Ozker M, Giglio L, Beyh A
… +2 more, Forkel SJ, Hagoort P
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330290
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Sensory feedback is essential for the fine-tuning of motor actions, and speech production is no exception. It depends on continuous self-monitoring to ensure that produced sounds match intended targets. Delaying auditory...Sensory feedback is essential for the fine-tuning of motor actions, and speech production is no exception. It depends on continuous self-monitoring to ensure that produced sounds match intended targets. Delaying auditory feedback (DAF) disrupts this alignment and impairs fluency, providing a powerful tool to investigate sensorimotor control. We combined functional and diffusion-weighted MRI in 31 participants performing a word-production task under delayed (DAF) and immediate (no-DAF) auditory feedback. While all participants slowed their speech under DAF, the extent of this effect varied across individuals and was quantified using a susceptibility index. At the group level, DAF > no-DAF elicited increased activation in a right-lateralized network encompassing the superior temporal gyrus, supramarginal gyrus, inferior frontal gyrus, supplementary motor area, and left cerebellum. Incorporating individual differences revealed that higher susceptibility was associated with greater activation in left-hemisphere speech motor homologues and larger volume of the right long segment of the arcuate fasciculus, a whitematter pathway connecting auditory and motor speech regions. This pattern suggests that susceptibility reflects increased recruitment of neural resources and a stronger reliance on auditory-motor coupling. In contrast, resilience was associated with greater engagement of the bilateral angular gyrus and higher fiber density in the right posterior AF, which connects auditory and somatosensory speech regions. This finding indicates that resilience is supported by a posterior temporo-parietal circuit that efficiently integrates multimodal sensory feedback. Together, these findings link functional dynamics with underlying structural connectivity to reveal how a right-lateralized network supports speech control, while accounting for individual differences in susceptibility to fluency disruption.
Norberg ES, Westerman TL, Cruz E
… +5 more, Bushman SD, Salogiannis J, Skaar EP, Elfenbein JR, Knodler LA
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330289
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There is a constant tug-of-war for transition metals at the pathogen-host interface. Vertebrate hosts modulate the availability of metals to pathogens in a process known as nutritional immunity, but pathogens have evolve...There is a constant tug-of-war for transition metals at the pathogen-host interface. Vertebrate hosts modulate the availability of metals to pathogens in a process known as nutritional immunity, but pathogens have evolved numerous countermeasures to this host defense strategy. The bioavailability of trace metals therefore shapes the outcome of disease. In mammals, epithelial cells lining the intestine are a major site of metal absorption. Intestinal epithelial cells (IECs) are also a target for invading enteric pathogens but the contribution of epithelium-intrinsic factors toward nutritional immunity is unclear. Using serovar Typhimurium (STm) harboring genetically encoded fluorescent sensors for transition metals, we mapped the spatiotemporal nature of metal competition during enteric salmonellosis. In contrast to the metal replete lumen, a subpopulation of STm experience a temporal, cell-specific restriction of Fe and Zn (≤0.1 µM), and possibly Mn, in both IECs and cells of the lamina propria during the early stages of infection. We further studied the contribution of the broad specificity divalent metal transporter, SLC11A2, in IECs to nutritional immunity against STm. SLC11A2 was recruited to maturing -containing vacuoles and knockout of led to increased bacterial proliferation in IECs. Metal-responsive fluorescent reporters showed that vacuolar STm were less starved for Fe, and possibly Mn, but not Zn or Mg in the absence of . STm counters SLC11A2-mediated growth restriction in IECs via the Mn/Fe transporter, MntH, and iron-binding siderophores. We conclude that SLC11A2-mediated sequestration of a subset of metals is an IEC innate defense mechanism against STm.
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330288
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The thermostatic mechanisms of Earth's persistent habitability remain unresolved. High-resolution Cenozoic C isotope records, P accumulation, and coarse-fraction I/Ca allow recalculation and assessment of controls on the...The thermostatic mechanisms of Earth's persistent habitability remain unresolved. High-resolution Cenozoic C isotope records, P accumulation, and coarse-fraction I/Ca allow recalculation and assessment of controls on the global proportion of total carbon buried as organic carbon (), a regulator of atmospheric CO and O. was suppressed during the Eocene hothouse, coincident with an oxygenated water column and low water-column phosphate. With decreased sea level, the area for efficient organic carbon and phosphate sedimentary burial diminished, leading increasingly to greater water-column phosphate, higher primary productivity, and emergent water column deoxygenation. The sea-level influence on the areal extent of high sedimentation in shelf regions acts as a control on phosphate availability for new production, respiratory demand, and ocean oxygenation, as proposed by hypsographic models [C. J. Bjerrum, J. Bendtsen, J. J. F. Legarth, , 1-24 (2006)]. During intermediate sea-level highs of the Neogene, pulses of enhanced organic carbon burial prevailed for multimillion years, in response to the redox recycling of phosphate when oxygen minimum zones with O < 90 µmol/kg were present. We propose the existence of a self-limiting intermediate sea-level sweet spot with peak C burial due to redox recycling of phosphate, whereby oxygen minimum zones (OMZ) with O < 90 µmol/kg impinge on the most C rich continental shelf sediments. Such a sweet spot has narrowed over Earth history due to deepening OMZs, stabilizing both atmospheric O and CO. Continental marine inundation controls on phosphate availability, and the sedimentary carbon flux, provide a positive-feedback and rectifier to perturbations during inception of the icehouse world.
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330287
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Cell polarity is essential for the formation and function of animal tissues. Atypical protein kinase C (aPKC), its cofactor PAR-6, and scaffold protein PAR-3 regulate cell polarity in many different animal cell types. PA...Cell polarity is essential for the formation and function of animal tissues. Atypical protein kinase C (aPKC), its cofactor PAR-6, and scaffold protein PAR-3 regulate cell polarity in many different animal cell types. PAR-3 oligomerization is important to establish cell polarity, but how oligomerization relates to the assembly of the PAR-3/aPKC/PAR-6 complex is still unclear. Here, we use in vivo and ex vivo single-molecule techniques to demonstrate cooperativity between PAR-3 oligomerization and its binding to aPKC/PAR-6 in the zygote. Using genetic perturbations, we present evidence that aPKC and PAR-6 have independent binding sites for PAR-3. We propose that multivalency drives cooperativity because a single aPKC/PAR-6 heterodimer can interact simultaneously with multiple PAR-3 molecules in an oligomer. Although single binding site mutations do not fully eliminate PAR-3/aPKC/PAR-6 binding, they do abolish anterior-posterior polarity, suggesting that PAR-3/aPKC cooperativity contributes to PAR-3 function during polarity establishment. Finally, PAR-3/aPKC cooperativity is downregulated in polarity maintenance, and this downregulation depends on the mitotic kinase PLK-1. Together, our results show how cells can developmentally regulate multivalent assembly of a key polarity complex to achieve timely segregation of cell fate determinants.
Mao H, Leong YC, Jiang Y
… +3 more, Koch A, Brady WJ, Jackson JC
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330286
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Most people believe that social media discourse is negative and divisive. Here we show how this negativity can evolve even when users are not motivated to be negative. We propose that social media users seek to different...Most people believe that social media discourse is negative and divisive. Here we show how this negativity can evolve even when users are not motivated to be negative. We propose that social media users seek to differentiate themselves from other users, and it is easier to differentiate oneself through negativity than positivity because negative information is more heterogeneous and counternormative than positive information. This makes users increasingly likely to post negative comments as a conversation unfolds and it becomes more challenging to make unique contributions. Analyzing 2.05 billion comments from 2,150 Reddit communities shows that comments become more negative over time, both within threads and community histories. This trend toward negativity is mediated by the semantic uniqueness of comments, suggesting that it arises from users differentiating themselves. This trend is strongest when initial dialogue is positive, making negative comments highly counternormative. We replicate these patterns in an experiment simulating social media dialogue ( = 3,685). Participants become more negative over time, but only when incentivized to be unique, and especially when dialogue begins positively. These findings suggest that the structure of social media platforms interacts with human motivation to foster a drift toward negativity over time in online discourse.
Miki K, Nakamura M, Yamada A
… +7 more, Bosser G, Adachi K, Hashizume D, Ogawa N, Okamoto S, Tokura Y, Kawasaki M
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330285
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Ferroelectric halide perovskites provide a fertile platform for optoelectronic functions based on the bulk photovoltaic effect, where broken inversion symmetry couples with quantum geometry of wave functions. The most pr...Ferroelectric halide perovskites provide a fertile platform for optoelectronic functions based on the bulk photovoltaic effect, where broken inversion symmetry couples with quantum geometry of wave functions. The most prominent manifestation is the shift current, second-order nonlinear photocurrent arising from change in the Berry connection during optical transitions. Here we report a gigantic shift current response in epitaxial thin films of a lead-free ferroelectric halide perovskite CsGeI. High-quality films grown by molecular beam epitaxy exhibit clear hallmarks of shift current, including spectral sign reversals, light-polarization dependence, and reversible electric-field modulation associated with switchable ferroelectric polarization. Remarkably, the normalized shift current magnitude surpasses those ever reported for other compounds by more than an order of magnitude, establishing a benchmark for bulk photovoltaic performance. These results identify ferroelectric halide perovskites as a powerful platform for exploring quantum-geometry-driven photoresponses and open a pathway toward next-generation photovoltaic and nonlinear optoelectronic technologies beyond the conventional junction-based architectures.
Salvato G, De Maio G, Bertolotti C
… +13 more, Fazia T, Scarpa P, Tassi L, Cardinale F, Castana L, Squarza SAC, Piano M, Bramerio M, Cerasetti M, Patai EZ, Nobre AC, Berlingeri M, Bottini G
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330284
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Past experiences stored in long-term memory (LTM) provide a valuable resource for making predictions that shape perception and guide goal-directed behavior. Contents from the high-capacity LTM system guide contextual sel...Past experiences stored in long-term memory (LTM) provide a valuable resource for making predictions that shape perception and guide goal-directed behavior. Contents from the high-capacity LTM system guide contextual selective attention to enhance sensory and higher-order processing of memory-predicted targets, in a process known as LTM-guided attention. While this essential cognitive function is believed to depend on the hippocampus, evidence is still scarce. In this study, we used a neuropsychological approach to test LTM-guided attention in the context of isolated hippocampal pathology and to explore structure-behavior covariance patterns. We tested healthy individuals (n = 20) and individuals suffering from focal epilepsy, with isolated, unilateral left (n = 20) or right (n = 17) hippocampal sclerosis (HS), in a task probing LTM-guided attention. Behavioral data indicated that individuals with left or right HS retained LTM-guided attention. We also assessed structure-behavior covariance using a multivariate structural neuroimaging approach. Hierarchical clustering analysis revealed that, in healthy individuals, LTM-guided attention performance covaried with atlas-derived subfield measures of the left hippocampal body. The volume of the left hippocampal body also covaried with attentional benefit in individuals with right HS. Interestingly, for individuals with left HS, LTM-guided attention covaried with the volume of the left hippocampus and with part of the right hippocampal volume. Together, these findings suggest that LTM-guided attention can be preserved in unilateral HS, with differences in hippocampal volume-behavior covariance depending on the side of hippocampal pathology.
Bu W, Lee TD, Anurag M
… +20 more, Dou Y, Ding Y, Shi Z, Xu R, He L, Bu AZ, Nagi C, Gutierrez C, Wang J, Hilsenbeck SG, Cheng C, Zhang B, Huang S, Xu J, Osborne CK, Sreekumar A, Chang EC, Creighton CJ, Zhang XH, Li Y
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330283
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Genetically engineered mouse models have advanced cancer research, but they fail to mimic some human diseases. Rats offer a powerful alternative for modeling human cancers that are inadequately represented in mice, yet t...Genetically engineered mouse models have advanced cancer research, but they fail to mimic some human diseases. Rats offer a powerful alternative for modeling human cancers that are inadequately represented in mice, yet their use has been constrained by technical barriers to genome editing. Here, we report somatic genome editing in rats and apply this approach to model estrogen receptor (ER)-positive breast cancer, which accounts for approximately 70% of human cases but remains poorly represented in mice. The resulting rat tumors reproduce hallmarks of human ER+ breast cancer, including ductal histology, hormone responsiveness, and immune microenvironment features. By contrast, identical genetic alterations in mice failed to yield ER+ tumors, underscoring critical species differences in tumorigenesis. Together, this work establishes a versatile platform for the rapid generation of clinically relevant rat tumor models, opening avenues to study tumor biology, therapeutic response, and immune interactions in cancer subtypes previously inaccessible to experimental modeling.
Tsao KC, Bakis I, Sun S
… +13 more, Nakayama M, Kalmanson Z, Abd Elmagid L, Shuster JS, Xia Y, Eichenbaum JV, Yu FZ, McCain ML, Evans T, Pearson CA, Butcher JT, Cao J, Harrison MRM
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330282
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During cardiac development, the myocardium expands in response to physiological demands to achieve proper cardiac morphology and functional contractility, while simultaneously integrating with the developing coronary vas...During cardiac development, the myocardium expands in response to physiological demands to achieve proper cardiac morphology and functional contractility, while simultaneously integrating with the developing coronary vasculature. However, the mechanisms governing this ordered expansion remain poorly understood. Here, we found that regional hypoxia drives local tissue thickening, which in turn exacerbates a hypoxic microenvironment. We demonstrate that epicardial hypoxia serves as a central regulatory mechanism, coordinating both coronary angiogenesis and myocardial expansion during juvenile zebrafish heart development. This mechanism activates discrete spatial patterns of epicardial gene expression, including , , and . Through live and fixed imaging, we find that cardiomyocytes and endothelial cells exhibit coordinated expansion patterns through third-party epicardial signals that are required for both coronary development and myocardial expansion. Using mutants lacking functional coronary vessels, we show that coronary vessels provide negative feedback on epicardial hypoxia, while positively responding to the same hypoxic cues that drive myocardial expansion. Disruption of this negative feedback leads to increased myocardial stiffness through dysregulated extracellular matrix crosslinking as observed in pathological conditions such as cardiomyopathies. These findings establish the role of regional epicardial hypoxia within a fundamental regulatory network that drives appropriate regional tissue growth with integrated vascular supply during cardiac morphogenesis.
Hu M, Yu Z, Griffis TJ
… +9 more, Aho K, Wang Y, Yang J, Yang WH, Bernacchi CJ, McGrath JM, Dahlgren RA, Tian H, Baker JM
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330281
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Riverine nitrous oxide (NO) emissions constitute a significant yet uncertain component of global greenhouse gas budgets. Integrating approximately 3,600 observations across the contiguous United States (CONUS), we presen...Riverine nitrous oxide (NO) emissions constitute a significant yet uncertain component of global greenhouse gas budgets. Integrating approximately 3,600 observations across the contiguous United States (CONUS), we present a monthly resolved, national-scale estimate of riverine NO emissions (60.7 Gg NO-N y; 95% CI: 41.9 to 71.2) using a machine-learning framework. Our analysis reveals that enhanced hydrologic connectivity strongly regulates nitrogen and NO delivery to streams, driving emission hot moments during high-flow periods, especially in nutrient-rich low-order streams. The Midwest Corn Belt is identified as a major emission hot spot, where seasonal increases in connectivity (e.g., late-winter thaws and postharvest rainfall) amplify riverine emissions relative to direct soil emissions. Our watershed-specific EF (0.0005 to 0.029) exceeds the IPCC default (0.0026) by more than twofold on average and up to 10-fold in intensively managed watersheds. These findings highlight the importance of incorporating hydrologic connectivity and nitrogen transport into climate models and watershed nitrogen management strategies.
Trofimenko E, Gervasi N, Perez S
… +6 more, Rodriguez N, Ravault D, Cribier S, Berry H, Venance L, Sagan S
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330280
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Homeoproteins (HPs) and cell-penetrating peptides (CPPs) enter cells by endocytosis and direct membrane crossing (translocation). However, unlike endocytosis, translocation remains globally unknown. Here, we developed an...Homeoproteins (HPs) and cell-penetrating peptides (CPPs) enter cells by endocytosis and direct membrane crossing (translocation). However, unlike endocytosis, translocation remains globally unknown. Here, we developed an electrophysiological approach to assess the internalization of CPPs (Tat, R, penetratin and RW) and the HPs Otx2 and En2 though single-cell unitary transient currents in mammalian cells. At resting membrane potential, CPPs or HPs lead to submillisecond transient pores, faster than any endocytosis event, which reveal the rapid passage of the peptide across the membrane i.e., by translocation. We evidenced that expression of specific membrane glycosaminoglycans is mandatory for translocation-induced transient pores. Associated transient currents are supralinearly enhanced by hyperpolarization and poorly affected by depolarization. Moreover, a CPP-conjugated bioactive cargo similarly translocates into cytosol. Finally, we show similar HPs-evoked transient pores in brain cortical pyramidal cells, showing the physiological relevance of translocation, with crucial biotechnological and therapeutical consequences for cell delivery purposes.
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330279
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While gender and economic outcomes in negotiation have been studied for decades, much less is known about gender differences in subjective outcomes, such as trust, rapport, and willingness to negotiate again, despite the...While gender and economic outcomes in negotiation have been studied for decades, much less is known about gender differences in subjective outcomes, such as trust, rapport, and willingness to negotiate again, despite their importance for long-term success. In a series of studies with over 2,000 participants, we find that people consistently report better subjective outcomes when negotiating with women. This preference persists even in anonymous negotiations where gender is unknown and cannot be inferred from behavior, as well as in conditions where negotiation partner gender is randomly assigned. Importantly, we find no gender difference in economic outcomes. To understand why, we analyzed transcripts of real negotiations for any behavioral differences. These findings reveal an overlooked gender dynamic: While men and women achieve similar economic results, women foster stronger interpersonal relationships, which in turn lead to greater satisfaction and greater desire for future negotiations with women.
He Q, Alhowty H, Paudel P
… +9 more, Zhang X, Wei W, Sipilä T, Pohl E, Mähönen AP, Paavilainen VO, Wightman R, Qin Y, Etchells JP
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330278
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In plant development, receptor kinases are often active in disparate cell types, with each requiring vastly different signaling outputs. The ERECTA (ER) receptor kinase and its homologs Erecta-Like1 (ERL1) and ERL2 exemp...In plant development, receptor kinases are often active in disparate cell types, with each requiring vastly different signaling outputs. The ERECTA (ER) receptor kinase and its homologs Erecta-Like1 (ERL1) and ERL2 exemplify this pleiotropy. In , they influence stomatal patterning, shoot meristem function, and vascular cambium activity, among other functions. Such diverse functionality raises the question of how ER signaling can specify distinct cell behaviors. One key mechanism occurs via cell-type specific interactions with coreceptors, ligands, or other proteins that modulate signaling. However, little is known about ER interactors in the vascular cambium, a bifacial stem cell niche that generates phloem and xylem. Combinatorial mutations between , and and receptor kinases of a second family, Phloem Intercalated with Xylem (, (, and , show severe cambial defects, but the mechanism underpinning these phenotypes is not known. Here, we show that PXY and PXL proteins form protein complexes with ER family members. In genetic analyses, plant lines in which PXY signaling was constitutively active had dramatic phenotypic changes that required the presence of ER or ERL2. Our results demonstrate that PXY signaling mediated cambium regulation in part depends on ER signaling and explains ER function in the cambium. Because the cambium produces xylem, which constitutes the wood in vascular plants, our findings position PXY-ER complexes at the center of the accumulation of this versatile biomaterial and essential carbon sink.
Niklasch M, Wingert I, Fogeron ML
… +2 more, Nassal M, Beck J
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330277
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Hepatitis B virus (HBV), a major human pathogen, replicates its DNA genome by protein-primed reverse transcription of a pregenomic RNA (pgRNA). This process is directed by the pgRNA-borne epsilon (ε) element, which provi...Hepatitis B virus (HBV), a major human pathogen, replicates its DNA genome by protein-primed reverse transcription of a pregenomic RNA (pgRNA). This process is directed by the pgRNA-borne epsilon (ε) element, which provides the origin for minus-strand DNA synthesis and mediates coencapsidation of pgRNA with the viral polymerase (P protein) into nucleocapsids. ε adopts a thermodynamically stable hairpin structure that is remodeled upon formation of functional ε-P complexes, but the nature of the rearranged RNA structure and its implication for pgRNA encapsidation has remained elusive. Guided by in silico analyses of ε-like elements from distantly related nackednaviruses, we identify a distinct conformation of HBVε whose defining feature is a cryptic stem-loop (cSL), masked within the upper stem of ε. The P-dependent cSL conformation reorganizes key sequences into a compact structural unit that enables initiation of DNA synthesis and packaging of the viral pgRNA-P complex. RNAs engineered to favor cSL formation exhibit increased P protein affinity and strongly enhanced priming activity in vitro while maintaining replication competence in cells. Mutational analyses identify the cSL and its immediate vicinity, but not the remaining upper stem sequence, as the dominant determinants of ε function. Genetic variation in cSL-forming potential across hepadnaviruses links in vitro priming competence to the energetic accessibility of this alternative fold. Together, our findings reveal ε as a P protein-dependent RNA switch that tightly couples pregenome encapsidation to reverse transcription competence. This regulatory mechanism advances our understanding of HBV replication and could be exploited for antiviral intervention.
Wei Z, Kiessling W, Guo Z
… +4 more, Benton MJ, Su L, Huang Y, Chen ZQ
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330276
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The ecological success of modern reef-building corals is rooted in photosymbiosis, yet its macroevolutionary benefit remains unclear. Analyzing the Phanerozoic record of inferred zooxanthellate (Z) and azooxanthellate (A...The ecological success of modern reef-building corals is rooted in photosymbiosis, yet its macroevolutionary benefit remains unclear. Analyzing the Phanerozoic record of inferred zooxanthellate (Z) and azooxanthellate (AZ) corals over geologic time scales using Bayesian methods, we identify a fundamental shift in diversification dynamics and their drivers across the Paleozoic-Mesozoic transition. Although Z corals dominate modern tropical reef ecosystems, their Paleozoic counterparts were outpaced by AZ forms and showed failed recoveries after the Late Devonian mass extinction. We found Z coral diversification was primarily driven by origination, whereas AZ diversification was controlled by extinction. Multivariate birth-death models reveal that Paleozoic coral diversification was governed by abiotic stressors like warming and anoxia, to which Z and AZ corals showed similar vulnerability. The rise of scleractinian corals in the Triassic marked a distinct macroevolutionary regime shift after which photosymbiosis spurred coral diversification. Positive correlations between temperature and Z coral extinction dominated the Paleozoic, while negative correlations prevailed in the Meso-Cenozoic. The long-term reversal of this relationship could be the reduced supersaturation of the oceans with respect to CaCO due to the emergence of calcareous plankton in the Triassic. Our deep-time perspective demonstrates that the advantage of photosymbiosis is not intrinsic but contingent on the broader ecological and environmental context.
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330275
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Meristems are the growth centers of plants and fundamental in understanding plant development, morphogenesis, and vegetative propagation. Across all plant groups, the phytohormone auxin controls meristem maintenance, rep...Meristems are the growth centers of plants and fundamental in understanding plant development, morphogenesis, and vegetative propagation. Across all plant groups, the phytohormone auxin controls meristem maintenance, represses the emergence of new meristems (apical dominance), and mediates cellular reprogramming when new meristems regenerate following removal of existing meristems. The liverwort Marchantia produces clonal propagules (gemmae) featuring two apical notches that develop into functional meristems. This presents a tractable experimental system to study meristem developmental biology. I used laser ablation microscopy to precisely disrupt cells in and around the developing premeristem in the apical notches of germinating gemma, finding that the first cell row is indispensable. Within this layer, a contiguous quorum of stem cells is required for activity. Apical notches reorientate in response to damage, demonstrating that the apical notch stem cells act as a communicating population. Feedback from the stem cell population is necessary to maintain notch activity and generate the notch apex. These experiments show communication between notches and regenerating meristems. The apical dominance signal represses cell division and requires both sources and sinks, features of auxin-mediated communication. Central regions of the gemma could transmit these apical dominance signals, but the tissues of the gemma periphery could not. I present a model of Marchantia gemma and apical notch organization, involving intra-, inter-, and extranotch communication. This provides a framework for further study of meristem formation, communication, and maintenance in Marchantia and improving knowledge of plant meristems more generally.
Poitout A, Ugalde JM, Gorgues L
… +13 more, Dongois A, Scholz P, Nacry P, Alcon C, Fiche JB, Dumont X, Nollman M, Jhala K, Schäffner AR, Jaillais Y, Verdoucq L, Meyer AJ, Martinière A
Proc Natl Acad Sci U S A
· 2026 Jun · PMID 42330274
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The spatiotemporal organization of proteins and lipids within membranes is crucial for ensuring proper cellular signaling. While the segregation of proteins and lipids into membrane nanodomains is well established, it re...The spatiotemporal organization of proteins and lipids within membranes is crucial for ensuring proper cellular signaling. While the segregation of proteins and lipids into membrane nanodomains is well established, it remains unclear whether nanodomains can generate gradients of small diffusible molecules. In plants, reactive oxygen species (ROS), especially hydrogen peroxide (HO), act as key signaling molecules in response to environmental stimuli such as osmotic stress. However, how extracellular HO affects intracellular signaling has remained unknown. Here, we show that osmotic stimulation induces the formation of localized, HO-rich nanoenvironments at the cytoplasmic face of the plasma membrane (PM) in root cells. Using a PM-tethered HO biosensor, we found that these oxidized nanodomains arise from the clustering of RESPIRATORY BURST OXIDASE HOMOLOGs (RBOHs) and RHO OF PLANTS 6 (ROP6), in coordination with aquaporin-mediated HO transport via the PLASMA MEMBRANE INTRINSIC PROTEIN2;7 (PIP2;7). These local redox hotspots at the PM create a feedforward loop in which HO enhances ROP6 nanoclustering, thereby amplifying ROS signaling. Disruption of HO production or transport dampens both ROP6 clustering and anisotropic cell expansion, indicating a crucial role for spatially confined redox signaling in regulating plant growth under osmotic stress. Our findings propose a model in which ROP6/RBOHD-F/PIP2;7 nanodomains function as discrete redox signaling units, redefining ROS signaling at the PM as a structured, signal-specific, and compartmentalized process.