[Objective]This study aimed to elucidate the differentiation patterns of aroma metabolism during fruit development across distinct peach flesh types,and identify key regulatory genes governing cultivar-specific aroma profiles,so as to provide a theoretical basis for flavor improvement in stony hard peaches.[Method]The melting-flesh cultivar Chunmei and the stony hard cultivar Zhongtao 9 were utilized as experimental materials.Seven critical sampling stages were established throughout the fruit development cycle.Volatile compounds were profiled using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry(HS-SPME-GC-MS).Transcriptome sequencing was performed to identify differentially expressed genes(DEGs),and Pearson correlation analysis was employed to pinpoint core genes significantly associated with key aroma compounds.[Result]A total of 57 volatile compounds were identified,with significant variation in composition and content across cultivars and developmental stages.The stony hard cultivar Zhongtao 9 exhibited no detectable ethylene production throughout development,maintained high levels of C6 aldehydes(e.g.,2-hexenal)at the mature stage,and showed almost no accumulation of esters and lactones.In contrast,the melting-flesh cultivar Chunmei exhibited a typical ethylene climacteric peak at the S3 to S4 transition,accompanied by a 3.1-3.8 fold increase in ester content and a marked decrease in C6 compounds.Transcriptome analysis identified 2 806 DEGs,with clear separation between the two cultivars at all developmental stages based on clustering analysis.KEGG enrichment analysis indicated that these DEGs were significantly involved in plant hormone signal transduction,α-linolenic acid metabolism,and carotenoid biosynthesis pathways.Correlation analysis identified 16 candidate genes associated with ester/lactone biosynthesis.Among them,BSK2(Prupe.2G110200)and PpYUC11(Prupe.6G157400/6G157500)showed strong positive correlations with hexyl acetate and γ-decalactone,respectively.[Conclusion]Ethylene was a key regulatory factor underlying aroma quality divergence between the two peach flesh types.Impaired ethylene signaling in Zhongtao 9 likely restricted fatty acid metabolism at the C6 aldehyde stage,preventing downstream esterification and lactone biosynthesis.Candidate genes,such as BSK2 and PpYUC11,together with hormone signaling pathways,were identified as potential regulators of aroma formation.

While multidrug-resistant Candida auris poses a global threat to public health, the impact and mechanism of drug resistance on fungal virulence remain unclear. By employing the same-parent-derived fluconazole-resistant C. auris strains, this study utilized in vitro screening and host–pathogen co-culture models. Labile zinc was visualized using the fluorescent probe Zinpyr and Zinquin. Mechanisms identified via dual RNA sequencing were further validated using genetic mutants and pharmacological inhibitors. For in vivo validation, a fly survival model was employed, followed by an infection model in C57BL/6J mice (n = 4 per group). Mice were challenged with C. auris via lateral tail vein injection and oral gavage. Efficacy was evaluated through daily survival monitoring, fungal burden via colony-forming unit (CFU) counting, histopathological examination of tissue sections, and cytokine level measurement. We revealed that fluconazole-resistant C. auris exhibits enhanced fitness and resistance to macrophage killing under zinc deficiency by mobilizing intracellular zinc. Mechanistically, Zn(II)2Cys6 transcription factor 4 (ZCF4) contributes to C. auris resistance to macrophage killing by suppressing the phosphoinositide 3-kinase (PI3K)-AKT-mammalian target of rapamycin (mTOR) pathway and downstream matrix metalloproteinase-9 (MMP-9) activity under low-zinc conditions. Furthermore, dietary zinc deficiency promotes the virulence of fluconazole-resistant C. auris. These findings highlight a fitness advantage of fluconazole-resistant C. auris under zinc-deficient conditions through host–fungal interactions, offering a potential nutrient intervention strategy against fungal infection.

Volatile organic compounds (VOCs) are the main chemical compounds that determine the characteristic aroma and flavor of fruit. In this study, we identified a total of 97 VOCs, including 5 C6 compounds, 12 aldehydes, 4 alcohols, 10 esters, 13 lactones, 18 terpenes, 8 norisoprenoids, 8 ketones, 3 hydrocarbons, 8 phenylalanine derivates, and 8 other compounds, in 60 peach cultivars using headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography-mass spectrophotometry (GC-MS). A wide range of VOCs were detected in these germplasm resources with respect to both quantity and concentration. Correlation analysis with different physiological traits demonstrated that the genetic background exerts a significant influence on the composition and content of VOCs among peach cultivars. For example, the content of norisoprenoid was significantly lower in yellow-fleshed peach than in white-fleshed peach, and lactones were almost undetectable in stony hard peach. Among the 97 VOCs, 26 exhibited odor activity values (OAVs) exceeding 1, suggesting that these compounds act as key odorants in the peach VOC composition. Moreover, six structural genes associated with the synthesis of γ-decalactone and (Z)-3-hexenyl acetate and five genes linked to aldehyde and 1-octen-3-one biosynthesis were identified through weighted gene co-expression network analysis (WGCNA). Additionally, 15 transcription factors (TFs) were identified as potentially regulating VOC synthesis. Overall, these data provide insight into the factors contributing to the differences in aroma qualities among peach cultivars, which can help to promote the development of peach breeding.

The "superbug" Candida auris has been ranked as a priority fungal pathogen and is becoming a serious threat to public health. However, the underlying mechanisms of real-world pathogen-host interactions remain elusive, in part due to the lack of powerful immunocompetent animal models. Here, we report that selected wild-type strains of Drosophila melanogaster can be developed as a promising infection model to recapitulate C. auris systemic infection. The systemic and organ-specific responses to C. auris infection in vivo were evaluated, as well as the corresponding transcriptional profiling. Our findings confirmed that Toll and JAK-STAT signaling pathways mediate antifungal responses in the Drosophila model following C. auris infection. Moreover, we identified certain conserved novel factors required for host-C. auris interactions, highlighting the fly model's potential to reveal subtle immune mechanisms not readily observed in mammalian systems. Taken together, our work demonstrates that wild-type Drosophila offers a robust immunocompetent animal model for further in-depth investigation of dynamic C. auris-host interactions in vivo.

Methyl jasmonate (MeJA) has emerged as a promising agent for mitigating chilling injury (CI) in peach fruit (Prunus persica); however, the molecular mechanisms underlying the role of MYC2, a key transcriptional regulator of jasmonic acid (JA) signaling, in mediating cold adaptation remain largely unexplored. In this study, we demonstrated that MeJA treatment effectively alleviated CI in peach fruit, accompanied by enhanced ethylene biosynthesis, elevated accumulation of polyphenols and flavonoids, and a marked reduction in reactive oxygen species levels. Using DNA affinity purification sequencing and transactivation assays, we identified PpMYC2.1 as a central regulator that directly activates key genes involved in ethylene-mediated fruit softening (PpIAA1, PpHB.G7, PpERF61, PpPL1, PpPG2, and PpXTH2) and phenylpropanoid metabolism (PpPAL1, Pp4CL, PpCHI3, and PpCHS). Stable overexpression of PpMYC2.1 in tomato (Solanum lycopersicum) significantly enhanced fruit tolerance to cold stress. Meanwhile, transient overexpression or silencing in peach fruit upregulated or downregulated the expression of its target genes, confirming its positive regulatory role in cold stress response. Mechanistically, MeJA downregulated the expression of transcriptional repressors PpJAZ2 and PpJAZ4, thereby alleviating their suppression of PpMYC2.1-mediated transactivation. Collectively, these findings reveal a previously uncharacterized JA-responsive transcriptional module, PpJAZ2/4-PpMYC2.1, that orchestrates cold stress adaptation in peach fruit, offering novel insights into postharvest preservation strategies for climacteric fruit.

Peach fruit quality deteriorates rapidly at room temperature. Therefore, cold storage is commonly used to extend postharvest shelf life of peaches. However, prolonged cold storage can lead to chilling injury (CI), which manifests as internal browning and affects fruit quality. This study explored the physiological, biochemical and transcriptomic responses of two peach cultivars (CP9 and mini) during cold storage. CP9 exhibited significant internal browning, reduction in soluble solid content (SSC) and firmness, and rapid increase in ethylene production. In contrast, mini showed no browning, retained higher SSC, experienced a slower decline in firmness and increase in ethylene production. After storage, CP9 showed elevated malondialdehyde (MDA) levels and increased activities of polyphenol oxidase (PPO), peroxidase (POD), and laccase (LAC), which are associated with browning symptoms. Transcriptome analysis identified two key candidate genes, PpPOD73 and PpPOD1, along with 10 transcription factors (PpMYB62, PpNAC100, PpbHLH62/93/94 and PpWRKY47/48/71/74/75) related to enzymatic browning. Co-expression network and promoter analyses revealed regulatory connections between these transcription factors and browning-related genes. This study sheds light on molecular mechanisms underlying peach fruit browningduring cold storage.

Slow-melting flesh (SMF) in peaches offers many advantages, including easy transportation, maintaining flavour after ripening, an extended harvest window, and reduced losses caused by fruit softening. However, the underlying molecular mechanism remains elusive. A high-quality genome of the SMF cultivar Chunrui was sequenced, assembled and annotated. The assembled genome was 249.6 Mb in size and characterized by a contig N50 of 12.35 Mb and a scaffold N50 of 30.27 Mb. Analysis of a segregating population indicated that a single dominant gene or major gene controlled the SMF trait. This trait was mapped to chromosome 4, which had a total length of 1.39 Mb. Fine mapping and gene expression analyses identified the receptor protein kinase THESEUS 1 (PpTHE1) as a candidate SMF gene. A Gypsy LTR-retrotransposon inserted downstream of PpTHE1 inhibited its expression. Functional analyses in peach and tomato fruits showed PpTHE1 played a positive role in maintaining fruit firmness. Screening of a yeast library using the kinase domain of PpTHE1 as the bait identified an ERF-type transcription factor PpERF61 and pectinlyase PpPL15. Luciferase complementation imaging, bimolecular fluorescence complementation and co-immunoprecipitation assays showed that PpTHE1 could interact with PpERF61 and PpPL15 in planta. Furthermore, our experimental data revealed that PpTHE1 significantly attenuates the DNA-binding capacity of PpERF61 to its target genes. These findings reveal the regulatory mechanism underlying the SMF fruit quality trait and thus provide theoretical support for breeding programmes to develop high-quality, storage-tolerant peach genotypes.

The PpAHL17-PpHYH module is involved in the accumulation of light-independent anthocyanins in peach peel. PpAHL17 activated the expression of PpHYH and positively regulated the synthesis of anthocyanin. The red color of peach peel is derived from the accumulation of anthocyanins, which significantly impacts its market value. While the understanding of the mechanism underlying light-dependent anthocyanin accumulation in peach peel is comprehensive, the process of light-independent anthocyanin accumulation remains elusive. Here, we examined two peach varieties, ‘Zhongyou 4’ (light-dependent) and ‘Luxing’ (light-independent), which showed different patterns of anthocyanin accumulation after shading bagging treatments. Analysis of these two peach varieties using RNA sequencing (RNA-seq) and weighted correlation network analysis (WGCNA) revealed that the genes PpAHL17 and PpHYH play a key role in regulating light-independent anthocyanin accumulation in peach peel. Under dark conditions, PpAHL17 and PpHYH have a high expression in the peel of the light-independent varieties, but not in the light-dependent varieties. Results from transient overexpression experiments demonstrated that the upregulation of PpAHL17 and PpHYH genes enhanced the biosynthesis of anthocyanins in peach peel. Furthermore, PpAHL17 can bind to the PpHYH promoter, thereby activating its expression, and PpHYH positively regulated the expression of anthocyanin synthesis-related genes PpF3H, PpUFGT, and PpMYB10.1. Our research provides new perspectives on the mechanisms governing the accumulation of anthocyanins in peach peel in the absence of light.

Red leaf peach has important ornamental value owing to its characteristic leaf coloration. However, this species is highly susceptible to powdery mildew, and the mechanisms of red leaf formation, resistance to powdery mildew, and their relationship remain unclear. We performed population genetic analyses of red leaf peach, revealing that the translocation of chromosomes 6 and 8 is genetically linked to both the red leaf trait and powdery mildew resistance. Bulk segregant analysis-sequencing, genome resequencing, and expression analysis indicated that the PpMYB114 and the resistance gene PpRPP13 are responsible for the red leaf phenotype and powdery mildew resistance, respectively. The chromosomal translocation causes a promoter fragment of PpRPP13 on chromosome 8 to integrate into the antisense chain of PpMYB114 on chromosome 6, thereby enhancing the expression of PpMYB114 and inhibiting the expression of PpRPP13. Further, lncRNA-seq identified a new antisense lncRNA, lncRNA_MYB114, which is generated by the translocation and can activate PpMYB114 expression to synthesize anthocyanin. Moreover, the overexpression of PpRPP13 resulted in enhanced resistance to powdery mildew. In summary, these results revealed the molecular mechanism of a chromosomal translocation altering the expression of PpMYB114 and PpRPP13 to form the red leaf phenotype that is linked to powdery mildew susceptibility.

Nectarine (Prunus persica var. nectarina) is an important variety of peach in the Rosaceae family. After the 1970s, China introduced some nectarine cultivars from Europe and America, which did not meet the taste preferences of domestic consumers. Through strategic hybridization and selection protocols, Chinese pomologists have recently developed multiple high-quality nectarine varieties with strong adaptability and sweet flavor, including early maturing varieties Zhongyoutao 4 Hao and Zhongyoutao 5 Hao, medium maturing variety Zhongyou 20 Hao, and late maturing variety Zhongyoutao 8 Hao. However, the breeding of early maturing and storage tolerant varieties still relatively lags behind. Zhongyou 19 Hao is a newly released early maturing, yellow firm-fleshed nectarine bred by Zhengzhou Fruit Research Institute, CAAS. In 1999, Bei1-9 was used as a female parent and Zhongyoutao 5 Hao, a early mature and white-fleshed nectarine as a pollen donater. Among the offsprings, 99-43-58 was selected for its maturation stage in mid to late June, but the fruit surface had insufficient coloring of fruit surface. In 2005, a cross was made using Zhongyoutao 14 Hao, a early repening, white and firm-fleshed with well colored surface nectarine variety, as female parent and 99-43-58 as male parent. A total of 45 hybrid seedlings were obtained that year, resulting in 16 hybrid seedlings. Seedlings were planted in spring 2006. The individual plant numbered 05-1-139 bloomed and bore fruit in 2009. Its main economic traits of the mother tree were stable in three consecutive years of observation. In 2011, the scions were collected from it for top grafting test. There was no significant difference in performance among the top grafting trees. In 2024, it was officially registered as Zhongyou 19 Hao under the non-major crop variety registration system of the Ministry of Agriculture and Rural Affairs of the People's Republic of China, with registration number GPD Tao (2024) 410043. The main characteristics were as follows: the annual new shoots are green, the sunny side of the shoot is red, and the average internode length is 3.0 cm. The leaf length is 18.8 cm, and the width is 4.6 cm. The petiole is kidney shaped with 2-4 nectaries. The flower has five petals, with pink corolla, orange yellow inner wall of calyx tube, abundant pollens. The average fruit weight is 210 g and the maximum weight is 240 g. The fruit surface has a light yellow base color, and more than 80% dark red coloration. The flesh is yellow and extremely firm. When mature, there is no anthocyanin under the skin or near the nucleus of the fruit. The flesh is fine and sweet with little fiber. The soluble solids content ranges from 11.7% to 15.9%. The fruit nucleus is of medium size, oval in shape, with a moderate degree of brown color. The surface of the nucleus is slightly grooved, without cracked or sticky nuclei. No cracking phenomenon was found. In Zhengzhou area, the sprouting time of Zhongyou19 Hao is in the end of February and the flowering time is in the mid to late March. The fruit matures in mid June, and the fruit development period is about 70 days. The leaves fall is in mid November, and the annual growth period is about 240 days. It exhibits superior edaphic adaptation to northern China's continental climate zone, yet requires proper water management in commercial orchards to prevent water stress and soil saturation.

BACKGROUND:Carotenoid cleavage dioxygenases (CCDs) are critical enzymes involved in carotenoid degradation. These enzymes play a significant role in determining fruit color and aroma by modifying carotenoid precursors and generating volatile compounds such as norisoprenoids, volatile carotenoid cleavage products. In peach (Prunus persica), there have been many studies showing that PpCCDs are associated with changes in fruit flesh color, but their role in volatile formation remains to be elucidated. This study aims to explore the function of PpCCD genes in carotenoid metabolism and volatile biosynthesis in peach. RESULTS:There were 10 PpCCD genes identified in peach genome. According to the phylogenetic tree, PpCCD proteins were classified into six groups, CCD1, CCD4, CCD7, CCD8, CCD10 and NCED. Analysis of the aroma content revealed that white-fleshed peaches contained significantly higher levels of norisoprenoids than yellow-fleshed peaches, and the expression pattern of PpCCD4 was consistent with this phenotype. The expression pattern of PpCCD4 was correlated with the accumulation of norisoprenoid during fruit development. In addition, MeJA treatment significantly induced the expression of PpCCD4. In addition, subcellular localization studies showed that PpCCD1 and PpNCED2 were localized in the membrane, while PpNCED3 and PpCCD4 were localized in the chloroplast. CONCLUSION:A total of 10 PpCCD genes were identified in peach, among which PpCCD4 was identified as a key gene for the biosynthesis of norisoprenoids. Its expression was higher in white-fleshed peaches and correlated with norisoprenoid levels. PpCCD4 expression was also induced by cold and MeJA treatment, indicating its involvement in stress responses. These findings suggest PpCCD4 is a potential target for improving peach fruit aroma quality.

With the evolution of consumer purchasing power and consumption concepts, external attributes such as fruit size, color, and peel smoothness have emerged as pivotal determinants influencing purchasing preferences; among these, the background color of the fruit peel exerts a considerable impact on fruit esthetics. The background color of fruit peel is predominantly influenced by the chlorophyll content. Consequently, examining the degradation patterns of chlorophyll in Prunus persica L. peel holds significant importance for cultivating varieties with a cleaner peel background color. In this study, Prunus persica L. CP14 and 20–29 were selected as experimental materials to evaluate the peel color variation and chlorophyll content during fruit development. Samples collected from three developmental stages of CP14 and 20–29 underwent transcriptome sequencing. Kyoto Encyclopedia of Genes and Genomes enrichment analysis identified chlorophyll-degradation-related genes within the purine metabolism pathway. Quantitative polymerase chain reaction analysis of chlorophyll degradation gene expression pinpointed PpPAO and PpSGR as likely key genes involved in chlorophyll degradation in Prunus persica L. Transient transformation assays in Nicotiana benthamiana leaves further substantiated that PpPAO and PpSGR markedly reduce chlorophyll levels. Yeast two-hybrid experiments also demonstrated an interaction between PpPAO and PpSGR.

Circadian clocks orchestrate temporal regulation of diverse physiological processes, including innate immunity and oxidative stress responses. However, the molecular mechanisms by which core clock components modulate immune tone and redox homeostasis remain elusive. Here, the circadian transcription factor CLOCK (CLK) is identified as a key regulator of oxidative stress resistance in Drosophila melanogaster. Loss of clk significantly enhances survival under oxidative stress, accompanied by constitutive activation of innate immune pathways. Mechanistically, the RNA-binding protein Achilles (ACHL) is identified as a critical downstream effector of CLK. Indeed, CLK drives rhythmic transcription of Achl, and ACHL post-transcriptionally represses the NF-κB homolog Relish by promoting its mRNA degradation, thereby limiting immune overactivation. Disruption of this regulatory cascade, through loss of either clk or Achl, leads to increased Relish abundance, excessive immune gene expression, and enhanced oxidative stress resistance. Genetic suppression of Relish reverses these phenotypes, establishing a functional CLK-ACHL-Relish axis that links circadian output to immune restraint. Importantly, this regulatory mechanism is evolutionarily conserved, as Clock-deficient mammalian cells exhibit increased resistance to oxidative injury. Together, the findings uncover a post-transcriptional immune checkpoint controlled by circadian networks, linking immune quiescence with redox adaptation.

Candidalysin, a cytolytic peptide toxin secreted by the human fungal pathogen Candida albicans , is critical for fungal pathogenesis. Yet, its intracellular targets have not been extensively mapped. Here, we performed a high-throughput enhanced yeast two-hybrid (HT-eY2H) screen to map the interactome of all eight Ece1 peptides with their direct human protein targets and identified a list of potential interacting proteins, some of which were shared between the peptides. CCNH, a regulatory subunit of the CDK-activating kinase (CAK) complex involved in DNA damage repair, was identified as one of the host targets of candidalysin. Mechanistic studies revealed that candidalysin triggers a significantly increased double-strand DNA breaks (DSBs), as evidenced by the formation of γ-H2AX foci and colocalization of CCNH and γ-H2AX. Importantly, candidalysin binds directly to CCNH to activate CAK to inhibit DNA damage repair pathway. Loss of CCNH alleviates DSBs formation under candidalysin treatment. Depletion of candidalysin-encoding gene fails to induce DSBs and stimulates CCNH upregulation in a murine model of oropharyngeal candidiasis. Collectively, our study reveals that a secreted fungal toxin acts to hijack the canonical DNA damage repair pathway by targeting CCNH and to promote fungal infection.

The storage of peach fruits at 4–5 °C can easily lead to chilling injury and greatly reduce the quality and commercial value of peach fruits. In this study, two kinds of peach fruits (CX and CM) were selected to analyze the mechanisms of chilling injury in fruits with different chilling sensitivity by means of their lipidomic, transcriptome, and dynamic changes in plant hormones. We found that the ethylene, abscisic acid (ABA), and lipid contents changed differently between CX and CM. The ABA and dilactosyl diacylglycerol (DGDG) contents significantly increased after refrigeration in CM fruit, leading to strong cold resistance. However, low temperatures induced a greater accumulation of ethylene, phospholipids, and ABA-GE in CX fruit than in CM fruit, eventually leading to more severe CI symptoms in CX fruit. Additionally, a transcriptional regulatory network for CM and CX fruits during cold storage was constructed, providing a new theoretical reference for the cultivation of cold-resistant peach cultivars and the development of postharvest preservation technology.

Stony hard (SH) peach ( Prunus persica ) fruits produce no ethylene and clingstone-type SH peaches have a crispy flesh texture; however, freestone-type SH peach fruits ripen to a soft, mealy state. During this study, we compared and analyzed changes in the microstructure, cell wall polysaccharides, and candidate cell wall-related genes of freestone-type SH ‘Zhongtao 14’ (‘CP14’), ‘Zhongtao White Jade 2’ (‘CPWJ2’), clingstone-type SH ‘Zhongtao 13’ (‘CP13’), and ‘Zhongtao 9’ (‘CP9’) during fruit ripening. The parenchyma cells of mealy freestone-type SH peaches became detached, were single, dried, and irregularly arranged, and remained intact in comparison with the nonmealy clingstone-type SH peaches. Methyl-esterified homogalacturonan was strongly immunolabeled in the cell wall of clingstone SH peaches; however, nonmethylated homogalacturonan was weakly immunolabeled in freestone SH peaches. A transcriptome analysis was performed to investigate the molecular mechanism of the mealiness process. A principal component analysis indicated that ‘CP14’ S4 III (mealy) could be distinguished from the samples of ‘CP13’ (S4 I, S4 II, S4 III) and ‘CP14’ (S4 I, S4 II). The highly coexpressed gene modules linked with firmness were found using a weighted gene coexpression network analysis; 189 upregulated genes and 817 downregulated genes were identified. Six upregulated cell wall-related genes ( PpPG1 , PpPG2 , PpAGP1 , PpAGP2 , PpEXT1 , and PpEXP1 ) and one downregulated cell wall-related gene ( PpXET2 ) were involved in the mealiness process during freestone-type SH fruit ripening. These findings will improve our understanding of the relationship between clingstone, freestone, and stony hard fruits and lay the foundation for further exploration of the mechanisms underlying the softening of peach fruits.

Piercing/sucking insects such as green peach aphid (GPA) (Myzus persicae) cause direct damage by obtaining phloem nutrients and indirect damage by spreading plant viruses. To investigate the response of peach trees (Prunus persica) to aphids, the leaf transcriptome and metabolome of two genotypes with different sensitivities to GPA were studied. The gene expression of aphid-susceptible plants infested with aphids was similar to that of control plants, whereas the gene expression of aphid-resistant plants infested with aphids showed strong induced changes in gene expression compared with control plants. Furthermore, gene transcripts in defense-related pathways, including plant-pathogen interaction, MAPK signaling, and several metabolic pathways, were strongly enriched upon aphid infestation. Untargeted secondary metabolite profiling confirmed that aphid infestation induced larger changes in aphid-resistant than in aphid-susceptible peaches. Consistent with transcriptomic alterations, nine triterpenoids showed highly significant GPA-induced accumulation in aphid-resistant peaches, whereas triterpenoid abundance remained predominantly unchanged or undetected in aphid-susceptible peaches. Furthermore, some types of transcription factors (including WRKYs, ERFs, and NACs) were strongly induced upon GPA infestation in aphid-resistant, but not in aphid-susceptible peaches. These results suggested that the accumulation of specialized triterpenoids and the corresponding pathway transcripts may play a key role in peach GPA resistance.

Here, we report a novel frameshift mutation caused by a single base deletion in exon 3 of the HBA2 gene (HBA2:c.337delC) detected by next-generation sequencing. The proband was a 26-year-old Chinese pregnant woman who originates from Hunan Province. Her mean corpuscular volume(MCV) and mean corpuscular hemoglobin (MCH) had a mild decrease. Capillary electrophoresis (CE) showed that both Hb A (97.8%) and Hb F (0.0%) values were within normal range, while the Hb A2 (2.2%) value was below normal. Sequence analysis of the alpha and beta-globin genes revealed a novel single base deletion at codon 112 (HBA2:c.337delC) in the heterozygous state, which resulted in a mild phenotype of alpha-thalassemia.

Transcription factor PpMYB5 promotes lignin synthesis by directly binding to the Pp4CL1/Pp4CL2 promoter and affecting their expression, which may be related to nectarine russeting formation. Nectarine russeting is usually considered to be a non-invasive physiological disease that usually occurs on late-maturing cultivars and seriously affects their appearance quality and commercial value. The cause of nectarine fruit rust is currently unknown. In this study, we compared two flat nectarine cultivars, ‘zhongyoupanweidi’ (HD; russeting-free cultivar) and ‘zhongyoupanweihou’ (TH; russeting-prone cultivar), with respect to nectarine russeting by means of microscopy, transcriptomics, and hormone analysis. Compared to HD fruits, TH fruits had a broken cuticle, missing wax layer, and heavy lignin deposition. RNA sequencing (RNA-seq) revealed significant alternations in the expression of genes related to lignin synthesis. Moreover, structure genes Pp4CL1 and Pp4CL2, MYB transcription factor (TF) gene PpMYB5 were identified through weighted gene co-expression network analysis (WGCNA). Molecular experiments and transgenic evidence suggested that PpMYB5 regulates Pp4CL1/Pp4CL2 expression to promote lignin synthesis. Overall, in addition to providing new insights into the formation of mechanisms for nectarine russeting, our study also establishes a foundation for nectarine russeting prevention.