Strawberry (Fragaria × ananassa Duch) are sensitive to salt stress, and breeding salt-tolerant strawberry cultivars is the primary method to develop resistance to increased soil salinization. However, the underlying molecular mechanisms mediating the response of strawberry to salinity stress remain largely unknown. This study evaluated the salinity tolerance of 24 strawberry varieties, and transcriptomic and metabolomic analysis were performed of ‘Sweet Charlie’ (salt-tolerant) and ‘Benihoppe’ (salt-sensitive) to explore salt tolerance mechanisms in strawberry. Compared with the control, we identified 3412 differentially expressed genes (DEGs) and 209 differentially accumulated metabolites (DAMs) in ‘Benihoppe,’ and 5102 DEGs and 230 DAMs in ‘Sweet Charlie.’ DEGs Gene Ontology (GO) enrichment analyses indicated that the DEGs in ‘Benihoppe’ were enriched for ion homeostasis related terms, while in ‘Sweet Charlie,’ terms related to cell wall remodeling were over-represented. DEGs related to ion homeostasis and cell wall remodeling exhibited differential expression patterns in ‘Benihoppe’ and ‘Sweet Charlie.’ In ‘Benihoppe,’ 21 ion homeostasis-related DEGs and 32 cell wall remodeling-related DEGs were upregulated, while 23 ion homeostasis-related DEGs and 138 cell wall remodeling-related DEGs were downregulated. In ‘Sweet Charlie,’ 72 ion homeostasis-related DEGs and 275 cell wall remodeling-related DEGs were upregulated, while 11 ion homeostasis-related DEGs and 20 cell wall remodeling-related DEGs were downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed only four KEGG enriched pathways were shared between ‘Benihoppe’ and ‘Sweet Charlie,’ including flavonoid biosynthesis, phenylalanine metabolism, phenylpropanoid biosynthesis and ubiquinone, and other terpenoid-quinone biosynthesis. Integrating the results of transcriptomic and metabolomics analyses showed that adenosine triphosphate-binding cassette (ABC) transporters and flavonoid pathway genes might play important roles in the salt stress response in strawberry, and DAMs and DEGs related to ABC transporter and flavonoid pathways were differentially expressed or accumulated. The results of this study reveal that cell wall remodeling and ABC transporters contribute to the response to salt stress in strawberry, and that related genes showed differential expression patterns in varieties with different salt tolerances. These findings provide new insights into the underlying molecular mechanism of strawberry response to salt stress and suggest potential targets for the breeding of salt-tolerant strawberry varieties.

Strawberry (Fragaria × ananassa) fruits are rich in ascorbic acid (AsA) and anthocyanin, which are essential antioxidants for human health. However, the underlying regulatory mechanism of these antioxidant accumulation, especially AsA accumulation in strawberry fruits, remains largely unknown. In this study, we identified FaAKR23 was a regulator of AsA and anthocyanin accumulation. We transiently expressed FaAKR23 in strawberry fruits and conducted metabolic and molecular analyses to explore the role of FaAKR23 in AsA and anthocyanin accumulation. Transient silencing of FaAKR23 (FaAKR23-RNAi) in strawberry fruits significantly decreased the AsA and anthocyanin contents compared with control (empty vector-RNAi, EV-RNAi). Correspondingly, expression of some structural genes and regulatory factors involved in these two antioxidants’ accumulation was dramatically repressed. In addition, transcriptome analysis of EV-RNAi and FaAKR23-RNAi fruits suggested that FaAKR23 was also involved in starch and sucrose metabolism as well as plant–pathogen interaction. Overall, these results not only provide the coordinated regulatory function of FaAKR23 on AsA and anthocyanin accumulation but also offer a promising candidate gene for strawberry breeding with high antioxidants.

Fragaria pentaphylla, a wild diploid quinquefoliolate species of Fragaria, is native to Southwest China. It has two morphs of red and white fruit color in nature and has characteristics of unique fragrance and resistance, which made it not only a valuable breeding material but also a potential model plant for molecular function researches. Here, we generate a high-quality chromosome-level genome assembly of a F. pentaphylla accession, BAAFS-FP039 employing a combination of PacBio Long-Read Sequencing, Illumina Short-Read Sequencing, and Hi-C Sequencing. The assembled genome contained 256.74 Mb and a contig N50 length of 32.38 Mb, accounting for 99.9% of the estimated genome (256.77 Mb). Based on Hi-C data, seven pseudo-chromosomes of F. pentaphylla-FP039 genome were assembled, covering 99.39% of the genome assembly. The genome was composed of 44.61% repetitive sequences and 29,623 protein-coding genes, 97.62% of protein-coding genes could be functionally annotated. Phylogenetic and chromosome syntenic analysis revealed that F. pentaphylla-FP039 was closely related to F. nubicola. This high-quality genome could provides fundamental molecular resources for evolutionary studies, breeding efforts, and exploring the unique biological characteristics of F. pentaphylla.

Tubby-like proteins (TLPs) play important roles in plant growth and development and in responses to abiotic stress. However, TLPs in strawberry remain poorly studied. In this study, eight TLPs were identified in woodland strawberry (Fragaria vesca subspecies vesca ‘Ruegen’). Protein structure analysis revealed that the structure of FvTLPs is highly conserved, but evolutionary and gene structure analyses revealed that the evolutionary pattern of FvTLP family members differs from that of their orthologous genes in Arabidopsis, poplar, and apple. Subcellular localization assays revealed that FvTLPs were localized to the nucleus and plasma membrane. FvTLPs showed no transcriptional activity. Yeast two-hybrid assays revealed that FvTLPs interact with specific FvSKP1s. The expression patterns of FvTLPs in different tissues and under various abiotic stresses (salt, drought, cold, and heat) and hormone treatments (ABA (abscisic acid) and MeJA (methyl jasmonate)) were determined. The expression patterns of FvTLPs indicated that they play a role in regulating growth and development and responses to abiotic stress in F. vesca. The GUS (beta-glucuronidase) activity of FvTLP1pro::GUS plants in GUS activity assays increased under salt and drought stress and abscisic acid treatment. The results of this study provide new insights into the molecular mechanisms underlying the functions of TLPs.

Prochloraz and its metabolites in strawberries have not been determined until now. Meanwhile, few reports in the literature have concerned the dissipation behavior and risk assessment of prochloraz and its metabolites in strawberries under greenhouse conditions in Beijing. A method for the determination of prochloraz and its metabolites in strawberries was developed using QuEChERS in combination with ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Prochloraz and its metabolites recovered from strawberries were present in concentrations of 73.06% to 116.01%, their RSDs ranged from 1.12% to 9.17%, and their limits of detection ranged from 0.1 to 1 μg kg⁻¹. Then, a study was conducted on the dissipation of prochloraz in strawberries under greenhouse conditions. The dissipation of prochloraz in strawberries followed the first-order kinetic equation, and its half-life was 8.06 days. The health risk associated with prochloraz in strawberries was evaluated using the target hazard quotient (THQ) method and EFSA PRIMo model. The results showed that the THQ values, %ARfD values, and %ADI values were less than 1. These results indicate that no health concerns of prochloraz are associated with the consumption of the studied strawberries. The government can use the results of this study to support the establishment of a maximum residue level for prochloraz in strawberries.

Growing market demand exists for strawberry, with nutrient-rich and health-promoting properties, beyond mere taste and flavor. Genetic biofortification is a powerful strategy to enhance nutrient metabolites in strawberry. Both GABA and organic acids contribute to human health by supporting nervous system relaxation and enhancing metabolic and digestive functions, respectively. However, the regulatory mechanisms underlying their accumulation remain poorly understood. In this study, we analyzed the accumulation patterns of GABA and organic acids across four fruit developmental stages in two representative cultivars, ‘Monterey’ and ‘Benihoppe’. Ripening ‘Benihoppe’ fruits accumulated higher levels of GABA and citric acid, whereas ‘Monterey’ fruits contained more malic acid. Integrated transcriptome analysis identified key structural genes and transcription factors (TFs) involved in GABA biosynthesis. Notably, functional characterization revealed that FaGAD4 significantly promotes GABA accumulation and simultaneously enhances the content of anthocyanin and ascorbic acid (AsA). Overall, this study provides novel insights into the regulatory mechanisms of GABA accumulation in strawberry fruit and identifies FaGAD4 and potential TFs as valuable genetic targets for molecular breeding.