Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport.

Availability of the essential macronutrient nitrogen in soil plays a critical role in plant growth, development, and impacts agricultural productivity. Plants have evolved different strategies for sensing and responding to heterogeneous nitrogen distribution. Modulation of root system architecture, including primary root growth and branching, is among the most essential plant adaptions to ensure adequate nitrogen acquisition. However, the immediate molecular pathways coordinating the adjustment of root growth in response to distinct nitrogen sources, such as nitrate or ammonium, are poorly understood. Here, we show that growth as manifested by cell division and elongation is synchronized by coordinated auxin flux between two adjacent outer tissue layers of the root. This coordination is achieved by nitrate-dependent dephosphorylation of the PIN2 auxin efflux carrier at a previously uncharacterized phosphorylation site, leading to subsequent PIN2 lateralization and thereby regulating auxin flow between adjacent tissues. A dynamic computer model based on our experimental data successfully recapitulates experimental observations. Our study provides mechanistic insights broadening our understanding of root growth mechanisms in dynamic environments.

Polar auxin transport modulates early leaf flattening.

The flattened leaf form is an important adaptation for efficient photosynthesis, and the developmental process of flattened leaves has been intensively studied. Classic microsurgery studies in potato and tomato suggest that the shoot apical meristem (SAM) communicates with the leaf primordia to promote leaf blade formation. More recently, it was found that polar auxin transport (PAT) could mediate this communication. However, it is unclear how the expression of leaf patterning genes is tailored by PAT routes originating from SAM. By combining experimental observations and computer model simulations, we show that microsurgical incisions and local inhibition of PAT in tomato interfere with auxin transport toward the leaf margins, reducing auxin response levels and altering the leaf blade shape. Importantly, oval auxin responses result in the bipolar expression of SlLAM1 that determines leaf blade formation. Furthermore, wounding caused by incisions promotes degradation of SlREV, a known regulator of leaf polarity. Additionally, computer simulations suggest that local auxin biosynthesis in early leaf primordia could remove necessity for external auxin supply originating from SAM, potentially explaining differences between species. Together, our findings establish how PAT near emerging leaf primordia determines spatial auxin patterning and refines SlLAM1 expression in the leaf margins to guide leaf flattening.

Computer models of cell polarity establishment in plants.

Plant development is a complex task, and many processes involve changes in the asymmetric subcellular distribution of cell components that strongly depend on cell polarity. Cell polarity regulates anisotropic growth and polar localization of membrane proteins and helps to identify the cell's position relative to its neighbors within an organ. Cell polarity is critical in a variety of plant developmental processes, including embryogenesis, cell division, and response to external stimuli. The most conspicuous downstream effect of cell polarity is the polar transport of the phytohormone auxin, which is the only known hormone transported in a polar fashion in and out of cells by specialized exporters and importers. The biological processes behind the establishment of cell polarity are still unknown, and researchers have proposed several models that have been tested using computer simulations. The evolution of computer models has progressed in tandem with scientific discoveries, which have highlighted the importance of genetic, chemical, and mechanical input in determining cell polarity and regulating polarity-dependent processes such as anisotropic growth, protein subcellular localization, and the development of organ shapes. The purpose of this review is to provide a comprehensive overview of the current understanding of computer models of cell polarity establishment in plants, focusing on the molecular and cellular mechanisms, the proteins involved, and the current state of the field.

Virulence- and signaling-associated genes display a preference for long 3'UTRs during rice infection and metabolic stress in the rice blast fungus.

Generation of mRNA isoforms by alternative polyadenylation (APA) and their involvement in regulation of fungal cellular processes, including virulence, remains elusive. Here, we investigated genome-wide polyadenylation site (PAS) selection in the rice blast fungus to understand how APA regulates pathogenicity. More than half of Magnaporthe oryzae transcripts undergo APA and show novel motifs in their PAS region. Transcripts with shorter 3'UTRs are more stable and abundant in polysomal fractions, suggesting they are being translated more efficiently. Importantly, rice colonization increases the use of distal PASs of pathogenicity genes, especially those participating in signalling pathways like 14-3-3B, whose long 3'UTR is required for infection. Cleavage factor I (CFI) Rbp35 regulates expression and distal PAS selection of virulence and signalling-associated genes, tRNAs and transposable elements, pointing its potential to drive genomic rearrangements and pathogen evolution. We propose a noncanonical PAS selection mechanism for Rbp35 that recognizes UGUAH, unlike humans, without CFI25. Our results showed that APA controls turnover and translation of transcripts involved in fungal growth and environmental adaptation. Furthermore, these data provide useful information for enhancing genome annotations and for cross-species comparisons of PASs and PAS usage within the fungal kingdom and the tree of life.

Molecular characterization of a novel ssRNA ourmia-like virus from the rice blast fungus Magnaporthe oryzae.

In this study we characterize a novel positive and single stranded RNA (ssRNA) mycovirus isolated from the rice field isolate of Magnaporthe oryzae Guy11. The ssRNA contains a single open reading frame (ORF) of 2,373 nucleotides in length and encodes an RNA-dependent RNA polymerase (RdRp) closely related to ourmiaviruses (plant viruses) and ourmia-like mycoviruses. Accordingly, we name this virus Magnaporthe oryzae ourmia-like virus 1 (MOLV1). Although phylogenetic analysis suggests that MOLV1 is closely related to ourmia and ourmia-like viruses, it has some features never reported before within the Ourmiavirus genus. 3' RLM-RACE (RNA ligase-mediated rapid amplification of cDNA ends) and extension poly(A) tests (ePAT) suggest that the MOLV1 genome contains a poly(A) tail whereas the three cytosine and the three guanine residues present in 5' and 3' untranslated regions (UTRs) of ourmia viruses are not observed in the MOLV1 sequence. The discovery of this novel viral genome supports the hypothesis that plant pathogenic fungi may have acquired this type of viruses from their host plants.

Ribosomic DNA intergenic spacer 1 region is useful when identifying Candida parapsilosis spp. complex based on high-resolution melting analysis.

The epidemiology of Candida parapsilosis and the closely related species C. orthopsilosis and C. metapsilosis has changed in recent years, justify the need to identify this complex at the species level. In this study we investigate the intergenic spacer 1 (IGS1) of the ribosomal DNA (rDNA) to evaluate the utility of this gene region as a phylogenetic molecular marker and the suitability of a high-resolution melting (HRM) strategy based on this region for identification of members of the C. parapsilosis spp. complex. We sequenced the IGS1 and the internal transcribed spacer (ITS) regions of the rDNA from 33 C. parapsilosis sensu lato strains. Although both regions are useful in identifying species, comparative sequence analysis showed that the diversity in the IGS1 region was higher than in the ITS sequences. We also developed an HRM analysis that reliably identifies C. parapsilosis spp. complex based on the amplification of 70 bp in the IGS1 region. All isolates were correctly identified with a confidence interval >98%. Our results demonstrate that HRM analysis based on the IGS1 region is a powerful tool for distinguishing C. parapsilosis from cryptic species.

Two orthogonal differentiation gradients locally coordinate fruit morphogenesis.

Morphogenesis requires the coordination of cellular behaviors along developmental axes. In plants, gradients of growth and differentiation are typically established along a single longitudinal primordium axis to control global organ shape. Yet, it remains unclear how these gradients are locally adjusted to regulate the formation of complex organs that consist of diverse tissue types. Here we combine quantitative live imaging at cellular resolution with genetics, and chemical treatments to understand the formation of Arabidopsis thaliana female reproductive organ (gynoecium). We show that, contrary to other aerial organs, gynoecium shape is determined by two orthogonal, time-shifted differentiation gradients. An early mediolateral gradient controls valve morphogenesis while a late, longitudinal gradient regulates style differentiation. Local, tissue-dependent action of these gradients serves to fine-tune the common developmental program governing organ morphogenesis to ensure the specialized function of the gynoecium.

Reuse of end-of-life personal protective equipment in hot asphalt mixtures: an environmental evaluation.

In the present global health emergency, face masks, gowns, caps, gloves play a key role in limiting the diffusion of the COVID-19 pandemic, by acting as physical barriers to avoid droplets and filtrate exhalations coming from infected subjects. Since the most widespread devices are disposable products made of plastic or rubber materials, this means that relevant quantities of fossil resources are consumed, and huge amounts of wastes are generated. Currently the end of life of personal protective equipment (PPE) represents a problem in environmental, economic, and social terms. The market considers two possible disposal scenarios: incineration with energy recovery or landfill. In both cases, significant impacts are achieved both on the environment and on human health. This study aims to propose and validate a new scenario for PPE based on material reuse for bituminous conglomerates. The Life Cycle Assessment methodology and the experimental tests has been used to assess the environmental impacts in terms of both ReCiPe midpoints and endpoints and for demonstrate the technical feasibility of this new scenario. From an environmental point of view, relevant benefits were observed in comparison with the standard incineration for energy recovery or disposal in landfill.

Single Use Personal Protective Equipment Reinforced Asphalt.

Due to the COVID-19 pandemic, global personal protective equipment (PPE) volume production and demand increased by 300-400% between 2019 and 2021. In this scenario, the present study aims to propose and validate an innovative circular economy scenario for end of life (EoL) PPEs, reusing them to produce reinforced bituminous mixtures. Despite that several studies confirmed the possibility of reusing plastic in the asphalt mixtures, none of them investigated the potential of PPEs, highlighting the innovativeness in the scientific panorama. Five different alternatives of EoL PPE mixtures (different products, materials, dosages, etc.) were tested at laboratory scale to verify the technical feasibility of the proposed scenario. The most promising solution resulted to be the mix of gloves and face masks composed by polypropylene, polyethylene, nitrile and lattice at a dosage of 0,5% weight/weight that allowed to produce bituminous mixtures with acceptable performances in terms of relevant mechanical parameters while recycling waste PPEs. This leads to environmental benefits, since more than 3kg of EoL PPEs per square meter of road pavement can be reused instead of disposed (about 1,5 million tons/year considering the bituminous mixtures produced at European level), as well as economic benefits for public administrations and the collectivity, due to the reduced landfilling of solid wastes.

Environmental assessment and eco-design of a surgical face mask.

After more than one year form the first cases of Sars-Cov-2 infection, it is now clear that the most effective mean to prevent the diffusion of the pandemic is the use of face masks, that however are based on fossil materials and could potentially generate an environmental problem. This study wants to quantitatively investigate the environmental impacts related to the life cycle of a single use surgical mask through the use of the Life Cycle Assessment methodology. Results highlight significant impacts due to the material supply and transport, as well as product packaging and distribution. The study outcomes can be also useful to set potential eco-design strategies for the product environmental improvement.

Design and Analysis of a Novel Ultraviolet-C Device for Surgical Face Mask Disinfection.

This paper deals with the design of a compact sanitization device and the definition of a specific protocol for UV-C disinfection of a surgical face mask. The system was designed considering the material properties, face mask shape, and UV-C light distribution. DIALux software was used to evaluate the irradiance distribution provided by the lamps emitting in the UV-C range. The irradiance needed for UV-C-decontaminated bacteria and virus, and other contaminating pathogens, without compromising their integrity and guaranteeing inactivation of the bacteria, was evaluated. The face mask's material properties were analyzed with respect to UV-C exposure in terms of physicochemical properties, breathability, and bacterial filtration performance. Information on the effect of time-dependent passive decontamination at room temperature storage was provided. Single and multiple cycles of UV-C sanitization did not adversely affect respirator breathability and bacterial filtration efficiency. This multidisciplinal approach may provide important information on how it is possible to correctly sanitize a face mask and, in case of shortage, safely reuse the face mask.

Shaping the Organ: A Biologist Guide to Quantitative Models of Plant Morphogenesis.

Organ morphogenesis is the process of shape acquisition initiated with a small reservoir of undifferentiated cells. In plants, morphogenesis is a complex endeavor that comprises a large number of interacting elements, including mechanical stimuli, biochemical signaling, and genetic prerequisites. Because of the large body of data being produced by modern laboratories, solving this complexity requires the application of computational techniques and analyses. In the last two decades, computational models combined with wet-lab experiments have advanced our understanding of plant organ morphogenesis. Here, we provide a comprehensive review of the most important achievements in the field of computational plant morphodynamics. We present a brief history from the earliest attempts to describe plant forms using algorithmic pattern generation to the evolution of quantitative cell-based models fueled by increasing computational power. We then provide an overview of the most common types of "digital plant" paradigms, and demonstrate how models benefit from diverse techniques used to describe cell growth mechanics. Finally, we highlight the development of computational frameworks designed to resolve organ shape complexity through integration of mechanical, biochemical, and genetic cues into a quantitative standardized and user-friendly environment.

A coupled mechano-biochemical model for cell polarity guided anisotropic root growth.

Plants develop new organs to adjust their bodies to dynamic changes in the environment. How independent organs achieve anisotropic shapes and polarities is poorly understood. To address this question, we constructed a mechano-biochemical model for Arabidopsis root meristem growth that integrates biologically plausible principles. Computer model simulations demonstrate how differential growth of neighboring tissues results in the initial symmetry-breaking leading to anisotropic root growth. Furthermore, the root growth feeds back on a polar transport network of the growth regulator auxin. Model, predictions are in close agreement with in vivo patterns of anisotropic growth, auxin distribution, and cell polarity, as well as several root phenotypes caused by chemical, mechanical, or genetic perturbations. Our study demonstrates that the combination of tissue mechanics and polar auxin transport organizes anisotropic root growth and cell polarities during organ outgrowth. Therefore, a mobile auxin signal transported through immobile cells drives polarity and growth mechanics to coordinate complex organ development.

Challenging the engineering design process for the development of facial masks in the constraint of the COVID-19 pandemic.

The most effective ways to mitigate the diffusion of the COVID-19 pandemic are social distancing and the use of face masks as barrier to avoid droplets and to filtrate exhalations coming from infected subjects. Currently used face masks are products developed to be used by workers, both in health care and other contexts, where their use is limited in time and the disposal scenario is properly managed. Their use in a pandemic situation can be thus considered a remedial action due to the emergency. New masks or mask families are needed based on the desirable requirements retrieved by the analysis of the current worldwide situation and covering the gap observed in the market. The present paper aims to describe the complete product development process of a new facial mask (or mask family) for a daily use on a pandemic situation. It challenges the time constraint of the COVID-19 pandemic by adopting a four-step approach and concurrent development of the first phases (definition of requirements and functional derivation). The engineering design process allows to derive two different solutions able to fulfil all the requirements (demands and wishes) of final users, by assuring high ergonomic performance, as well as environmental, economic, and social sustainability.

Environmental implication of personal protection equipment in the pandemic era: LCA comparison of face masks typologies.

In the present global health emergency, face masks play a key role in limiting the diffusion of the COVID-19 pandemic, by acting as physical barriers to avoid droplets and filtrate exhalations coming from infected subjects. Since the most widespread devices are disposable products made of plastic materials, this means that relevant quantities of fossil resources will be consumed, and huge amounts of wastes will be generated. The present paper aims to compare the environmental performances of five different typologies of face masks (i.e. 3D printed reusable mask with filter, surgical mask, filtering face-piece masks - FFPs with and without valve, washable masks), considering an average Italian use scenario and the whole mask lifecycle: materials, manufacturing processes, use, sanitization, and disposal. The Life Cycle Assessment methodology has been used to assess the environmental impacts in terms of both ReCiPe midpoints and endpoints. Reusable masks and masks with interchangeable filters could potentially contribute to improve the environmental performances in all the considered impact and damage categories. Eco-design actions can be developed starting from the study results.

An auxin-regulable oscillatory circuit drives the root clock in Arabidopsis.

In Arabidopsis, the root clock regulates the spacing of lateral organs along the primary root through oscillating gene expression. The core molecular mechanism that drives the root clock periodicity and how it is modified by exogenous cues such as auxin and gravity remain unknown. We identified the key elements of the oscillator (AUXIN RESPONSE FACTOR 7, its auxin-sensitive inhibitor IAA18/POTENT, and auxin) that form a negative regulatory loop circuit in the oscillation zone. Through multilevel computer modeling fitted to experimental data, we explain how gene expression oscillations coordinate with cell division and growth to create the periodic pattern of organ spacing. Furthermore, gravistimulation experiments based on the model predictions show that external auxin stimuli can lead to entrainment of the root clock. Our work demonstrates the mechanism underlying a robust biological clock and how it can respond to external stimuli.

Implantable electrical devices for prevention of sudden cardiac death: data on implant rates from a 'real world' regional registry.

AIMS: International and national consensus guidelines define appropriate indications for implantable cardioverter-defibrillators (ICDs), but the variability in implant rates in 'real world' clinical practice is still unknown. METHODS AND RESULTS: In Emilia-Romagna, an Italian region with around 4.3 million inhabitants, a web-based registry was instituted to collect data for all ICDs implanted. Between January 2006 and December 2008, data from all consecutive patients resident in this region who underwent first implant of an ICD or a biventricular ICD were collected and standardized, considering each regional area (i.e. each of the nine provinces). The overall number of implanted ICDs had an increase in years 2007 and 2008, with a relative increase in comparison to 2006, by 14 and 48% respectively, reaching an average value of 16.2 per 10,000 inhabitants in 2008. Most of the increase was due to a rise in ICDs for primary prevention. The ratio between the implant rates of the provinces with the highest and the lowest implant rates, respectively, was around 2 in 2008. CONCLUSION: Implant rates for ICDs, considering both primary and secondary prevention of sudden death, show up to two-fold variations even in a geographical region where the general level of health care is advanced and well appreciated by the population. The lack of a common strategy for sudden death prevention, approved by both physicians and institutional regional authorities, together with some degree of variability in translating guidelines into clinical practice, were identified as the main factors explaining the heterogeneity in ICD implant rates.

Pulsed Electric Field Processing of Red Grapes (cv. Rondinella): Modifications of Phenolic Fraction and Effects on Wine Evolution.

Pulsed electric field (PEF) is a non-thermal technology able to promote color and polyphenols extraction from grape skins. Most of the publications about PEF in winemaking report data concerning international varieties, poorly considering minor cultivars and the medium/long-term effects of the treatment on wine composition during storage. PEF was applied at different specific energies (2, 10, and 20 kJ kg-1) on grapes of the low-color red cv. Rondinella, after crushing-destemming. Pressing yield, the evolution of color, and total phenolic index (TPI) were measured during skin maceration. Moreover, the wines were characterized for basic compositional parameters, color, anthocyanin profile, phenolic composition (glories indices), metal content (Fe, Cr, and Ni), and sensory characters, two and twelve months after the processing, in comparison with untreated samples and pectolytic enzymes (PE). PEF did not affect fermentation evolution, nor did it modify wine basic composition or metal content. Treatments at 10 and 20 kJ kg-1 led to higher color and TPI in wines, in comparison to PE, because of increased content of anthocyanins and tannins. The sensory evaluation confirmed these findings. Modifications remained stable in wines after twelve months. Glories indices and vitisin A content highlighted greater potential stability of wine color in PEF-treated wines.

Contribution of morphology discrimination algorithm for improving rhythm discrimination in slow and fast ventricular tachycardia zones in dual-chamber implantable cardioverter-defibrillators.

AIMS: Morphology discrimination (MD) is an algorithm based on QRS morphology analysis, that can be used alone or in various combinations with other discriminators in order to diagnose ventricular tachycardia (VT) [the implantable cardioverter-defibrillator (ICD) may be set to diagnose VT if 'Any' or 'All' the discriminators indicate VT)]. METHODS AND RESULTS: We evaluated the contribution of MD in terms of Specificity (SP) and Sensitivity (SE) of rhythm discrimination in slow and fast VT zones (rates <150 bpm and between 150 and 180 bpm, respectively). Detection results (682 spontaneous episodes in 58 patients) were corrected for multiple episodes within a patient (generalized estimating equations method). Rhythm discrimination in slow VT zones was characterized by SE and SP below 80% without MD, while the use of MD alone allowed to enhance SP, maintaining SE at 96%. Use of MD in combination with other discriminators resulted in a decrease in SP (setting 'Any'). In fast VT zones, MD allows an increase in SE for VT detection from around 82% up to approximately 94%, coupled with an SP of 95-96%., although SP is much higher with MD alone (94.8%) than with any other combination (78.4%). Both in slow and fast VT zones, use of multiple discriminators with the setting 'All' resulted in an unacceptable decrease in SE. CONCLUSION: MD in a dual-chamber ICD in combination with a rate branch classification system makes it possible to achieve a very high SP in discriminating detected events both in slow and fast VT zones, while maintaining SE for VT detection.