30 research outputs found
Promoter elements of rice susceptibility genes are bound and activated by specific TAL effectors from the bacterial blight pathogen, Xanthomonas oryzae pv. oryzae.
Summary âą Plant pathogenic bacteria of the genus Xanthomonas inject transcription activator-like effector (TALe) proteins that bind to and activate host promoters, thereby promoting disease or inducing plant defense. TALes bind to corresponding UPT (up-regulated by TALe) promoter boxes via tandemly arranged 34 â 35-amino acid repeats. Recent studies uncovered the TALe code in which two amino acid residues of each repeat define specific pairing to UPT boxes. âą Here we employed the TALe code to predict potential UPT boxes in TALeinduced host promoters and analyzed these via b-glucuronidase (GUS) reporter and electrophoretic mobility shift assays (EMSA). âą We demonstrate that the Xa13, OsTFX1 and Os11N3 promoters from rice are induced directly by the Xanthomonas oryzae pv. oryzae TALes PthXo1, PthXo6 and AvrXa7, respectively. We identified and functionally validated a UPT box in the corresponding rice target promoter for each TALe and show that box mutations suppress TALe-mediated promoter activation. Finally, EMSA demonstrate that code-predicted UPT boxes interact specifically with corresponding TALes. âą Our findings show that variations in the UPT boxes of different rice accessions correlate with susceptibility or resistance of these accessions to the bacterial blight pathogen
Transient reprogramming of crop plants for agronomic performance
The development of a new crop variety is a time-consuming and costly process due to the reliance of plant breeding on gene shuffling to introduce desired genes into elite germplasm, followed by backcrossing. Here, we propose alternative technology that transiently targets various regulatory circuits within a plant, leading to operator-specified alterations of agronomic traits, such as time of flowering, vernalization requirement, plant height or drought tolerance. We redesigned techniques of gene delivery, amplification and expression around RNA viral transfection methods that can be implemented on an industrial scale and with many crop plants. The process does not involve genetic modification of the plant genome and is thus limited to a single plant generation, is broadly applicable, fast, tunable and versatile, and can be used throughout much of the crop cultivation cycle. The RNA-based reprogramming may be especially useful in plant pathogen pandemics but also for commercial seed production and for rapid adaptation of orphan crops
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICâHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICâHF) trial. Here we describe the baseline characteristics of participants in GALACTICâHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)ââ„âII, EF â€35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticâguided dosing: 25, 37.5 or 50âmg bid). 8256 patients [male (79%), nonâwhite (22%), mean age 65âyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTâproBNP 1971âpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICâHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureâ<â100âmmHg (n = 1127), estimated glomerular filtration rate <â30âmL/min/1.73 m2 (n = 528), and treated with sacubitrilâvalsartan at baseline (n = 1594).
Conclusions:
GALACTICâHF enrolled a wellâtreated, highârisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
Recognition of AvrBs3-Like Proteins Is Mediated by Specific Binding to Promoters of Matching Pepper Bs3 Alleles1[W]
The pepper (Capsicum annuum) bacterial spot (Bs) resistance gene Bs3 and its allelic variant Bs3-E mediate recognition of the Xanthomonas campestris pv vesicatoria type III effector protein AvrBs3 and its deletion derivative AvrBs3Îrep16. Recognition specificity resides in the Bs3 and Bs3-E promoters and is determined by a defined promoter region, the UPA (for up-regulated by AvrBs3) box. Using site-directed mutagenesis, we defined the exact boundaries of the UPAAvrBs3 box of the Bs3 promoter and the UPAAvrBs3Îrep16 box of the Bs3-E promoter and show that both boxes overlap by at least 11 nucleotides. Despite partial sequence identity, the UPAAvrBs3 box and the UPAAvrBs3Îrep16 box were bound specifically by the corresponding AvrBs3 and AvrBs3Îrep16 proteins, respectively, suggesting that selective promoter binding of AvrBs3-like proteins is the basis for promoter activation specificity. We also demonstrate that the UPAAvrBs3 box retains its functionality at different positions within the pepper Bs3 promoter and confers AvrBs3 inducibility in a novel promoter context. Notably, the transfer of the UPAAvrBs3 box to different promoter locations is always correlated with a new transcriptional start site. The analysis of naturally occurring Bs3 alleles revealed many pepper accessions that encode a nonfunctional Bs3 variant. These accessions showed no apparent abnormalities, supporting the supposition that Bs3 functions only in disease resistance and not in other developmental or physiological processes
Renarrating Italian Fascism: New Directions in the Historiography of a European Dictatorship
Rcompadre and RageâTwo R packages to facilitate the use of the COMPADRE and COMADRE databases and calculation of lifeâhistory traits from matrix population models
Matrix population models (MPMs) are an important tool for biologists seeking to understand the causes and consequences of variation in vital rates (e.g. survival, reproduction) across life cycles. Empirical MPMs describe the age- or stage-structured demography of organisms and usually represent the life history of a population during a particular time frame at a specific geographical location.
The COMPADRE Plant Matrix Database and COMADRE Animal Matrix Database are the most extensive resources for MPM data, collectively containing >12,000 individual projection matrices for >1,100 species globally. Although these databases represent an unparalleled resource for researchers, land managers and educators, the current computational tools available to answer questions with MPMs impose significant barriers to potential COM(P)ADRE database users by requiring advanced knowledge to handle diverse data structures and program custom analysis functions.
To close this knowledge gap, we present two interrelated R packages designed to (a) facilitate the use of these databases by providing functions to acquire, quality control and manage both the MPM data contained in COMPADRE and COMADRE, and a user's own MPM data (Rcompadre) and (b) present a range of functions to calculate life-history traits from MPMs in support of ecological and evolutionary analyses (Rage). We provide examples to illustrate the use of both.
Rcompadre and Rage will facilitate demographic analyses using MPM data and contribute to the improved replicability of studies using these data. We hope that this new functionality will allow researchers, land managers and educators to unlock the potential behind the thousands of MPMs and ancillary metadata stored in the COMPADRE and COMADRE matrix databases, and in their own MPM data
Enhanced efficiency of a novel porous tip irrigated RF ablation catheter for pulmonary vein isolation
Irrigated tip radiofrequency (RF) catheter ablation is the most frequently used technology for pulmonary vein isolation (PVI). The purpose of this study was to compare the efficiency and the safety of 2 different open irrigated tip RF ablation catheters
Degradation behavior and osseointegration of MgâZnâCa screws in different bone regions of growing sheep: a pilot study
Magnesium (Mg)-based implants are highly attractive for the orthopedic field and may replace titanium (Ti) as support for fracture healing. To determine the implantâbone interaction in different bony regions, we implanted Mg-based alloy ZX00 (Mg < 0.5 Zn < 0.5 Ca, in wt%) and Ti-screws into the distal epiphysis and distal metaphysis of sheep tibiae. The implant degradation and osseointegration were assessed in vivo and ex vivo after 4, 6 and 12âweeks, using a combination of clinical computed tomography, medium-resolution micro computed tomography (”CT) and high-resolution synchrotron radiation ”CT (SR”CT). Implant volume loss, gas formation and bone growth were evaluated for both implantation sites and each bone region independently. Additionally, histological analysis of bone growth was performed on embedded hard-tissue samples. We demonstrate that in all cases, the degradation rate of ZX00-implants ranges between 0.23 and 0.75âmm/year. The highest degradation rates were found in the epiphysis. Bone-to-implant contact varied between the time points and bone types for both materials. Mostly, bone-volume-to-total-volume was higher around Ti-implants. However, we found an increased cortical thickness around the ZX00-screws when compared with the Ti-screws. Our results showed the suitability of ZX00-screws for implantation into the distal meta- and epiphysis