This study is the first to apply spatial metabolomics techniques, MALDI-IMS to investigate differential distributions of sugars, organic acids, and pigments in the red and yellow regions of Yanzhihong apricot fruit. PCA and OPLS-DA analyses indicated that sucrose was significantly higher in the red region (21.39 mg/g) than in the yellow region (17.79 mg/g). In contrast, the yellow region exhibited significantly greater levels of fructose (31.54 mg/100g), ascorbic acid (11.03 mg/g), malic acid (3.61 mg/g), and citric acid (6.41 mg/g) than the red region (16.88mg/100g, 8.29, 2.34, and 4.27 mg/g, respectively). The red region also exhibited higher carotenoid levels (29.25 mg/g) and the anthocyanin cyanidin-3-O-(6’’-O-malonyl)glucoside, primarily in the peel and adjacent tissues, thereby enhancing pigment deposition and antioxidant capacity. These findings demonstrate notable spatial variability in sugar–acid metabolism and pigment accumulation between red and yellow fruit regions, which not only determine taste and color but also provide valuable insights for targeted fruit quality improvement and breeding of apricot cultivars with optimized sensory and nutritional traits.

Based on the single nucleotide polymorphism (SNP) markers developed by whole genome resequencing (WGRS), the relationship and population genetic structure of 53 common apricot (P. armeniaca) varieties were analyzed to provide a theoretical basis for revealing the phylogenetic relationship and classification of the common apricot. WGRS was performed on 53 common apricot varieties, and high-quality SNP sites were obtained after alignment with the “Yinxiangbai” apricot genome as a reference. Phylogenetic analysis, G matrix analysis, principal component analysis, and population structure analysis were performed using Genome-wide Complex Trait Analysis (GCTA), FastTree, Admixture, and other software. The average comparison ratio between the sequencing results and the reference genome was 97.66%. After strict screening, 88,332,238 high-quality SNP sites were finally obtained. Based on the statistical SNP variation type, it was found that LNLJX had the largest number of variations (3,951,322) and the lowest base transition/base transversion ratio (ts/tv = 1.77), indicating that its gene exchange events occurred less frequently. Based on the SNP point estimation of the relationship and genetic distance between samples, the relationship between species was 1.41–0.01, among which PLDJX and BK1 had the closest relationship of 1.41, and YZH and LGWSX had the farthest relationship of 0.01. The genetic distance between species was 0.00367–0.264344, the genetic distance between HMX and JM was the closest, and the genetic distance between WYX and YX was the farthest, which was the largest. Phylogenetic tree, PCA, and genetic structure analysis results all divided 53 common apricot varieties into four groups, and the classification results were consistent. The SNP markers mined using WGRS technology are useful not only to analyze the variation of common apricots, but also to effectively identify their kinship and genetic structure, which plays a critical role in the classification and utilization of common apricot germplasm resources.

Studying the evolutionary history of plants in the Qinghai-Tibetan Plateau region provides a theoretical basis for the conservation and use of plant genetic resources. In this study, we analyzed five chloroplast gene fragments to examine the genetic diversity and phylogeography of Prunus mira in 577 individuals from 32 populations. The results indicated that P. mira populations exhibit high genetic diversity and significant phylogeographic structure (NST > GST). High genetic differentiation (FST = 0.979) and limited gene flow were detected among populations, likely due to geographic isolation. Neutrality tests and mismatch analysis indicated that the P. mira population has not experienced significant expansion during the historical period and remains relatively stable. Additionally, based on haplotype distribution and genetic diversity levels, we propose that P. mira had three refugia during the glacial period. Considering the genetic diversity of P. mira populations, we propose dividing all populations into two conservation units and prioritizing in situ conservation of populations with high genetic diversity within each unit. Furthermore, ex situ conservation of specific populations could prevent the loss of unique genes, such as those in populations with low genetic diversity but distinct haplotypes.

In the present study, we identified the members of the small auxin-up RNA (SAUR) gene family in Prunus sibirica and analyzed their localization, phylogeny, duplication, cis-elements in the promoter, and expression patterns. In total, 57 PsSAURs were identified, which were randomly distributed along eight chromosomes. Among them, eight and ten pairs of segmentally duplicated genes and tandem duplication genes were found in 13 and 21 PsSAURs, respectively. Phylogenetic analysis indicated that the PsSAURs were divided into five groups (Group A–E). Light-responsive, methyl jasmonate, abscisic acid, salicylic acid, and gibberellin, as well as low-temperature responsiveness, and defense and stress responsiveness were identified by analyzing PsSAURs promoter sequences. The collinearity analysis of P. sibirica SAURs and Prunus mume and Prunus persica SAURs family genes detected 35 and 59 pairs of gene pairs, respectively, and the Ks values of all collinearity gene pairs were almost less than 1. Expression pattern analysis showed that PsSAURs had different tissue and stage expression patterns. However, research on SAURs in non-model plants remains limited, and studies on the expression and function of SAURs are lacking. This study pro­vides a foundation for further investigations into the functional analyses of SAURs in P. sibirica.

Introduction: Spatial metabolic heterogeneity associated with fruit color and tissue type remains insufficiently characterized in postharvest apricot fruit. In this study, MALDI-MSI-based spatial metabolomics was used to characterize color- and tissue-associated ion-response heterogeneity in postharvest ‘Yanzhihong’ apricot fruit. Methods: RMS-normalized ion responses were analyzed using spatial shrunken-centroid segmentation, principal component analysis (PCA), exploratory orthogonal partial least-squares discriminant analysis (OPLS-DA), fold-change analysis, and sample-level Pearson correlation assessment. Results: Clear overall differentiation was observed between the red- and yellow-colored sides, indicating color-associated spatial metabolic heterogeneity within the fruit. Exploratory differential-feature screening and subsequent spatial analyses highlighted candidate ion features related to monolignol/phenylpropanoid metabolism, phenolic acids, flavonols, sugar phosphates, nucleotide sugars, and membrane lipids. Candidate ion features tentatively assigned to caffeyl alcohol, 4-hydroxycinnamic acid, and dihydroferulic acid, together with most selected membrane-lipid-related candidate features, showed stronger relative responses on the yellow-colored side. In contrast, candidate ion features tentatively assigned to myricetin-3-O-(4″-acetyl)rhamnoside and UDP-GalNAcA showed stronger relative responses on the red-colored side. Among the selected monolignol/phenylpropanoid-, phenolic-acid-, and flavonol-related candidate ion features, the 4-hydroxycinnamic-acid-related ion was the only feature that showed the same regional ordering on both fruit sides, with lower mean responses in the flesh than in the peel and near-stone regions. Other regional mean differences were feature dependent and were not statistically validated at the current sample size. Discussion: These findings characterize candidate color- and tissue-associated ion-response features under the sampled postharvest condition. Given the single cultivar, three paired biological replicates, and one postharvest sampling point, the findings remain exploratory and do not establish postharvest-quality markers.