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Background: Mortality from breast cancer is principally due to tumor recurrence. Recurrent breast cancers arise from the pool of residual tumor cells, termed minimal residual disease, that survive treatment and may exist in a dormant state for 20 years or more following treatment of the primary tumor. As recurrent breast cancer is typically incurable, understanding the mechanisms underlying dormant tumor cell survival is a critical priority in breast cancer research. The importance of this goal is further underscored by emerging evidence suggesting that targeting dormant residual tumor cells in early-stage breast cancer patients may be a means to prevent tumor recurrence and its associated mortality. In this regard, the role of autophagy in dormant tumor cell survival and recurrence remains unresolved, with conflicting reports of both pro-survival/recurrence-promoting and pro-death/recurrence-suppressing effects of autophagy inhibition in dormant tumor cells. Resolving this question has important clinical implications. Methods: We used genetically engineered mouse models that faithfully recapitulate key features of human breast cancer progression, including minimal residual disease, tumor dormancy, and recurrence. We used genetic and pharmacological approaches to inhibit autophagy, including treatment with chloroquine, genetic knockdown of ATG5 or ATG7, or deletion of BECN and determined their effects on dormant tumor cell survival and recurrence. Results: We demonstrate that the survival and recurrence of dormant mammary tumor cells following therapy is dependent upon autophagy. We find that autophagy is induced in vivo following HER2 downregulation and remains activated in dormant residual tumor cells. Using genetic and pharmacological approaches we show that inhibiting autophagy by chloroquine administration, ATG5 or ATG7 knockdown, or deletion of a single allele of the tumor suppressor Beclin 1 is sufficient to inhibit mammary tumor recurrence, and that autophagy inhibition results in the death of dormant mammary tumor cells in vivo. Conclusions: Our findings demonstrate a pro-tumorigenic role for autophagy in tumor dormancy and recurrence following therapy, reveal that dormant tumor cells are uniquely reliant upon autophagy for their survival, and indicate that targeting dormant residual tumor cells by inhibiting autophagy impairs tumor recurrence. These studies identify a pharmacological target for a cellular state that is resistant to commonly used anti-neoplastic agents and suggest autophagy inhibition as an approach to reduce dormant minimal residual disease in order to prevent lethal tumor recurrence. [ABSTRACT FROM AUTHOR]

Summary: Two functional responses largely guide woody plants' survival to winter conditions: cold hardiness and dormancy. Dormancy affects budbreak timing based on chill accumulation. Effects of warming on dormancy may appear time‐shifted: fall and winter warming events decrease chill accumulation, delaying budbreak observed in spring. The same warming events also affect cold hardiness dynamics, having immediate implications. As cold deacclimation rates increase with dormancy progression, the same amount of warming has greater damage risk the later it occurs in the season, depending on return of low temperatures. Should frequency of erratic weather increase with climate change, more instances of risk are expected. However, understanding how plants fare through seasons now and in future climates still requires better knowledge of winter physiology. [ABSTRACT FROM AUTHOR]

This article discusses the concept of quiescence and dormancy in plants and their importance in plant development, acclimation, and survival. The article highlights recent research on the molecular and metabolic regulation of quiescence, as well as the ecological modeling and molecular perception of temperature in relation to dormancy. The integration of hormone and cell-to-cell signaling, as well as the role of epigenetic mechanisms in establishing and maintaining dormancy, is also explored. The article concludes by emphasizing the potential applications of this research in enhancing plant resilience in the face of climate change. [Extracted from the article]

Winter dormancy is a key process in the phenology of temperate perennials. Climate change is severely impacting its course leading to economic losses in agriculture. A better understanding of the underlying mechanisms, as well as the genetic basis of the different responses, is necessary for the development of climate-resilient cultivars. This study aims to provide an insight into winter dormancy in red raspberry (Rubus idaeus L). We report the transcriptomic profiles during dormancy in two raspberry cultivars with contrasting responses. The cultivar 'Glen Ample' showed a typical perennial phenology, whereas 'Glen Dee' registered consistent dormancy dysregulation, exhibiting active growth and flowering out of season. RNA-seq combined with weighted gene co-expression network analysis identified gene clusters in both genotypes that exhibited time-dependent expression profiles. Functional analysis of 'Glen Ample' gene clusters highlighted the significance of the cell and structural development prior to dormancy entry as well the role of genetic and epigenetic processes such as RNAi and DNA methylation in regulating gene expression. Dormancy release in 'Glen Ample' was associated with up-regulation of transcripts associated with the resumption of metabolism, nucleic acid biogenesis, and processing signal response pathways. Many of the processes occurring in 'Glen Ample' were dysregulated in 'Glen Dee' and 28 transcripts exhibiting time-dependent expression in 'Glen Ample' that also had an Arabidopsis homologue were not found in 'Glen Dee'. These included a gene with homology to Arabidopsis VRN1 (RiVRN1.1) that exhibited a sharp decline in expression following dormancy induction in 'Glen Ample'. Characterization of the gene region in the 'Glen Dee' genome revealed two large insertions upstream of the ATG start codon. We propose that expression below detection level of a specific VRN1 homologue in 'Glen Dee' causes dormancy misregulation as a result of inappropriate expression of a subset of genes that are directly or indirectly regulated by RiVRN1.1. [ABSTRACT FROM AUTHOR]

This article, published in the Journal of Experimental Botany, reinterprets the concept of olive bud dormancy. The authors argue that olive buds do not undergo true physiological dormancy, but rather go through a process of para-dormancy and eco-dormancy. They discuss the challenges of studying bud dormancy in olive trees, which are evergreen and have different growth patterns compared to deciduous trees. The article also explores the relationship between cold temperatures and flowering in olive trees, highlighting the role of the FT gene in promoting flower induction. Overall, the authors suggest that further research is needed to better understand the reproductive biology of olive trees and improve olive production. [Extracted from the article]

Fundamental questions in bud dormancy remain, including what temperatures fulfill dormancy requirements (i.e. chill accumulation). Recent studies demonstrate freezing temperatures promote chill accumulation and cold hardiness influences time to budbreak—the phenotype used for dormancy evaluations. Here we evaluated bud cold hardiness and budbreak responses of grapevines (Vitis hybrids) throughout chill accumulation under three treatments: constant (5 °C), fluctuating (−3.5 to 6.5 °C daily), and field conditions (Madison, WI, USA). Chill treatments experiencing lower temperatures promoted greater gains in cold hardiness (field>fluctuating>constant). All treatments decreased observed time to budbreak with increased chill accumulation. However, perceived treatment effectiveness changed when time to budbreak was adjusted to remove cold acclimation effects. Among three classic chill models (North Carolina, Utah, and Dynamic), none was able to correctly describe adjusted time to budbreak responses to chill accumulation. Thus, a new model is proposed that expands the range of chill accumulation temperatures to include freezing temperatures and enhances chill accumulation under fluctuating temperature conditions. Most importantly, our analysis demonstrates that adjustments for uneven acclimation change the perceived effectiveness of chill treatments. Therefore, future work in bud dormancy would benefit from simultaneously evaluating cold hardiness. [ABSTRACT FROM AUTHOR]

Plants exhibit opportunistic developmental patterns, alternating between growth and dormancy in response to external cues. Moreover, quiescence plays a critical role in proper plant growth and development, particularly within the root apical meristem and the shoot apical meristem. In these meristematic tissues, cells with relatively slower mitotic activity are present in the quiescent center and the central zone, respectively. These centers form long-term reservoirs of stem cells maintaining the meristematic stem cell niche, and thus sustaining continuous plant development and adaptation to changing environments. This review explores early observations, structural characteristics, functions, and gene regulatory networks of the root and shoot apical meristems. It also highlights the intricate mechanism of dormancy within the shoot apical meristem. The aim is to contribute to a holistic understanding of quiescence in plants, which is fundamental for the proper growth and environmental response of plants. [ABSTRACT FROM AUTHOR]

Seasonal bud dormancy in perennial woody plants is a crucial and intricate process that is vital for the survival and development of plants. Over the past few decades, significant advancements have been made in understanding many features of bud dormancy, particularly in model species, where certain molecular mechanisms underlying this process have been elucidated. We provide an overview of recent molecular progress in understanding bud dormancy in trees, with a specific emphasis on the integration of common signaling and molecular mechanisms identified across different tree species. Additionally, we address some challenges that have emerged from our current understanding of bud dormancy and offer insights for future studies. [ABSTRACT FROM AUTHOR]

Plant quiescence and seed dormancy can be triggered by reduced oxygen availability. Under water, oxygen depletion caused by flooding can culminate in a quiescent state, which is a plant strategy for energy preservation and survival. In adult plants, a quiescent state can be activated by sugar starvation, leading to metabolic depression. In seeds, secondary dormancy can be activated by reduced oxygen availability, which creates an unfavourable state for germination. The physical dormancy of some seeds and buds includes barriers to external conditions, which indirectly results in hypoxia. The molecular processes that support seed dormancy and plant survival through quiescence under hypoxia include the N-degron pathway, which enables the modulation of ethylene-responsive factors of group VII and downstream targets. This oxygen- and nitric oxide-dependent mechanism interacts with phytohormone-related pathways to control growth. [ABSTRACT FROM AUTHOR]

Quiescence is an essential property of meristematic cells, which restrains the cell cycle while retaining the capacity to divide. This crucial process not only facilitates life-long tissue homeostasis and regenerative capacity but also provides protection against adverse environmental conditions, enabling cells to conserve the proliferative potency while minimizing DNA damage. As a survival attribute, quiescence is inherently regulated by the products of aerobic life, in particular reactive oxygen species (ROS) and the redox (reduction/oxidation) mechanisms that plant have evolved to channel these into pervasive signals. Adaptive responses allow quiescent cells to compensate for reduced oxygen tension (hypoxia) in a reversible manner, while the regulated production of the superoxide anion (O2·−) facilitates cell division and the maintenance of stem cells. Here we discuss the role of ROS and redox reactions in the control of the quiescent state in plant meristems, and how this process is integrated with cellular energy and hormone biochemistry. We consider the pathways that sense and transmit redox signals with a focus on the central significance of redox regulation in the mitochondria and nucleus, which is a major regulator of quiescence in meristems. We discuss recent studies that suggest that ROS are a critical component of the feedback loops that control stem cell identity and fate, and suggest that the ROS/hypoxia interface is an important 'outside/in' positional cue for plant cells, particularly in meristems. [ABSTRACT FROM AUTHOR]

Introduction: This report presents a case of an exceptionally delayed distant recurrence of a choroidal melanoma, occurring 4 decades after the enucleation of the affected eye. Case Presentation: In 1977, a 29-year-old man underwent enucleation for a choroidal melanoma. At the age of 68 years, he was diagnosed with advanced prostate cancer. Although the metastatic prostate cancer responded to treatment, a persistent lung lesion warranted further examination. A lung biopsy, somewhat surprisingly, confirmed the presence of melanoma metastasis, 4 decades after the enucleation. The cells were positive for Melan-A, while no BRAF mutation was identified. Two years later, new lesions appeared in the liver, and CT showed progression with multiple new sites. A liver biopsy revealed again melanoma recurrence, and its choroidal origin was verified by the presence of a GNA11 mutation. The patient underwent radiation therapy for the lung and liver lesions, followed by immunotherapy. However, the patient died 11 months after the recurrence in the liver. In this case report, the micrometastatic melanoma cells appear to have remained dormant for an extended period, before the patient’s treatment in 1977, but the reason for the late reactivation from the dormant state remains unclear. Conclusion: The recurrence of a choroidal melanoma is substantiated by the histopathological and molecular analyses, including the finding of a GNA11 mutation. This case exemplifies a remarkably delayed distant recurrence of a choroidal melanoma, which manifested clinically 40 years following enucleation. [ABSTRACT FROM AUTHOR]

Dormancy allows organisms to survive hostile conditions and is hypothesized to enable species to coexist in fluctuating environments. Although determining how species avoid extinction is critical to understanding the dynamics of natural populations, experimental work exploring if and when dormancy rescues populations from extinction remains rare. We conducted an experiment, where we grew two species of nematode at three temperatures. Strains of Caenorhabditis elegans had mutations altering their propensity to enter a dormant stage and Caenorhabditis briggsae was a single strain with a wildtype background. We used those empirical results to parameterize a model and simulate competitive outcomes in fluctuating environments between the two species. We show that upregulating the dormancy pathway rescues populations that would otherwise go extinct, thereby increasing coexistence between competing species. By leveraging the genetic tools available from a model system, this study provides experimental confirmation that dormancy specifically facilitates species coexistence and thereby promotes diversity. This study system could be used more expansively to explore the role of dormancy in species interactions. [ABSTRACT FROM AUTHOR]

Life on Earth has been through numerous challenges over eons and, one way or another, has always triumphed. From mass extinctions to more daily plights to find food, unpredictability is everywhere. The adaptability of life-forms to ever-changing environments is the key that confers life's robustness. Adaptability has become synonymous with Darwinian evolution mediated by heritable genetic changes. The extreme gene-centric view, while being of central significance, at times has clouded our appreciation of the cell as a self-regulating entity informed of, and informing, the genetic data. An essential element that powers adaptability is the ability to regulate cell growth. In this review, we provide an extensive overview of growth regulation spanning species, tissues, and regulatory mechanisms. We aim to highlight the commonalities, as well as differences, of these phenomena and their molecular regulators. Finally, we curate open questions and areas for further exploration. [ABSTRACT FROM AUTHOR]

Summary: Persistent bacteria are subset of cells capable of surviving bactericidal treatments longer. They originate in response to environmental stressors and show a longer lag phase compared to the rest of the population they are part of. Impact of persistent cells on food safety and role of common food preservation techniques in their formation are still unclear. This study aims to investigate whether osmotic stress induces formation of persistent cells in Listeria monocytogenes capable of resisting longer during cooking cycle of pork sausages. Lag‐phase duration at single‐cell level of a strain grown in 6%‐NaCl broth using image processing software was first investigated. Then, trend of the strain inactivation curve was evaluated in experimentally contaminated pork sausages cooked at 65 °C for 11 min. Results showed that salt triggers the formation of persistent cells characterised by a longer lag phase and increased heat resistance, posing a concern especially for ready‐to‐eat foods. [ABSTRACT FROM AUTHOR]

Dormancy is an essential ecological characteristic for the survival of organisms that experience harsh environments. Although factors that initiate dormancy vary, suppression or cessation of feeding activities are common among taxa. To distinguish between extrinsic and intrinsic causes of metabolic reduction, we focused on estivation, which occurs in summer when the feeding activity is generally enhanced. Sand lances (genus Ammodytes) are a unique marine fish with a long estivation period from early summer to late autumn. In the present study, we aimed to elucidate the control mechanisms of estivation in western sand lance (A. japonicus), and firstly examined behavioral changes in 8 months including a transition between active and dormant phases. We found that swimming/feeding behavior gradually decreased from June, and completely disappeared by late August, indicating all individuals had entered estivation. Next, we focused on leptin, known as a feeding suppression hormone in various organisms, and examined leptin‐A gene (AjLepA) expression in the brain that may regulate the seasonal behavioral pattern. AjLepA expression decreased after 7 days of fasting, suggesting that leptin has a function to regulate feeding in this species. The monthly expression dynamics of AjLepA during the feeding (active) and non‐feeding (estivation) periods showed that the levels gradually increased with the onset of estivation and reached its peak when all the experimental fish had estivated. The present study suggests that the suppression of feeding activity by leptin causes shift in the physiological modes of A. japonicus before estivation. Research highlights: Sand lance spends in sand for more than half a year without feeding, a unique dormancy among teleosts called estivationLeptin, a peptide hormone, was found to be involved in appetite suppression in brain and work to exert the onset of estivation [ABSTRACT FROM AUTHOR]

Sinopodophyllum hexandrum (Royle) Ying, an endangered perennial medicinal herb, exhibits morpho-physiological dormancy in its seeds, requiring cold stratification for germination. However, the precise molecular mechanisms underlying this transition from dormancy to germination remain unclear. This study integrates transcriptome and plant hormone-targeted metabolomics techniques to unravel these intricate molecular regulatory mechanisms during cold stratification in S. hexandrum seeds. Significant alterations in the physicochemical properties (starch, soluble sugars, soluble proteins) and enzyme activities (PK, SDH, G-6-PDH) within the seeds occur during stratification. To characterize and monitor the formation and transformation of plant hormones throughout this process, extracts from S. hexandrum seeds at five stratification stages of 0 days (S0), 30 days (S1), 60 days (S2), 90 days (S3), and 120 days (S4) were analyzed using UPLC-MS/MS, revealing a total of 37 differential metabolites belonging to seven major classes of plant hormones. To investigate the biosynthetic and conversion processes of plant hormones related to seed dormancy and germination, the transcriptome of S. hexandrum seeds was monitored via RNA-seq, revealing 65,372 differentially expressed genes associated with plant hormone synthesis and signaling. Notably, cytokinins (CKs) and gibberellins (GAs) exhibited synergistic effects, while abscisic acid (ABA) displayed antagonistic effects. Furthermore, key hub genes were identified through integrated network analysis. In this rigorous scientific study, we systematically elucidate the intricate dynamic molecular regulatory mechanisms that govern the transition from dormancy to germination in S. hexandrum seeds during stratification. By meticulously examining these mechanisms, we establish a solid foundation of knowledge that serves as a scientific basis for facilitating large-scale breeding programs and advancing the artificial cultivation of this highly valued medicinal plant. [ABSTRACT FROM AUTHOR]

Barley (Hordeum vulgare L.) is a major cereal grain with uses in the feed, food, and malting industries. Growth habit, seed dormancy, and disease resistance are important considerations when selecting germplasm for production or release. With the ever-increasing availability of sequencing technologies, a deeper understanding of the genes underlying these key traits is within reach. In the present case study, the VRN-H1 (HvBM5A), SD2 (HvMKK3), and the novel stem and stripe rust resistance quantitative trait locus (QTL) described by Hernandez et al. (Hernandez et al. Phytopathology 110:1082–1092, 2020b) were investigated. These loci in three advanced barley inbred genotypes were the focus of the present study using next-generation sequencing. The intent behind the study was the identification and exploration of possible causal sequence variation in the genotypes within the context of the whole gene or QTL region. The sequence data was used to identify an intron one deletion in the HvBM5A sequence of the spring genotype that was conserved in the winter and facultative genotypes. Interestingly, a tandem duplication of the HvMKK3 sequence was identified in one of the genotypes, Thunder, that merits further investigation. Finally, 13 high confidence genes were identified within the Morex V3 reference genome in proximity to the rust QTL identified previously. Sequence variation between all tested genotypes was identified for 11 of the genes. This study explored structural and sequence variation of key genes in barley development and outlined directions for future research. The remaining, unexplored genome sequence will be a resource for identifying allelic variation and will contribute to the growing barley pangenome. [ABSTRACT FROM AUTHOR]

Opisthoplatia orientalis Burmeister is a traditional medicinal insect in China that is mass‐produced by entrepreneur farmers. However, low temperatures pose a serious threat to the survival and quality of this insect, causing economic losses to the farmers. This study aimed to test the hypothesis that low temperatures induce a trade‐off between immunity and physical condition of O. orientalis. The phenoloxidase activity and hemocyte concentration of O. orientalis under 25°C and 5°C were measured by micro‐determination and haemocytometre, respectively. The immunocompetence of the insect was also evaluated by inoculating it with Metarhizium anisopliae M11, an entomopathogenic fungus. The physical factors (protein content, fatty acid content and body weight) of O. orientalis were determined accordingly. The results showed that phenoloxidase activity and hemocyte concentration increased from 9.21 mOD/min and 122.30 hemocyte/ml to 3.64 mOD/min and 55.70 hemocyte/ml when temperature down‐regulated from 25 to 5°C. However, the insects at 5°C had higher protein and fatty acid content, but lower body weight, than those at 25°C. Moreover, there was a significant negative correlation between immunity and protein or fatty acid content, indicating a trade‐off between immunity and physical condition in O. orientalis under low temperatures. This study provides useful insights for improving the efficiency of insect breeding and enhancing the quality of this medicinal insect. [ABSTRACT FROM AUTHOR]

Dormancy has been suggested to be used for metal oxide gas sensors to specifically refer to their response decrease or disappearance after long periods of inactivity at room temperature. In this paper, 1 wt% Pt–SnO 2 composite nanoceramics with especially strong responses to hydrogen–containing atmospheres at room temperature, e.g. a response of 11170 to 1 % H 2 –20 % O 2 –N 2 , were successfully prepared through pressing and sintering. A clear dormancy has been observed for them as their responses decreased seriously with time when they were stored in ambient air at room temperature. Commercial ceramic heating plates (Metal Ceramics Heater, MCH) of 10 mm × 10 mm were attached to bars of 1 wt% Pt–SnO 2 composite nanoceramics. Dormant bars after 12 months of storage were completely regenerated through a heat–treatment of 200 °C for 10 min by attached MCH ceramic heating plates. According to X-ray photoelectron spectroscopy analyses, the formation of hydroxyl groups on SnO 2 in Pt–SnO 2 composite nanoceramics and deposition of impurity gases like H 2 S were proposed responsible for the dormancy, and their removal through mild heat–treatments result in the regeneration. It is suggested that heaters like commercial MCH ceramic heating plates should be included in future room–temperature gas sensors to provide a practicable regeneration from dormancy when needed. [ABSTRACT FROM AUTHOR]

When ribosome-targeting antibiotics attack actively growing bacteria, they occupy ribosomal active centers, causing the ribosomes to stall or make errors that either halt cellular growth or cause bacterial death. However, emerging research indicates that bacterial ribosomes spend a considerable amount of time in an inactive state known as ribosome hibernation, in which they dissociate from their substrates and bind to specialized proteins called ribosome hibernation factors. Since 60% of microbial biomass exists in a dormant state at any given time, these hibernation factors are likely the most common partners of ribosomes in bacterial cells. Furthermore, some hibernation factors occupy ribosomal drug-binding sites-leading to the question of how ribosome hibernation influences antibiotic efficacy, and vice versa. In this review, we summarize the current state of knowledge on physical and functional interactions between hibernation factors and ribosome-targeting antibiotics and explore the possibility of using antibiotics to target not only active but also hibernating ribosomes. Because ribosome hibernation empowers bacteria to withstand harsh conditions such as starvation, stress, and host immunity, this line of research holds promise for medicine, agriculture, and biotechnology: by learning to regulate ribosome hibernation, we could enhance our capacity to manage the survival of microorganisms in dormancy. [ABSTRACT FROM AUTHOR]

Seasonal peaks in river discharge, such as snowmelt-dominated freshets, are predictable events that can have a large effect on flushing rates and salinity in estuaries. Resting eggs, which many coastal and estuarine copepods produce for overwintering or aestivation, could also serve to bridge predictable peaks in river discharge. We assessed the timing of resting egg production of the egg-carrying estuarine copepod, Eurytemora affinis (Poppe), in relation to river discharge in the Fraser River Estuary, Canada. Approximately 30 field-collected females were individually incubated on 12 occasions over the period February 2015–May 2016. Eurytemora affinis abundance and population structure were investigated from vertical net tow samples collected twice monthly to monthly. Resting eggs occurred primarily in May 2015 and May 2016 (6.5 and 9.2 eggs day−1, respectively), a month prior to peak flows, and the proportion of offspring that were resting eggs increased with river discharge. Eurytemora affinis reached a minimum abundance in July 2015, when the population was dominated by adults (86%). Resting egg production in E. affinis is typically considered an overwintering mechanism but we suggest that the ultimate driver of resting egg production in this population is avoidance of flushing and/or low salinities. [ABSTRACT FROM AUTHOR]

This study used seeds of two endemic sage plants (Salvia siirtica and Salvia kronenburgii) as a starting material. Mucilage causes dormancy in the seeds of these plants. Therefore, it is important to improve the germination performance of these plants' seeds, and in this study, some treatments were applied to the seeds before or during sowing. To this end, sodium hypochlorite, ethyl alcohol, gibberellic acid, seed cracking, removal of the seed coat, pre-cold treatment, and sulfuric acid treatments were applied to the seeds of the two species separately or in combination, and their germination performances were investigated in comparison with a control group. Considering the results higher germination rates were obtained for both plants compared to the control group in all treatments except sulfuric acid treatments. The best germination rate for both plants was obtained from the treatments where the seed coat was mechanically removed. In this treatment, the germination rate in S. siirtica increased 3.3 times, while it increased 2.4 times in S. kronenburgii compared to the control group. Additionally, GA treatments for S. siirtica and cold pre-treatments for S. kronenburgii significantly increased germination rates. In light of these results, the removal of the seed coat, gibberellic acid, and cold pre-treatment effectively broke dormancy in sage seeds and increased germination rates. [ABSTRACT FROM AUTHOR]

Persister cells (PCs), a subpopulation occurring within normal cells, exhibit a transient tolerance to antibiotics because of their dormant state. PCs are categorized into two types: type I PCs, which emerge during the stationary phase, and type II PCs, which emerge during the logarithmic phase. Using the conventional colony-forming method, we previously demonstrated that type I PCs of Escherichia coli form more frequently in air–solid biofilm culture than in liquid culture. In the current study, we modified a cell filamentation method as a more efficient and rapid alternative for quantifying PCs. This modified method yielded results consistent with those of the conventional method with 103–104 times higher sensitivity and less detection time, within several hours, and further revealed the existence of multiple levels of type I PCs, including a substantial number of deeply dormant cells. This study also discovered a potential epigenetic memory mechanism, spanning several generations (four or six cell divisions), which influences type II PC formation based on prior biofilm experience in E. coli. [ABSTRACT FROM AUTHOR]

Shoot branches grow from axillary buds and play a crucial role in shaping shoot architecture and determining crop yield. Shade signals inactivate phytochrome B (phyB) and induce bud dormancy, thereby inhibiting shoot branching. Prior transcriptome profiling of axillary bud dormancy in a phyB‐deficient mutant (58M, phyB‐1) and bud outgrowth in wild‐type (100M, PHYB) sorghum genotypes identified differential expression of genes associated with flowering, plant hormones, and sugars, including SbCN2, SbNCED3, SbCKX1, SbACO1, SbGA2ox1, and SbCwINVs. This study examined the expression of these genes during bud dormancy induced by shade and defoliation in 100M sorghum. The aim was to elucidate the molecular mechanisms activated by shade in axillary buds by comparing them with those activated by defoliation. The expression of marker genes for sugar levels suggests shade and defoliation reduce the sugar supply to the buds and induce bud dormancy. Intriguingly, both shade signals and defoliation downregulated SbNCED3, suggesting that ABA might not play a role in promoting axillary bud dormancy in sorghum. Whereas the cytokinin (CK) degrading gene SbCKX1 was upregulated solely by shade signals in the buds, the CK inducible genes SbCGA1 and SbCwINVs were downregulated during both shade‐ and defoliation‐induced bud dormancy. This indicates a decrease in CK levels in the dormant buds. Shade signals dramatically upregulated SbCN2, an ortholog of the Arabidopsis TFL1 known for inhibiting flowering, whereas defoliation did not increase SbCN2 expression in the buds. Removing shade temporarily downregulated SbCN2 in dormant buds, further indicating its expression is not always correlated with bud dormancy. Because shade signals also trigger a systemic early flowering signal, SbCN2 might be activated to protect the buds from transitioning to flowering before growing into branches. In conclusion, this study demonstrates that shade signals activate two distinct molecular mechanisms in sorghum buds: one induces dormancy by reducing CK and sugars, whereas the other inhibits flowering by activating SbCN2. Given the agricultural significance of TFL1‐like genes, the rapid regulation of SbCN2 by light signals in axillary buds revealed in this study warrants further investigation to explore its potential in crop improvement strategies. [ABSTRACT FROM AUTHOR]

Branchiopods use resting eggs to maintain permanent populations in temporally dynamic environments as well as for dispersing to neighboring habitat patches. We used a large-scale longitudinal salinity gradient that overlays the Nebraska Sandhills, USA to determine how changes in metacommunity environmental heterogeneity influences species composition and biodiversity of branchiopod egg banks from freshwater and saline temporary wetlands. We sampled the egg banks of 54 wetlands from three metacommunities across the Nebraska Sandhills (eastern, central, and western) in which the relative abundance and salinity of saline wetlands increased westwards. Salinity had a strong effect on structuring the egg-bank metacommunities with a clear shift in species composition and species richness from the eastern to western metacommunities. Egg-bank alpha richness of the freshwater wetlands and metacommunity gamma richness declined westwards as the abundance of freshwater wetlands decreased relative to the saline wetlands. The low-salinity wetlands represented an intermediate stage between the freshwater and high-salinity wetlands, overlapping in species composition with both habitat types and supporting similar numbers of species as freshwater wetlands. High-salinity wetlands had the lowest alpha richness with only halotolerant and halophilic species. [ABSTRACT FROM AUTHOR]

Background/Objectives: Bacteria are well known to enter dormancy under stress conditions. However, the mechanisms of different dormancy-related phenotypes are still under debate and many questions remain unanswered. This study aims to better understand the effects of toxin gene expression on the dormancy of Escherichia coli. Methods: The effects of toxin gene expression on growth, persistence, and culturability were characterized. Specifically, we detailed dose- and time-dependent dormancy of E. coli and its susceptibility to ofloxacin via arabinose-induced hipA toxin gene expression under the PBAD promoter. A new plot was developed to better describe the dynamic changes in culturability and persistence. The expression level of hipA was determined using qPCR and cellular activities were monitored using fluorescence imaging and flow cytometry. Results: High-level persister formation and strong tolerance to ofloxacin were observed after high-level hipA induction. The new plot reveals more information than the changes in persistence alone, e.g., reduced culturability of E. coli and thus deeper dormancy under high-level hipA induction. Consistently, controlled hipA induction led to decreased cellular activities at promoter PrrnBP1 and an increase in the non-culturable subpopulation. Conclusions: Overall, this study provides new insights into dormancy induced by toxin gene expression and a more comprehensive view of persistence and culturability. The findings may help develop better control agents against dormant bacterial cells. [ABSTRACT FROM AUTHOR]

ABSTRACT Dormancy in barley has been thoroughly studied and shown to negatively impact malt quality, resulting in selection against dormancy. However, reduced dormancy coincides with increased preharvest sprout (PHS) risk, thus sparking a new interest in integrating dormancy back into American barley lines if the negative effects of dormancy on malt quality can be overcome. We evaluated the dormancy and hydration index (HYI) in a biparental mapping population to determine the genotypes that would protect against PHS but have good malt quality. We found 4 HYI QTLs and 4 dormancy QTLs, one of which was near the well‐described SD2 QTL. The HYI QTLs were pleiotropically related to seed size (1H), dormancy (5H) and malt quality (2H). Lines with dormancy (5H) and increased HYI (2H and 3H) had malt quality similar to nondormant lines while maintaining PHS resistance, suggesting improvements in HYI could be the key to overcoming the negative effects of dormancy in malting. [ABSTRACT FROM AUTHOR]

Simple Summary: High levels of the transcription factor Grainyhead-like protein 2 (GRHL2) contribute to worse outcomes for patients with breast cancer tumors that express estrogen receptor (ER). Using multiple methods to increase GRHL2 expression in breast cancer cells, we found that high GRHL2 promotes both epithelial and mesenchymal phenotypes. This is indicative of an intermediate state between epithelial and mesenchymal cells, which is associated with metastasis. We also observed that elevated GRHL2 stimulates properties characteristic of cellular plasticity, including a decrease in cellular proliferation with a reciprocal increase in dormancy and stem cell markers. Elevated levels of GRHL2 broadly changed its control of gene expression at the level of DNA and shifted nearby transcription factor binding sites from those associated with development to those associated with disease progression. These results provide a possible explanation for how elevated GRHL2 levels could contribute to poorer prognosis in ER-positive breast cancer. Estrogen receptor (ER)-positive breast cancer is characterized by late recurrences following initial treatment. The epithelial cell fate transcription factor Grainyhead-like protein 2 (GRHL2) is overexpressed in ER-positive breast cancers and is linked to poorer prognosis as compared to ER-negative breast cancers. To understand how GRHL2 contributes to progression, GRHL2 was overexpressed in ER-positive cells. We demonstrated that elevated GRHL2 imparts plasticity with stem cell- and dormancy-associated traits. RNA sequencing and immunocytochemistry revealed that high GRHL2 not only strengthens the epithelial identity but supports a hybrid epithelial to mesenchymal transition (EMT). Proliferation and tumor studies exhibited a decrease in growth and an upregulation of dormancy markers, such as NR2F1 and CDKN1B. Mammosphere assays and flow cytometry revealed enrichment of stem cell markers CD44 and ALDH1, and increased self-renewal capacity. Cistrome analyses revealed a change in transcription factor motifs near GRHL2 sites from developmental factors to those associated with disease progression. Together, these data support the idea that the plasticity and properties induced by elevated GRHL2 may provide a selective advantage to explain the association between GRHL2 and breast cancer progression. [ABSTRACT FROM AUTHOR]

Data on changes in energy status, activity of pro-/antioxidant metabolism during overwintering of Heracleum sosnowskyi vegetative buds were obtained. The buds of H. sosnowskyi are not endodormant and their growth is limited by the decrease of the soil temperature to negative values at the end of November. The optimum temperature for energy storage in autumn was found to be in the range of low positive temperatures (2–5°C). The autumn buds were characterized a high capacity for the cytochrome respiratory pathway (CP, Vcyt), which accounted for 78% of the total respiration. During autumn morphogenesis and winter dormancy of buds, the levels of pro-oxidants, which are the content of thiobarbituric acid reactive substances (TBARS) and H2O2 content, remained stable. In December, when a stable snow cover and negative soil temperatures were established, the dormant buds showed 2.5 times lower rate of energy storage and activated alternative respiration capacity (AP, Valt), as indicated by a 2 times lower Vcyt/Valt ratio. In early spring, compared to winter dormancy, H2O2 levels increased 2-fold and antioxidant enzymes activity increased by 27–78% as insolation increased. Spring buds showed an increase in rate of heat production and a decrease in rate of energy storage, which may be due to spring stress caused by increased insolation. It was concluded that in the tissues of H. sosnowskyi buds subjected to exogenous dormancy, an energy balance between dormancy and growth processes is achieved at the level of respiratory capacity and pro-/antioxidant metabolism. [ABSTRACT FROM AUTHOR]

Diapause is a strategy in insects to mitigate seasonal stress and synchronize lifecycles with favorable times. Forests are 3D, dynamic ecosystems with contrasting microhabitats where numerous insects enter diapause and the duration of diapause affects their phenology. Ecologically important forest insects, like defoliators, bark breeders, or soil/litter-dwelling species have diverse diapause strategies. Anthropogenic change, like climate change and urbanization, has and will have substantial impacts on forest insects. Some species may increase their impact on ecosystems, while that of others may be reduced. Understanding how climate change or urbanization factors, like artificial light at night and the urban-heat-island effect, affect diapause may help develop generalizable rules to predict which species will show population expansion and which are likely to contract. Insects have major impacts on forest ecosystems, from herbivory and soil-nutrient cycling to killing trees at a large scale. Forest insects from temperate, tropical, and subtropical regions have evolved strategies to respond to seasonality; for example, by entering diapause, to mitigate adversity and to synchronize lifecycles with favorable periods. Here, we show that distinct functional groups of forest insects; that is, canopy dwellers, trunk-associated species, and soil/litter-inhabiting insects, express a variety of diapause strategies, but do not show systematic differences in diapause strategy depending on functional group. Due to the overall similarities in diapause strategies, we can better estimate the impacts of anthropogenic change on forest insect populations and, consequently, on key ecosystems. [ABSTRACT FROM AUTHOR]

The timing and size of metamorphosis are crucial for the future fitness of organisms with complex life cycles, such as amphibians. In some amphibian species, a portion of tadpoles will metamorphose in their natal year whereas others from the same cohort overwinter as tadpoles. Low temperature and food availability were previously assumed to be the underlying reasons; however, the factors influencing the decision to overwinter as tadpoles or metamorphose in the natal year have not been extensively studied. This study investigated these factors by conducting laboratory‐rearing experiments on Babina subaspera tadpoles. The tadpoles were individually reared under controlled temperature and light conditions that simulated five different growing seasons (i.e., the start month) observed in the field. Four different food quantity levels were set to induce different growth rates, which were measured individually. The results revealed that 33 tadpoles metamorphosed within their natal year, whereas 52 tadpoles were overwintered as tadpoles and metamorphosed the following spring. The size at metamorphosis was larger in tadpoles that metamorphosed after winter than in those that metamorphosed before winter. Whether tadpoles metamorphosed before or after winter was influenced by the individual growth rate and growing season. Tadpoles with slower growth rates were more likely to metamorphose after winter, possibly because slower growth prevented them from reaching the critical size threshold required for metamorphosis before winter. The threshold for the occurrence of larval overwintering varied with the growing season; tadpoles that spawned later in the year were more likely to overwinter, even with a high growth rate. The results suggested that slow‐growing B. subaspera tadpoles with insufficient time until the onset of winter would gain a higher fitness by metamorphosing after winter. This would be advantageous due to the tadpoles' potentially high survival rate during dormancy as well as their larger size at metamorphosis in the following year. [ABSTRACT FROM AUTHOR]

The use of native plants for arid land restoration requires the application of pre‐germination treatments to alleviate seed dormancy mechanisms. As it is known, scarification allows several valuable species to overcome the primary forms of dormancy. However, supplying large quantities of scarified seeds at a low cost represents a significant challenge. In this context, our objective was to evaluate locally constructed machines accessible to people of degraded lands in a state of poverty. The effectiveness was evaluated by comparing two native shrubs from South American arid lands, Larrea divaricata and L. cuneifolia. Four treatments were applied: control (T0), mechanical scarification with a hand drill equipped with sandpaper on its head (T1), and mechanical scarification for 15 seconds (T2) and 30 seconds (T3) with a self‐constructed machine, capable of regulating pressure and speed. For both species, the germination probability was higher with T2 (0.82 ± 0.02) compared to T0 (0.28 ± 0.03) and T1 (0.65 ± 0.03). T3 presented intermediate values (0.75 ± 0.03) but did not differ significantly from T1 and T2. Our results show the effectiveness of a locally constructed seed scarification tool to upscale seed‐based restoration in arid lands. [ABSTRACT FROM AUTHOR]

Knowledge of the genetic variability of different species for conservation purposes and quality seedling production after longer storage time is important. The aim of the research paper was to examine the effect of longer seed storage periods (19–30 year) on seed viability, seed vigour and initial growth of seedlings from five provenances of Pterolobium stellatum (Forssk). Seeds collected from Dabena, Gambo, Agaro, Bishofitu, and Merti localities and stored for 19, 19, 21, 25, and 30 years, respectively used for the study. Different seed dormancy-breaking treatments such as; soaking in cold water for 48 h (CW-48); soaking in hot water for 10 min (HW-10); 20 min (HW-20) and mechanical scarification; i.e., nicking (NK) used for the germination of the seeds. A randomized complete block design was used for the experiment and the study undertaken in a greenhouse. For each treatment, four replications and for each replication, 50 seeds were used. One-way analysis of variance was used for germination index, early seedling growth and seed vigour index data. The results showed that for all the provenance seeds stored for different periods, NK treatment resulted relatively in a higher mean germination percentage and germination indices as compared to the other pre-treatments. The seed vigour index result showed significant differences among the different provenances (P < 0.001). Similarly, there were significant differences among the early growth of seedlings germinated from different provenance seeds (P < 0.001). The seeds collected from Merti provenance and stored for 30 years and Dabena provenance, stored for 19 years, have relatively resulted in higher mean germination index, seed vigour and seedling growth relative to the other studied provenance seeds. We observed that provenance had a more significant influence on germination, seed vigour and seedling growth than the seed storage period for the P. stellatum. Finally it is recommended that despite there is inter population variation, the seeds of P. stellatum can be stored for a longer time and application of nicking as a dormancy breaking treatment could enhance seed germination of the species. [ABSTRACT FROM AUTHOR]

The life history aspects of dormancy of the weevil Anthonomus rufipennis LeConte (Coleoptera: Curculionidae) were studied a 57-month period in a seasonally dry tropical forest of central Mexico. Weevil populations and their physiological status were monitored on both the reproductive host tree, Senna polyantha (Collad.) H.S: Irwin & Barneby (Fabales: Fabaceae) and the highly favored refuge host, Tillandsia recurvata L. (Poales: Bromeliaceae) or "ball moss." During the dry season, weevils were only found on the refuge host with a mean total density of 1.014 ± 2.532 individuals/ball moss (N  = 1,681). Weevil densities on T. recurvata between early and late dry seasons were not significantly different, suggesting that dry season survival was relatively high. Weevils collected during these seasons revealed little reproductive development and relatively high-fat accumulation in both sexes. During 5 of 6 yr, densities of the weevils in T. recurvata dropped significantly during the early rainy seasons, when the reproductive host trees leafed out and began producing oviposition sites (flower buds). At this time, more males than females initially moved to vegetative trees and showed significant signs of reproductive development. Recolonization of ball moss by weevils began during the late rainy season when oviposition sites (flower buds) were still available. A proportion of the weevils remained on the reproductive host, suggesting that A. rufipennis is facultatively multivoltine. The methodologies and results of the study can serve as a model system for future studies of the dormancy of other insects in dry tropical forests and provide insight into the dormancy of other anthonomine weevils of economic importance. [ABSTRACT FROM AUTHOR]

Cancer cells can leave their primary sites and travel through the circulation to distant sites, where they lodge as disseminated cancer cells (DCCs), even during the early and asymptomatic stages of tumor progression. In experimental models and clinical samples, DCCs can be detected in a non-proliferative state, defined as cellular dormancy. This state can persist for extended periods until DCCs reawaken, usually in response to niche-derived reactivation signals. Therefore, their clinical detection in sites like lymph nodes and bone marrow is linked to poor survival. Current cancer therapy designs are based on the biology of the primary tumor and do not target the biology of the dormant DCC population and thus fail to eradicate the initial or subsequent waves of metastasis. In this brief review, we discuss the current methods for detecting DCCs and highlight new strategies that aim to target DCCs that constitute minimal residual disease to reduce or prevent metastasis formation. Furthermore, we present current evidence on the relevance of DCCs derived from early stages of tumor progression in metastatic disease and describe the animal models available for their study. We also discuss our current understanding of the dissemination mechanisms utilized by genetically less- and more-advanced cancer cells, which include the functional analysis of intermediate or hybrid states of epithelial–mesenchymal transition (EMT). Finally, we raise some intriguing questions regarding the clinical impact of studying the crosstalk between evolutionary waves of DCCs and the initiation of metastatic disease. [ABSTRACT FROM AUTHOR]

Abstract Background Mortality from breast cancer is principally due to tumor recurrence. Recurrent breast cancers arise from the pool of residual tumor cells, termed minimal residual disease, that survive treatment and may exist in a dormant state for 20 years or more following treatment of the primary tumor. As recurrent breast cancer is typically incurable, understanding the mechanisms underlying dormant tumor cell survival is a critical priority in breast cancer research. The importance of this goal is further underscored by emerging evidence suggesting that targeting dormant residual tumor cells in early-stage breast cancer patients may be a means to prevent tumor recurrence and its associated mortality. In this regard, the role of autophagy in dormant tumor cell survival and recurrence remains unresolved, with conflicting reports of both pro-survival/recurrence-promoting and pro-death/recurrence-suppressing effects of autophagy inhibition in dormant tumor cells. Resolving this question has important clinical implications. Methods We used genetically engineered mouse models that faithfully recapitulate key features of human breast cancer progression, including minimal residual disease, tumor dormancy, and recurrence. We used genetic and pharmacological approaches to inhibit autophagy, including treatment with chloroquine, genetic knockdown of ATG5 or ATG7, or deletion of BECN and determined their effects on dormant tumor cell survival and recurrence. Results We demonstrate that the survival and recurrence of dormant mammary tumor cells following therapy is dependent upon autophagy. We find that autophagy is induced in vivo following HER2 downregulation and remains activated in dormant residual tumor cells. Using genetic and pharmacological approaches we show that inhibiting autophagy by chloroquine administration, ATG5 or ATG7 knockdown, or deletion of a single allele of the tumor suppressor Beclin 1 is sufficient to inhibit mammary tumor recurrence, and that autophagy inhibition results in the death of dormant mammary tumor cells in vivo. Conclusions Our findings demonstrate a pro-tumorigenic role for autophagy in tumor dormancy and recurrence following therapy, reveal that dormant tumor cells are uniquely reliant upon autophagy for their survival, and indicate that targeting dormant residual tumor cells by inhibiting autophagy impairs tumor recurrence. These studies identify a pharmacological target for a cellular state that is resistant to commonly used anti-neoplastic agents and suggest autophagy inhibition as an approach to reduce dormant minimal residual disease in order to prevent lethal tumor recurrence.

Introduction: This report presents a case of an exceptionally delayed distant recurrence of a choroidal melanoma, occurring 4 decades after the enucleation of the affected eye. Case Presentation: In 1977, a 29-year-old man underwent enucleation for a choroidal melanoma. At the age of 68 years, he was diagnosed with advanced prostate cancer. Although the metastatic prostate cancer responded to treatment, a persistent lung lesion warranted further examination. A lung biopsy, somewhat surprisingly, confirmed the presence of melanoma metastasis, 4 decades after the enucleation. The cells were positive for Melan-A, while no BRAF mutation was identified. Two years later, new lesions appeared in the liver, and CT showed progression with multiple new sites. A liver biopsy revealed again melanoma recurrence, and its choroidal origin was verified by the presence of a GNA11 mutation. The patient underwent radiation therapy for the lung and liver lesions, followed by immunotherapy. However, the patient died 11 months after the recurrence in the liver. In this case report, the micrometastatic melanoma cells appear to have remained dormant for an extended period, before the patient’s treatment in 1977, but the reason for the late reactivation from the dormant state remains unclear. Conclusion: The recurrence of a choroidal melanoma is substantiated by the histopathological and molecular analyses, including the finding of a GNA11 mutation. This case exemplifies a remarkably delayed distant recurrence of a choroidal melanoma, which manifested clinically 40 years following enucleation.

Pre-harvest sprouting (PHS) poses a significant global challenge to cereal production, impacting both yield and quality. In this study, we employed genome-wide association studies (GWAS) on diverse rice accessions to identify novel PHS-associated haplotypes. An assessment of 127 cultivated accessions for panicle germination (PHS) and detached grain germination (germination rate of detached grains at the 14th day (D14)) revealed considerable phenotypic variation among rice ecotypes. GWAS analysis identified 91 significant signals at –log10(P-value)>5, including 15 SNPs for PHS and 76 SNPs for D14. A subsequent linkage disequilibrium (LD) block-based GWAS analysis detected 227 significant SNPs for both traits, consisting of 18 nonsynonymous substitutions located on the coding regions of nine genes. Further haplotype analysis identified 32 haplotypes, with 10 specific to cultivated accessions, 19 specific to the wild type, and three shared between them. A phenotypic assessment of major haplotypes revealed significant differences between resistant (Hap1 and Hap2) and susceptible haplotypes (Hap5, Hap27, and Hap28), distinguished by a G/A SNP within a novel gene, Os04g0545200. The identified haplotypes offer promising prospects for haplotype-based breeding aimed at enhancing PHS resistance in rice.

BACKGROUND: The invasive freshwater snail Pomacea canaliculata is an agricultural pest with a certain level of tolerance to abiotic stress. After the harvest of late rice, the snails usually burrow themselves into the soil surface layers to overwinter and pose a renewed threat to rice production in the following year. Revealing the response of snails to environmental stresses is crucial for developing countermeasures to control their damage and spread. RESULTS: In this study, we conducted a 120‐day in situ experiment during the winter to investigate the survival and physiological changes of hibernating snails in 0‐5 and 5‐10 cm soil depths, aiming to explore their overwintering strategies. Our results showed that 73.61%, 87.50%, and 90.28% of male, female, and juvenile snails survived after hibernation for 120 days in 0–10 cm soil depth, respectively. The differences in survival rates based on sex and size of snails potentially reflect the countermeasures of snails to rapidly reproduce after hibernation. Simultaneously, the hibernating snails exhibited the ability to maintain a certain level of body weight. During this period, the snails increased their antioxidant enzyme activities to cope with oxidative stress, and enhanced their lipid storage. The hibernation survival of snails was not significantly affected by different soil depths, indicating that they have the potential to hibernate into deeper soils. Furthermore, snails were capable of increasing their contents of bound water and glycerol to cope with sudden cold spells during hibernation. CONCLUSION: Our findings emphasize the adaptive changes of P. canaliculata snails overwintering in paddy soils. In future studies, the vulnerabilities of P. canaliculata during hibernation (e.g. shell characteristics, nutrient reserves, and dehydration tolerance, etc.,) should be investigated to develop effective control methods for this period. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) complex, is a zoonotic disease that remains one of the leading causes of death worldwide. Latent tuberculosis infection reactivation is a challenging obstacle to eradicating TB globally. Understanding the gene regulatory network of Mtb during dormancy is important. This review discusses up-to-date information about TB gene regulatory networks during dormancy, focusing on the regulation of lipid and energy metabolism, dormancy survival regulator (DosR), White B-like (Wbl) family, Toxin-Antitoxin (TA) systems, sigma factors, and MprAB. We outline the progress in vaccine and drug development associated with Mtb dormancy.

Understanding the process of Prunus species floral development is crucial for developing strategies to manipulate bloom time and prevent crop loss due to climate change. Here, we present a detailed examination of flower development from initiation until bloom for early- and late-blooming sour cherries (Prunus cerasus) from a population segregating for a major bloom time QTL on chromosome 4. Using a new staging system, we show floral buds from early-blooming trees were persistently more advanced than those from late-blooming siblings. A genomic DNA coverage analysis revealed the late-blooming haplotype of this QTL, k , is located on a subgenome originating from the late-blooming P. fruticosa progenitor. Transcriptome analyses identified many genes within this QTL as differentially expressed between early- and late-blooming trees during the vegetative-to-floral transition. From these, we identified candidate genes for the late bloom phenotype, including multiple transcription factors homologous to Reproductive Meristem B3 domain-containing proteins. Additionally, we determined that the basis of k in sour cherry is likely separate from candidate genes found in sweet cherry—suggesting several major regulators of bloom time are located on Prunus chromosome 4. [ABSTRACT FROM AUTHOR]

Throughout the tree of life, cells and organisms enter states of dormancy or hibernation as a key feature of their biology: from a bacterium arresting its growth in response to starvation, to a plant seed anticipating placement in fertile ground, to a human oocyte poised for fertilization to create a new life. Recent research shows that when cells hibernate, many of their essential enzymes hibernate too: they disengage from their substrates and associate with a specialized group of proteins known as hibernation factors. Here, we summarize how hibernation factors protect essential cellular enzymes from undesired activity or irreparable damage in hibernating cells. We show how molecular hibernation, once viewed as rare and exclusive to certain molecules like ribosomes, is in fact a widespread property of biological molecules that is required for the sustained persistence of life on Earth. [ABSTRACT FROM AUTHOR]

Animals can alter their body compositions in anticipation of dormancy to endure seasons with limited food availability. Accumulation of lipid reserves, mostly in the form of triglycerides (TAGs), is observed during the preparation for dormancy in diverse animals, including insects (diapause) and mammals (hibernation). However, the mechanisms involved in the regulation of lipid accumulation and the ecological consequences of failure to accumulate adequate lipid stores in preparation for animal dormancy remain understudied. In the broadest sense, lipid reserves can be accumulated in two ways: the animal either receives lipids directly from the environment or converts the sugars and amino acids present in food to fatty acids through de novo lipogenesis and then to TAGs. Here, we show that preparation for diapause in the Colorado potato beetle (Leptinotarsa decemlineata) involves orchestrated upregulation of genes involved in lipid metabolism with a transcript peak in 8-and 10-d-old diapause-destined insects. Regulation at the transcript abundance level was associated with the accumulation of substantial fat stores. Furthermore, the knockdown of de novo lipogenesis enzymes (ACCase and FAS-1) prolonged the preparatory phase, while the knockdown of fatty acid transportation genes shortened the preparatory phase. Our findings suggest a model in which the insects dynamically decide when to transition from the preparation phase into diapause, depending on the progress in lipid accumulation through de novo lipogenesis. [ABSTRACT FROM AUTHOR]

The timing of seed germination is controlled by the combination of internal dormancy and external factors. Temperature is a major environmental factor for seed germination. The permissive temperature range for germination is narrow in dormant seeds and expands during after-ripening (AR) (dormancy release). Quantitative trait loci analyses of preharvest sprouting in cereals have revealed that MKK3, a mitogen-activated protein kinase (MAPK) cascade protein, is a negative regulator of grain dormancy. Here, we show that the MAPKKK19/20-MKK3-MPK1/2/7/14 cascade modulates the germination temperature range in Arabidopsis seeds by elevating the germinability of the seeds at sub-and supraoptimal temperatures. The expression of MAPKKK19 and MAPKKK20 is induced around optimal temperature for germination in after-ripened seeds but repressed in dormant seeds. MPK7 activation depends on the expression levels of MAPKKK19/20, with expression occurring under conditions permissive for germination. Abscisic acid (ABA) and gibberellin (GA) are two major phytohormones which are involved in germination control. Activation of the MKK3 cascade represses ABA biosynthesis enzyme gene expression and induces expression of ABA catabolic enzyme and GA biosynthesis enzyme genes, resulting in expansion of the germinable temperature range. Our data demonstrate that the MKK3 cascade integrates temperature and AR signals to phytohormone metabolism and seed germination. [ABSTRACT FROM AUTHOR]

The rare and threatened Heliosciadium repens grows in moist grasslands and has a distinct life cycle. Plants reproduce both clonally, although ramets tend to be short‐lived, and sexually, with seeds that can form a persistent soil seed bank. The germination requirements of H. repens were investigated, yielding important information for its habitat management and conservation. We examined the soil seed bank in three populations and carried out germination experiments and embryo growth measurements with fresh seeds in laboratory, greenhouse and outdoor conditions. We also investigated the effects of storage and burial of seeds. H. repens formed a long‐term persistent (>6 years) soil seed bank with very pronounced primary dormancy, but no secondary dormancy or dormancy cycles. Seeds can germinate throughout the growing season when temperatures are sufficiently high. Embryo growth and seed germination are triggered by light and, to a lesser extent, daily temperature fluctuations. Seeds of H. repens seem to have developed a unique germination syndrome with several strategies to remain dormant in the soil until optimal conditions are present for seedling establishment and survival. Both sexual reproduction and seed bank formation are crucial for the long‐term survival of the populations. [ABSTRACT FROM AUTHOR]

Cryptococcus neoformans is a fungal pathogen of the top critical priority recognized by the World Health Organization. This clinically important fungus also serves as a eukaryotic model organism. A variety of resources have been generated to facilitate investigation of the C. neoformans species complex, including congenic pairs, well-annotated genomes, genetic editing tools, and gene deletion sets. Here, we generated a set of strains with all major organelles fluorescently marked. We tested short organelle-specific targeting sequences and successfully labeled the following organelles by fusing the targeting sequences with a fluorescence protein: the plasma membrane, the nucleus, the peroxisome, and the mitochondrion. We used native cryptococcal Golgi and late endosomal proteins fused with a fluorescent protein to label these two organelles. These fluorescence markers were verified via colocalization using organelle-specific dyes. All the constructs for the fluorescent protein tags were integrated in an intergenic safe haven region. These organelle-marked strains were examined for growth and various phenotypes. We demonstrated that these tagged strains could be employed to track cryptococcal interaction with the host in phagocytosis assays. These strains also allowed us to discover remarkable differences in the dynamics of proteins targeted to different organelles during sexual reproduction. Additionally, we revealed that "dormant" spores transcribed and synthesized their own proteins and trafficked the proteins to the appropriate subcellular compartments, demonstrating that spores are metabolically active. We anticipate that these newly generated fluorescent markers will greatly facilitate further investigation of cryptococcal biology and pathogenesis. [ABSTRACT FROM AUTHOR]

Cytotoxic therapies expose cancer cells to direct killing, instigating the process of natural selection favoring survival of resistant cells that become the foundation for tumor progression and therapy failure. Recognizing this phenomenon has prompted the development of alternative therapeutic strategies. Strategies targeting cancer hallmarks beyond proliferation have potential to re-educate cancer cells towards a less malignant phenotype. These strategies include controlling cell dormancy, transdifferentiation therapy, normalizing the cancer microenvironment, and migrastatic therapy. Adaptive resistance to these educational strategies does not provide resistant cells with a direct proliferative advantage, holding substantial promise in delaying or preventing the development of therapy-resistant tumors. Traditionally, anticancer therapies focus on restraining uncontrolled proliferation. However, these cytotoxic therapies expose cancer cells to direct killing, instigating the process of natural selection favoring survival of resistant cells that become the foundation for tumor progression and therapy failure. Recognizing this phenomenon has prompted the development of alternative therapeutic strategies. Here we propose strategies targeting cancer hallmarks beyond proliferation, aiming at re-educating cancer cells towards a less malignant phenotype. These strategies include controlling cell dormancy, transdifferentiation therapy, normalizing the cancer microenvironment, and using migrastatic therapy. Adaptive resistance to these educative strategies does not confer a direct proliferative advantage to resistant cells, as non-resistant cells are not subject to eradication, thereby delaying or preventing the development of therapy-resistant tumors. [ABSTRACT FROM AUTHOR]

Oocytes spend the majority of their lifetime in a primordial state. The cellular and molecular biology of primordial oocytes is largely unexplored; yet, it is necessary to study them to understand the mechanisms through which oocytes maintain cellular fitness for decades, and why they eventually fail with age. Here, we develop enabling methods for live-imaging-based comparative characterization of Xenopus, mouse and human primordial oocytes. We show that primordial oocytes in all three vertebrate species contain active mitochondria, Golgi and lysosomes. We further demonstrate that human and Xenopus oocytes have a Balbiani body characterized by a dense accumulation of mitochondria in their cytoplasm. However, despite previous reports, we did not find a Balbiani body in mouse oocytes. Instead, we demonstrate that what was previously used as a marker for the Balbiani body in mouse primordial oocytes is in fact a ring-shaped Golgi that is not functionally associated with oocyte dormancy. This study provides the first insights into the organization of the cytoplasm in mammalian primordial oocytes, and clarifies the relative advantages and limitations of choosing different model organisms for studying oocyte dormancy. [ABSTRACT FROM AUTHOR]

Unlike in most laboratory settings, microbes in natural habitats often lack essential nutrients and withstand widely fluctuating or extreme temperatures; thus, laboratory studies fail to capture the widespread phenomenon of slowed or suspended lives of microbes manifested as, for example, in dormancy and quiescence. Quantitative, single-cell-level measurements and mathematical modeling are overcoming the challenges of observing and understanding slow dynamics of individual cells at long timescales. New conceptual, quantitative frameworks have re-defined and clarified microbes' suspended states, with dormancy defined as a continuous spectrum and antibiotic-induced growth-arrest defined into distinct states. Studying slowed and suspended growth in microbes revealed fundamental constraints to remaining viable without growing and limits to slowing a cell's life. Microbes in nature often lack nutrients and face extreme or widely fluctuating temperatures, unlike microbes in growth-optimized settings in laboratories that much of the literature examines. Slowed or suspended lives are the norm for microbes. Studying them is important for understanding the consequences of climate change and for addressing fundamental questions about life: are there limits to how slowly a cell's life can progress, and how long cells can remain viable without self-replicating? Recent studies began addressing these questions with single-cell-level measurements and mathematical models. Emerging principles that govern slowed or suspended lives of cells – including lives of dormant spores and microbes at extreme temperatures – are re-defining discrete cellular states as continuums and revealing intracellular dynamics at new timescales. Nearly inactive, lifeless-appearing microbes are transforming our understanding of life. Microbes in nature often lack nutrients and face extreme or widely fluctuating temperatures, unlike microbes in growth-optimized settings in laboratories that much of the literature examines. Slowed or suspended lives are the norm for microbes. Studying them is important for understanding the consequences of climate change and for addressing fundamental questions about life: are there limits to how slowly a cell's life can progress, and how long cells can remain viable without self-replicating? Recent studies began addressing these questions with single-cell-level measurements and mathematical models. Emerging principles that govern slowed or suspended lives of cells– including lives of dormant spores and microbes at extreme temperatures – are re-defining discrete cellular states as continuums and revealing intracellular dynamics at new timescales. Nearly inactive, lifeless-appearing microbes are transforming our understanding of life. [ABSTRACT FROM AUTHOR]