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'Ganlv 1' is a new cultivar of Actinidia eriantha selected from the wild natural population, which has the advantages of moderate taste, high yield, easy peeling and high ascorbic acid (AsA) content. In this study, 'Ganlv 1' was used to explore the changes in fruit quality, soluble sugar components, sucrose metabolism-related enzymes activities and sucrose metabolism-related enzyme genes' expression during the fruit's development. The results showed that, except for AsA, the changes in the fruit quality index and fruit growth and development during the development of 'Ganlv 1' basically exhibited the same trend. The fruit shape index was different in the different development stages of the fruit, and tended to be stable with fruit growth and development. The dynamic changes of the dry matter content indicated that the best time for fruit harvest was about 160 days after full bloom. The main sugar components in the fruit were fructose, glucose and sucrose, and sucrose and glucose were the main sugars in the soft-ripening stage. The trend of sucrose accumulation, the activities of the sucrose metabolism-related enzymes and the expression of the sucrose metabolism-related genes indicated that 130–145 days after full bloom (DAFB) might be the critical period of sucrose metabolism. The results are of great significance for clarifying the developmental characteristics and dynamic changes in the sugar components in A. eriantha fruits, and lay a foundation for further studying of the mechanism of sugar metabolism in A. eriantha. [ABSTRACT FROM AUTHOR]

Abstract Background NAC transcription factors (TFs) are plant-specific proteins encoded by a large gene family. They play important roles in diverse biological processes, such as plant growth and development, leaf senescence, and responses to biotic or abiotic stresses. Functions of a number of NAC TFs have been identified mainly in model plants. However, very few studies on NAC TFs have been conducted in the fruit tree of kiwifruit. Results Genome-wide NAC genes were identified and their phylogeny, genomic structure, chromosomal location, synteny relationships, protein properties and conserved motifs were analyzed. In addition, the fruit developmental process was evaluated in a new kiwifruit cultivar of Actinidia eriantha ‘Ganlu 1’. And expressions for all those NAC genes were analyzed by quantitative real-time PCR method in fruits of ‘Ganlu 1’ during its developmental process. Our research identified 142 NAC TFs which could be phylogenetically divided into 23 protein subfamilies. The genomic structures of those NAC genes indicated that their exons were between one and ten. Analysis of chromosomal locations suggested that 116 out of 142 NACs distributed on all the 29 kiwifruit chromosomes. In addition, genome-wide gene expression analysis showed that expressions of 125 out of 142 NAC genes could be detected in fruit samples. Conclusion Our comprehensive study provides novel information on NAC genes and expression patterns in kiwifruit fruit. This research would be helpful for future functional identification of NAC genes involved in kiwifruit fruit development.

‘Ganlv 1’ is a new cultivar of Actinidia eriantha selected from the wild natural population, which has the advantages of moderate taste, high yield, easy peeling and high ascorbic acid (AsA) content. In this study, ‘Ganlv 1’ was used to explore the changes in fruit quality, soluble sugar components, sucrose metabolism-related enzymes activities and sucrose metabolism-related enzyme genes’ expression during the fruit’s development. The results showed that, except for AsA, the changes in the fruit quality index and fruit growth and development during the development of ‘Ganlv 1’ basically exhibited the same trend. The fruit shape index was different in the different development stages of the fruit, and tended to be stable with fruit growth and development. The dynamic changes of the dry matter content indicated that the best time for fruit harvest was about 160 days after full bloom. The main sugar components in the fruit were fructose, glucose and sucrose, and sucrose and glucose were the main sugars in the soft-ripening stage. The trend of sucrose accumulation, the activities of the sucrose metabolism-related enzymes and the expression of the sucrose metabolism-related genes indicated that 130–145 days after full bloom (DAFB) might be the critical period of sucrose metabolism. The results are of great significance for clarifying the developmental characteristics and dynamic changes in the sugar components in A. eriantha fruits, and lay a foundation for further studying of the mechanism of sugar metabolism in A. eriantha.

Background: NAC transcription factors (TFs) are plant-specific proteins encoded by a large gene family. They play important roles in diverse biological processes, such as plant growth and development, leaf senescence, and responses to biotic or abiotic stresses. Functions of a number of NAC TFs have been identified mainly in model plants. However, very few studies on NAC TFs have been conducted in the fruit tree of kiwifruit. Results: Genome-wide NAC genes were identified and their phylogeny, genomic structure, chromosomal location, synteny relationships, protein properties and conserved motifs were analyzed. In addition, the fruit developmental process was evaluated in a new kiwifruit cultivar of Actinidia eriantha 'Ganlu 1'. And expressions for all those NAC genes were analyzed by quantitative real-time PCR method in fruits of 'Ganlu 1' during its developmental process. Our research identified 142 NAC TFs which could be phylogenetically divided into 23 protein subfamilies. The genomic structures of those NAC genes indicated that their exons were between one and ten. Analysis of chromosomal locations suggested that 116 out of 142 NACs distributed on all the 29 kiwifruit chromosomes. In addition, genome-wide gene expression analysis showed that expressions of 125 out of 142 NAC genes could be detected in fruit samples. Conclusion: Our comprehensive study provides novel information on NAC genes and expression patterns in kiwifruit fruit. This research would be helpful for future functional identification of NAC genes involved in kiwifruit fruit development. [ABSTRACT FROM AUTHOR]

Studies on organic acid metabolism have been mainly concentrated on the fruit, whereas, few have focused on the mechanism of high organic acids content in the fruit of Actinidia eriantha. Fruits of ‘Ganmi 6’ harvested at eleven developmental periods were used as materials. The components and content of organic acids were determined by high-performance liquid chromatography (HPLC) system, the activities of the related enzyme were detected, and gene expression levels were measured by quantitative real-time PCR (qRT-PCR). Components of ascorbic acid (AsA) and eight kinds of organic acids were detected. These results showed that quinic acid and citric acid were the main organic acids in the fruit of ‘Ganmi 6’. Correlation analysis showed that NADP-Quinate dehydrogenase (NADP-QDH), NADP-Shikimate dehydrogenase (NADP-SDH), and Cyt-Aconitase (Cyt-Aco) may be involved in regulating organic acids biosynthesis. Meanwhile, the SDH gene may play an important role in regulating the accumulation of citric acid. In this study, the activities of NADP-SDH, Mit-Aconitase (Mit-Aco), and NAD-Isocitrate dehydrogenase (NAD-IDH) were regulated by their corresponding genes at the transcriptional level. The activity of Citrate synthase (CS) may be affected by post-translational modification. Our results provided new insight into the characteristics of organic acid metabolism in the fruit of A. eriantha.

Ethnopharmacological relevance The roots of Actinidia eriantha Benth have been used clinically to treat a variety of cancers in traditional Chinese medicine. The polysaccharide from this drug (AEPS) was previously reported to be a potential antitumor agent with immunomodulatory activity. However, the mechanisms of its antitumor action in immunomodulation have not yet been well-defined. Aim of the study To investigate the effects of AEPS on the phenotypic and functional maturation of dendritic cells and to explore the intracellular signaling mechanisms of its antitumor action in the immunomodulation. Materials and methods The effects of AEPS on the phagocytic activity, expression of surface molecules, mRNA and protein expression levels of cytokines and chemokines in mouse bone-marrow derived dendritic cells (BMDCs) were determined by flow cytometry, qRT-PCR and ELISA, respectively. The transcriptional profile induced by AEPS was established using oligonucleotide microarray, and Ingenuity Pathway Analysis (IPA) was used to identify potential signaling pathways. Western blotting, neutralization experiments and inhibition assay were performed to confirm signaling pathway involved in maturation of DCs induced by AEPS. Furthermore, we discussed the downstream effects of the action of AEPS using clustering, network and pathway mapping approaches. Results AEPS could significantly reduced phagocytic activity, promoted expression of accessory and co-stimulatory molecules, and up-regulated the mRNA and protein expression levels of cytokines and chemokines in BMDCs. Microarray assay revealed that AEPS induced significantly differential expression of 452 genes including up-regulated cytokines (IL-6, IL-1β, TNF-α, IL-10, IL-12p40, IFN-β and IFN-γ), chemokines (MIP-1α, MIP-1β, CCL5, MDC and MCP-1), transcription factors (STAT1, STAT2, STAT5b, IRF1 and IRF7) and pattern recognition receptors (TLR3, DDX58, DHX58 and IFIH1) in the BMDCs. AEPS-induced production of TNF-α and IL-12p40 from BMDCs was inhibited by antibodies against TLR2 and TLR4. Furthermore, AEPS induced the phosphorylation of NF-κB p65 in a time-dependent manner, and BAY 11-7082, an inhibitor of NF-κB, remarkably suppressed the production of cytokines induced by AEPS. Conclusion AEPS triggers the phenotypic and functional maturation of DCs via TLR2/4 and NF-κB signaling pathway, resulting in augmented antitumor immune responses. Our results suggested that AEPS might be helpful in potentiating the efficiency of DC-based cancer immunotherapy. This study further expanded current knowledge on the mechanisms of antitumor action of AEPS. [ABSTRACT FROM AUTHOR]

Studies on organic acid metabolism have been mainly concentrated on the fruit, whereas, few have focused on the mechanism of high organic acids content in the fruit of Actinidia eriantha. Fruits of 'Ganmi 6' harvested at eleven developmental periods were used as materials. The components and content of organic acids were determined by high-performance liquid chromatography (HPLC) system, the activities of the related enzyme were detected, and gene expression levels were measured by quantitative real-time PCR (qRT-PCR). Components of ascorbic acid (AsA) and eight kinds of organic acids were detected. These results showed that quinic acid and citric acid were the main organic acids in the fruit of 'Ganmi 6'. Correlation analysis showed that NADP-Quinate dehydrogenase (NADP-QDH), NADP-Shikimate dehydrogenase (NADP-SDH), and Cyt-Aconitase (Cyt-Aco) may be involved in regulating organic acids biosynthesis. Meanwhile, the SDH gene may play an important role in regulating the accumulation of citric acid. In this study, the activities of NADP-SDH, Mit-Aconitase (Mit-Aco), and NAD-Isocitrate dehydrogenase (NAD-IDH) were regulated by their corresponding genes at the transcriptional level. The activity of Citrate synthase (CS) may be affected by post-translational modification. Our results provided new insight into the characteristics of organic acid metabolism in the fruit of A. eriantha. [ABSTRACT FROM AUTHOR]

Studies on anthocyanin biosynthesis have been mainly concentrated on the fruit, whereas few have focused the mechanism of flower coloration in kiwifruit. Here, we report that the structural gene, AeCHS, is involved in anthocyanin accumulation and indispensable for normal petal coloration in Actinidia eriantha. Petals from three different species including Actinidia eriantha (red petals), Actinidia hemsleyana (light pink petals) and Actinidia arguta (white petals) were selected for anthocyanin determination and gene expression analysis. The anthocyanin components in A. eriantha were significantly higher than in A. hemsleyana or A. arguta. Consistently, gene expression profiles suggested that AeCHS expression in A. eriantha was higher than in A. hemsleyana or A. arguta. Cluster analysis showed that AeCHS was clustered into a single group and distinctly separated from other genes, indicating the expression pattern of AeCHS gene was different from any other. Additionally, correlation analysis revealed AeCHS expression significantly correlated with anthocyanin content. The complete coding sequence of AeCHS was cloned from petals of A. eriantha 'Zaoxu', showing the length of AeCHS was 1170 bp encoding a protein of 389 amino acids. AeCHS was located in the cytoplasm, indicating it is indeed a structural gene involved in anthocyanin biosynthesis. AeCHS silencing performed by infiltration grafting-mediated virus-induced gene silencing (VIGS) reduced petal anthocyanin content and bleached red petals in A. eriantha. Our results confirm a crucial role of AeCHS in anthocyanin biosynthesis and accumulation in A. eriantha petals; furthermore, they offer important basic information and constitute a reference point for further research. [ABSTRACT FROM AUTHOR]

• Bagging treatments did not affect the content of soluble solid, dry matter, soluble sugar and titrable acid. • Bagging significantly improve fruit appearance and flesh color, reduced the content of chlorophyll, carotenoid and AsA. • Different expression of GalLDH , GalUR and DHAR was the key factors for decrease of AsA after bagging. Three lines of Actinidia eriantha with high AsA content were used to determine the effects of bagging and control (never bagged) on fruit external and internal qualities, as well as transcript levels for key genes involved in ascorbic acid (AsA) synthesis. Compared with the control, there was no significant difference between bagging and control in soluble solid, dry matter, soluble sugar and titrable acid, but bagging would significantly improve fruit appearance and flesh color, reduced the content of chlorophyll, carotenoid and AsA. The key gene expression involved in AsA synthesis showed that the expressions of GME , GMP , GGP , GPP and GalDH in bagging were inconsistent with the control on three lines. Whereas GalLDH , GalUR and DHAR had the same expression trend and significantly lower than the control. Therefore, we speculated that the different expression of GalLDH , GalUR and DHAR was the key factors for decrease of AsA after bagging. Bagging on A. eriantha can effectively improve the appearance and flesh color of the fruit, improve the ornamental value of the fruit, and has little effect on the sugar and acid content of the fruit. Although the AsA content was reduced, the AsA content (>1250 mg/100 g) was still at a high level. [ABSTRACT FROM AUTHOR]