Q-type C2H2 zinc finger proteins (ZFPs), the largest family of transcription factors, have been extensively studied in plant genomes. However, the genes encoding this transcription factor family have not been explored in grapevine genomes. Therefore, in this study, we conducted a genome-wide identification of ZFP genes in three species of grapevine, namely Vitis vinifera, Vitis riparia, and Vitis amurensis, based on the sequence databases and phylogenetic and their conserved domains. We identified 52, 54, and 55 members of Q-type C2H2 ZFPs in V. vinifera, V. riparia, and V. amurensis, respectively. The physical and chemical properties of VvZFPs, VrZFPs, and VaZFPs were examined. The results showed that these proteins exhibited differences in the physical and chemical properties and that they all were hydrophobic proteins; the instability index showed that the four proteins were stable. The subcellular location of the ZFPs in the grapevine was predicted mainly in the nucleus. The phylogenetic tree analysis of the amino acid sequences of VvZFP, VaZFP, VrZFP, and AtZFP proteins showed that they were closely related and were divided into six subgroups. Chromosome mapping analysis showed that VvZFPs, VrZFPs, and VaZFPs were unevenly distributed on different chromosomes. The clustered gene analysis showed that the motif distribution was similar and the sequence of genes was highly conserved. Exon and intron structure analysis showed that 118 genes of ZFPs were intron deletion types, and the remaining genes had variable numbers of introns, ranging from 2 to 15. Cis-element analysis showed that the promoter of VvZFPs contained multiple cis-elements related to plant hormone response, stress resistance, and growth, among which the stress resistance elements were the predominant elements. Finally, the expression of VvZFP genes was determined using real-time quantitative PCR, which confirmed that the identified genes were involved in response to methyl jasmonate (MeJA), abscisic acid (ABA), salicylic acid (SA), and low-temperature (4 °C) stress. VvZFP10-GFP and VvZFP46-GFP fusion proteins were localized in the nucleus of tobacco cells, and VvZFP10 is the most responsive gene among all VvZFPs with the highest relative expression level to MeJA, ABA, SA and low-temperature (4 °C) stress. The present study provides a theoretical basis for exploring the mechanism of response to exogenous hormones and low-temperature tolerance in grapes and its molecular breeding in the future.

Foliar fertilizers are efficient in enhancing nutrient utilization. This experiment aims to improve leaf physiological functions, enhance fruit quality, increase yield, and boost orchard productivity through the screening of foliar fertilizers suitable for apple trees. The 6-year-old apple trees of the ‘Snick’ were used as experiment material. The results of measurements amino acids, calcium, boron, and potassium indicate that different foliar fertilizers can improve fruit quality and aroma by enhancing leaf physiological functions. In apple fruit, amino acid foliar fertilizer increased the tartaric acid content by 44.26%. Calcium foliar fertilizer resulted in a 32.39% increase in vitamin C, a 19.71% increase in sucrose compared to the control, with a total aroma substance increase of 13.41%. Boron foliar fertilizer elevated flavonoid content in the peel to 3.67 mg·g⁻¹, a 70.69% increase over the CK. Potassium foliar fertilizer significantly improved fruit appearance, phenolic substances in the peel, soluble protein content by 25.39%, and glucose content by 55.91%. Therefore, mineral source fulvic acid potassium foliar fertilizer was demonstrated the best overall effect, effectively enhancing fruit quality and flavor. These results provide a theoretical basis and scientific reference for improving apple quality.

Caffeic acid-O-methyltransferase (COMT) is a key enzyme in lignin synthesis and secondary metabolism in plants, and it participates in the regulation of plant growth and development as well as plants’ stress response. To further investigate the function of COMT in grapevine, a total of 124 COMT family genes were identified from three Vitis species in this study, namely Pinot noir (Vitis vinifera L.), Vitis amurensis, and Vitis riparia. The amino acid sequence encoded by these genes ranged from 55 to 1422 aa, and their molecular mass ranged from 6640.82 to 77,034.43 Da. Subcellular localization prediction inferred that they were mainly located in the plasma membrane and cytoplasm. The prediction of secondary structures showed that α-helix and irregular coiled-coil were primary structural elements. These genes were unevenly distributed across 10 different chromosomes, respectively. Phylogenetic tree analysis of the amino acid sequences of VvCOMT, VaCOMT, VrCOMT, and AtCOMT proteins showed that they were closely related and were divided into four subgroups. The motif distribution was similar among the cluster genes, and the gene sequence was notably conserved. The 124 members of the COMT gene family possessed a variable number of exons, ranging from 2 to 13. The promoter region of all of these COMTs genes contained multiple cis-acting elements related to hormones (e.g., ABA, IAA, MeJA, GA, and SA), growth and development (e.g., endosperm, circadian, meristem, light response), and various stress responses (e.g., drought, low temperature, wounding, anaerobic, defense, and stress). The intraspecies collinearity analysis suggested that there were one pair, three pairs, and six pairs of collinear genes in Va, Pinot noir, and Vr, respectively, and that tandem duplication contributed more to the expansion of these gene family members. In addition, interspecific collinearity revealed that the VvCOMTs had the strongest homology with the VaCOMTs, followed by the VrCOMTs, and the weakest homology with the AtCOMTs. The expression patterns of different tissues and organs at different developmental stages indicated that the VvCOMT genes had obvious tissue expression specificity. The majority of VvCOMT genes were only expressed at higher levels in certain tissues. Furthermore, we screened 13 VvCOMT genes to conduct qRT-PCR verification according to the transcriptome data of VvCOMTs under abiotic stresses (NaCl, PEG, and cold). The results confirmed that these genes were involved in the responses to NaCl, PEG, and cold stress. This study lays a foundation for the exploration of the function of the COMT genes, and is of great importance for the genetic improvement of abiotic stress resistance in grapes.

The Arabidopsis thaliana Heat Shock Protein-Related (AtHSPR) gene participates in plant growth and abiotic stress tolerance, while its role in biotic stress resistance remains unclear. Here, we report that the athspr mutant is sensitive to Pseudomonas syringae pv. tomato (Pst) DC3000, whereas over-expression of AtHSPR enhances the defense of Arabidopsis against the pathogen. AtHSPR expression was induced by treatment with Pst DC3000, flg22, or salicylic acid (SA). Transcriptome analysis showed that mutation of AtHSPR changed the expression patterns of genes associated with defense response, oxidation–reduction, and SA responses, as well as transcription factors. The biochemical evidence revealed that AtHSPR interacted with Thimet Oligopeptidase 1 (TOP1), which modulated the SA-mediated immune response. Co-expression of AtHSPR and TOP1 showed that the TOP1 protein, normally located in the chloroplasts, gathered around the nucleus in response to a pathogen. After pathogen treatment, dynamic tubular projections (stromules) were present, extending from the chloroplasts toward the nucleus, and TOP1 was observed in the nucleus, together with AtHSPR. The top1athspr double mutant had lower SA levels and was more sensitive to pathogens than the top1 and athspr single mutants. Taken together, our results demonstrated that the interaction between AtHSPR and TOP1 plays a positive role in SA-mediated plant resistance against Pst DC3000.