SUMMARY
Jasmonic acid (JA) induces chlorophyll degradation and leaf senescence. B‐box (BBX) proteins play important roles in the modulation of leaf senescence, but the molecular mechanism of BBX ...protein‐mediated leaf senescence remains to be further studied. Here, we identified the BBX protein MdBBX37 as a positive regulator of JA‐induced leaf senescence in Malus domestica (apple). Further studies showed that MdBBX37 interacted with the senescence regulatory protein MdbHLH93 to enhance its transcriptional activation on the senescence‐associated gene MdSAG18, thereby promoting leaf senescence. Moreover, the JA signaling repressor MdJAZ2 interacted with MdBBX37 and interfered with the interaction between MdBBX37 and MdbHLH93, thereby negatively mediating MdBBX37‐promoted leaf senescence. In addition, the E3 ubiquitin ligase MdSINA3 delayed MdBBX37‐promoted leaf senescence through targeting MdBBX37 for degradation. The MdJAZ2‐MdBBX37‐MdbHLH93‐MdSAG18 and MdSINA3‐MdBBX37 modules realized the precise modulation of JA on leaf senescence. In parallel, our data demonstrate that MdBBX37 was involved in abscisic acid (ABA)‐ and ethylene‐mediated leaf senescence through interacting with the ABA signaling regulatory protein MdABI5 and ethylene signaling regulatory protein MdEIL1, respectively. Taken together, our results not only reveal the role of MdBBX37 as an integration node in JA‐, ABA‐ and ethylene‐mediated leaf senescence, but also provide new insights into the post‐translational modification of BBX proteins.
Significance Statement
BBX37 interacted with the senescence regulatory protein bHLH93 to enhance its transcriptional activation on the senescence‐associated gene SAG18, thereby promoting leaf senescence. JAZ2 interacted with BBX37 and interfered with the interaction between BBX37 and bHLH93, thereby negatively mediating BBX37‐promoted leaf senescence. SINA3 delayed the BBX37‐promoted leaf senescence through targeting BBX37 for ubiquitination and degradation.
Abstract
Abscisic acid is involved in the regulation of cold stress response, but its molecular mechanism remains to be elucidated. In this study, we demonstrated that the APETALA2/ethylene ...responsive factor (AP2/ERF) family protein MdABI4 positively regulates abscisic acid-mediated cold tolerance in apple. We found that MdABI4 interacts with MdICE1, a key regulatory protein involved in the cold stress response, and enhances the transcriptional regulatory function of MdICE1 on its downstream target gene MdCBF1, thus improving abscisic acid-mediated cold tolerance. The jasmonate-ZIM domain (JAZ) proteins MdJAZ1 and MdJAZ2 negatively modulate MdABI4-improved cold tolerance in apple by interacting with the MdABI4 protein. Further investigation showed that MdJAZ1 and MdJAZ2 interfere with the interaction between the MdABI4 and MdICE1 proteins. Together, our data revealed that MdABI4 integrates jasmonic acid and abscisic acid signals to precisely modulate cold tolerance in apple through the JAZ-ABI4-ICE1-CBF regulatory cascade. These findings provide insights into the crosstalk between jasmonic acid and abscisic acid signals in response to cold stress.
The APETALA2/ethylene responsive factor family protein MdABI4 integrates jasmonic acid and abscisic acid signals to modulate cold tolerance through the JAZ-ABI4-ICE1-CBF regulatory cascade in apple.
Light affects many physiological and developmental processes of plants by regulating the expression and activity of light-responsive proteins. Among them, phytochrome interacting factors (PIFs) play ...pivotal roles in the regulation of anthocyanin accumulation and hypocotyl growth. However, the molecular mechanism is not well understood, especially in woody plants, such as apple (Malus × domestica). In this study, we identified a light-responsive PIF protein, MdPIF7, in apple and investigated the molecular mechanism of its regulation of anthocyanin biosynthesis and hypocotyl growth. We found that overexpression of MdPIF7 decreased anthocyanin accumulation in transgenic apple materials and promoted hypocotyl elongation in ectopically expressed Arabidopsis (Arabidopsis thaliana). Further investigation showed that MdPIF7 functioned by interacting with B-box 23 (MdBBX23), a positive regulator of anthocyanin biosynthesis in apple and hypocotyl growth inhibition in ectopically expressed Arabidopsis, and attenuating the transcriptional activation of MdBBX23 on LONG HYPOCOTYL 5 (MdHY5). In addition, MdPIF7 interacted with basic region leucine zipper 44 (MdbZIP44) and ethylene response factor 38 (MdERF38), two positive regulators of anthocyanin biosynthesis, and it negatively regulated MdbZIP44- and MdERF38-promoted anthocyanin accumulation by interfering with the interaction between MdbZIP44/MdERF38 and MdMYB1. Taken together, our results reveal that MdPIF7 regulates anthocyanin biosynthesis in apple and hypocotyl growth in ectopically expressed Arabidopsis through MdPIF7-MdBBX23-MdHY5 and MdPIF7-MdbZIP44/MdERF38-MdMYB1 modules. Our findings enrich the functional studies of PIF proteins and provide insights into the molecular mechanism of PIF-mediated anthocyanin biosynthesis and hypocotyl growth.
4-Nonylphenol (4-NP) is one of the common endocrine-disrupting chemicals (EDCs) in estuaries and coastal zones, which can exert detrimental effects on the physiological function of aquatic organisms. ...However, the molecular response triggered by 4-NP remains largely unknown in Pacific white shrimp (Litopenaeus vannamei). In this study, transcriptomic analysis was performed to investigate the underlying mechanisms of 4-NP toxicity in the hepatopancreas of L. vannamei. Nine RNA-Seq libraries were generated from L. vannamei at 0 h, 24 h, and 48 h following exposure to 4-NP. Compared with 0 h vs 24 h, 962 up- and 463 down-regulated differentially expressed genes (DEGs) were identified, indicating that many genes in L. vannamei were induced to resist adverse circumstances by 4-NP exposure. In contrast, 902 up- and 1027 down-regulated DEGs were revealed in the comparison of 0 h vs 48 h, demonstrating that prolonged exposure to the stress from 4-NP resulted in more inhibited genes. To validate the accuracy of the transcriptome data, eight DEGs were selected for quantitative real-time polymerase chain reaction (qRT-PCR), which were consistent with the RNA-Seq results. Through KEGG pathway enrichment analysis, three specific pathways related to hormonal effects and endocrine function of L. vannamei were enriched significantly, including tyrosine metabolism, insect hormone biosynthesis, and melanogenesis. After 4-NP stress, genes involved in tyrosine metabolism (Tyr) and melanogenesis pathway (AC, CBP, Wnt, Frizzled, Tcf, and Ras) were induced to promote melanin pigment to help shrimp resist adverse environments. In the insect hormone biosynthesis, ALDH, CYP15A1, CYP15A1/C1, and JHE genes were activated to synthesize juvenile hormone (JH), while Spook, Phm, Sad, and CYP18A1 were induced to generate molting hormone. There is an enhanced interaction between the molting hormone and JH, with JH playing a dominant role and maintaining its “classic status quo action”. Our study demonstrated that 4-NP exposure led to impairments of biological functions in L. vannamei hepatopancreas. The genes and pathways identified provide novel insights into the molecular mechanisms underlying 4-NP toxicity effects in prawns and enrich the information on the toxicity mechanism of crustaceans in response to EDCs exposure.
•The first transcriptome profiling for the L.vannamei hepatopancreas after 4-nonylphenol exposure.•1425 and 1929 DEGs were identified at 24 h and 48 h after 4-nonylphenol exposure, respectively.•Three specific pathways were found to play important roles in L. vannamei response to 4-nonylphenol exposure.
Abstract
Cold stress limits plant growth, geographical distribution, and crop yield. The MYC-type bHLH transcription factor ICE1 is recognized as the core positive regulator of the cold-stress ...response. However, how ICE1 protein levels are regulated remains to be further studied. In this study, we observed that a U-box-type E3 ubiquitin ligase, MdPUB23, positively regulated the cold-stress response in apple. The expression of MdPUB23 increased at both the transcriptional and post-translational levels in response to cold stress. Overexpression of MdPUB23 in transgenic apple enhanced sensitivity to cold stress. Further study showed that MdPUB23 directly interacted with MdICE1, promoting the ubiquitination-mediated degradation of the MdICE1 protein through the 26S-proteasome pathway and reducing the MdICE1-improved cold-stress tolerance in apple. Our results reveal that MdPUB23 regulates the cold-stress response by directly mediating the stability of the positive regulator MdICE1. The PUB23–ICE1 ubiquitination module may play a role in maintaining ICE1 protein homeostasis and preventing overreactions from causing damage to plants. The discovery of the ubiquitination regulatory pathway of ICE1 provides insights for the further exploration of plant cold-stress-response mechanisms.
Until recently, there has been no unified definition of the metabolic syndrome (MetS) in the youth. Therefore, the prevalence of MetS and its association with potential correlates are largely ...unknown.
The objective was to quantify the prevalence, identify the correlates, and examine the independent associations between potential correlates with MetS.
A population-based cohort study was conducted in 10- and 15-y-old youth from Estonia, Denmark, and Portugal (n = 3193). MetS was defined according to the International Diabetes Federation. Correlates included maternal socioeconomic status, body mass index (BMI), hypertension, and prevalent diabetes and maternally reported child’s birth weight and duration of breastfeeding. Data on sexual maturity, objectively measured physical activity, cardiorespiratory fitness, self-reported sports participation, television viewing, and regular play were collected for the children.
The prevalence of MetS was 0.2% and 1.4% in 10- and 15-y-olds, respectively. Cardiorespiratory fitness (standardized odds ratio: 0.33; 95% CI: 0.15, 0.75), physical activity (standardized odds ratio: 0.40; 95% CI: 0.18, 0.88), and maternal BMI (standardized odds ratio: 1.61; 95% CI: 1.11, 2.34) were all independently associated with MetS after adjustment for sex, age group, study location, birth weight, and sexual maturity. An increase in daily moderate-intensity physical activity by 10–20% was associated with a 33% lower risk of being categorized with MetS.
High maternal BMI and low levels of cardiorespiratory fitness and physical activity independently contribute to the MetS and may be targets for future interventions. Relatively small increases in physical activity may significantly reduce the risk of MetS in healthy children.
SUMMARY
Esophageal carcinoma (EC) occurs at high rate in Chaoshan region of southern China. Human leukocyte antigen (HLA) polymorphism has been implicated in risk for various cancers. To investigate ...the impact of HLA‐A and HLA‐B polymorphisms on susceptibility to EC, a case–control study was conducted among 206 patients with esophageal squamous cell carcinoma and 524 controls from Chaoshan Han population. HLA‐A and HLA‐B polymorphisms were genotyped by polymerase chain reaction‐sequence‐specific primers. Genotypic association tests for dominant, recessive, and additive models, and haplotypic association were calculated using unconditional logistic regression. A*11 was identified in a recessive model as an only allele strongly associated with EC risk (odds ratios OR= 2.10, 95% confidence interval CI= 1.33–3.31) even after correction for multiple test. The haplotypes A*02‐B*46 (OR = 1.53, 95% CI = 1.04–2.24) and A*11‐B*51 (OR = 2.29, 95% CI = 1.20–4.40) showed association with increased risk for EC, whereas A*11‐B*58 (OR = 0.00, 95% CI = 0.00–0.82) was associated with decreased risk, though the significance of these haplotypes was lost after correction. This is a first association study at genetic level identifying HLA‐A and HLA‐B‐related variations in genetic susceptibility to EC among Chaoshan population. The variation pattern is likely to be EC‐specific because it is different from that observed for nasopharyngeal carcinoma in the same study population and might, at least in part, explain the high rate of EC in this ethnic group.
Disentangling the genetics of lean mass Karasik, David; Hsu, Yi-Hsiang; Akesson, Kristina ...
The American journal of clinical nutrition,
02/2019, Letnik:
109, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Lean body mass (LM) plays an important role in mobility and metabolic function. We previously identified five loci associated with LM adjusted for fat mass in kilograms. Such an adjustment may reduce ...the power to identify genetic signals having an association with both lean mass and fat mass.
To determine the impact of different fat mass adjustments on genetic architecture of LM and identify additional LM loci.
We performed genome-wide association analyses for whole-body LM (20 cohorts of European ancestry with n = 38,292) measured using dual-energy X-ray absorptiometry) or bioelectrical impedance analysis, adjusted for sex, age, age2, and height with or without fat mass adjustments (Model 1 no fat adjustment; Model 2 adjustment for fat mass as a percentage of body mass; Model 3 adjustment for fat mass in kilograms).
Seven single-nucleotide polymorphisms (SNPs) in separate loci, including one novel LM locus (TNRC6B), were successfully replicated in an additional 47,227 individuals from 29 cohorts. Based on the strengths of the associations in Model 1 vs Model 3, we divided the LM loci into those with an effect on both lean mass and fat mass in the same direction and refer to those as “sumo wrestler” loci (FTO and MC4R). In contrast, loci with an impact specifically on LM were termed “body builder” loci (VCAN and ADAMTSL3). Using existing available genome-wide association study databases, LM increasing alleles of SNPs in sumo wrestler loci were associated with an adverse metabolic profile, whereas LM increasing alleles of SNPs in “body builder” loci were associated with metabolic protection.
In conclusion, we identified one novel LM locus (TNRC6B). Our results suggest that a genetically determined increase in lean mass might exert either harmful or protective effects on metabolic traits, depending on its relation to fat mass.
The clinical applications of fibrin glue span over several surgical modalities. The aim of this study was to evaluate the biocompatibility and biodegradation of different formulations of ...platelet-rich fibrin glue in vivo and examine its effects on the neovascularization of wound sites.
Human-derived single-unit fibrin glue was prepared. Incisions were made on the backs of rats, and these were coated with homemade glues containing different concentrations of aminomethylbenzoic acid (Groups A-F) or commercial adhesives (Group G). A sham control group was included (Group H). The wounds were examined by histological analysis and immunohistochemistry at several time points.
Successful wound closure was achieved in all groups by day 12. Acute inflammation occurred during the first six days, but gradually disappeared. The longest sealant duration was achieved using the lowest concentration of anti-fibrinolytic agent in a 1:10 volume ratio with cryoprecipitate. Expression levels of the platelet endothelial cell adhesion molecule-1 were significantly higher in Groups A and C compared to the control groups (Groups G and H) on day 3 (P < 0.05).
Single-unit platelet-rich fibrin glue has excellent biocompatibility and is associated with the upregulation of neovascularization. The addition of aminomethylbenzoic acid could prevent the degradation of fibrin glue.
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