Key message
Sustaining yield gains of grain legume crops under growing salt-stressed conditions demands a thorough understanding of plant salinity response and more efficient breeding techniques that ...effectively integrate modern omics knowledge.
Grain legume crops are important to global food security being an affordable source of dietary protein and essential mineral nutrients to human population, especially in the developing countries. The global productivity of grain legume crops is severely challenged by the salinity stress particularly in the face of changing climates coupled with injudicious use of irrigation water and improper agricultural land management. Plants adapt to sustain under salinity-challenged conditions through evoking complex molecular mechanisms. Elucidating the underlying complex mechanisms remains pivotal to our knowledge about plant salinity response. Improving salinity tolerance of plants demand enriching cultivated gene pool of grain legume crops through capitalizing on ‘adaptive traits’ that contribute to salinity stress tolerance. Here, we review the current progress in understanding the genetic makeup of salinity tolerance and highlight the role of germplasm resources and omics advances in improving salt tolerance of grain legumes. In parallel, scope of next generation phenotyping platforms that efficiently bridge the phenotyping–genotyping gap and latest research advances including epigenetics is also discussed in context to salt stress tolerance. Breeding salt-tolerant cultivars of grain legumes will require an integrated “omics-assisted” approach enabling accelerated improvement of salt-tolerance traits in crop breeding programs.
Summary
The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ...ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation‐free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune‐based ocular surface disorders, which could be related to an age‐related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.
In the eye, the peripheral immune tolerance mechanisms at play differ markedly between the exposed ocular surface and the intraocular tissues. The mucosal surface that protects the outer ocular structures shares many immunoregulatory pathways with the mucosal linings of the gut and the respiratory tract that are collectively known as mucosal tolerance. Similarly, aging brings about immune dysregulation in all three mucosal sites that has broad implications in pathophysiology and that can be better appreciated by comparison, which is the aim of this review.
Random VDJ recombination early in T and B cell development enables the adaptive immune system to recognize a vast array of evolving pathogens via antigen receptors. However, the potential of such ...randomly generated TCRs and BCRs to recognize and respond to self‐antigens requires layers of tolerance mechanisms to mitigate the risk of life‐threatening autoimmunity. Since they were originally cloned more than three decades ago, the NR4A family of nuclear hormone receptors have been implicated in many critical aspects of immune tolerance, including negative selection of thymocytes, peripheral T cell tolerance, regulatory T cells (Treg), and most recently in peripheral B cell tolerance. In this review, we discuss important insights from many laboratories as well as our own group into the function and mechanisms by which this small class of primary response genes promotes self‐tolerance and immune homeostasis to balance the need for host defense against the inherent risks posed by the adaptive immune system.
The perception and relay of cell-wall signals are critical for plants to regulate growth and stress responses, but the underlying mechanisms are poorly understood. We found that the cell-wall ...leucine-rich repeat extensins (LRX) 3/4/5 are critical for plant salt tolerance in Arabidopsis. The LRXs physically associate with the RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23, which in turn interact with the plasma membrane-localized receptor-like protein kinase FERONIA (FER). The lrx345 triplemutant as well as fer mutant plants display retarded growth and salt hypersensitivity, which are mimicked by overexpression of RALF22/23. Salt stress promotes S1P protease-dependent release of mature RALF22 peptides. Treatment of roots with mature RALF22/23 peptides or salt stress causes the internalization of FER. Our results suggest that the LRXs, RALFs, and FER function as a module to transduce cell-wall signals to regulate plant growth and salt stress tolerance.
The immune system is regulated to protect the host from exaggerated stimulatory signals establishing a state of tolerance in healthy individuals. The disequilibrium in immune regulatory vs effector ...mechanisms results in allergic or autoimmune disorders in genetically predisposed subjects under certain environmental conditions. As demonstrated in allergen‐specific immunotherapy and in the healthy immune response to high‐dose allergen exposure models in humans, T regulatory cells are essential in the suppression of Th2‐mediated inflammation, maintenance of immune tolerance, induction of the two suppressive cytokines interleukin‐10 and transforming growth factor‐β, inhibition of allergen‐specific IgE, and enhancement of IgG4 and IgA. Also, suppression of dendritic cells, mast cells, and eosinophils contributes to the construction of peripheral tolerance to allergens. This review focuses on mechanisms of peripheral tolerance to allergens with special emphasis on recent developments in the area of immune regulation.
Outstanding questions in transplantation: Tolerance Leventhal, Joseph R.; Mathew, James M.
American journal of transplantation,
February 2020, 2020-02-00, 20200201, Letnik:
20, Številka:
2
Journal Article
Recenzirano
Odprti dostop
In 2017, the American Society of Transplantation (AST) launched the Outstanding Questions in Transplantation Research forum to stimulate a community‐wide discussion of how the field is evolving and ...to help identify areas where a better dialogue between clinicians and researchers could result in great advancements. Tolerance emerged as a topic of great interest to the AST community. This minireview provides an overview of clinical transplantation tolerance. Historical background followed by a review of the current status of attempts to establish tolerance in the clinic, highlighting the dynamic online discussion surrounding this important topic from the AST Transplantation Research forum, is provided.
This minireview provides an overview of the current state of clinical transplantation tolerance, highlighting discussions on the topic by the "Outstanding Questions in Transplantation Research" forum organized by the American Society of Transplantation.
Because of the rise in global temperature, heat stress has become a major concern for crop production. Heat stress deteriorates plant productivity and alters phenological and physiological responses ...that aid in precise monitoring and sensing of mild-to-severe transient heat stress. Plants have evolved several sophisticated mechanisms including hormone-signaling pathways to sense heat stimuli and acquire heat stress tolerance. In response to heat stress, ethylene, a gaseous hormone, is produced which is indispensable for plant growth and development and tolerance to various abiotic stresses including heat stress. The manipulation of ethylene in developing heat stress tolerance targeting ethylene biosynthesis and signaling pathways has brought promising out comes. Conversely increased ethylene biosynthesis and signaling seem to exhibit inhibitory effects in plant growth responses from primitive to maturity stages. This review mainly focuses on the recent studies of ethylene involvement in plant responses to heat stress and its functional regulation, and molecular mechanism underlying the plant responses in the mitigation of heat-induced damages. Furthermore, this review also describes the crosstalk between ethylene and other signaling molecules under heat stress and approaches to improve heat stress tolerance in plants.
Tropical forests are experiencing unprecedented high‐temperature conditions due to climate change that could limit their photosynthetic functions. We studied the high‐temperature sensitivity of ...photosynthesis in a rainforest site in southern Amazonia, where some of the highest temperatures and most rapid warming in the Tropics have been recorded. The quantum yield (Fv/Fm) of photosystem II was measured in seven dominant tree species using leaf discs exposed to varying levels of heat stress. T50 was calculated as the temperature at which Fv/Fm was half the maximum value. T5 is defined as the breakpoint temperature, at which Fv/Fm decline was initiated. Leaf thermotolerance in the rapidly warming southern Amazonia was the highest recorded for forest tree species globally. T50 and T5 varied between species, with one mid‐storey species, Amaioua guianensis, exhibiting particularly high T50 and T5 values. While the T50 values of the species sampled were several degrees above the maximum air temperatures experienced in southern Amazonia, the T5 values of several species are now exceeded under present‐day maximum air temperatures.
Although high‐temperature tolerance of photosystem II (PSII) in trees from the southern Amazonian forests was the highest in the literature, maximum air temperatures during the dry periods has already reached levels that overlap with the range of PSII temperature sensitivity.
Trained immunity in organ transplantation Ochando, Jordi; Fayad, Zahi A.; Madsen, Joren C. ...
American journal of transplantation,
January 2020, Letnik:
20, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Consistent induction of donor‐specific unresponsiveness in the absence of continuous immunosuppressive therapy and toxic effects remains a difficult task in clinical organ transplantation. Transplant ...immunologists have developed numerous experimental treatments that target antigen‐presentation (signal 1), costimulation (signal 2), and cytokine production (signal 3) to establish transplantation tolerance. While promising results have been obtained using therapeutic approaches that predominantly target the adaptive immune response, the long‐term graft survival rates remain suboptimal. This suggests the existence of unrecognized allograft rejection mechanisms that contribute to organ failure. We postulate that trained immunity stimulatory pathways are critical to the immune response that mediates graft loss. Trained immunity is a recently discovered functional program of the innate immune system, which is characterized by nonpermanent epigenetic and metabolic reprogramming of macrophages. Since trained macrophages upregulate costimulatory molecules (signal 2) and produce pro‐inflammatory cytokines (signal 3), they contribute to potent graft reactive immune responses and organ transplant rejection. In this review, we summarize the detrimental effects of trained immunity in the context of organ transplantation and describe pathways that induce macrophage training associated with graft rejection.
Ochando and colleagues describe the detrimental effects of trained immunity in organ transplantation and review mechanistic pathways that induce macrophage training associated with graft rejection.
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