Overexpression of tonoplast Ca2+-ATPase in guard cells synergistically enhances stomatal opening and drought tolerance.

Stomata play a crucial role in plants by controlling water status and responding to drought stress. However, simultaneously improving stomatal opening and drought tolerance has proven to be a significant challenge. To address this issue, we employed the OnGuard quantitative model, which accurately represents the mechanics and coordination of ion transporters in guard cells. With the guidance of OnGuard, we successfully engineered plants that overexpressed the main tonoplast Ca2+-ATPase gene, ACA11, which promotes stomatal opening and enhances plant growth. Surprisingly, these transgenic plants also exhibited improved drought tolerance due to reduced water loss through their stomata. Again, OnGuard assisted us in understanding the mechanism behind the unexpected stomatal behaviors observed in the ACA11 overexpressing plants. Our study revealed that the overexpression of ACA11 facilitated the accumulation of Ca2+ in the vacuole, thereby influencing Ca2+ storage and leading to an enhanced Ca2+ elevation in response to abscisic acid. This regulatory cascade finely tunes stomatal responses, ultimately leading to enhanced drought tolerance. Our findings underscore the importance of tonoplast Ca2+-ATPase in manipulating stomatal behavior and improving drought tolerance. Furthermore, these results highlight the diverse functions of tonoplast-localized ACA11 in response to different conditions, emphasizing its potential for future applications in plant enhancement.

Arabidopsis SNARE SYP132 impacts on PIP2;1 trafficking and function in salinity stress.

In plants so-called plasma membrane intrinsic proteins (PIPs) are major water channels governing plant water status. Membrane trafficking contributes to functional regulation of major PIPs and is crucial for abiotic stress resilience. Arabidopsis PIP2;1 is rapidly internalised from the plasma membrane in response to high salinity to regulate osmotic water transport, but knowledge of the underlying mechanisms is fragmentary. Here we show that PIP2;1 occurs in complex with SYNTAXIN OF PLANTS 132 (SYP132) together with the plasma membrane H+-ATPase AHA1 as evidenced through in vivo and in vitro analysis. SYP132 is a multifaceted vesicle trafficking protein, known to interact with AHA1 and promote endocytosis to impact growth and pathogen defence. Tracking native proteins in immunoblot analysis, we found that salinity stress enhances SYP132 interactions with PIP2;1 and PIP2;2 isoforms to promote redistribution of the water channels away from the plasma membrane. Concurrently, AHA1 binding within the SYP132-complex was significantly reduced under salinity stress and increased the density of AHA1 proteins at the plasma membrane in leaf tissue. Manipulating SYP132 function in Arabidopsis thaliana enhanced resilience to salinity stress and analysis in heterologous systems suggested that the SNARE influences PIP2;1 osmotic water permeability. We propose therefore that SYP132 coordinates AHA1 and PIP2;1 abundance at the plasma membrane and influences leaf hydraulics to regulate plant responses to abiotic stress signals.

Development and validation of a nomogram model for predicting unfavorable functional outcomes in ischemic stroke patients after acute phase.

Introduction: Prediction of post-stroke functional outcome is important for personalized rehabilitation treatment, we aimed to develop an effective nomogram for predicting long-term unfavorable functional outcomes in ischemic stroke patients after acute phase. Methods: We retrospectively analyzed clinical data, rehabilitation data, and longitudinal follow-up data from ischemic stroke patients who underwent early rehabilitation at multiple centers in China. An unfavorable functional outcome was defined as a modified Rankin Scale (mRS) score of 3-6 at 90 days after onset. Patients were randomly allocated to either a training or test cohort in a ratio of 4:1. Univariate and multivariate logistic regression analyses were used to identify the predictors for the development of a predictive nomogram. The area under the receiver operating characteristic curve (AUC) was used to evaluate predictive ability in both the training and test cohorts. Results: A total of 856 patients (training cohort: n = 684; test cohort: n = 172) were included in this study. Among them, 518 patients experienced unfavorable outcomes 90 days after ischemic stroke. Trial of ORG 10172 in Acute Stroke Treatment classification (p = 0.024), antihypertensive agents use [odds ratio (OR) = 1.86; p = 0.041], 15-day Barthel Index score (OR = 0.930; p < 0.001) and 15-day mRS score (OR = 13.494; p < 0.001) were selected as predictors for the unfavorable outcome nomogram. The nomogram model showed good predictive performance in both the training (AUC = 0.950) and test cohorts (AUC = 0.942). Conclusion: The constructed nomogram model could be a practical tool for predicting unfavorable functional outcomes in ischemic stroke patients underwent early rehabilitation after acute phase.

An optical and visual multi-mode sensing platform base on nitrogen, sulfur, boron co-doped carbon dots for rapid and simple determination of ferric ions in water.

Abnormal iron ions levels may lead to some diseases and serious environmental pollution. Herein, optical and visual detection strategies of Fe3+ in water based on co-doped carbon dots (CDs) were established in the present study. Firstly, a one-pot synthetic strategy for the preparation of the N, S, B co-doped CDs with a home microwave oven was developed. Secondly, the optical properties, chemical structures, and morphology of CDs were further characterized by fluorescence spectroscopy, Uv-vis absorption spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscope. Finally, the results indicated that the fluorescence of the co-doped CDs was quenched by ferric ions via the static mechanism and the aggregation of CDs, accompanied by the increased red color. The multi-mode sensing strategies of Fe3+ with fluorescence photometer, UV-visible spectrophotometer, portable colorimeter and smartphone had the advantages of good selectivity, excellent stability and high sensitivity. Fluorophotometry based on co-doped CDs was a powerful probe platform for measuring lower concentrations of Fe3+ due to its higher sensitivity, better linear relationship, lower limit of detection (0.27 µM) and limit of quantitation (0.91 µM). In addition, the visual detection methods with a portable colorimeter and smartphone had been proven to be very suitable for rapid and simple sensing of higher concentrations of Fe3+. Moreover, the co-doped CDs utilized for Fe3+ probes in tap water and boiler water obtained satisfactory results. Consequently, the efficient, versatile optical and visual multi-mode sensing platform could be extended to apply such a visual analysis of ferric ions in the biological, chemical and other fields.

SNARE SYP132 mediates divergent traffic of plasma membrane H+-ATPase AHA1 and antimicrobial PR1 during bacterial pathogenesis.

The vesicle trafficking SYNTAXIN OF PLANTS132 (SYP132) drives hormone-regulated endocytic traffic to suppress the density and function of plasma membrane (PM) H+-ATPases. In response to bacterial pathogens, it also promotes secretory traffic of antimicrobial pathogenesis-related (PR) proteins. These seemingly opposite actions of SYP132 raise questions about the mechanistic connections between the two, likely independent, membrane trafficking pathways intersecting plant growth and immunity. To study SYP132 and associated trafficking of PM H+-ATPase 1 (AHA1) and PATHOGENESIS-RELATED PROTEIN1 (PR1) during pathogenesis, we used the virulent Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) bacteria for infection of Arabidopsis (Arabidopsis thaliana) plants. SYP132 overexpression suppressed bacterial infection in plants through the stomatal route. However, bacterial infection was enhanced when bacteria were infiltrated into leaf tissue to bypass stomatal defenses. Tracking time-dependent changes in native AHA1 and SYP132 abundance, cellular distribution, and function, we discovered that bacterial pathogen infection triggers AHA1 and SYP132 internalization from the plasma membrane. AHA1 bound to SYP132 through its regulatory SNARE Habc domain, and these interactions affected PM H+-ATPase traffic. Remarkably, using the Arabidopsis aha1 mutant, we discovered that AHA1 is essential for moderating SYP132 abundance and associated secretion of PR1 at the plasma membrane for pathogen defense. Thus, we show that during pathogenesis SYP132 coordinates AHA1 with opposing effects on the traffic of AHA1 and PR1.

The Effects of Reversibility of H2-H3 Phase Transition on Ni-Rich Layered Oxide Cathode for High-Energy Lithium-Ion Batteries.

Although LiNi0.8Co0.1Mn0.1O2 is attracting increasing attention on account of its high specific capacity, the moderate cycle lifetime still hinders its large-scale commercialization applications. Herein, the Ti-doped LiNi0.8Co0.1Mn0.1O2 compounds are successfully synthesized. The Li(Ni0.8Co0.1Mn0.1)0.99Ti0.01O2 sample exhibits the best electrochemical performance. Under the voltage range of 2.7-4.3 V, it maintains a reversible capacity of 151.01 mAh·g-1 with the capacity retention of 83.98% after 200 cycles at 1 C. Electrochemical impedance spectroscopy (EIS) and differential capacity profiles during prolonged cycling demonstrate that the Ti doping could enhance both the abilities of electronic transition and Li ion diffusion. More importantly, Ti doping can also improve the reversibility of the H2-H3 phase transitions during charge-discharge cycles, thus improving the electrochemical performance of Ni-rich cathodes.

Unusual Roles of Secretory SNARE SYP132 in Plasma Membrane H+-ATPase Traffic and Vegetative Plant Growth.

The plasma membrane proton (H+)-ATPases of plants generate steep electrochemical gradients and activate osmotic solute uptake. H+-ATPase-mediated proton pumping orchestrates cellular homeostasis and is a prerequisite for plastic cell expansion and plant growth. All evidence suggests that the population of H+-ATPase proteins at the plasma membrane reflects a balance of their roles in exocytosis, endocytosis, and recycling. Auxin governs both traffic and activation of the plasma membrane H+-ATPase proteins already present at the membrane. As in other eukaryotes, in plants, SNARE-mediated membrane traffic influences the density of several proteins at the plasma membrane. Even so, H+-ATPase traffic, its relationship with SNAREs, and its regulation by auxin have remained enigmatic. Here, we identify the Arabidopsis (Arabidopsis thaliana) Qa-SNARE SYP132 (Syntaxin of Plants132) as a key factor in H+-ATPase traffic and demonstrate its association with endocytosis. SYP132 is a low-abundant, secretory SNARE that primarily localizes to the plasma membrane. We find that SYP132 expression is tightly regulated by auxin and that augmented SYP132 expression reduces the amount of H+-ATPase proteins at the plasma membrane. The physiological consequences of SYP132 overexpression include reduced apoplast acidification and suppressed vegetative growth. Thus, SYP132 plays unexpected and vital roles in auxin-regulated H+-ATPase traffic and associated functions at the plasma membrane.