surrogate Minimal Depth, with triacylglycerides containing oxidized, odd chained or short chained fatty acids and some phospholipids proven to be the most suitable marker substances. Our results show that focusing on the identified lipids (e. g., using a QqQ-MS instrument) is a promising approach to transfer the origin determination of almonds to routine analysis.

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.

Integrative transcriptomic and metabolomic analyses reveal the phenylpropanoid and flavonoid biosynthesis of Prunus mume.

Prunus mume is an important medicinal plant with ornamental and edible value. Its flowers contain phenylpropanoids, flavonoids and other active components, that have important medicinal and edible value, yet their molecular regulatory mechanisms in P. mume remain unclear. In this study, the content of total flavonoid and total phenylpropanoid of P. mume at different developmental periods was measured first, and the results showed that the content of total flavonoid and total phenylpropanoid gradually decreased in three developmental periods. Then, an integrated analysis of transcriptome and metabolome was conducted on three developmental periods of P. mume to investigate the law of synthetic accumulation for P. mume metabolites, and the key enzyme genes for the biosynthesis of phenylpropanoids and flavonoids were screened out according to the differentially expressed genes (DEGs). A total of 14,332 DEGs and 38 differentially accumulate metabolites (DAMs) were obtained by transcriptomics and metabolomics analysis. The key enzyme genes and metabolites in the bud (HL) were significantly different from those in the half-opening (BK) and full-opening (QK) periods. In the phenylpropanoid and flavonoid biosynthesis pathway, the ion abundance of chlorogenic acid, naringenin, kaempferol, isoquercitrin, rutin and other metabolites decreased with the development of flowers, while the ion abundance of cinnamic acid increased. Key enzyme genes such as HCT, CCR, COMT, CHS, F3H, and FLS positively regulate the downstream metabolites, while PAL, C4H, and 4CL negatively regulate the downstream metabolites. Moreover, the key genes FLS (CL4312-2, CL4312-3, CL4312-4, CL4312-5, CL4312-6) regulating the synthesis of flavonols are highly expressed in bud samples. The dynamic changes of these metabolites were validated by determining the content of 14 phenylpropanoids and flavonoids in P. mume at different developmental periods, and the transcription expression levels of these genes were validated by real-time PCR. Our study provides new insights into the molecular mechanism of phenylpropanoid and flavonoid accumulation in P. mume.

Effect of preharvest melatonin applications at dusk on quality and bioactive compounds content of early sweet cherries.

BACKGROUND: Early sweet cherries have a high economic impact on cherry growers but have poorer quality characteristics and shorter shelf-life than late cherries. Melatonin has been proposed as a biostimulant that regulates plant and fruit growth and increases fruit quality and shelf-life but, in general in fruit and vegetables, there is controversy about its effects. Therefore, this work aimed to evaluate the impact of exogenous preharvest melatonin applications at dusk on the quality and bioactive compounds of two early sweet cherry cultivars. RESULTS: The M3 and M5 (3 × 10-4 and 5 × 10-4 mol L-1 melatonin, respectively) treatments effectively enhanced the endogenous melatonin and hydroxycinnamic acid concentration, enhancing the functional properties of the fruit. Additionally, the M5 treatment enhanced skin colour and consumer acceptance of 'Samba' cherries, while the M3 treatment improved cherry size in 'Sandon Rose'. CONCLUSION: Preharvest melatonin applications at dusk could be included in the scheduled preharvest treatments for early cherry cultivars in order to improve the quality and to stimulate the functionality of the fruit. However, further studies are needed to adjust the concentration depending on the cultivar and the objective pursued. © 2023 Society of Chemical Industry.

Identification, characterization, and expression of lipoxygenase genes in sweet cherry (Prunus avium L.) cv. Regina and their relationship with the development of an herbaceous off-flavor during fruit ripening.

Flavor is an essential characteristic of fruit quality and is significant for consumers. Off-flavors have been reported in several fruits, including sweet cherry. This fruit has been reported to show an herbaceous/grassy-like flavor. The herbaceous off-flavor in sweet cherries detected in cultivar Regina has been related to the differential development of aroma compounds such as short-chain aldehydes and esters. One of the main biosynthesis pathways for these compounds is the fatty acid oxidation mediated by lipoxygenases (LOX). In order to have a better understanding of the biological basis of the differences in the volatile profile, the LOX gene expression profile was characterized during fruit development with and without herbaceous off-flavor. A genome-wide analysis of LOX in sweet cherry was carried out and compared to other species such as Arabidopsis, tomato, apple, prunus and strawberry. The structural features of 9-LOX and 13-LOX genes, encoded protein domains and their synteny were examined. Moreover, we analyzed the LOX expression at four developmental stages along ripening by RT-qPCR. Thirteen LOX gene candidates (six 9-LOX and seven 13-LOX) were identified. The 13-LOXs, PaLOX10, PaLOX11, and PaLOX12 were differentially expressed in herbaceous sweet cherries. Furthermore, their expression profile positively correlated with key volatile compounds linked to the herbaceous off-flavor. Overall, this study involves the genome-wide characterization of the LOX family in Prunus avium cv. Regina and provides information that can aid in studying LOX-related fruit deterioration in sweet cherries and associated species.

Complete chloroplast genome sequences of the ornamental plant Prunus cistena and comparative and phylogenetic analyses with its closely related species.

BACKGROUND: Prunus cistena is an excellent color leaf configuration tree for urban landscaping in the world, which has purplish red leaves, light pink flowers, plant shape and high ornamental value. Genomic resources for P. cistena are scarce, and a clear phylogenetic and evolutionary history for this species has yet to be elucidated. Here, we sequenced and analyzed the complete chloroplast genome of P. cistena and compared it with related species of the genus Prunus based on the chloroplast genome. RESULTS: The complete chloroplast genome of P. cistena is a 157,935 bp long typical tetrad structure, with an overall GC content of 36.72% and higher GC content in the in the inverted repeats (IR) regions than in the large single-copy (LSC) and small single-copy (SSC) regions. It contains 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The ycf3 and clpP genes have two introns, with the longest intron in the trnK-UUU gene in the LSC region. Moreover, the genome has a total of 253SSRs, with the mononucleotide SSRs being the most abundant. The chloroplast sequences and gene arrangements of P. cistena are highly conserved, with the overall structure and gene order similar to other Prunus species. The atpE, ccsA, petA, rps8, and matK genes have undergone significant positive selection in Prunus species. P. cistena has a close evolutionary relationship with P. jamasakura. The coding and IR regions are more conserved than the noncoding regions, and the chloroplast DNA sequences are highly conserved throughout the genus Prunus. CONCLUSIONS: The current genomic datasets provide valuable information for further species identification, evolution, and phylogenetic research of the genus Prunus.

A chromosome-scale assembly of the early-flowering Prunus campanulata and comparative genomics of cherries.

Prunus campanulata is an important flowering cherry germplasm of high ornamental value. Given its early-flowering phenotypes, P. campanulata could be used for molecular breeding of ornamental species and fruit crops belonging to the subgenus Cerasus. Here, we report a chromosome-scale assembly of P. campanulata with a genome size of 282.6 Mb and a contig N50 length of 12.04 Mb. The genome contained 24,861 protein-coding genes, of which 24,749 genes (99.5%) were functionally annotated, and 148.20 Mb (52.4%) of the assembled sequences are repetitive sequences. A combination of genomic and population genomic analyses revealed a number of genes under positive selection or accelerated molecular evolution in P. campanulata. Our study provides a reliable genome resource, and lays a solid foundation for genetic improvement of flowering cherry germplasm.

Evolution of Cherries (Prunus Subgenus Cerasus) Based on Chloroplast Genomes.

Cherries (Prunus Subgenus Cerasus) have economic value and ecological significance, yet their phylogeny, geographic origin, timing, and dispersal patterns remain challenging to understand. To fill this gap, we conducted a comprehensive analysis of the complete chloroplast genomes of 54 subg. Cerasus individuals, along with 36 additional genomes from the NCBI database, resulting in a total of 90 genomes for comparative analysis. The chloroplast genomes of subg. Cerasus exhibited varying sizes and consisted of 129 genes, including protein-coding, transfer RNA, and ribosomIal RNA genes. Genomic variation was investigated through InDels and SNPs, showcasing distribution patterns and impact levels. A comparative analysis of chloroplast genome boundaries highlighted variations in inverted repeat (IR) regions among Cerasus and other Prunus species. Phylogeny based on whole-chloroplast genome sequences supported the division of Prunus into three subgenera, I subg. Padus, II subg. Prunus and III subg. Cerasus. The subg. Cerasus was subdivided into seven lineages (IIIa to IIIg), which matched roughly to taxonomic sections. The subg. Padus first diverged 51.42 Mya, followed by the separation of subg. Cerasus from subg. Prunus 39.27 Mya. The subg. Cerasus started diversification at 15.01 Mya, coinciding with geological and climatic changes, including the uplift of the Qinghai-Tibet Plateau and global cooling. The Himalayans were the refuge of cherries, from which a few species reached Europe through westward migration and another species reached North America through northeastward migration. The mainstage of cherry evolution was on the Qing-Tibet Plateau and later East China and Japan as well. These findings strengthen our understanding of the evolution of cherry and provide valuable insights into the conservation and sustainable utilization of cherry's genetic resources.

Evaluation of drought stress level in Sargent's cherry (Prunus sargentii Rehder) using photosynthesis and chlorophyll fluorescence parameters and proline content analysis.

Sargent's cherry trees (Prunus sargentiiRehder) are widely planted as an ornamental, climate change-sensing species. This study investigated changes in the soil moisture content, fresh weight, photosynthesis and chlorophyll fluorescence properties, and the chlorophyll and proline content of four-year-old P. sargentii seedlings after 30 days of drought stress. In the trees subjected to drought stress treatment, soil moisture content decreased, and the fresh weight of the aboveground part of the plant decreased. However, there was no significant difference in the root growth of the dried plants. Among the photosynthesis parameters, Pn MAX, E and gs showed a significant (p  <  0.001) decrease after 15 days in dry-stressed seedlings, but there was no difference between treatments in WUE until 20 days, and there was a significant (p  <  0.001) difference after 24 days. Chlorophyll fluorescence parameters, Fv/Fm, ΦPSII, Rfd, NPQ, and Pn MAX, also increased after 10 days in dry-stressed seedlings, but these changes did not reach statistical significance compared to the control treatment. These results may suggest that drought stress highly correlates with photosynthesis and chlorophyll fluorescence parameters. Chlorophyll content also significantly decreased in the seedlings under drought stress compared with the control treatment. The proline content decreased until the 10th day of drought stress treatment and increased after the 15th day, showing an increase of 10.9% on the 15th day and 57.1% on the 30th day, compared to the control treatment. These results suggest that photosynthesis, chlorophyll fluorescence parameters, and proline content can be used to evaluate drought stress in trees. The results of this study can contribute to the management of forests, such as the irrigation of trees when pore control ability and photosynthesis ability decrease.

Profiling of primary and phytonutrients in edible mahlab cherry (Prunus mahaleb L.) seeds in the context of its different cultivars and roasting as analyzed using molecular networking and chemometric tools.

Prunus mahaleb L. (mahlab cherry) is a deciduous plant that is native to the Mediterranean region and central Europe with a myriad of medicinal, culinary and cosmetic uses. The present study explored different cultivars of mahlab (white from Egypt and Greece, red from Egypt and post roasting). UPLC-MS led to the detection of 110 primary and secondary metabolites belonging to different classes including phenylpropanoids (hydroxy cinnamates, coumaroyl derivatives), organic acids, coumarins, cyanogenic glycosides, flavonoids, nitrogenous compounds, amino acids and fatty acids, of which 39 are first time to be detected in Prunus mahaleb L. A holistic assessment of metabolites was performed for further analysis of dataset using principal component analysis (PCA) among mahlab cultivars to assess variance within seeds. The results revealed that phenolic acids (coumaric acid-O-hexoside, ferulic acid-O-hexoside, ferulic acid-O-hexoside dimer, dihydrocoumaroyl-O-hexoside dimer and ferulic acid), coumarins (coumarin and herniarin) and amino acids (pyroglutamic acid) were abundant in white mahlab cultivars (cvs.) from different locations. In contrast, red mahlab and its roasted seeds were more rich in organic acids (citric and malic acids), amygdalin derivative and sphingolipids. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) revealed for markers in red mahlab and in response to roasting, where red mahlab was rich in nitrogenous compounds viz. nonamide, deoxy fructosyl leucine, glutaryl carnitine and isoleucine, while roasted product (REM) was found to be enriched in choline.