In the absence of specialized immune cells, the need for plants to reprogram transcription to transition from growth-related activities to defence is well understood. However, little is known about ...translational changes that occur during immune induction. Using ribosome footprinting, here we perform global translatome profiling on Arabidopsis exposed to the microbe-associated molecular pattern elf18. We find that during this pattern-triggered immunity, translation is tightly regulated and poorly correlated with transcription. Identification of genes with altered translational efficiency leads to the discovery of novel regulators of this immune response. Further investigation of these genes shows that messenger RNA sequence features are major determinants of the observed translational efficiency changes. In the 5' leader sequences of transcripts with increased translational efficiency, we find a highly enriched messenger RNA consensus sequence, R-motif, consisting of mostly purines. We show that R-motif regulates translation in response to pattern-triggered immunity induction through interaction with poly(A)-binding proteins. Therefore, this study provides not only strong evidence, but also a molecular mechanism, for global translational reprogramming during pattern-triggered immunity in plants.
The aromatic amino acids L-phenylalanine and L-tyrosine and their plant-derived natural products are essential in human and plant metabolism and physiology. Here we identified Petunia hybrida and ...Arabidopsis thaliana genes encoding prephenate aminotransferases (PPA-ATs), thus completing the identification of the genes involved in phenylalanine and tyrosine biosyntheses. Biochemical and genetic characterization of enzymes showed that PPA-AT directs carbon flux from prephenate toward arogenate, making the arogenate pathway predominant in plant phenylalanine biosynthesis.
The plant hormone salicylic acid (SA) is essential for local defense and systemic acquired resistance (SAR). When plants, such as Arabidopsis , are challenged by different pathogens, an increase in ...SA biosynthesis generally occurs through transcriptional induction of the key synthetic enzyme isochorismate synthase 1 (ICS1). However, the regulatory mechanism for this induction is poorly understood. Using a yeast one-hybrid screen, we identified two transcription factors (TFs), NTM1-LIKE 9 (NTL9) and CCA1 HIKING EXPEDITION (CHE), as activators of ICS1 during specific immune responses. NTL9 is essential for inducing ICS1 and two other SA synthesis-related genes, PHYTOALEXIN-DEFICIENT 4 ( PAD4 ) and ENHANCED DISEASE SUSCEPTIBILITY 1 ( EDS1 ), in guard cells that form stomata. Stomata can quickly close upon challenge to block pathogen entry. This stomatal immunity requires ICS1 and the SA signaling pathway. In the ntl9 mutant, this response is defective and can be rescued by exogenous application of SA, indicating that NTL9-mediated SA synthesis is essential for stomatal immunity. CHE, the second identified TF, is a central circadian clock oscillator and is required not only for the daily oscillation in SA levels but also for the pathogen-induced SA synthesis in systemic tissues during SAR. CHE may also regulate ICS1 through the known transcription activators CALMODULIN BINDING PROTEIN 60g (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) because induction of these TF genes is compromised in the che-2 mutant. Our study shows that SA biosynthesis is regulated by multiple TFs in a spatial and temporal manner and therefore fills a gap in the signal transduction pathway between pathogen recognition and SA production.
Biosynthesis of the plant immune signal salicylic acid (SA) is normally induced upon pathogen challenge through transcriptional activation of the key SA synthetic enzyme gene, ICS1 . However, how different pathogenic signals trigger SA synthesis in both local and systemic tissues and during different immune responses is poorly understood. Our study filled this knowledge gap by the identification of two transcription factors (TFs): one is required for SA biosynthesis in stomata to prevent pathogen entry through these epidermal openings, and the other is essential for both the circadian oscillation in SA levels and the accumulation of SA in distal tissue during systemic acquired resistance. Our study shows that SA biosynthesis is regulated by multiple TFs in a spatial and temporal manner.
Abstract
This study was designed to build models predicting early graft failure after liver transplantation. Cox regression model for predicting early graft failure after liver transplantation using ...post-transplantation aspartate aminotransferase, total bilirubin, and international normalized ratio of prothrombin time was constructed based on data from both living donor (n = 1153) and deceased donor (n = 359) liver transplantation performed during 2004 to 2018. The model was compared with Model for Early Allograft Function Scoring (MEAF) and early allograft dysfunction (EAD) with their C-index and time-dependent area-under-curve (AUC). The C-index of the model for living donor (0.73, CI = 0.67–0.79) was significantly higher compared to those of both MEAF (0.69, P = 0.03) and EAD (0.66, P = 0.001) while C-index for deceased donor (0.74, CI = 0.65–0.83) was only significantly higher compared to C-index of EAD. (0.66, P = 0.002) Time-dependent AUC at 2 weeks of living donor (0.96, CI = 0.91–1.00) and deceased donor (0.98, CI = 0.96–1.00) were significantly higher compared to those of EAD. (both 0.83, P < 0.001 for living donor and deceased donor) Time-dependent AUC at 4 weeks of living donor (0.93, CI = 0.86–0.99) was significantly higher compared to those of both MEAF (0.87, P = 0.02) and EAD. (0.84, P = 0.02) Time-dependent AUC at 4 weeks of deceased donor (0.94, CI = 0.89–1.00) was significantly higher compared to both MEAF (0.82, P = 0.02) and EAD. (0.81, P < 0.001). The prediction model for early graft failure after liver transplantation showed high predictability and validity with higher predictability compared to traditional models for both living donor and deceased donor liver transplantation.
Phenylalanine is a vital component of proteins in all living organisms, and in plants is a precursor for thousands of additional metabolites. Animals are incapable of synthesizing phenylalanine and ...must primarily obtain it directly or indirectly from plants. Although plants can synthesize phenylalanine in plastids through arogenate, the contribution of an alternative pathway via phenylpyruvate, as occurs in most microbes, has not been demonstrated. Here we show that plants also utilize a microbial-like phenylpyruvate pathway to produce phenylalanine, and flux through this route is increased when the entry point to the arogenate pathway is limiting. Unexpectedly, we find the plant phenylpyruvate pathway utilizes a cytosolic aminotransferase that links the coordinated catabolism of tyrosine to serve as the amino donor, thus interconnecting the extra-plastidial metabolism of these amino acids. This discovery uncovers another level of complexity in the plant aromatic amino acid regulatory network, unveiling new targets for metabolic engineering.
The Arabidopsis (Arabidopsis thaliana) genome includes eight PIN-FORMED (PIN) members that are molecularly diverged. To comparatively examine their differences in auxin-transporting activity and ...subcellular behaviors, we expressed seven PIN proteins specifically in Arabidopsis root hairs and analyzed their activities in terms of the degree of PIN-mediated root hair inhibition or enhancement and determined their subcellular localization. Expression of six PINs (PIN1-PIN4, PIN7, and PIN8) in root hair cells greatly inhibited root hair growth, most likely by lowering auxin levels in the root hair cell by their auxin efflux activities. The auxin efflux activity of PIN8, which had not been previously demonstrated, was further confirmed using a tobacco (Nicotiana tabacum) cell assay system. In accordance with these results, those PINs were localized in the plasma membrane, where they likely export auxin to the apoplast and formed internal compartments in response to brefeldin A. These six PINs conferred different degrees of root hair inhibition and sensitivities to auxin or auxin transport inhibitors. Conversely, PIN5 mostly localized to internal compartments, and its expression in root hair cells rather slightly stimulated hair growth, implying that PIN5 enhanced internal auxin availability. These results suggest that different PINs behave differentially in catalyzing auxin transport depending upon their molecular activity and subcellular localization in the root hair cell.
This prospective study sought to investigate serum levels of trace elements (cobalt, copper, zinc, and selenium) and to assess their effects on pregnancy and neonatal outcomes. Serum levels of trace ...elements in 245 Korean pregnant women (median gestational age at delivery was 39 + 4 weeks and interquartile range was 38 + 4-40 + 1 weeks) were compared with those of 527 general adults and those of previous studies in other ethnic groups. Pregnancy and neonatal outcomes including gestational diabetes, preeclampsia, neonatal birth weight, and congenital abnormalities were assessed. The median serum trace element concentrations of all pregnant women were: cobalt: 0.39 μg/L (interquartile range, IQR 0.29-0.53), copper: 165.0 μg/dL (IQR 144.0-187.0), zinc: 57.0 μg/dL (IQR 50.0-64.0), and selenium: 94.0 μg/L (IQR 87.0-101.0). Serum cobalt and copper concentrations were higher in pregnant women than in the general population, whereas zinc and selenium levels were lower (
< 0.01). Concentrations of all four trace elements varied significantly during the three trimesters (
< 0.05), and seasonal variation was found in copper, zinc, and selenium, but was not observed for cobalt. The prevalence of preeclampsia was significantly lower with high copper (
= 0.03). Trace element levels varied by pregnancy trimester and season, and alteration in copper status during pregnancy might influence pregnancy outcomes such as preeclampsia.
The prevalence of Alzheimer's disease (AD) and other dementias is increasing; therefore, identifying individuals at risk for dementia is crucial. Traditional neuropsychological assessments are ...expensive and time-consuming; however, computerized cognitive testing is becoming popular in clinical and research settings, particularly during the COVID-19 pandemic. This study aimed to investigate the correlation between the computerized cognitive test, Inbrain cognitive screening test (CST), and the traditional neuropsychological battery, the consortium to establish a registry for Alzheimer's disease assessment packet (CERAD-K).
We enrolled 166 participants from five districts in Republic of Korea, including cognitively unimpaired individuals and those with mild cognitive impairment (MCI) diagnosed by experienced neurologists. We used the Inbrain CST and CERAD-K to evaluate the cognitive function of the participants, and the scores of each subtest of the Inbrain CST and CERAD-K were compared.
A significant correlation was found between the Inbrain CST and CERAD-K subtests. Furthermore, multivariate analysis revealed a significant correlation between the Inbrain CST and the CERAD-K test pairs after adjusting for age, educational level, and sex.
In conclusion, this study demonstrates that the Inbrain CST is a reliable tool for detecting cognitive impairment in cognitively unimpaired individuals and patients with MCI, because it has a high correlation and agreement with CERAD-K. Therefore, the Inbrain CST can be a useful, time-efficient, and cost-effective computer-based cognitive test for individuals at risk for cognitive impairment.
Background
Previous studies have suggested a relationship between Helicobacter pylori infection and dyslipidemia; however, large‐scale longitudinal studies have not elucidated this association. This ...study assessed the longitudinal effects of H. pylori infection and eradication on lipid profiles in a large cohort.
Methods
This cohort study included 2,626 adults without dyslipidemia at baseline, who participated in a repeated, regular health‐screening examination, which included upper gastrointestinal endoscopy, between January 2009 and December 2018. The primary outcome was incident dyslipidemia at follow‐up.
Results
During the 10,324 person‐years of follow‐up, participants with persistent H. pylori infection had a higher incidence rate (130.5 per 1,000 person‐years) of dyslipidemia than those whose infections had been successfully controlled (98.1 per 1,000 person‐years). In a multivariable model adjusted for age, sex, waist circumference, smoking status, alcohol intake, and education level, the H. pylori eradication group was associated with a lower risk of dyslipidemia than the persistent group (HR, 0.85; 95% CI, 0.77–0.95; p = 0.004). The association persisted after further adjustment for baseline levels of low‐density and high‐density lipoprotein cholesterol (HR, 0.87; 95% CI, 0.79–0.97; p = 0.014).
Conclusions
H. pylori infection may play a pathophysiologic role in the development of dyslipidemia, whereas H. pylori eradication might decrease the risk of dyslipidemia.
Cardiorenal syndrome (CRS) frequently occurs in end-stage heart failure patients waiting for heart transplantation (HT). Decision-making regarding simultaneous heart and kidney transplantation is an ...unresolved issue in these patients. We investigated clinical factors associated with renal outcome after HT. A total of 180 patients who received HT from 1996 to 2015 were included. Factors associated with early post-HT chronic kidney disease (CKD, estimated glomerular filtration rate eGFR < 60 mL/minute/1.73 m2 within 1 year post-HT), post-HT end-stage kidney disease (ESKD), and significant renal function improvement (%ΔeGFR > 15%) at 1 year post-HT were analyzed. Early post-HT CKD and post-HT ESKD developed in 61 (33.9%) and 8 (4.4%) of 180 patients, respectively. Old age was only independently associated with early post-HT CKD and preexisting CKD tended to be associated with early post-HT CKD. Old age and preexisting CKD were independently associated with post-HT ESKD. Low pre-HT eGFR and preoperative renal replacement therapy were not associated with early post-HT CKD or post-HT ESKD. Young age, low pre-HT eGFR, and high %ΔeGFR 1 month post-HT were independently associated with significant renal function improvement. Preoperative renal function, including preoperative RRT, was not associated with post-HT mortality. In conclusion, preexisting CKD may impact renal outcomes after HT, but preoperative severe renal dysfunction, even that severe enough to require RRT, may not be a contraindication for HT alone. Our data suggest the necessity of early HT in end-stage heart failure patients with CRS and the importance of careful management during the early postoperative period.
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