Injectable self-assembled GDF5-containing dipeptide hydrogels for enhanced tendon repair.

Owing to the tissue characteristics of tendons with few blood vessels and cells, the regeneration and repair of injured tendons can present a considerable challenge, which considerably affects the motor function of limbs and leads to serious physical and mental pain, along with an economic burden on patients. Herein, we designed and fabricated a dipeptide hydrogel (DPH) using polypeptides P11-4 and P11-8. This hydrogel exhibited self-assembly characteristics and could be administered in vitro. To endow the hydrogel with differentiation and regeneration abilities, we added different concentrations of growth differentiation factor 5 (GDF5) to form GDF5@DPH. GDF5@DPH promoted the aggregation and differentiation of tendon stem/progenitor cells and promoted the regeneration and repair of tendon cells and collagen fibers in injured areas. In addition, GDF5@DPH inhibited inflammatory reactions in the injured area. Owing to its injectable properties, DPH can jointly inhibit adhesion and scar hyperplasia between tissues caused by endogenous inflammation and exogenous surgery and can provide a favorable internal environment for the regeneration and repair of the injured area. Overall, the GDF5@DPH system exhibits considerable promise as a novel approach to treating tendon injury.

The haplotype-resolved T2T genome of teinturier cultivar Yan73 reveals the genetic basis of anthocyanin biosynthesis in grapes.

Teinturier grapes are characterized by the typical accumulation of anthocyanins in grape skin, flesh, and vegetative tissues, endowing them with high utility value in red wine blending and nutrient-enriched foods developing. However, due to the lack of genome information, the mechanism involved in regulating teinturier grape coloring has not yet been elucidated and their genetic utilization research is still insufficient. Here, the cultivar 'Yan73' was used for assembling the telomere-to-telomere (T2T) genome of teinturier grapes by combining the High Fidelity (HiFi)， Hi-C and ultralong Oxford Nanopore Technologies (ONT) reads. Two haplotype genomes were assembled, at the sizes of 501.68 Mb and 493.38 Mb, respectively. In the haplotype 1 genome, the transposable elements (TEs) contained 32.77% of long terminal repeats (LTRs), while in the haplotype 2 genome, 31.53% of LTRs were detected in TEs. Furthermore, obvious inversions were identified in chromosome 18 between the two haplotypes. Transcriptome profiling suggested that the gene expression patterns in 'Cabernet Sauvignon' and 'Yan73' were diverse depending on tissues, developmental stages, and varieties. The transcription program of genes in the anthocyanins biosynthesis pathway between the two cultivars exhibited high similarity in different tissues and developmental stages, whereas the expression levels of numerous genes showed significant differences. Compared with other genes, the expression levels of VvMYBA1 and VvUFGT4 in all samples, VvCHS2 except in young shoots and VvPAL9 except in the E-L23 stage of 'Yan73' were higher than those of 'Cabernet Sauvignon'. Further sequence alignments revealed potential variant gene loci and structure variations of anthocyanins biosynthesis related genes and a 816 bp sequence insertion was found in the promoter of VvMYBA1 of 'Yan73' haplotype 2 genome. The 'Yan73' T2T genome assembly and comparative analysis provided valuable foundations for further revealing the coloring mechanism of teinturier grapes and the genetic improvement of grape coloring traits.

Biomass estimation and characterization of the nutrient components of thinned unripe grapes in China and the global grape industries.

The biomass of thinned unripe grape (TUR) was investigated and estimated in China and the world. In addition, the physicochemical parameters, nutritional and functional components and antioxidant activity of nine TUR and ripe grape fruit (RGF) samples were determined and analyzed. The results showed that about 1695.75 kt TUR was produced in China and as much as 14436.16 kt worldwide, which was closely related to the fruit thinning time. The total sugar and protein contents of TUR were significantly lower than those of RGF (p < 0.05), while the organic acids (especially tartaric acid and malic acid) and crude fiber of TUR were significantly higher than those of RGF (p < 0.05). Moreover, the total polyphenol, flavonoid, tannin and flavan-3-ols contents of TUR were 4.2-13.5, 3.6-12.3, 4.3-62.8 and 1.5-7.6 times those of RGF, respectively. Meanwhile, the antioxidant capacity of TUR was significantly higher than that of RGF, as well (p < 0.05). This study aimed to conduct in-depth research into the nutritional characteristics of TUR, propose the targeted direction for their further investigation and then lay a theoretical foundation from which the research findings could be applied in practice.

Diversity of epiphytic fungi on the surface of Kyoho grape berries during ripening process in summer and winter at Nanning region, Guangxi, China.

The two-harvest-per-year farming system allow table grape to be harvested a year both in summer and winter in southern China. Herein, we used high-throughput sequencing to investigate the diversity of fungi on grape fruits surface during the ripening process in summer and winter at subtropical Nanning region, Guangxi, China. The results showed that 23 fungal species existed in all samples. Among them, the five most dominant species were Cladosporium ramotenellum, Pseudozyma aphidis, Gyrothrix spp., Gibberella intricans and Acremonium alternatum, with abundance from 61.62 % to 91.26 %. Analysis using the student's t-test for Shannon index indicated that components of fungal community varied significantly between the two ripening seasons. The dominant genera of core fungal community were Cladosporium, Gyrothrix, Paramycosphaerella, Acremonium, Penicillium and Tilletiopsis in the summer and Cladosporium, Pseudozyma, Gibberella, Colletotrichum, Sporobolomyces, Rhodosporidium, Alternaria and Aspergillus in the winter. Overall, fungi diversity on grape fruits surface at Nanning showed significantly differences between different ripening seasons. Our results ennrich the understanding of epiphytic communities of grape fruits in subtropics.

Evolutionary, interaction and expression analysis of floral meristem identity genes in inflorescence induction of the second crop in two-crop-a-year grape culture system.

The fruitfulness of grapevines (Vitis viniferaL.) is determined to a large extent by the differentiation of uncommitted meristems, especially in the second-crop production of some varieties, where the intermediate of inflorescence and tendril accounts for a significant proportion in two-crop-a-year grape culture system. The differentiation of uncommitted lateral meristem was reported to be regulated by a network, whose backbone was composed of several floral meristem identity genes. In the present study, the phylogenetics of grape floral meristem identity genes with their orthologues in other species, and their conserved domain and interaction networks were analysed. In addition, the effects of chlormequat chloride and pinching treatments on the expression profiles of floral meristem identity genes and content of gibberellic acid (GAs) and zeatin riboside (ZR), as well as the ratio of ZR/GAs in buds that were used to produce the second crop, and the ratio of inflorescence induction of the second crop were studied in 'Summer Black'. The present results showed that floral meristem identity genes of grape and their orthologues in one or more among Malus domastic, Citrus sinensis, heobroma cacaoT, Nicotiana tabacum, Solanum lycopersicum and Glycine hirsutum, probably originated from a common ancestor. Interaction networks of six grape-floral meristem identity genes indicated that the inflorescence induction and floral development were regulated by one more complex network, and expression profiles of genes that involved in this network could be affected by each other. Expression profiles of eight floral meristem identity genes were affected by chlormequat chloride and pinching treatments, and higher expression levels of FT, TFL1A and TFL1B, as well as lower expression levels of LFY from 3 days before full bloom to 11 days after full bloom were thought to play important roles in promoting the formation of inflorescence primordial of the second crop, and higher expression levels of CAL A, SOC1 and TFL1A at 18 days after full bloom (DAF) could promote the development of inflorescence primordial. In addition, lower ratio of ZR/GAs at 3 days before full bloom and 4 days after full bloom could promote the formation of uncommitted lateral meristems in chlormequat chloride and pinching-treated plants, and higher ratio at 11 days after full bloom was the main reason for the formation of more inflorescences after chlormequat chloride treatment.

Dissecting the Variations of Ripening Progression and Flavonoid Metabolism in Grape Berries Grown under Double Cropping System.

A double cropping system has been commercially adopted in southern China, where there is abundant sunshine and heat resources. In this viticulture system, the first growing season normally starts as a summer cropping cycle; then, the vine is pruned and forced, resulting in a second crop in winter. Due to climate differences between the summer and winter growing seasons, grape ripening progression and flavonoid metabolism vary greatly. Here, the metabolites and transcriptome of flavonoid pathways were analyzed in grapes grown under two growing seasons at different stages. Notably, the winter cropping cycle strongly increased flavonoid levels by several times in comparison to summer grapes, while the summer season took a major toll on anthocyanin and flavonol accumulation, since the winter cropping greatly triggered the expression of upstream genes in the flavonoid pathway in a coordinated expression pattern. Moreover, the ratio of VviF3'5'Hs (flavonoid 3'5'-hydroxylase) to VviF3'Hs (flavonoid 3'-hydroxylase) transcript levels correlated remarkably well with the ratio of 3'5'-substituted to 3'-substituted flavonoids, which was presumed to control the flux of intermediates into different flavonoid branches. On the other hand, the phenological phase also varied greatly in the two crops. Compared to summer cropping, winter growing season accelerated the duration from budburst to veraison, therefore advancing the onset of ripening, but also prolonging the duration of ripening progression due to the purposes to harvest high-quality grapes. The differential expression pattern of hormone-related genes between the two cropping cycles might explain this phenomenon.

A high throughput method for rapid screening of chitosanase-producing fungal strain under acidic conditions.

A novel high-throughput method was established for rapid screening of a large numbers of Aspergillus fumigatus (A. fumigatus) mutants with high chitosanase production under acidic culture condition by exploiting the fact that iodine can be used as the indicator to stain chitosan but is ineffective for chitooligosaccharides. The mutant population was generated by irradiating A. fumigatus CICC 2434 with Co(60)-γ rays. Mutants were cultured on acidic plates containing colloidal chitosan and preliminary screened according to diameter of haloes formed around colonies. Then, chitosanase production of the isolates were verified by dinitrosalicylic acid assay. Lastly, molecular masses on enzymolysis products of isolated mutants were rapidly compared by aniline blue plate assay. Using this method, the mutant strain Co-8 was selected, which had chitosanase activity of 24.87 U/mL (increased by 369.2 % as compared to that of its parental strain).Taking together, the method is easy, efficient and particularly suited to rapid screen acidophilic fungal strains with high chitosanase-production.