Search

• Three kinds of preservatives (1-MCP, chitosan, Nata) were applied to jujube storage. • Comparison of different storage temperatures reflects the advantages of low temperature. • Comparison of different treatments shows the advantages of composite membrane treatment. The purpose of this study was to explore the effects of coating treatment using a composite of 1-methylcyclopropene (1-MCP), chitosan and natamycin (NATA) on the quality and antioxidant capacity of Chinese jujube (Zizyphus jujuba cv. Junzao) stored at different temperatures (Room temperature and 0 ± 1 °C). Respiration, ethylene release, and decay rates; Malondialdehyde (MDA); total phenol, flavonoid, and Ascorbic Acid (AsA) contents; Peroxidase (POD), Polyphenol Oxidase (PPO), Superoxide Dismutase (SOD), and Ascorbate Peroxidase (APX) activities; and free-radical scavenging ability were considered. The results showed that the low-temperature composite coating treatment of Chinese jujube effectively inhibits its decay and MDA accumulation; delays its respiration and ethylene release peaks; increases the activities of the antioxidant enzymes POD, SOD, and APX; and inhibits its PPO activity. Furthermore, the jujube retains its high concentrations of total phenols, flavonoids, and AsA as well as its free-radical-scavenging rate into the later storage period. Thus, the low-temperature composite coating treatment is an effective method for improving the postharvest quality of Chinese jujube and extending its preservation period. [ABSTRACT FROM AUTHOR]

• The mechanism of CPPU promoting grape fruiting was elucidated from two aspects, energy metabolism and respiratory metabolism. • Establish the relationship between CPPU and energy. • It provides new insights for the study of 'Kyoho' grape berry setting. The energy status, the level of respiration metabolism are improtant index reflecting plant growth state, participates in many growth processes. However, their relationship to berry setting remain unclear. In this study, the grape of 'kyoho' of CPPU [CPPU, N-(2-coloro-4-pyridinyl)-N-phenylurea] treated were used to measurement physiological indicators. The results showed that CPPU treatment reduced respiratory rate, reduced Cytochrome C oxidase (CCO) and ascorbic acid oxidase (AAO) activity, reduced NAD kinase (NADK) activity, maintained low nicotinamide adenine denucleotie phosphate (NADP) and nicotinamide adenine denucleotie phosphate reduced form (NADPH) levels, reduced nicotinamide adenine denucleotie (NADH) levels, and slowed down the reduction of energy charge. These results provided strong evidence that CPPU treatment promoted grape berry setting due to increased energy status, increased Embden-Meyerhof pathway (EMP) and the tricarboxylic acid (TCA) cycle respiratory metabolic pathways, decreased pentose phosphate pathway (PPP), and decreased CCO and AAO activity of respiratory terminal oxidase. [ABSTRACT FROM AUTHOR]

• VdGATA2 is specific expression and is inducible expression by powdery mildew, SA, MeJA and ETH in grapes. • VdGATA2 is localized in nucleus and has transcriptional activation activity in yeast. • VdGATA2 involved in plant disease resistance by H 2 O 2 pathway in Arabidopsis. The GATA transcription factor, composed of a type IV zinc finger (CX 2 CX 17–20 CX 2 C) and a highly alkaline region widely distributed in eukaryotes. In plants, nearly 30 plant GATA factors can be subdivided into four conservative and distinct groups: classes A through D. The first, AGTAs, were mainly studied in model plants, so our knowledge of them in grape species is quite limited. In this study, an A-GATA transcription factor, VdGATA2, isolated and characterized in Vitis davidii Tangwei which was found to contain one CX 2 CX 18 CX 2 C zinc finger in its C-terminal. The accumulation of VdGATA2 was rapidly induced by exogenous hormones and pathogens in grape. Transgenic VdGATA2 plants showed significantly improved resistance to powdery mildew disease. In transgenic Arabidopsis plants, the number of conidia of powdery mildew decreased compared with the wild Arabidopsis while the expression of PR1, the key gene in salicylic acid (SA) pathway, the concentration of hydrogen peroxide (H 2 O 2), and the catalase (CAT) enzyme activity all increased. After methyl viologen (MV), the contents of H 2 O 2 and malondialdenyde (MDA) reduced, whereas the activity of CAT and ascorbate (APX) increased. Therefore, according to these results, VdGATA2 benefitted transgenic Arabidopsis plants in two ways: by preventing oxidative damage and enhancing their resistance to powdery mildew. [ABSTRACT FROM AUTHOR]

• Compound treatment (1-MCP+chitosan) was applied to the storage and preservation of jujube fruit. • The effect of composite treatment is better than that of single treatment of chitosan and 1MCP. • The compound treatment can effectively improve the activity of antioxidant enzymes and delay the senescence of fruit. • Compound treatment has a great contribution to prolong the storage and fresh-keeping period of jujube fruit. The purpose of this study was to investigate the effects of 1-methylcyclopropene (1-MCP) and chitosan treatment on the storage of Xinjiang jujube fruit at 0 ± 1 °C (relative humidity 90 %–95 %) for 42 d. Indicators such as rotting rate, firmness, and soluble solids as well as peroxidase (POD), polyphenol oxidase (PPO), lipoxygenase (LOX), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities were measured. The results showed that 1-MCP or chitosan treatment alone inhibits rotting, delays the decline of soluble solids, maintains fruit firmness, and inhibits the accumulation of malondialdehyde. Furthermore, the activities of antioxidant enzymes such as POD, SOD, CAT, and APX are increased, while those of PPO and LOX are inhibited. However, the effect of 1-MCP and chitosan together is superior to that of 1-MCP or chitosan treatment alone. In conclusion, our results indicate that combined 1-MCP and chitosan treatment is an effective strategy for improving the postharvest quality and prolonging the shelf life of Xinjiang jujube fruit. [ABSTRACT FROM AUTHOR]

• VvbZIP60 is constitutively expressed and can be induced by pathogens, SA, JA in grapes. • VvbZIP60 is localized in the nucleus and has transcriptional activation activity. • VvbZIP60 contributes to disease resistance and activation of SA pathway in Arabidopsis. Powdery mildew is a fungus that causes major losses in grape production worldwide. Recent studies demonstrate bZIP transcription factors (TFs) play an important role in plant defense against fungal pathogens. To investigate whether one or more bZIP TFs is involved in the common grapevine's defense against powdery mildew, which could provide candidate genes for breeding powdery mildew-resistant grape plants, we isolated its VvbZIP60 gene and analyzed its functional role in plants against powdery mildew. Amino acid sequence alignment and phylogenetic analysis indicated that VvbZIP60 is a U member of the bZIP gene family and is similar to AtbZIP60 of Arabidopsis. The gene expression profile of the 'Jing Xiu' variety of grape (Vitis vinifera) showed that the VvbZIP60 transcript accumulated in various tissues (especially leaves) and could quickly accumulate when this plant was treated with exogenous pathogen (PA), 1 1 Abbreviations: DAPI, 4',6-diamidino-2-phenylindole; GFP, green fluorescent protein; HPI, hours post-inoculation; JA, jasmonic acid; MeJA, methyl jasmonate; OE, overexpressing plants; PA, pathogen; PR1, pathogenesis related 1; PDF1.2, plant defensin 1.2; SA, salicylic acid; SAR, systemic acquired resistance; TFs, transcription factors; WT, wild type. salicylic acid (SA) and jasmonic acid (JA). VvbZIP60 was found localized to the nucleus and has transcriptional activation in yeast. Crucially, overexpression of VvbZIP60 increased Arabidopsis resistance to powdery mildew. Transgenic plants accumulated SA and up-regulated their expression of the pathogenesis related 1 (PR1) gene involved in the SA-signaling pathway. Taken together, these results show that VvbZIP60 is a positive regulator of resistance to fungal disease and contributes importantly to SA signaling against powdery mildew. [ABSTRACT FROM AUTHOR]

• Hydrogen peroxide (H 2 O 2) treatment improves K+ uptake in grapes. • H 2 O 2 treatment activates flavonoid biosynthesis pathway. • H 2 O 2 changes ethylene signaling to promote K+ uptake by regulating K+ transporters. Potassium ion (K+) is an essential nutrient for plants. Grapes are an important industrial crop with an extremely high demand for potassium. However, potassium deficiency occurs frequently in viticulture and greatly restricts the grape industry. Developing a technique to improve potassium uptake efficiency is of vital importance for grapes. In this study, we found that hydrogen peroxide (H 2 O 2) treatment could improve K+ uptake in grapes. To determine the mechanisms underlying H 2 O 2 -induced K+ uptake, transcriptome sequencing (RNA-seq) was conducted and the differentially expressed genes were further analyzed. Gene Ontology (GO) enrichment indicated that ion transport-related pathways and genes changed after H 2 O 2 treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and weighted gene co-expression network analysis (WGCNA) showed that the flavonoid biosynthesis pathway was closely related to H 2 O 2 -induced K+ uptake, and H 2 O 2 treatment could activate the flavonoid biosynthesis pathway. Further analysis demonstrated that H 2 O 2 treatment could activate ethylene synthesis and the ethylene signaling pathway, which promoted K+ uptake by regulating K+ transporter genes. Overall, this study demonstrates a new technique, H 2 O 2 treatment, for enhancing potassium uptake efficiency in grapes and reveals the molecular mechanisms underlying H 2 O 2 -induced K+ uptake. [ABSTRACT FROM AUTHOR]

Highlights • Azacitidine (5-azaC) could promote the early ripening of the grape. • The treatment of 100 μM 5-azaC reduced the level of DNA methylation during the development of 'Kyoho' grape berries. • The ROS metabolic activities and related physiological indexes in berries treated with 5-azaC were also investigated. • There was a connection between ROS metabolism and DNA methylation during the grape berry development. Abstract DNA methylation has been proved to function in fruit ripening. The different concentrations of azacitidine (5-azaC), an inhibitor of methyltransferase, were sprayed on 'Kyoho' grape berries to explore the changes of DNA methylation, the effect of 5-azaC on berry ripening, and the relationship between DNA methylation and reactive oxygen species (ROS) metabolism during the grape berry development. The results showed that the treatment of 100 μM 5-azaC could promote the berry ripening of 'Kyoho' 20 days earlier than the control. The assessment of methylation by methylation sensitive amplification polymorphism (MSAP) markers after the treatment of 100 μM 5-azaC, demonstrated that the methylation rate of the treatment was all lower than the control at any berry development periods. 5-azaC treatments influenced the ROS metabolic activities and related physiological indexes of berries. The sucrose and soluble solid content of 5-azaC-treated berries were significantly higher than control at 75 dpa. The change trend of H 2 O 2 content of the control was similar with the 100 μM 5-azaC treatment. All treatments enhanced rates of superoxide anion (O 2 −) production. Superoxide dismutase (SOD) activity in treated berries were higher than the control and had significant difference with the control at 35 dpa. The results demonstrated that 5-azaC could accelerate grape berries ripening, and there was a connection between ROS metabolism and DNA methylation during the grape berry development. [ABSTRACT FROM AUTHOR]

Highlights • The early ripening derived varieties of Pearl of Csaba were analyzed based on SSR markers. • The inheritance of early ripening trait was investigated at the DNA level. • Three markers were steadily transmitted from Pearl of Csaba to its descendants. Abstract In order to dissect the inheritance of the grapevine early ripening trait, Pearl of Csaba, 32 derived varieties of Pearl of Csaba and 5 other parents for the breeding of the derived varieties were analyzed based on the SSR (Simple Sequence Repeats) markers. Fifty SSR markers evenly distributed on 19 chromosomes of grapevine were initially employed and only 36 markers could transmit to all the descendants of four generations. Then, the false positive loci were excluded by tracing the high steadily transmitted loci in one consecutive line including three generation varieties (11 markers left), comparing to the other 5 medium and late ripening parents used in the formation of the descendants (8 markers left), considering the stability of the inheritance frequency from the generations to generations (3 markers left) and three SSR markers, VVMD5, VVMD32 and VMC4F8 were identified as the candidate. These three markers could be stably inherited in four generations and their inheritance frequency, genetic contribution rate and allele frequency were all above 40%, 70% and 0.4, respectively. The genomic loci corresponding to these markers and their adjacent chromosomal regions may be associated with the inheritance of early ripening trait in the derived varieties of Pearl of Csaba. [ABSTRACT FROM AUTHOR]

• Grapevine plants were dwarfed by Chlormequat chloride (CCC). • Transcriptome data analysis showed that VviEXPA7 plays an important role. • The high expression of VviRAP2.12 transcription factor suppressed the expression of VviEXPA7 after CCC treatment, which led to the inhibition of cell elongation and plant dwarfing. Treatment with chlormequat chloride (CCC) can lead to dwarfism, which has been studied in many plants. However, the underlying molecular mechanisms have been less studied. Herein, the phenotypic changes and gene expression levels of grapevine in response to CCC were investigated. Results showed that the height of grape plants became significantly shorter after CCC treatment, especially between the first two stems above the roots. Transcriptome sequencing was then performed and analyzed, 120 differentially expressed genes (DEGs) were detected in the stems after CCC treatment compared to the control. The gene ontology (GO) enrichment results showed that processes such as cellulose synthase (UDP-forming) activity, regulation of the auxin-mediated signaling pathway, and the cellulose biosynthetic process were common. In addition, weighted gene co-expression network analysis (WGCNA) identified the strong correlation between the MEbrown module and stem development. VviEXAP7 was selected from the genes belonging to key GO pathways and WGCNA modules. The quantitative real-time PCR (qRT-PCR) results showed that VviEXPA7 was significantly downregulated because of the CCC treatment. Additionally, analysis of VviEXPA7 promoter activity showed that VviEXPA7 activated GUS gene expression, and was induced by CCC, abscisic acid (ABA), and other hormones. VviEXPA7 was used as a target gene for transcription factor prediction, and after employing the PlantTFDB and JASPAR databases, VviRAP2.12 was identified as a transcription factor that might regulate VviEXPA7. qRT-PCR revealed that VviRAP2.12 was significantly upregulated after CCC treatment. Finally, the interaction between VviEXPA7 and VviRAP2.12 was verified by the dual-luciferase assay. Thus, the current study shows that CCC decreased the expression of the cell growth-related gene VviEXPA7 by promoting the expression of VviRAP2.12, which resulted in dwarfed plants. This study generated new information that will increase our understanding of the mechanism of action of CCC and provides a scientific basis for simplified cultivation of grapes. [ABSTRACT FROM AUTHOR]

• Six genes are determined as proline biosynthesis- or proline catabolism-related genes in grapevines. • P5CS1, OAT, PDH and P5CDH can be significantly induced by osmotic and oxidative stresses. • Proline is greatly accumulated under abiotic stresses, especially osmotic and oxidative stresses. • Proline biosynthesis and proline catabolism-related genes synergistically regulate proline accumulation in response to abiotic stresses. Proline is an important osmotic regulator for plants under abiotic stresses. Proline accumulation is regulated by various enzymes, while genes encoding these enzymes have not been fully investigated in grapevines. In this study, we identified four proline biosynthesis-related genes (P5CS1, P5CS2, P5CR and OAT) and two proline catabolism-related genes (PDH and P5CDH) from grapevines, and conducted bioinformatics analysis including protein characteristic, gene structure, phylogenetic relationship and cis-acting element of promoters. Promoter analysis found that cis-acting elements related to stress and phytohormone responsiveness were present in the promoters of these genes. Tissue-specific expression analysis of these genes indicated that P5CS2, OAT and PDH expressed highly in flower, and P5CS1, P5CR and P5CDH had highest expression levels in tendril, berry and leaf respectively. Expression patterns of these genes under abiotic stresses revealed that P5CS1, OAT and PDH could be significantly induced by salt, dehydration, PEG and H 2 O 2 treatments, and P5CDH was significantly suppressed under these stress treatments. By measuring proline accumulation in grapevines, we found that proline content dramatically increased after treatments of salt, dehydration, PEG and H 2 O 2. Our results revealed the molecular responses (especially P5CS1, OAT, PDH and P5CDH) in the proline metabolism pathway to osmotic and oxidative stresses in grapevines, demonstrating that proline synthesis and proline catabolism synergistically regulate proline accumulation in response to abiotic stresses. [ABSTRACT FROM AUTHOR]

• Overexpression of VvZFP11 improves powdery mildew resistance in grapes. • The PME element of the VvZFP11 gene is essential for its function. • The VvZFP11 gene enables plants to acquire resistance by affecting the salicylic acid signaling pathway. VvZFP11 is up-regulated by powdery mildew (PM), methyl jasmonate (MeJA), and salicylic acid (SA) treatment, yet the underlying transcriptional regulatory mechanism remains unclear. Here, we demonstrate that a powdery mildew response element (PME) in the VvZFP11 promoter is important for countering the challenge to grapevine from PM, in which the defensive and stress response element (GTAAGGAAAC) is critical for specific responsiveness to SA, MeJA, and PM. Analysis of VvZFP11 promoter activity showed that VvZFP11 can activate GUS gene expression. SA induced VvZFP11 's expression, while VvZFP11 responded swiftly to PM. Analysis of cis- acting elements revealed that VvZFP11 contained diverse elements related to plant responses to biotic/abiotic stresses. Further experiments revealed PME in the VvZFP11 promoter was crucial for responding to PM. The PME and MV35S core promoters were fused and constructed into a single promoter, then inserted directionally into VvZFP11-GUS's upstream region to obtain a fusion construct. VvZFP11 transcript levels were significantly suppressed in transgenic plants with mutant PEM element after their inoculation with PM (based on Fig. 6). RT-qPCR results indicated the genes AtPR1, AtNPR1, AtPDF1.2 , and AtCOI , these related to SA and MeJA, were down-regulated in transgenic plants. The results also confirmed the defensive and stress response element in PME is a key component for the VvZFP11 promoter's function and that VvZFP11 enables plants to gain resistance to PM via the SA pathways. [ABSTRACT FROM AUTHOR]

• Transcriptome analysis shows the responsive pathways to K + deficiency in grapevines. • Ethylene signal (especially ERFs) are activated after K + deficiency. • Cell wall biosynthesis in roots is inhibited after K + deficiency. • Photosynthesis in shoots is inhibited after K + deficiency. • Ion transporters are induced by K + deficiency. Grapevine is sensitive to potassium (K +) deficiency, while its underlying responsive mechanisms are unknown. In this study, transcriptome profiling of grapevine seedlings under K + deficiency conditions over a time course were investigated. Morphological measurements showed that K + deficiency inhibited the normal growth of grapevine seedlings. RNA-sequencing (RNA-seq) was performed with samples of roots and shoots collected under K + deficiency and normal conditions, and numerous differentially expressed genes (DEGs) induced by K + deficiency were identified, including some ion transporter genes, ethylene-responsive transcription factor (ERF) genes, and cell wall biosynthesis-related genes. In roots, by functional and regulatory pathway analysis, genes in ethylene signal (especially ERF) and in cell wall biosynthesis pathway were upregulated and downregulated, respectively, indicating that ethylene signal was activated, while cell wall biosynthesis was inhibited under K + deficiency treatment. And in shoots, genes in ethylene signal and in photosynthesis pathway were upregulated and downregulated, respectively, revealing that ethylene signal was activated, while photosynthesis was suppressed under K + deficiency treatment. Analysis of transcription factors indicated that ERF family extensively involved in the response to K + deficiency. Taken together, this study reveals the multiple molecular responses, including ethylene signal, ion homeostasis, and other metabolic pathways, to K + deficiency treatment in grapevines. [ABSTRACT FROM AUTHOR]

• The intersection of the variants detected by 'Kyoho' vs 'Fengzao' and 'Zana' vs '90–1′ with Genome Analysis Tool Kit (GATK) and samtools were taken. • The candidate genes located in the QTL regions were screened. • Five of the SNPs were verified. Single nucleotide polymorphisms (SNPs), insertion-deletion mutations (InDels) and structural variation (SV) play an important role in the generation of mutant genotypes. In this study, we conducted whole genome resequencing analysis of 'Kyoho', 'Zana' and their early-ripening bud sports, 'Fengzao' and '90–1′, respectively, to identify variants related to the early ripening trait. First, we determined the variants between 'Kyoho' vs. 'Fengzao' and 'Zana' vs. '90–1′ comparison groups using Genome Analysis Tool Kit (GATK) and samtools. Then, 324 genes harboring 1,135 SNPs and InDels were identified, based on sequencing depth and variant allele frequency. We also detected 39,112 and 35,825 SVs specific to 'Fengzao' and '90–1′, based on their comparison with 'Kyoho' and 'Zana' sequence data, respectively. Among these SVs, 89 were common to both 'Fengzao' and '90–1′. Then, variants were found in the coding sequences (CDSs) or upstream regions of 204 genes, of which 96 mapped to early ripening-related quantitative trait loci (QTLs). Subsequently, transcriptome analysis of 'Kyoho' and 'Fengzao' genotypes at four development stages revealed that 69 genes affected by variants were differentially expressed at one or more time points. Finally, five SNPs were validated in 'Kyoho' and 'Fengzao' by Sanger sequencing. Overall, abundant genetic variation was detected in 'Kyoho' and 'Fengzao' genomes, which may play a role in their early ripening phenotype. [ABSTRACT FROM AUTHOR]