Plants often adapt to adverse or stress conditions via differential growth. The trans-Golgi network (TGN) has been implicated in stress responses, but it is not clear in what capacity it mediates adaptive growth decisions. In this study, we assess the role of the TGN in stress responses by exploring the previously identified interactome of the Transport Protein Particle II (TRAPPII) complex required for TGN structure and function. We identified physical and genetic interactions between AtTRAPPII and shaggy-like kinases (GSK3/AtSKs) and provided in vitro and in vivo evidence that the TRAPPII phosphostatus mediates adaptive responses to abiotic cues. AtSKs are multifunctional kinases that integrate a broad range of signals. Similarly, the AtTRAPPII interactome is vast and considerably enriched in signaling components. An AtSK-TRAPPII interaction would integrate all levels of cellular organization and instruct the TGN, a central and highly discriminate cellular hub, as to how to mobilize and allocate resources to optimize growth and survival under limiting or adverse conditions.

Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these compounds into the rhizosphere and atmosphere where they affect animal and microbe behavior. To survive, nematodes must have evolved the sensory capacity to distinguish plant-made small molecules (SMs) that are harmful and must be avoided from those that are beneficial and should be sought. This ability to classify chemical cues as a function of their value is fundamental to olfaction, and represents a capacity shared by many animals, including humans. Here, we present an efficient platform based on multi-well plates, liquid handling instrumentation, inexpensive optical scanners, and bespoke software that can efficiently determine the valence (attraction or repulsion) of single SMs in the model nematode, Caenorhabditis elegans. Using this integrated hardware-wetware-software platform, we screened 90 plant SMs and identified 37 that attracted or repelled wild-type animals, but had no effect on mutants defective in chemosensory transduction. Genetic dissection indicates that for at least 10 of these SMs, response valence emerges from the integration of opposing signals, arguing that olfactory valence is often determined by integrating chemosensory signals over multiple lines of information. This study establishes that C. elegans is an effective discovery engine for determining chemotaxis valence and for identifying natural products detected by the chemosensory nervous system.

Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these compounds into the rhizosphere and atmosphere where they affect animal and microbe behavior. To survive, nematodes must have evolved the sensory capacity to distinguish plant-made small molecules (SMs) that are harmful and must be avoided from those that are beneficial and should be sought. This ability to classify chemical cues as a function of their value is fundamental to olfaction, and represents a capacity shared by many animals, including humans. Here, we present an efficient platform based on multi-well plates, liquid handling instrumentation, inexpensive optical scanners, and bespoke software that can efficiently determine the valence (attraction or repulsion) of single SMs in the model nematode, Caenorhabditis elegans. Using this integrated hardware-wetware-software platform, we screened plant SMs and identified 37 that attracted or repelled wild-type animals, but had no effect on mutants defective in chemosensory transduction. Genetic dissection indicates that for at least 10 of these SMs, response valence emerges from the integration of opposing signals, arguing that olfactory valence is often determined by integrating chemosensory signals over multiple lines of information. This study establishes that C. elegans is an effective discovery engine for determining chemotaxis valence and for identifying natural products detected by the chemosensory nervous system.

Noninvasive phenotyping can quantify dynamic plant growth processes at higher temporal resolution than destructive phenotyping and can reveal phenomena that would be missed by end-point analysis alone. Additionally, whole-plant phenotyping can identify growth conditions that are optimal for both above- and below-ground tissues. However, noninvasive, whole-plant phenotyping approaches available today are generally expensive, complex, and non-modular. We developed a low-cost and versatile approach to non-invasively measure whole-plant physiology over time by growing plants in isolated hydroponic chambers. We demonstrate the versatility of our approach by measuring whole-plant biomass accumulation, water consumption, and water use efficiency every two days on unstressed and osmotically-stressed sorghum accessions. We identified relationships between root zone acidification and photosynthetic efficiency on whole-plant water use efficiency over time. Our system can be implemented using cheap, basic components, requires no specific technical expertise, and is suitable for any non-aquatic vascular plant species.

Rhamnose is an essential component of the plant cell wall and is synthesized from uridine diphosphate (UDP)-glucose by the RHAMNOSE1 (RHM1) enzyme. RHM1 localizes to biomolecular condensates in plants, but their identity, formation, and function remain elusive. Combining live imaging, genetics, and biochemical approaches in Arabidopsis and heterologous systems, we show that RHM1 alone is sufficient to form enzymatically active condensates, which we name ‘rhamnosomes’. Rhamnosome formation is required for UDP-rhamnose synthesis and organ development. Overall, our study demonstrates a novel role for biomolecular condensation in metabolism and organismal development, and provides further support for how organisms have harnessed this biophysical process to regulate small molecule metabolism.

Noninvasive phenotyping can quantify dynamic plant growth processes at higher temporal resolution than destructive phenotyping and can reveal phenomena that would be missed by end-point analysis alone. Additionally, whole-plant phenotyping can identify growth conditions that are optimal for both above- and below-ground tissues. However, noninvasive, whole-plant phenotyping approaches available today are generally expensive, complex, and non-modular. We developed a low-cost and versatile approach to noninvasively measure whole-plant physiology over time by growing plants in isolated hydroponic chambers. We demonstrate the versatility of our approach by measuring whole-plant biomass accumulation, water use, and water use efficiency every two days on unstressed and osmotically stressed sorghum accessions. We identified relationships between root zone acidification and photosynthesis on whole-plant water use efficiency over time. Our system can be implemented using cheap, basic components, requires no specific technical expertise, and should be suitable for any non-aquatic vascular plant species.

We find that Large Igneous Province (LIP) volcanism, mostly continental flood basalts (CFBs), along with the largest extraterrestrial impacts show significant correlations with mass -extinction events in the Phanerozoic geologic record. The ages of the 6 major marine mass extinctions (>= 40% extinction of genera) of the last 541 My-the end -Ordovician (-444 Ma), late Devonian (-372 Ma), end-Guadalupian (-259 Ma), end -Permian (-252 Ma), end -Triassic (-201 Ma), and end -Cretaceous (66 Ma) extinctions are significantly correlated with high -quality U-Pb zircon and 40Ar/39Ar ages of 6 continental flood basalts (CFBs) -the Cape St. Mary's, Viluy, Emeishan, Siberian, CAMP, and the Deccan Basalts, The mass extinctions also coincide with stratigraphic Hg anomalies representing proxy evidence for the synchrony of the extinctions and the basaltic volcanism. Furthermore, ages of 6 minor extinction events (15% to 25% extinction of marine genera) at - 94 Ma, 124 Ma, 134 Ma, 183 Ma, 290 Ma and 510 Ma also coincided with 6 well -dated CFB eruptions (the Madagascar, HALIP, Parana/Etendeka, Karoo/Ferrar, Panjal and Kakarindji Basalts) and with associated Hg anomalies. At least 3 minor extinction events (at - 145 Ma, 215 Ma and 227 Ma) apparently occurred close to times of oceanic plateau (OP) volcanism in the Pacific Ocean (Shatsky Rise, Angayucham and Wrangellia Basalts). Major and minor marine mass -extinction episodes at times of CFB eruptions were commonly accompanied by ocean anoxic/euxinic events, increased ocean acidity, high atmospheric pCO2, increases in UV -B radiation from ozone -layer destruction, and pulses of high ambient temperatures, providing potential immediate causes for the mass extinctions. The 4 most recent major marine extinctions (-66 Ma, 201 Ma, 252 Ma, and 260 Ma) and a minor extinction (-290 Ma) coincided with the ages of CFBs and with concurrent mass extinctions of non -marine vertebrates, indicating global -scale volcanogenic environmental crises on land and in the sea. The age of the abrupt end -Cretaceous major mass extinction (66 Ma) overlaps with the age of the Deccan eruptions, but is exactly coincident with the very large Chicxulub impact (180 km diameter crater), possibly the largest terrestrial impact of the last -3 By. The ages of the 3 next largest well -dated Phanerozoic terrestrial impact craters (>= 100 km in diameter), the Popigai, Morokweng and Manicouagan craters, capable of causing widespread environmental effects, are concurrent with the ages of minor extinction events at -37 Ma, 145 Ma and 215 Ma. The significant correlations and the predicted severe environmental consequences of these major volcanic and impact events are very convincing that 12 CFB eruptions, at least 3 oceanic plateau eruptions, and the 4 largest impacts were involved with recognized biotic mass -extinction episodes of the last 541 My, and leave little room for alternate primary causes of the extinctions.

Wind droughts, or prolonged periods of low wind speeds, pose challenges for electricity systems largely reliant on wind generation. Using weather reanalysis data, we analyzed the global distribution of and trends in wind droughts using an energy deficit metric that integrates the depth and duration of wind droughts. We identified regions with high power densities, low seasonal variability, and limited weather fluctuations that favor wind power generation, such as the American Midwest, Australia, the Sahara, Argentina, Central Asia, and Southern Africa. Northwestern Europe has high power densities but experiences more frequent and prolonged wind droughts due to higher weather variability. We found little evidence for strong trends in wind droughts over recent decades in most places. Rather, the most severe wind droughts in many places occurred before wind power substantially penetrated power systems, which suggests that historical weather data can be useful in designing reliable wind-reliant electricity systems.

Skeletal muscles connect bones and tendons for locomotion and posture. Understanding the regenerative processes of muscle, bone and tendon is of importance to basic research and clinical applications. Despite their interconnections, distinct transcription factors have been reported to orchestrate each tissue developmental and regenerative processes. Here we show that Scx expression is not detectable in adult muscle stem cells (also known as satellite cells, SCs) during quiescence. Scx expression begins in activated SCs and continues throughout regenerative myogenesis after injury. By SC-specific Scx gene inactivation (ScxcKO), we show that Scx function is required for SC expansion/renewal and robust new myofiber formation after injury. We combined single-cell RNA-sequencing and CUT&RUN to identify direct Scx target genes during muscle regeneration. These target genes help explain the muscle regeneration defects of ScxcKO, and are not overlapping with Scx-target genes identified in tendon development. Together with a recent finding of a subpopulation of Scx-expressing connective tissue fibroblasts with myogenic potential during early embryogenesis, we propose that regenerative and developmental myogenesis co-opt the Scx gene via different mechanisms.