Yueyan Wu

Grape leaf serration morphology is a key physiological trait that influences photosynthetic efficiency, leaf boundary layer dynamics, and stress adaptability, thereby affecting yield and quality. In this study, we phenotyped 10 mature leaf morphological traits in 153 grape accessions over two consecutive years. Among these traits, five showed high interannual stability (|r| ≥ 0.8). GWAS of these five stable traits using three models (GLM, MLM, and FarmCPU) identified seven high-confidence SNP loci reproducibly associated with mature leaf serration morphology. Ten candidate genes were screened within ±15 kb of these SNPs, including genes related to ubiquitin-mediated protein degradation (Cullin-4), ubiquitin ligase activity (SP-RING-type protein), and two-component signaling (histidine kinase). Based on their predicted roles in leaf development and cell differentiation, we selected four genes for qRT-PCR validation. We observed differential expression patterns associated with serration morphological variation: Cullin-4 and SP-RING-type protein were upregulated in straight-sided serrations, whereas histidine kinase was upregulated in convex-sided serrations. These expression patterns provide preliminary evidence that ubiquitin-proteasome pathway activity and phosphorylation signaling may be associated with serration variation, although direct functional validation is required. This study characterizes the genetic architecture of grape leaf serration morphology and suggests possible differential regulatory mechanisms involving protein degradation and signaling pathways, providing a foundation for future functional studies.

As the primary organ for photosynthesis in plants, the leaf surface trichomes play crucial roles in modulating light energy absorption and defending agains

The flower color of Rhododendron is primarily determined by anthocyanin biosynthesis, with cytochrome P450 CYP75 family members, particularly flavonoid 3′,5′-hydroxylase (F3′5′H), playing a central role. However, the composition and functional characterization of CYP75 genes in Rhododendron remain insufficiently explored. This study performed genome-wide identification of the CYP75 gene family using the Rhododendron simsii reference genome and functionally characterized the corresponding F3′5′H homolog cloned from Rhododendron × hybridum petals (red cultivar and pink cultivar). Seven RsCYP75 genes were identified, categorized into two subfamilies: RsCYP75A (A1–A5) and RsCYP75B (B1–B2), with a prominent cluster on chromosome 13. All encoded proteins contained a conserved cytochrome P450 domain and typical heme-binding motifs. Among these, RhCYP75A2 showed the highest expression level in red petals at full blooming period and was designated as RhF3′5′H. RhF3′5′H encodes a basic membrane protein with the characteristic F3′5′H motif, with its transcript most abundant in flowers. Transient overexpression of RhF3′5′H in red R. × hybridum petals resulted in a 9.74-fold increase in its transcript levels and a 1.25-fold increase in anthocyanin content compared to that in the control accompanied by the up-regulation of CHS, F3H, DFR and ANS. Conversely, RhF3′5′H silencing reduced anthocyanin accumulation but increased CHS and F3H transcript levels, suggesting a compensatory transcriptional response in the upstream anthocyanin pathway. Moreover, RhF3′5′H was heterologously expressed in E. coli Rosetta as an MBP fusion protein, purified, and identified by LC-MS/MS and ELISA. The protein showed the ability to promote anthocyanin accumulation. Molecular docking analysis demonstrated that RhF3′5′H can bind to naringenin and dihydrokaempferol. These results confirm that RhF3′5′H is a functional F3′5′H-type CYP75A enzyme and a positive regulator of anthocyanin accumulation in Rhododendron petals. This work enriches the CYP75 gene catalog in Rhododendron and provides candidate genes for future studies on flower color regulation and molecular breeding.

The perception of sweetness and sourness is a critical sensory indicator of the sensory quality of table grapes. This study comprehensively analyzed the relationships between traditional physicochemical evaluation metrics (soluble solids content, SSC; titratable acidity, TAC; and their ratio, RTT) and the perceived sweetness and perceived sourness assessed by a trained sensory panel across 42 grape varieties. Our findings reveal significant discrepancies between these traditional metrics and the perceived sweetness and sourness, indicating limitations in their accuracy for precisely characterizing the sensory experience. To achieve a more accurate description of grape perceived sweetness and sourness, we employed high‐performance liquid chromatography and liquid chromatography–mass spectrometry to quantify the individual sugar and acid components within the grape juice from these 42 cultivars. Subsequently, we integrated correlation analysis and principal component analysis (PCA) for dimensionality reduction to conduct a comprehensive assessment of the sensory attributes. Ultimately, we identified tartaric acid and fructose contents as reliable key indicators for representing perceived sweetness and sourness, and the overall sensory quality of table grapes.

The aroma quality of grape fruit is a crucial trait for table grapes, yet its relationship with plant disease resistance remains unclear. Using ‘Shine Muscat’ grapes as material, this study employed HS-SPME-GC-MS combined with odor activity value (OAV) and PLS-DA analysis to investigate the regulatory effects of different rootstocks and GA₃/MeJA treatments on volatile aroma compounds. Linalool and α-terpineol were selected as representative compounds for antibacterial experiments and gene expression analysis of terpenoid synthesis. Results indicate that the Lot rootstock and 15.25 mg·L⁻¹ GA₃ treatment significantly promoted the accumulation of terpenoid aroma compounds. Linalool exhibited significant inhibitory effects on the mycelial growth of Colletotrichum fructicola and induced upregulation of DXS, TPS56, and TPS gene expression. This study reveals a potential link between aroma metabolism and defense responses, providing a theoretical basis for synergistic optimization of grape aroma quality improvement and disease-resistant cultivation.

The coloration of vegetative organs in grapevine (Vitis vinifera L.) is an important phenotypic trait associated with environmental responsiveness and stress adaptation; however, its genetic regulatory mechanisms remain poorly understood. To systematically elucidate the genetic basis of vegetative coloration, a genome-wide association study (GWAS) was performed using 151 grapevine accessions, integrating high-depth whole-genome resequencing data with phenotypic evaluations of eight coloration traits across two consecutive years (2023–2024). Using a mixed linear model (MLM), 13 stable and significant SNP loci were identified on chromosomes 3, 5, 6, 13, 14, 15, 16, and 18, explaining 13.28–19.35% of the phenotypic variation. Within ±15 kb of these loci, 16 candidate genes were identified. qRT-PCR analysis of key candidates revealed that VIT_06s0004g03620 (mitogen-activated protein kinase), VIT_16s0039g01900 (MYB-like domain-containing protein), and VIT_14s0083g01050 (MADS-box protein 2) showed significant positive correlations between expression levels and coloration intensity, with distinct expression patterns among accessions exhibiting different coloration grades. These genes are likely involved in the regulation of anthocyanin accumulation. Collectively, this study elucidates the genomic architecture underlying vegetative organ coloration in grapevine and provides valuable candidate genes and SNP markers for functional validation and molecular-assisted breeding.

Berry color is a critical determinant of grape quality and market value. While the genetic basis of skin color has been extensively studied, the regulatory network controlling flesh coloration remains largely uncharacterized. To systematically dissect the independent genetic architectures underlying these traits, we performed a genome-wide association study (GWAS) on 130 grape accessions, integrated with spatiotemporal expression profiling, subcellular localization, and functional validation. Our analysis revealed distinct genetic loci for skin and flesh color, confirming their independent regulation. For skin color, GWAS robustly validated VvMYBA2 as a major locus, explaining up to 51.5% of the phenotypic variance. More importantly, for flesh color, we identified and prioritized VvF3′M (Flavonoid 3′-monooxygenase) as a key candidate gene. Heterologous overexpression of VvF3′M in tobacco resulted in a profound 13.5-fold increase in anthocyanin content, suggesting its potential role as a rate-limiting enzyme in flesh pigmentation. Intriguingly, VvF3′M-overexpressing plants also exhibited a significant increase in flower number, suggesting a novel role beyond pigment biosynthesis. This study provides a comprehensive genetic and functional framework for understanding berry coloration, identifies VvF3′M as a prime target for breeding red-fleshed grapes, and reveals unexpected crosstalk between color metabolism and reproductive development.

Background Glutathione S-transferases (GSTs) mediate vacuolar sequestration of anthocyanins and are key determinants of flower color. Several Phi (GSTF) and Tau (GSTU) members have been linked to anthocyanin transport, but how GST repertoires in woody ornamentals respond to light quality is largely unknown in Rhododendron . Results We identified 87 GST genes in the Rhododendron simsii genome and classified them into seven subfamilies, with Tau and Phi predominating. Segmental duplication was the main driver of family expansion, and most promoters carried multiple light-responsive cis-elements. Twelve representative RsGST homologues were mapped to Rhododendron hybridum and showed distinct tissue- and stage-specific expression, including a group ( RsGSTF2 , RsGSTL7 , RsGSTU1 ) preferentially expressed in floral organs. Under defined light-quality treatments, GST transcripts in buds were rapidly induced by UV-A/blue light, whereas red/far-red light elicited stronger and more sustained induction in fully open flowers. Total petal anthocyanin content increased markedly under red and far-red light, broadly paralleling the expression of RsGSTF2 , RsGSTL7 and RsGSTU1 . Conclusions Our integrative genomic and expression analyzes indicate that the GST family in Rhododendron is tightly connected to light signaling and floral development, and highlight flower-preferential, light-quality-responsive Tau and Phi members as candidate vacuolar anthocyanin transporters for light-dependent flower color formation.

Rhododendron fortunei Lindl is known for its unique aroma, but the molecular mechanism behind plant hormone-mediated aroma biosynthesis remains unclear. To explore how brassinosteroids (BRs) and methyl jasmonate (MeJA) regulate its aroma, this study analyzed R. fortunei petal samples via physiological assays, volatile metabolome analysis, and transcriptome sequencing. Physiologically, BR/MeJA significantly increased the superoxide dismutase (SOD) and catalase (CAT) activity and decreased the malondialdehyde (MDA) content. Metabolome analysis identified 1268 volatile organic compounds (VOCs), with 265/70 VOCs up-/downregulated in the BR group and 248/181 VOCs up-/downregulated in the MeJA group compared to the controls. Transcriptome sequencing identified 19,333 differentially expressed genes (DEGs), which were enriched in pathways such as terpenoid and polyketide metabolism. Multi-omics screening revealed the candidate gene RfCYP92C6, whose transient overexpression in Nicotiana benthamiana increased the terpenoid content 2.2-fold. These findings clarify the aroma regulation mechanism of BRs/MeJA in R. fortunei and support the improvement of its aroma traits via genetic engineering.

Brassinazole-resistant (BZR) gene is a key transcription factor in the brassinosteroid signaling pathway and plays a critical role in regulating plant growth, development, and environmental stress responses. However, systematic studies on the BZR gene family in grape remain limited. In this study, eight BZR genes were identified in the grape genome, which were unevenly distributed across seven chromosomes and classified into four subfamilies. Bioinformatics analysis was performed to characterize their physicochemical properties, conserved motifs, chromosomal locations, and expression across tissues and in response to hormones. Further experimental results showed that VvBZR7 expression is induced by brassinosteroid and its inhibitor. Subcellular localization confirmed that VvBZR7 is localized in the nucleus. Transient overexpression assays demonstrated that VvBZR7 promotes the degradation of cell wall components, which reduces fruit firmness and consequently accelerates softening. These findings establish a foundation for elucidating the functional roles and regulatory mechanisms of the BZR gene family in grapevine.