Fig fruit firmness decreases rapidly during ripening and after harvest, resulting in poor storability and transportation loss, which severely restricts development of the fresh fig industry. APETALA2/ethylene-responsive factor (AP2/ERF) transcription factors are downstream components of the ethylene-signaling pathway that play crucial roles in quality formation during fruit ripening. In this study, Ficus carica (Fc) ERF12 was clustered in repressor subfamily VIII of ERFs through phylogenetic analysis, and further recruited by its two EAR motifs and expression pattern during fig ripening. DNA affinity purification sequencing analysis indicated that FcERF12 binds to the promoter or gene body regions of multiple ripening-related genes, including cell wall-modification genes FcPG, FcXTH and FcPME, and ethylene-biosynthesis genes FcACS and FcACO. Yeast two-hybrid assay demonstrated that FcERF12 interacts with TOPLESS (TPL) co-repressors FcTPL1, FcTPL4 and FcTPL5, and histone deacetylases FcHDA6 and FcHDA19; interaction with FcTPL4 and FcTPL5 relied on the C-terminal EAR motif. Overexpressing FcERF12 in tomato did not change fruit size or yield, but resulted in an 18.37% increment in fruit firmness and a 49.62% reduction in ethylene-release rate at fruit ripening, accompanied by a significant decrease in seed number per fruit. Transcriptomic analysis revealed downregulation of tomato cell wall-modification genes SlPL, SlEXP and SlPG, and ethylene-synthesis genes SlACO and SlACS. Metabolomic profiling identified 82 differentially accumulated flavonoid metabolites, 61 of them showing significantly decreased contents. Taken together, our results exhibit the negative regulatory role of FcERF12 in fig ethylene-signal transduction, providing new information on precise control of fruit firmness and other quality traits at ripening.
Bioprospecting of more novel probiotic strains has attained continuous interest. This study aimed to investigate the beneficial effects of Lactobacillus paracasei strain L14, an isolate from a traditional Chinese dairy product, on type 2 diabetes mellitus (T2DM) rats. Preventive supplementation of strain L14 showed excellent anti-diabetic effects on high-fat diet/low-dose streptozotocin (HFD/STZ)-induced T2DM rats. It significantly reduced hyperglycemia, protected pancreatic β-cell and liver function, and ameliorated oxidative stress while considerably improving dyslipidemia and inflammation. Furthermore, the strain modulated the gut microbiota to alleviate gut dysbiosis. Interestingly, most of these biochemical parameters could even restore to normal levels by the intervention of strain L14. The whole-genome sequencing of L14 was performed to provide a critical molecular basis for its probiotic activities. Genes related to antioxidant systems and other beneficial microbial metabolites like exopolysaccharides (EPS) biosynthesis were found. This study demonstrates that probiotic L. paracasei L14 has good potential for applications in functional food and pharmaceutical industries.
Insects and animals are attracted to, and feed on ripe fruit, thereby promoting seed dispersal. As a vital vitamin and nutrient source, fruit make up an indispensable and enjoyable component of the human diet. Fruit ripening involves a series of physiological and biochemical changes in, among others, pigmentation, chlorophyll (Chl) degradation, texture, sugar accumulation, and flavor. Growing evidence indicates that the coordinated and ordered trait changes during fruit ripening depend on a complex regulatory network consisting of transcription factors, co-regulators, hormonal signals, and epigenetic modifications. As one of the predominant transcription factor families in plants and a downstream component of ethylene signaling, more and more studies are showing that APETALA2/ethylene responsive factor (AP2/ERF) family transcription factors act as critical regulators in fruit ripening. In this review, we focus on the regulatory mechanisms of AP2/ERFs in fruit ripening, and in particular the recent results on their target genes and co-regulators. We summarize and discuss the role of AP2/ERFs in the formation of key fruit-ripening attributes, the enactment of their regulatory mechanisms by interaction with other proteins, their role in the orchestration of phytohormone-signaling networks, and the epigenetic modifications associated with their gene expression. Our aim is to provide a multidimensional perspective on the regulatory mechanisms of AP2/ERFs in fruit ripening, and a reference for understanding and furthering research on the roles of AP2/ERF in fruit ripening.
Fruit flesh cell vacuoles play a pivotal role in fruit growth and quality formation. In the present study, intact vacuoles were carefully released and collected from protoplasts isolated from flesh cells at five sampling times along fig fruit development. Label-free quantification and vacuole proteomic analysis identified 1,251 proteins, 1,137 of which were recruited as differentially abundant proteins (DAPs) by fold change >= 1.5, P < 0.05. DAPs were assigned to 10 functional categories; among them, 238, 186, 109, 93 and 90 were annotated as metabolism, transport proteins, membrane fusion or vesicle trafficking, protein fate and stress response proteins, respectively. Decreased numbers of DAPs were uncovered along fruit development. The overall changing pattern of DAPs revealed two major proteome landscape conversions in fig flesh cell vacuoles: the first occurred when fruit developed from late-stage I to mid-stage II, and the second occurred when the fruit started ripening. Metabolic proteins related to glycosidase, lipid and extracellular proteins contributing to carbohydrate storage and vacuole expansion, and protein-degrading proteins determining vacuolar lytic function were revealed. Key tonoplast proteins contributing to vacuole expansion, cell growth and fruit quality formation were also identified. The revealed comprehensive changes in the vacuole proteome during flesh development were compared with our previously published vacuole proteome of grape berry. The information expands our knowledge of the vacuolar proteome and the protein basis of vacuole functional evolution during fruit development and quality formation.
The basic helix–loop–helix (bHLH) transcription factor family is the second largest transcription factor family in plants, and participates in various plant growth and development processes. A total of 118 bHLH genes were identified from fig (Ficus carica L.) by whole-genome database search. Phylogenetic analysis with Arabidopsis homologs divided them into 25 subfamilies. Most of the bHLHs in each subfamily shared a similar gene structure and conserved motifs. Seventy-two bHLHs were found expressed at fragments per kilobase per million mapped (FPKM) > 10 in the fig fruit; among them, 15 bHLHs from eight subfamilies had FPKM > 100 in at least one sample. bHLH subfamilies had different expression patterns in the female flower tissue and peel during fig fruit development. Comparing green and purple peel mutants, 13 bHLH genes had a significantly different (≥ 2-fold) expression. Light deprivation resulted in 68 significantly upregulated and 22 downregulated bHLH genes in the peel of the fruit. Sixteen bHLH genes in subfamily III were selected by three sets of transcriptomic data as candidate genes related to anthocyanin synthesis. Interaction network prediction and yeast two-hybrid screening verified the interaction between FcbHLH42 and anthocyanin synthesis-related genes. The transient expression of FcbHLH42 in tobacco led to an apparent anthocyanin accumulation. Our results confirm the first fig bHLH gene involved in fruit color development, laying the foundation for an in-depth functional study on other FcbHLH genes in fig fruit quality formation, and contributing to our understanding of the evolution of bHLH genes in other horticulturally important Ficus species.
Fig is an ancient gynodioecious fruit tree with females for commercial fruit production and hermaphrodites (males) sometimes used as pollen providers. An early sex-identification method would improve breeding efficiency. Three AGAMOUS (AG) genes were recruited from the Ficus carica genome using AG sequences from Ficus microcarpa and Ficus hispida. FcAG was 5230 bp in length, with 7 exons and 6 introns, and a 744-bp coding sequence. The gene was present in both female and male fig genomes, with a 15-bp deletion in the 7th exon. The other two AG genes (FcAG2-Gall_Stamen and FcAG3-Gall_Stamen) were male-specific, without the 15-bp deletion (759-bp coding sequence), and were only expressed in the gall and stamen of the male fig fruit. Using the deletion as the forward primer (AG-Marker), male plants were very efficiently identified by the presence of a 146-bp PCR product. The previously reported fig male and female polymorphism gene RESPONSIVE-TO-ANTAGONIST1 (RAN1) was also cloned and compared between male and female plants. Fifteen SNPs were found in the 3015-bp protein-coding sequence. Among them, 12 SNPs were identified as having sex-differentiating capacity by checking the sequences of 27 known male and 24 known female cultivars. A RAN1-Marker of 608 bp, including 6 SNPs, was designed, and a PCR and sequencing-based method was verified with 352 fig seedlings from two hybrid populations. Our results confirmed that the newly established AG-Marker is as accurate as the RAN1-Marker, and provide new clues to understanding Ficus sex determination.
The papain-like cysteine proteases (PLCPs) are the most abundant family of cysteine proteases in plants, with essential roles in biotic/abiotic stress responses, growth and senescence. Papain, bromelain and ficin are widely used in food, medicine and other industries. In this study, 31 PLCP genes (FcPCLPs) were identified in the fig (Ficus carica L.) genome by HMM search and manual screening, and assigned to one of nine subfamilies based on gene structure and conserved motifs. SAG12 and RD21 were the largest subfamilies with 10 and 7 members, respectively. The FcPCLPs ranged from 1,128 to 5,075 bp in length, containing 1–10 introns, and the coding sequence ranged from 624 to 1,518 bp, encoding 207–505 amino acids. Subcellular localization analysis indicated that 24, 2, and 5 PLCP proteins were targeted to the lysosome/vacuole, cytoplasm and extracellular matrix, respectively. Promoter (2,000 bp upstream) analysis of FcPLCPs revealed a high number of plant hormone and low temperature response elements. RNA-seq revealed differential expression of 17 FcPLCPs in the inflorescence and receptacle, and RD21 subfamily members were the major PLCPs expressed in the fruit; 16 and 5 FcPLCPs responded significantly to ethylene and light, respectively. Proteome analyses revealed 18 and 5 PLCPs in the fruit cell soluble proteome and fruit latex, respectively. Ficins were the major PLCP in fig fruit, with decreased abundance in inflorescences, but increased abundance in receptacles of commercial-ripe fruit. FcRD21B/C and FcALP1 were aligned as the genes encoding the main ficin isoforms. Our study provides valuable multi-omics information on the FcPLCP family and lays the foundation for further functional studies.
This study aimed to investigate the effects of probiotic Lactobacillus paracasei NL41 on inflammation and the gut microbiota of type 2 diabetic (T2D) rats induced by high-fat diet (HFD) and low-dose streptozotocin (STZ). A T2D rat model was established by inducing Sprague-Dawley rats with HFD/STZ, followed by 12-weeks L. paracasei NL41 gavage. The blood, colonic tissues, and feces samples of these rats were collected for inflammation, histology, and intestinal microbiota profiling. L. paracasei NL41 treatment induced remarkable improvement in the inflammatory status by decreasing the levels of serum lipopolysaccharides (LPS), free fatty acids (FFA), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-8 and increasing the level of IL-10. Gut barrier function was significantly protected in NL41-treated rats. Moreover, the strain NL41 induced changes in the microbiota structure and influenced the relative abundance of the key species. Specifically, Bacteroides, Clostridia (specifically, Ruminococcus torques), and Parasutterella were significantly reduced, while some beneficial microorganisms (Bacteroidales_S24-7_group and the families Lachnospiraceae and Ruminococcaceae) were enriched by NL41. The correlational analyses indicated that L. paracasei NL41 ameliorating inflammation was closely related to the key species of the gut microbiota. The present study indicates that probiotic L. paracasei NL41 decreases LPS-induced inflammation by improving the gut microbiota and preserving intestinal integrity.
Background Bagging can improve the appearance of fruits and increase the food safety and commodification, it also has effects on intrinsic quality of the fruits, which was commonly reported negative changes. Fig can be regarded as a new model fruit with its relatively small genome size and long fruit season. Results In this study, widely targeted metabolomics based on HPLC MS/MS and RNA-seq of the fruit tissue of the ‘Zibao’ fig before and after bagging were analyzed to reveal the metabolites changes of the edible part of figs and the underneath gene expression network changes. A total of 771 metabolites were identified in the metabolome analysis using fig female flower tissue. Of these, 88 metabolites (including one carbohydrate, eight organic acids, seven amino acids, and two vitamins) showed significant differences in fruit tissue before and after bagging. Changes in 16 structural genes, 13 MYB transcription factors, and endogenous hormone (ABA, IAA, and GA) metabolism and signal transduction-related genes in the biosynthesis pathway of flavonoids after bagging were analyzed by transcriptome analysis. KEGG enrichment analysis also determined significant differences in flavonoid biosynthesis pathways in female flower tissue before and after bagging. Conclusions This work provided comprehensive information on the composition and abundance of metabolites in the female flower tissue of fig. The results showed that the differences in flavor components of the fruit before and after bagging could be explained by changes in the composition and abundance of carbohydrates, organic acids, amino acids, and phenolic compounds. This study provides new insights into the effects of bagging on changes in the intrinsic and appearance quality of fruits.
The regulatory landscape of ethephon-accelerated fig ripening is revealed; flowers and receptacles exhibit opposite responses in anthocyanin accumulation; PG, PL and EXP are suggested key genes in fig softening. Ethephon is used to accelerate fig-fruit ripening for improvement of harvesting efficiency, but the underlying molecular mechanism is still unclear. To elucidate the detailed biological mechanism of ethylene-accelerated fig ripening, fruit in phase II (the lag phase on the double sigmoid growth curve) were treated with ethephon, and reached commercial ripeness 6 days earlier than the nontreated controls. Transcriptomes of flowers and the surrounding receptacles—which together make up the pseudocarp in fig fruit—were analyzed. There were 5189, 5818 and 2563 differentially expressed genes (DEGs) 2, 4 and 6 days after treatment (DAT) in treated compared to control fruit, screened by p-adjust < 0.05 and |log2(fold change) |≥ 2. The DEGs were significantly enriched in plant hormone metabolism and signal transduction, cell-wall modification, sugar accumulation and anthocyanin accumulation pathways. DEGs in the first three pathway categories demonstrated an overall similar expression change in flowers and receptacles, whereas DEGs in anthocyanin pigmentation revealed divergent transcript abundance. Specifically, in both flowers and receptacles, ethephon significantly upregulated 1-aminocyclopropane-1-carboxylate oxidase and downregulated most of the ethylene-response factor genes; polygalacturonase, pectate lyase and expansin were mainly upregulated; two acid beta-fructofuranosidases were upregulated. However, structural genes in the anthocyanin-synthesis pathway were mainly downregulated in female flowers 2 and 4 DAT, whereas they were upregulated in the receptacles. Our study reveals the regulatory landscape of the two tissues of fig fruit in ethylene-induced ripening; the differentially expressed pathways and genes provide valuable resources for the mining of target genes for crucial biological and commercial trait improvement.
利用α-葡萄糖苷酶抑制剂体外筛选模型,分析了来源于传统乳制品的10株乳杆菌对猪小肠提取的α-葡萄糖苷酶的抑制活性;对这些菌株的基本益生特性,包括对人工模拟胃肠液的耐受性及对肠上皮细胞的粘附性等进行了评价;最后,通过Caco-2细胞建立的Transwell模型分析了乳杆菌对人肠道α-葡萄糖苷酶活性及其基因表达的影响.结果 表明,这10株乳杆菌对猪小肠提取的α-葡萄糖苷酶均具有不同程度的抑制作用;乳杆菌的α-葡萄糖苷酶抑制活性在菌株生长的对数期或稳定期达到高峰,随后出现下降的趋势;结合菌株的基本益生特性评价发现,有3株具有较高抑制活性的乳杆菌能够耐受人工模拟的胃肠液,并具有较强的黏附肠上皮细胞HT-29的能力;由Transwell模型发现,乳杆菌能同时抑制α-葡萄糖苷酶的活性及基因表达量.研究表明,筛选出的3株乳杆菌(副干酪乳杆菌L14和Z3-11以及植物乳杆菌NL42)均具有较高的α-葡萄糖苷酶抑制活性和较好的益生特性,可作为潜在的辅助降血糖的益生菌株.
ObjectivePatients with renal failure suffer from symptoms caused by uraemic toxins, possibly of gut microbial origin, as deduced from studies in animals. The aim of the study is to characterise relationships between the intestinal microbiome composition, uraemic toxins and renal failure symptoms in human end-stage renal disease (ESRD).DesignCharacterisation of gut microbiome, serum and faecal metabolome and human phenotypes in a cohort of 223 patients with ESRD and 69 healthy controls. Multidimensional data integration to reveal links between these datasets and the use of chronic kidney disease (CKD) rodent models to test the effects of intestinal microbiome on toxin accumulation and disease severity.ResultsA group of microbial species enriched in ESRD correlates tightly to patient clinical variables and encode functions involved in toxin and secondary bile acids synthesis; the relative abundance of the microbial functions correlates with the serum or faecal concentrations of these metabolites. Microbiota from patients transplanted to renal injured germ-free mice or antibiotic-treated rats induce higher production of serum uraemic toxins and aggravated renal fibrosis and oxidative stress more than microbiota from controls. Two of the species, Eggerthella lenta and Fusobacterium nucleatum, increase uraemic toxins production and promote renal disease development in a CKD rat model. A probiotic Bifidobacterium animalis decreases abundance of these species, reduces levels of toxins and the severity of the disease in rats.ConclusionAberrant gut microbiota in patients with ESRD sculpts a detrimental metabolome aggravating clinical outcomes, suggesting that the gut microbiota will be a promising target for diminishing uraemic toxicity in those patients.Trial registration numberThis study was registered at ClinicalTrials.gov (NCT03010696).
Bifidobacteria are members of the human gut microbiota and have shown to exert beneficial effects on their host. Certain strains have a long history of safe and effective use as probiotics. Due to the lack of efficient genetic tools, however, little is known about the molecular mechanisms on which these health-promoting properties are based, thus limiting the synthetic biology applications in bifidobacteria. Here, we discuss the recent development of genetic tools and their engagement in engineering bifidobacteria for food and biomedical applications, from eliminating antibiotic resistance mobile elements and improving robustness to preventing pathogen infections and delivering therapeutics for cancer treatment. In addition, we highlight the application of emerging genome engineering techniques for manipulating the bifidobacterial genome. Finally, we provide our perspective on the future development of synthetic biology techniques and programmed probiotic bifidobacteria with enhanced robustness and designer functionalities.
Fig fruit are highly perishable at the tree-ripe (TR) stage. Commercial-ripe (CR) fruit, which are harvested before the TR stage for their postharvest transportability and shelf-life advantage, are inferior to TR fruit in size, color and sugar content. The succulent urn-shaped receptacle, serving as the protective structure and edible part of the fruit, determines fruit quality. Quantitative iTRAQ and RNA-Seq were performed to reveal the differential proteomic and transcriptomic traits of the receptacle at the two harvest stages. We identified 1226 proteins, of which 84 differentially abundant proteins (DAPs) were recruited by criteria of abundance fold-change (FC) ≥1.3 and p < 0.05 in the TR/CR receptacle proteomic analysis. In addition, 2087 differentially expressed genes (DEGs) were screened by ≥2-fold expression change: 1274 were upregulated and 813 were downregulated in the TR vs. CR transcriptomic analysis. Ficin was the most abundant soluble protein in the fig receptacle. Sucrose synthase, sucrose-phosphate synthase and hexokinase were all actively upregulated at both the protein and transcriptional levels. Endoglucanase, expansin, beta-galactosidase, pectin esterase and aquaporins were upregulated from the CR to TR stage at the protein level. In hormonal synthesis and signaling pathways, high protein and transcriptional levels of aminocyclopropane-1-carboxylate oxidase were identified, together with a few diversely expressed ethylene-response factors, indicating the potential leading role of ethylene in the ripening process of fig receptacle, which has been recently reported as a non-climacteric tissue. We present the first delineation of intra- and inter-omic changes in the expression of specific proteins and genes of TR vs. CR fig receptacle, providing valuable candidates for further study of fruit-quality formation control and fig cultivar innovation to accommodate market demand.
Intestinal bifidobacteria benefit human health by promoting and modulating the gut flora, and boosting therapeutic efficiency for chronic metabolic diseases and cancer. Recently, Bifidobacterium adolescentis strains with high adhesion to intestinal epithelial cells were associated with induction of T-helper 17 (Th17) cells in humans and rodents. Here, two B. adolescentis strains with similar adhesive ability but different aggregation properties were investigated for specific immunoregulatory effects, including the underlying cellular pathway, on macrophage and T-regulatory (Treg)/Th17 axis activation in vitro and in the colon of dextran sodium sulfate (DSS)-colitis mice in vivo. In-vitro, the auto-aggregative B. adolescentis strain IF1-11 induced significantly higher IL-6 and lower IL-10 secretion from immune cells, and it induced abundant Th17 cells. The non-aggregating strain IF1-03 induced significantly higher IL-10, less IL-6 and a high proportion of Treg/Th17 cells compared to total T cells. In vivo, orally administered IF1-03 protected DSS-colitis mice via activation of dendritic cells or macrophages and skewing of Treg/Th17 cells, consistent with Treg cell induction in vitro. IF1-03 exopolysaccharides showed a functional recognition pattern similar to IF1-03 for IL-10 cytokine secretion and Treg cell-differentiation induction, both dependent on the toll-like receptor 2–ERK/p38 MAPK-signaling cascade for macrophage activation. We suggest that B. adolescentis exopolysaccharide-associated enterocyte adhesion/aggregation phenotypes determine strain-specific adaptive immune responses in the gut via the macrophage-regulated Treg/Th17 axis.
Scope The present study aims to assess the antidiabetic effect of Lactobacillus paracasei strain NL41 and its potential mechanisms in rats with type 2 diabetes mellitus (T2DM) induced by a high-fat diet and low-dose streptozotocin administration (HFD/STZ). Methods and results Eighteen Sprague-Dawley (SD) rats are randomly assigned to three groups: one control, one HFD/STZ model, and one HFD/STZ-Lactobacillus protection group with administration of strain NL41 for 12 weeks. Blood is collected for biochemical parameters analysis and tissue samples for histological analysis. Treatment with strain NL41 results in excellent blood glucose regulation and significantly decreases insulin resistance, and HbA1c, glucagon, and leptin levels, accompanied by remarkable improvement of dyslipidemia and oxidative stress status in the animals. Islets of Langerhans, liver, and kidney are significantly protected in the NL41-treated rats compared to the HFD/STZ-T2DM model rats. Histochemistry shows that strain NL41 inhibits beta-cell loss and alpha-cell expansion, indicating pancreatic islets as the targeted tissues for the primary ameliorative effect of the probiotic strain on HFD/STZ-T2DM rats. Crosstalk between the gut-liver and liver-pancreas endocrine axes is discussed. Conclusion Probiotic strain NL41 prevents HFD/STZ-T2DM by decreasing insulin resistance and oxidative stress status, and protecting beta-cell function.
Color directly affects fruit quality and consumer preference. In fig syconia, the female flower tissue is contained in a receptacle. Anthocyanin pigmentation of this tissue and the peel differs temporally and spatially. A transcriptome study was carried out to elucidate key genes and transcription factors regulating differences in fig coloring. Anthocyanins in the female flower tissue were identified mainly as pelargonidin-3-glucoside and cyanidin-3-rutinoside; in the peel, the major anthocyanins were cyanidin 3-O-glucoside and cyanidin-3-rutinoside. Anthocyanin content was significantly higher in the female flower tissue vs. peel before fig ripening, whereas at ripening, the anthocyanin content in the peel was 5.39 times higher than that in the female flower tissue. Light-deprivation treatment strongly inhibited peel, but not female flower tissue, anthocyanin pigmentation. RNA-Seq revealed 522 differentially expressed genes (recruited with criteria log2 ≥ 2 and P < 0.05) at fig ripening, with 50 upregulated and 472 downregulated genes in the female flower tissue. Light deprivation upregulated 1180 and downregulated 856 genes in the peel, and upregulated 909 and downregulated 817 genes in the female flower tissue. KEGG enrichment revealed significantly changed expression in the phenylpropanoid-biosynthesis and flavonoid-biosynthesis pathways in the peel, but not in the female flower tissue, with significant repression of FcCHS, FcCHI, FcF3H, FcF3’H, FcDFR and FcUFGT transcripts. Light deprivation led to differential expression of 71 and 80 transcription factor genes in the peel and female flower tissue, respectively. Yeast one-hybrid screen revealed that FcHY5 and FcMYB114 bind the promoter regions of FcCHS and FcDFR, respectively in the flavonoid-biosynthesis pathway. Phenylpropanoid- and flavonoid-biosynthesis pathways were differentially expressed spatially and temporally in the peel and female flower tissue of fig syconia; pathway expression in the peel was strongly regulated by light signal. Differentially expressed transcription factors were recruited as candidates to screen important expression regulators in the light-dependent and light-independent anthocyanin-synthesis pathway. Our study lays the groundwork for further elucidation of crucial players in fig pigmentation.
The vacuole plays a central role in fruit growth and quality formation, yet its proteomic landscape is largely unknown. In the present study, a protocol for isolating intact vacuoles from grape flesh tissue was successfully established. Quantitative proteome analysis identified 2533 proteins from five sampling dates along Cabernet Sauvignon berry development from stage I to III; among them, 1443 proteins were identified on all five sampling dates in at least two biological replicates per sample and were designated core proteome, and 1820 were recruited as differentially abundant proteins (DAPs) by sequential pairwise comparisons using arbitrary fold change of >1.5 and P < 0.05. Metabolism consistently constituted the largest category of identified proteins for both core proteome and DAPs, together with a consistently high proportion of protein-fate category proteins, indicating that the classic lytic functions of vegetative cell vacuoles are maintained throughout berry development; accumulation of metabolites involved in high sugar and other berry qualities in the late developmental stage added to the conventional lytic role of the flesh cell vacuoles. Overall increases in abundance of the DAPs were seen in the transporter proteins, membrane fusion/vesicle trafficking, and protein-fate categories, and decreased abundance was seen for DAPs in the stress, energy and cytoskeleton categories as berry development progressed. A very pronounced proteomic change was revealed between late stage I and mid stage II, with 915 increased and 114 decreased DAPs, demonstrating a significant surge of the vacuolar proteome underlying the rather static phenotypical and physiological phase. We identified 161 transport proteins with differential abundance, including proton pumps, aquaporins, sugar transporters, ATP-binding cassette transporters and ion transport proteins, together with organic compound transport proteins, the highest number and variety of berry tonoplast transporters found in grape proteome efforts to date. We further found a pre-positive increment of 96 transport proteins from the middle of stage II, before the berry undergoes its dramatic physiological changes at and following véraison. Our results are the first to describe the proteome of a vacuole-enriched preparation, toward understanding the functions of the largest compartment in berry cells during grape growth and ripening.
CPPU-induced San Pedro type fig main crop parthenocarpy exhibited constantly increasing IAA content and more significantly enriched KEGG pathways in the receptacle than in female flowers. N-(2-chloro-4-pyridyl)-N-phenylurea (CPPU) was applied to San Pedro fig (Ficus carica L.) main crop to induce parthenocarpy; the optimal effect was obtained with 25 mg L−1 application to syconia when female flowers were at anthesis. To elucidate the key expression changes in parthenocarpy conversion, significant changes in phytohormone level and transcriptome of fig female flowers and receptacles were monitored. HPLC–MS revealed increased IAA content in female flowers and receptacle 2, 4 and 10 days after treatment (DAT), decreased zeatin level in the receptacle 2, 4 and 10 DAT, decreased GA3 content 2 and 4 DAT, and increased GA3 content 10 DAT. ABA level increased 2 and 4 DAT, and decreased 10 DAT. CPPU-treated syconia released more ethylene than the control except 2 DAT. RNA-Seq and bioinformatics analysis revealed notably more differentially expressed KEGG pathways in the receptacle than in female flowers. In the phytohormone gene network, GA-biosynthesis genes GA20ox and GA3ox were upregulated, along with GA signal-transduction genes GID1 and GID2, and IAA-signaling genes AUX/IAA and GH3. ABA-biosynthesis gene NCED and signaling genes PP2C and ABF were downregulated 10 DAT. One ACO gene showed consistent upregulation in both female flowers and receptacle after CPPU treatment, and more than a dozen of ERFs demonstrated opposing changes in expression. Our results revealed early-stage spatiotemporal phytohormone and transcriptomic responses in CPPU-induced San Pedro fig main crop parthenocarpy, which could be valuable for further understanding the nature of the parthenocarpy of different fig types.
Dipeptidyl peptidase-IV (DPP-IV) is a serine exo-peptidase that can inactivate incretins by removing N-terminal dipeptides. Currently, inhibiting the DPP-IV activity is a common treatment for type 2 diabetes (T2D). The goal of this study is to investigate whether IADHFL, a novel DPP-IV inhibitory peptide identified from bighead carp (Hypophthalmichthys nobilis), has the potential to modulate T2D. IADHFL remained stable after simulated gastrointestinal digestion and significantly decreased the activity and expression of both soluble and membrane-bound DPP-IV after 24 h and 48 h of treatment. Intact peptide absorption was observed, but a percentage of the peptide was degraded while passing through a monolayer of Caco-2 cells. In addition, a double-layered cell model showed that the peptide could increase insulin secretion from INS-1 cells after glucose treatments of 2.8 mM and 16.7 mM. Finally, IADHFL could regulate the expression levels of genes associated with insulin secretion and T2D in INS-1 cells.