scholarly journals Evo-physio: on stress responses and the earliest land plants

2020 ◽  
Vol 71 (11) ◽  
pp. 3254-3269 ◽  
Author(s):  
Janine M R Fürst-Jansen ◽  
Sophie de Vries ◽  
Jan de Vries
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Plant Cells ◽  
Land Plant ◽  
Land Plants ◽  
Comparative Approach ◽  
Environmental Cues ◽  
Evolutionary Event ◽  
Shed Light ◽  
Genetic Toolkit

Abstract Embryophytes (land plants) can be found in almost any habitat on the Earth’s surface. All of this ecologically diverse embryophytic flora arose from algae through a singular evolutionary event. Traits that were, by their nature, indispensable for the singular conquest of land by plants were those that are key for overcoming terrestrial stressors. Not surprisingly, the biology of land plant cells is shaped by a core signaling network that connects environmental cues, such as stressors, to the appropriate responses—which, thus, modulate growth and physiology. When did this network emerge? Was it already present when plant terrestrialization was in its infancy? A comparative approach between land plants and their algal relatives, the streptophyte algae, allows us to tackle such questions and resolve parts of the biology of the earliest land plants. Exploring the biology of the earliest land plants might shed light on exactly how they overcame the challenges of terrestrialization. Here, we outline the approaches and rationale underlying comparative analyses towards inferring the genetic toolkit for the stress response that aided the earliest land plants in their conquest of land.

scholarly journals Make and break the alarmone: regulation of (p)ppGpp synthetase/hydrolase enzymes in bacteria

2019 ◽  
Vol 43 (4) ◽  
pp. 389-400 ◽  
Author(s):  
Séverin Ronneau ◽  
Régis Hallez
Keyword(s):  
Cell Cycle ◽  
Stress Response ◽  
Stress Responses ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Second Messengers ◽  
Molecular Devices ◽  
Environmental Cues ◽  
Fluctuating Environments ◽  
Harsh Conditions

ABSTRACTBacteria use dedicated mechanisms to respond adequately to fluctuating environments and to optimize their chances of survival in harsh conditions. One of the major stress responses used by virtually all bacteria relies on the sharp accumulation of an alarmone, the guanosine penta- or tetra-phosphate commonly referred to as (p)ppGpp. Under stressful conditions, essentially nutrient starvation, these second messengers completely reshape the metabolism and physiology by coordinately modulating growth, transcription, translation and cell cycle. As a central regulator of bacterial stress response, the alarmone is also involved in biofilm formation, virulence, antibiotics tolerance and resistance in many pathogenic bacteria. Intracellular concentrations of (p)ppGpp are determined by a highly conserved and widely distributed family of proteins called RelA-SpoT Homologs (RSH). Recently, several studies uncovering mechanisms that regulate RSH activities have renewed a strong interest in this field. In this review, we outline the diversity of the RSH protein family as well as the molecular devices used by bacteria to integrate and transform environmental cues into intracellular (p)ppGpp levels.

scholarly journals Recruitment of archaeal DTD is a key event toward the emergence of land plants

2021 ◽  
Vol 7 (6) ◽  
pp. eabe8890
Author(s):  
Mohd Mazeed ◽  
Raghvendra Singh ◽  
Pradeep Kumar ◽  
Ankit Roy ◽  
Bakthisaran Raman ◽  
...  
Keyword(s):  
Stress Responses ◽  
Elongation Factor ◽  
Methanogenic Archaea ◽  
Land Plant ◽  
Land Plants ◽  
Central Component ◽  
Toxic Metabolite ◽  
Biotic And Abiotic Stresses ◽  
Transfer Event ◽  
Anaerobic Stress

Streptophyte algae emerged as a land plant with adaptations that eventually led to terrestrialization. Land plants encounter a range of biotic and abiotic stresses that elicit anaerobic stress responses. Here, we show that acetaldehyde, a toxic metabolite of anaerobic stress, targets and generates ethyl adducts on aminoacyl-tRNA, a central component of the translation machinery. However, elongation factor thermo unstable (EF-Tu) safeguards l-aminoacyl-tRNA, but not d-aminoacyl-tRNA, from being modified by acetaldehyde. We identified a unique activity of archaeal-derived chiral proofreading module, d-aminoacyl-tRNA deacylase 2 (DTD2), that removes N-ethyl adducts formed on d-aminoacyl-tRNAs (NEDATs). Thus, the study provides the molecular basis of ethanol and acetaldehyde hypersensitivity in DTD2 knockout plants. We uncovered an important gene transfer event from methanogenic archaea to the ancestor of land plants. While missing in other algal lineages, DTD2 is conserved from streptophyte algae to land plants, suggesting its role toward the emergence and evolution of land plants.

scholarly journals Diversity, development and evolution of archegonia in land plants

2020 ◽  
Author(s):  
Dmitry D Sokoloff ◽  
Margarita V Remizowa
Keyword(s):  
Pollen Tube ◽  
Reproductive Organs ◽  
Land Plant ◽  
Land Plants ◽  
Comparative Approach ◽  
Egg Cell ◽  
Plant Structure ◽  
Male Gametes ◽  
Canal Cell ◽  
Cover Cell

Abstract We review the diversity and development of archegonia, the female reproductive organs of land-plant gametophytes. The archegonium is a uniquely land-plant structure, and studies of its evolution benefit from use of a comparative approach in a phylogenetic context. Archegonia of most land plants share a common developmental motif, here termed a T-shaped pattern. A primary axial cell produces a primary cover cell and a central cell by horizontal division. The upper cell usually divides vertically and the lower one horizontally. In mosses such as Atrichum, the T-shaped stage is shifted towards the end of archegonium development, whereas in vascular plants it appears at the beginning of development, but these stages are still probably homologous. The fully exposed archegonia are traditionally viewed as an ancestral (plesiomorphic) condition in land plants, but there is no direct support for this view. We speculate that the fully exposed condition is derived and synapomorphic for setaphytes (mosses and liverworts). The fully sunken hornwort archegonia may be similar to the ancestral type of land-plant archegonia. Developmental evidence suggests that archegonium necks of setaphytes and tracheophytes are not homologous to each other. The neck wall of pteridophytes is composed of four-celled tiers, and one such tier is present in gymnosperms with motile male gametes. Neck-cell arrangement is much more plastic in archegonia of gymnosperms with sperm cell delivery by pollen tube (siphonogamy), in which the neck plays a role similar to pollen-tube transmitting tissue of angiosperms. Angiosperm synergids are probably homologues of gymnosperm neck cells, and the angiosperm egg cell is probably homologous to the ventral canal cell of gymnosperms. Developmental genetic bases of archegonium diversity in land plants remain to be understood. Even descriptive developmental data are currently missing or controversial for some key lineages of land plants.

scholarly journals Interaction of causative agents of sapronoses with the land plant Lithospermum erythrorhizon

2022 ◽  
Vol 98 (6) ◽  
pp. 664-670
Author(s):  
N. F. Timchenko ◽  
М. G. Еliseikina ◽  
G. K. Tchernoded ◽  
O. V. Grishchenko ◽  
А. V. Rakov ◽  
...  
Keyword(s):  
Yersinia Pseudotuberculosis ◽  
Plant Cells ◽  
Callus Cultures ◽  
Land Plant ◽  
Land Plants ◽  
Lithospermum Erythrorhizon ◽  
Root Crops ◽  
Causative Agents ◽  
Terrestrial Biodiversity ◽  
Scanning Electron

Background. A significant role in the ecology of the sapronotic pathogens Yersinia pseudotuberculosis and Listeria monocytogenes and in the epidemiology of the infections they cause is played by land plants used for food. These microorganisms are often found on plant substrates, they multiply on various vegetable and root crops. In this regard, it is relevant to study the viability and biological activity of Y. pseudotuberculosis and L. monocytogenes in contact with various land plants, including those that are not eaten, but are used in medicine.Aim. Study of the interaction of sapronotic pathogens Y. pseudotuberculosis and L. monocytogenes with callus cultures of the land plant Lithospermum erythrorhizon Siebold et Zucc.Materials and methods. The studies included strains of Y. pseudotuberculosis 512 serotype 1b, pYV+, 82MD+ and L. monocytogenes NCTC (4b) 10527 from the Collection of Somov Institute of Epidemiology and Microbiology, and cell culture from the roots of red-root gromwell Lithospermum erythrorhizon line VC-39 (from the Collection of FSC of the East Asia Terrestrial Biodiversity FEB RAS).Before the study, Y. pseudotuberculosis and L . monocytogenes were cultured 18–20 hours on nutrient agar pH 7.1–7.2. A working dilution of microorganisms was prepared (106 micobial cells per 1 ml) and applied at a dose of 100 μl to the surface of plant calli. Material samples were taken in dynamics after 3 and 14 days and prepared for scanning electron microscopy.Results. Y. pseudotuberculosis and L. monocytogenes formed biofilms on the surface of plant cells within 3 days after the start of the experiment. It was noted that Y. pseudotuberculosis destroyed the components of the plant cell membrane.Conclusion. New data obtained during the study expand the understanding of environments and forms of habitation, as well as the potential for pathogenicity of sapronotic pathogens in the environment.

scholarly journals Proteomics and Metabolomics Studies on the Biotic Stress Responses of Rice: an Update

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kieu Thi Xuan Vo ◽  
Md Mizanor Rahman ◽  
Md Mustafizur Rahman ◽  
Kieu Thi Thuy Trinh ◽  
Sun Tae Kim ◽  
...  
Keyword(s):  
Stress Responses ◽  
Biotic Stress ◽  
Defense Mechanisms ◽  
Defense Responses ◽  
Global Changes ◽  
Biotic Stresses ◽  
Novel Proteins ◽  
Stress Agent ◽  
Global Food ◽  
Shed Light

AbstractBiotic stresses represent a serious threat to rice production to meet global food demand and thus pose a major challenge for scientists, who need to understand the intricate defense mechanisms. Proteomics and metabolomics studies have found global changes in proteins and metabolites during defense responses of rice exposed to biotic stressors, and also reported the production of specific secondary metabolites (SMs) in some cultivars that may vary depending on the type of biotic stress and the time at which the stress is imposed. The most common changes were seen in photosynthesis which is modified differently by rice plants to conserve energy, disrupt food supply for biotic stress agent, and initiate defense mechanisms or by biotic stressors to facilitate invasion and acquire nutrients, depending on their feeding style. Studies also provide evidence for the correlation between reactive oxygen species (ROS) and photorespiration and photosynthesis which can broaden our understanding on the balance of ROS production and scavenging in rice-pathogen interaction. Variation in the generation of phytohormones is also a key response exploited by rice and pathogens for their own benefit. Proteomics and metabolomics studies in resistant and susceptible rice cultivars upon pathogen attack have helped to identify the proteins and metabolites related to specific defense mechanisms, where choosing of an appropriate method to identify characterized or novel proteins and metabolites is essential, considering the outcomes of host-pathogen interactions. Despites the limitation in identifying the whole repertoire of responsive metabolites, some studies have shed light on functions of resistant-specific SMs. Lastly, we illustrate the potent metabolites responsible for resistance to different biotic stressors to provide valuable targets for further investigation and application.

scholarly journals Flavonoids: Potential Candidates for the Treatment of Neurodegenerative Disorders

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 99
Author(s):  
Shweta Devi ◽  
Vijay Kumar ◽  
Sandeep Kumar Singh ◽  
Ashish Kant Dubey ◽  
Jong-Joo Kim
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Neurodegenerative Disorders ◽  
Cell Damage ◽  
Cellular Stress ◽  
Clinical Manifestations ◽  
Cellular Stress Response ◽  
Dramatic Rise ◽  
Cellular Stress Responses

Neurodegenerative disorders, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.

scholarly journals Environmental Conditions Modulate the Transcriptomic Response of Both Caulobacter crescentus Morphotypes to Cu Stress

2021 ◽  
Vol 9 (6) ◽  
pp. 1116
Author(s):  
Laurens Maertens ◽  
Pauline Cherry ◽  
Françoise Tilquin ◽  
Rob Van Houdt ◽  
Jean-Yves Matroule
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Stress Responses ◽  
Caulobacter Crescentus ◽  
Oxidative Stress Response ◽  
Transport Systems ◽  
Transcriptomic Response ◽  
Swarmer Cell ◽  
Cu Stress ◽  
Cellular Environment

Bacteria encounter elevated copper (Cu) concentrations in multiple environments, varying from mining wastes to antimicrobial applications of copper. As the role of the environment in the bacterial response to Cu ion exposure remains elusive, we used a tagRNA-seq approach to elucidate the disparate responses of two morphotypes of Caulobacter crescentus NA1000 to moderate Cu stress in a complex rich (PYE) medium and a defined poor (M2G) medium. The transcriptome was more responsive in M2G, where we observed an extensive oxidative stress response and reconfiguration of the proteome, as well as the induction of metal resistance clusters. In PYE, little evidence was found for an oxidative stress response, but several transport systems were differentially expressed, and an increased need for histidine was apparent. These results show that the Cu stress response is strongly dependent on the cellular environment. In addition, induction of the extracytoplasmic function sigma factor SigF and its regulon was shared by the Cu stress responses in both media, and its central role was confirmed by the phenotypic screening of a sigF::Tn5 mutant. In both media, stalked cells were more responsive to Cu stress than swarmer cells, and a stronger basal expression of several cell protection systems was noted, indicating that the swarmer cell is inherently more Cu resistant. Our approach also allowed for detecting several new transcription start sites, putatively indicating small regulatory RNAs, and additional levels of Cu-responsive regulation.

Clade III cytokinin response factors share common roles in response to oxidative stress responses linked to cytokinin synthesis

2021 ◽  
Vol 72 (8) ◽  
pp. 3294-3306
Author(s):  
Ariel M Hughes ◽  
H Tucker Hallmark ◽  
Lenka Plačková ◽  
Ondrej Novák ◽  
Aaron M Rashotte
Keyword(s):  
Oxidative Stress ◽  
Transcription Factors ◽  
Stress Response ◽  
Stress Responses ◽  
Oxidative Stress Response ◽  
Response Factors ◽  
Ontology Term ◽  
Regulated Expression ◽  
Cytokinin Response ◽  
Oxidative Stress Responses

Abstract Cytokinin response factors (CRFs) are transcription factors that are involved in cytokinin (CK) response, as well as being linked to abiotic stress tolerance. In particular, oxidative stress responses are activated by Clade III CRF members, such as AtCRF6. Here we explored the relationships between Clade III CRFs and oxidative stress. Transcriptomic responses to oxidative stress were determined in two Clade III transcription factors, Arabidopsis AtCRF5 and tomato SlCRF5. AtCRF5 was required for regulated expression of >240 genes that are involved in oxidative stress response. Similarly, SlCRF5 was involved in the regulated expression of nearly 420 oxidative stress response genes. Similarities in gene regulation by these Clade III members in response to oxidative stress were observed between Arabidopsis and tomato, as indicated by Gene Ontology term enrichment. CK levels were also changed in response to oxidative stress in both species. These changes were regulated by Clade III CRFs. Taken together, these findings suggest that Clade III CRFs play a role in oxidative stress response as well as having roles in CK signaling.

scholarly journals Stress Responses in Down Syndrome Neurodegeneration: State of the Art and Therapeutic Molecules

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Chiara Lanzillotta ◽  
Fabio Di Domenico
Keyword(s):  
Down Syndrome ◽  
Stress Response ◽  
Stress Responses ◽  
Redox Balance ◽  
Antioxidant Response ◽  
Chromosome 21 ◽  
Therapeutic Approaches ◽  
Genomic Disorder ◽  
Therapeutic Molecules ◽  
Early Alzheimer’S Disease

Down syndrome (DS) is the most common genomic disorder characterized by the increased incidence of developing early Alzheimer’s disease (AD). In DS, the triplication of genes on chromosome 21 is intimately associated with the increase of AD pathological hallmarks and with the development of brain redox imbalance and aberrant proteostasis. Increasing evidence has recently shown that oxidative stress (OS), associated with mitochondrial dysfunction and with the failure of antioxidant responses (e.g., SOD1 and Nrf2), is an early signature of DS, promoting protein oxidation and the formation of toxic protein aggregates. In turn, systems involved in the surveillance of protein synthesis/folding/degradation mechanisms, such as the integrated stress response (ISR), the unfolded stress response (UPR), and autophagy, are impaired in DS, thus exacerbating brain damage. A number of pre-clinical and clinical studies have been applied to the context of DS with the aim of rescuing redox balance and proteostasis by boosting the antioxidant response and/or inducing the mechanisms of protein re-folding and clearance, and at final of reducing cognitive decline. So far, such therapeutic approaches demonstrated their efficacy in reverting several aspects of DS phenotype in murine models, however, additional studies aimed to translate these approaches in clinical practice are still needed.

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