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In the course of evolutionary changes pathogens have developed many invasion strategies, to which the host organisms responded with a broad range of defense reactions involving endogenous signaling molecules, such as nitric oxide (NO). There is evidence that pathogenic microorganisms, including two most important groups of eukaryotic plant pathogens, also acquired the ability to synthesize NO via nonunequivocally defined oxidative and/or reductive routes. Although the both kingdoms Chromista and Fungi are remarkably diverse, the experimental data clearly indicate that pathogen-derived NO is an important regulatory molecule controlling not only developmental processes, but also pathogen virulence and its survival in the host. An active control of mitigation or aggravation of nitrosative stress within host cells seems to be a key determinant for the successful invasion of plant pathogens representing different lifestyles and an effective mode of dispersion in various environmental niches. [ABSTRACT FROM AUTHOR]

Calcium and nitric oxide (NO) are two important biological messengers. Increasing evidence indicates that Ca2+ and NO work together in mediating responses to pathogenic microorganisms and microbe-associated molecular patterns. Ca2+ fluxes were recognized to account for NO production, whereas evidence gathered from a number of studies highlights that NO is one of the key messengers mediating Ca2+ signaling. Here, we present a concise description of the current understanding of the molecular mechanisms underlying the cross talk between Ca2+ and NO in plant cells exposed to biotic stress. Particular attention will be given to the involvement of cyclic nucleotide-gated ion channels and Ca2+ sensors. Notably, we provide new evidence that calmodulin might be regulated at the posttranslational level by NO through S-nitrosylation. Furthermore, we report original transcriptomic data showing that NO produced in response to oligogalacturonide regulates the expression of genes related to Ca2+ signaling. Deeper insight into the molecules involved in the interplay between Ca2+ and NO not only permits a better characterization of the Ca2+ signaling system but also allows us to further understand how plants respond to pathogen attack. [ABSTRACT FROM AUTHOR]

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Abstract: In this study, we investigated a role for nitric oxide (NO) in mediating the elevation of the free cytosolic Ca2+ concentration ([Ca2+]cyt) in plants using Nicotiana plumbaginifolia cells expressing the Ca2+ reporter apoaequorin. Hyperosmotic stress induced a fast increase of [Ca2+]cyt which was strongly reduced by pretreating cell suspensions with the NO scavenger carboxy PTIO, indicating that NO mediates [Ca2+]cyt changes in plant cells challenged by abiotic stress. Accordingly, treatment of transgenic N. plumbaginifolia cells with the NO donor diethylamine NONOate was followed by a transient increase of [Ca2+]cyt sensitive to plasma membrane Ca2+ channel inhibitors and antagonist of cyclic ADP ribose. We provided evidence that NO might activate plasma membrane Ca2+ channels by inducing a rapid and transient plasma membrane depolarization. Furthermore, NO-induced elevation of [Ca2+]cyt was suppressed by the kinase inhibitor staurosporine, suggesting that NO enhances [Ca2+]cyt by promoting phosphorylation-dependent events. This result was further supported by the demonstration that the NO donor induced the activation of a 42-kDa protein kinase which belongs to SnRK2 families and corresponds to Nicotiana tabacum osmotic-stress-activated protein kinase (NtOSAK). Interestingly, NtOSAK was activated in response to hyperosmotic stress through a NO-dependent process, supporting the hypothesis that NO also promotes protein kinase activation during physiological processes. [Copyright &y& Elsevier]

Nitric oxide (NO) is a free radical gas involved in a myriad of plant physiological processes including immune responses. How NO mediates its biological effects in plant facing microbial pathogen attack is an unresolved question. Insights into the molecular mechanisms by which it propagates signals reveal the contribution of this simple gas in complex signaling pathways shared with reactive oxygen species (ROS) and the second messenger Ca 2+ . Understanding of the subtle cross-talks operating between these signals was greatly improved by the recent identification and the functional analysis of proteins regulated through S-nitrosylation, a major NO-dependent post-translational protein modification. Overall, these findings suggest that NO is probably an important component of the mechanism coordinating and regulating Ca 2+ and ROS signaling in plant immunity. [ABSTRACT FROM AUTHOR]

• Arbuscular mycorrhizal symbiosis lowers walnut rootstock dependency on Pi supply. • Symbiosis improves sapling development and quality under low Pi fertilization. • Arbuscular mycorrhizal benefits are rootstock-dependent. • Symbiotic growth gains are observed after acclimatization and post-acclimatization. The English walnut (Juglans regia L.) is the main species cultivated for the production of edible nuts. In vitro micropropagation of walnut explants, necessary for mass propagation of high-quality walnut rootstocks, needs an ex vitro acclimatization phase followed by a post -acclimatization growth in greenhouse when plantlets become photoautotrophic. However, poor survival and slow growth rates are common difficulties encountered in nurseries when establishing micropropagated walnut saplings. Walnut exhibits dependency on symbiotic soil-borne arbuscular mycorrhizal fungi for better soil nutrient acquisition and development due to a coarse root architecture that limits soil inorganic phosphate (Pi) uptake. In the context of rootstock production, the objective of this study was to investigate for the first time the effect of the arbuscular mycorrhizal fungus Rhizophagus irregularis on the growth, quality, and Pi nutrition of seven in vitro grown walnut rootstocks of economic interest (RG2, RG6, R17, RX1, VLACH, VX211, and WIP3). For this purpose, inoculation was performed before both acclimatization and post -acclimatization of rootstocks under two contrasting Pi fertilization regimes. Two months after inoculation, we analysed mycorrhizal growth, phosphate and quality responses in the four conditions tested by measuring plant height, root length, root surface, branch number, collar, biomass dry weight, Pi content, and quality (Dickson's index). The results indicated that Pi fertilization impacted root colonization parameters only in a few cases. Irrespective of root colonization parameters and developmental stages, mycorrhizal growth depression after inoculation with R. irregularis was generally observed with increasing Pi availability in the substrate. Principal component analysis showed that mycorrhizal dependency, growth and quality responses were positively correlated to each other under the lowest Pi fertilization regime tested, both at the acclimatization and post -acclimatization stages. We also found that mycorrhizal benefits in terms of growth, quality and Pi nutrition, were rootstock-dependent, indicating that walnut dependency for Pi nutrition varies between cultivars. [ABSTRACT FROM AUTHOR]

Real-time prediction of product temperature is a challenge for cold chain monitoring. The use of machine learning methods, especially neural networks, has been suggested as a possible approach. However, their training requires a large amount of good quality data. We found that experimental data leads to better results (by 20–40% compared with synthetic data) but require material investment, while synthetic data generated from thermal model is plentiful but tends to cause overfitting and overestimation of prediction performance (up to 150%). Our study shows that increasing the amount of synthetic data only decreases the variance, but not the mean error. The best strategy is to improve the thermal model used. As for experimental data, it is more useful to find an optimal position of the sensor in the pallet than using ever increasing realistic scenarios. Overall, even with imperfect predictions, machine learning models are able to predict temperature in real time thus enabling to take preventive measures when needed. • Product temperature in a pallet is predicted with neural networks trained on experimental and synthetic data. • Neural networks trained using experimental data give better performance. • Increasing the size of the synthetic dataset helps reducing the model's variance. • Noise addition to the synthetic dataset did not improve the model's performance. • Realistic time temperature scenarios based from field studies are not required to train machine learning model. [ABSTRACT FROM AUTHOR]

Carpooling is an emerging alternative transportation mode that is eco-friendly and sustainable as it enables commuters to save time, travel resource, reduce emission and traffic congestion. The procedure of carpooling consists of a number of steps namely; (i) create a motive to carpool, (ii) communicate this motive with other agents, (iii) negotiate a plan with the interested agents, (iv) execute the agreed plans, and (v) provide a feedback to all concerned agents. In this paper, we present a conceptual design of an agent-based model (ABM) for the carpooling a that serves as a proof of concept. Our model for the carpooling application is a computational model that is used for simulating the interactions of autonomous agents and to analyze the effects of change in factors related to the infrastructure, behavior and cost. In our carpooling application, we use agent profiles and social networks to initiate our agent communication model and then employ a route matching algorithm, and a utility function to trigger the negotiation process between agents. We developed a prototype of our agent-based carpooling application based on the work presented in this paper and carried out a validation study of our results with real data collected in Flanders, Belgium. [ABSTRACT FROM AUTHOR]

Abstract: Testing algorithms with real cars is a mandatory step in developing new intelligent abilities for future transportation systems. However, this step is sometimes hard to accomplish especially due to several problems. It is also difficult to reproduce the same scenario several times. Besides, some critical and/or real world forbidden scenarios cannot be tested. Thus, the comparison of several algorithms using the same experimental conditions is hard to realize. Considering that, it seems important to use simulation tools to perform scenarios with realistic conditions. The main problem with these tools is their distance from real conditions, since they deeply simplify the reality. This paper presents the architecture of the simulation/prototyping tool named Virtual Intelligent Vehicle Urban Simulator (vivus). The goal of vivus is thus to overcome the general drawbacks of classical solutions by providing the possibility of designing a vehicle virtual prototype with simulated embedded sensors and physical properties. Experiments made on linear platoon algorithms are exposed in this paper in order to illustrate the similarities between simulated results and those obtained with real cars. [Copyright &y& Elsevier]

Ectopic expression of defensins in plants correlates with their increased capacity to withstand abiotic and biotic stresses. This applies to Arabidopsis thaliana, where some of the seven members of the PLANT DEFENSIN 1 family (AtPDF1) are recognised to improve plant responses to necrotrophic pathogens and increase seedling tolerance to excess zinc (Zn). However, few studies have explored the effects of decreased endogenous defensin expression on these stress responses. Here, we carried out an extensive physiological and biochemical comparative characterization of (i) novel artificial microRNA (amiRNA) lines silenced for the five most similar AtPDF1s, and (ii) a double null mutant for the two most distant AtPDF1s. Silencing of five AtPDF1 genes was specifically associated with increased aboveground dry mass production in mature plants under excess Zn conditions, and with increased plant tolerance to different pathogens - a fungus, an oomycete and a bacterium, while the double mutant behaved similarly to the wild type. These unexpected results challenge the current paradigm describing the role of PDFs in plant stress responses. Additional roles of endogenous plant defensins are discussed, opening new perspectives for their functions., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)