The pivotal role of ethylene in plant growth

Being continuously exposed to variable environmental conditions, plants produce phytohormones to react quickly and specifically to these changes. The phytohormone ethylene is produced in response to multiple stresses. While the role of ethylene in defense responses to pathogens is widely recognized, recent studies in arabidopsis and crop species highlight an emerging key role for ethylene in the regulation of organ growth and yield under abiotic stress. Molecular connections between ethylene and growth-regulatory pathways have been uncovered, and altering the expression of ethylene response factors (ERFs) provides a new strategy for targeted ethylene-response engineering. Crops with optimized ethylene responses show improved growth in the field, opening new windows for future crop improvement. This review focuses on how ethylene regulates shoot growth, with an emphasis on leaves

Gene regulatory network inference : connecting plant biology and mathematical modeling

Plant responses to environmental and intrinsic signals are tightly controlled by multiple transcription factors (TFs). These TFs and their regulatory connections form gene regulatory networks (GRNs), which provide a blueprint of the transcriptional regulations underlying plant development and environmental responses. This review provides examples of experimental methodologies commonly used to identify regulatory interactions and generate GRNs. Additionally, this review describes network inference techniques that leverage gene expression data to predict regulatory interactions. These computational and experimental methodologies yield complex networks that can identify new regulatory interactions, driving novel hypotheses. Biological properties that contribute to the complexity of GRNs are also described in this review. These include network topology, network size, transient binding of TFs to DNA, and competition between multiple upstream regulators. Finally, this review highlights the potential of machine learning approaches to leverage gene expression data to predict phenotypic outputs

From network to phenotype : the dynamic wiring of an Arabidopsis transcriptional network induced by osmotic stress

Plants have established different mechanisms to cope with environmental fluctuations and accordingly fine-tune their growth and development through the regulation of complex molecular networks. It is largely unknown how the network architectures change and what the key regulators in stress responses and plant growth are. Here, we investigated a complex, highly interconnected network of 20 Arabidopsis transcription factors (TFs) at the basis of leaf growth inhibition upon mild osmotic stress. We tracked the dynamic behavior of the stress-responsive TFs over time, showing the rapid induction following stress treatment, specifically in growing leaves. The connections between the TFs were uncovered using inducible overexpression lines and were validated with transient expression assays. This study resulted in the identification of a core network, composed of ERF6, ERF8, ERF9, ERF59, and ERF98, which is responsible for most transcriptional connections. The analyses highlight the biological function of this core network in environmental adaptation and its redundancy. Finally, a phenotypic analysis of loss-of-function and gain-of-function lines of the transcription factors established multiple connections between the stress-responsive network and leaf growth

RALFL34 regulates formative cell divisions in Arabidopsis pericycle during lateral root initiation

We describe the role of RALFL34 during early events in lateral root development, and demonstrate its specific importance in orchestrating formative cell divisions in the pericycle.In plants, many signalling molecules, such as phytohormones, miRNAs, transcription factors, and small signalling peptides, drive growth and development. However, very few small signalling peptides have been shown to be necessary for lateral root development. Here, we describe the role of the peptide RALFL34 during early events in lateral root development, and demonstrate its specific importance in orchestrating formative cell divisions in the pericycle. Our results further suggest that this small signalling peptide acts on the transcriptional cascade leading to a new lateral root upstream of GATA23, an important player in lateral root formation. In addition, we describe a role for ETHYLENE RESPONSE FACTORs (ERFs) in regulatingRALFL34 expression. Taken together, we put forward RALFL34 as a new, important player in lateral root initiation

Comparison of functional outcome after extended versus super-extended pelvic lymph node dissection during radical prostatectomy in high-risk localized prostate cancer

Background: Urinary continence and erectile function (EF) are best preserved whenmeticulous dissection of prostate and nerve sparing technique are used during radicalprostatectomy (RP). However, extent of lymph node dissection (LND) may also adverselyaffect functional results.Objective: To determine whether performing a super-extended LND (seLND) has asignificant effect on recovery of urinary continence and EF after RP.Design, setting, and participants: All patients who underwent RP from January 2007until December 2013 were handed questionnaires assessing continence and EF. Allpatients in whom at least an extended LND (eLND) was performed were selected. Thissearch yielded 526 patients. 172 of these patients had filed out 2 or more questionnairesand were included in our analysis.Outcome measurements and statistical analysis: All questionnaires were reviewed.We used Kaplan–Meier analyses and multivariate Cox analysis to assess the differencein recovery of continence and EF over time for eLND/seLND. Primary endpoints were fullrecovery of continence (no loss of urine) and full recovery of EF (successful intercoursepossible). Patients who did not reach the endpoint when the last questionnaire was filledout were censored at that time. Median follow-up was 12.43 months for continence, and18.97 months for EF.results and limitations: Patients undergoing seLND have a lower chance of regainingboth urinary continence [hazard ratio (HR) 0.59, 95% CI 0.39–0.90, p = 0.026] and EF(HR 0.28, 95% CI 0.13–0.57, p = 0.009). Age at surgery had a significant influence onboth continence and EF in multivariate analysis. Major limitation of the study was that noformal preoperative assessment of continence and potency was done.conclusion: Extending the LND template beyond the eLND template may cause atleast a significant delay in recovery of urinary continence and leads to less recovery of EF.</p

A hierarchical search for gravitational waves from supermassive black hole binary mergers

We present a method to search for gravitational waves from coalescing supermassive binary black holes in LISA data. The search utilizes the $\mathcal{F}$-statistic to maximize over, and determine the values of, the extrinsic parameters of the binary system. The intrinsic parameters are searched over hierarchically using stochastically generated multi-dimensional template banks to recover the masses and sky locations of the binary. We present the results of this method applied to the mock LISA data Challenge 1B data set.Comment: 11 pages, 2 figures, for GWDAW-12 proceedings edition of CQ

Protein complex stoichiometry and expression dynamics of transcription factors modulate stem cell division

11 Pág.Stem cells divide and differentiate to form all of the specialized cell types in a multicellular organism. In the Arabidopsis root, stem cells are maintained in an undifferentiated state by a less mitotically active population of cells called the quiescent center (QC). Determining how the QC regulates the surrounding stem cell initials, or what makes the QC fundamentally different from the actively dividing initials, is important for understanding how stem cell divisions are maintained. Here we gained insight into the differences between the QC and the cortex endodermis initials (CEI) by studying the mobile transcription factor SHORTROOT (SHR) and its binding partner SCARECROW (SCR). We constructed an ordinary differential equation model of SHR and SCR in the QC and CEI which incorporated the stoichiometry of the SHR-SCR complex as well as upstream transcriptional regulation of SHR and SCR. Our model prediction, coupled with experimental validation, showed that high levels of the SHR-SCR complex are associated with more CEI division but less QC division. Furthermore, our model prediction allowed us to propose the putative upstream SHR regulators SEUSS and WUSCHEL-RELATED HOMEOBOX 5 and to experimentally validate their roles in QC and CEI division. In addition, our model established the timing of QC and CEI division and suggests that SHR repression of QC division depends on formation of the SHR homodimer. Thus, our results support that SHR-SCR protein complex stoichiometry and regulation of SHR transcription modulate the division timing of two different specialized cell types in the root stem cell niche.This work was supported by the NSF Graduate Research Fellowship Program (DGE-1252376, to N.M.C. and A.P.F.). Research in the R. Simon lab was funded by the Deutsche Forschungsge-meinschaft (Si947/10 and an Alexander von Humboldt Foundation fellowship, to B.B.). This work was also supported by a grant from the Ministerio de Economía y Competitividad of Spain and European Regional Development Fund (BFU2016-80315-P, to M.A.M.-R.). E.B.A. is supported by Ayudante de Investigacion contract PEJ-2017-AI/BIO-7360 from Comunidad Madrid. S.G.Z. was supported by the HHMI and by a grant from the NIH (GM118036). Research in the K.L.G. lab was funded by NSF Grant 1243945. The R. Sozzani lab is supported by an NSF CAREER grant (MCB-1453130) and the North Carolina Agricultural & Life Sciences Research Foundation at North Carolina State University’s College of Agricultural and Life Sciences.Peer reviewe

Benefits and Risks of Primary Treatments for High-risk Localized and Locally Advanced Prostate Cancer : An International Multidisciplinary Systematic Review

Copyright © 2020 European Association of Urology. Published by Elsevier B.V. All rights reserved.Peer reviewedPostprin

Vestibular Infant Screening (VIS)–Flanders : results after 1.5 years of vestibular screening in hearing-impaired children

Due to the close anatomical relationship between the auditory and vestibular end organs, hearing-impaired children have a higher risk for vestibular dysfunction, which can affect their (motor) development. Unfortunately, vestibular dysfunction often goes unnoticed, as vestibular assessment in these children is not standard of care nowadays. To timely detect vestibular dysfunction, the Vestibular Infant Screening–Flanders (VIS–Flanders) project has implemented a basic vestibular screening test for hearing-impaired infants in Flanders (Belgium) with a participation rate of 86.7% during the first year and a half. The cervical Vestibular Evoked Myogenic Potentials (cVEMP) test was applied as vestibular screening tool to map the occurrence of vestibular (mainly saccular) dysfunction in this population. At the age of 6 months, 184 infants were screened. No refers on vestibular screening were observed in infants with permanent conductive hearing loss. In infants with permanent sensorineural hearing loss, a cVEMP refer rate of 9.5% was observed. Failure was significantly more common in infants with severe-profound compared to those with mild-moderate sensorineural hearing loss (risk ratio = 9.8). Since this is the first regional study with a large sample size and successful participation rate, the VIS–Flanders project aims to set an example for other regions worldwide