Vision, challenges and opportunities for a Plant Cell Atlas

With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, resulting in a roadmap that acknowledges the current knowledge gaps and technical challenges, and underscores how the PCA initiative can help to overcome them.</jats:p

Delineating vanadium (V) ecological distribution, its toxicant potential, and effective remediation strategies from contaminated soils

Vanadium (V) is a multivalent redox-sensitive metal that is widely distributed in the environment. It enters the environment mainly through anthropogenic activities, such as industry, mining, fossil fuel burning, and fertilization, and imposes serious problems for plants, animals, and human health. The adverse effects of V on human health are determined by its movement through the environmental components (i.e., atmosphere, water, and soil). Exceeding the well-defined threshold level of V intake in animals (species-specific) and humans (V > 4500 µg per day) causes diseases such as vasoconstriction, congestion, focal hemorrhage in the lungs and adrenal cortex, congestion, fatty liver, and diarrhea, dehydration, cardiac disturbances, reduction in food intake, or weight loss. The threshold level of V toxicity varies from species to species. Low concentrations of V increased the root length, plant height, and biomass yield due to increased seed germination, chlorophyll, nutrient uptake, and nitrogen utilization. High concentrations of V inhibit protein synthesis, enzyme activities, and ion transport, resulting in stunted plant growth, shoot and root abnormalities, and even plant death. Various soil properties, including organic matter status, pH, calcium, phosphorus, aluminum, and iron (hydr) oxides, are the crucial determinants of V bioavailability and uptake by plants. Alteration in these properties could improve plant growth by inhibiting V uptake. Phytoremediation using microorganisms and organic amendments can be a feasible technique to remediate V-polluted soils. In this review, we concise an overview of V distribution in different environmental components and its impact on plants and human health. In addition, we also discussed the possible remedial approaches to eliminate as well as reduce the V concentration in soil

Silicon-mediated metabolic upregulation of ascorbate glutathione (AsA-GSH) and glyoxalase reduces the toxic effects of vanadium in rice

Although beneficial metalloid silicon (Si) has been proven to reduce the toxicity of several heavy metals, there is a lack of understanding regarding Si potential function in mitigating phytotoxicity induced by vanadium (V). In this study, effect of Si (1.5 mM) on growth, biomass production, V uptake, reactive oxygen species (ROS), methylglyoxal (MG) formation, selected antioxidants enzymes activities, glyoxalase enzymes under V stress (35 mg L−1) was investigated in hydroponic experiment. The results showed that V stress reduced rice growth, caused V accumulation in rice. Addition of Si to the nutritional medium increased plant growth, biomass yield, root length, root diameter, chlorophyll parameters, photosynthetic assimilation, ion leakage, antioxidant enzymes activities under V stress. Notably, Si sustained V-homeostasis and alleviated V caused oxidative stress by boosting ascorbate (AsA) levels and the activity of antioxidant enzymes in V stressed rice plants. Furthermore, Si protected rice seedlings against the harmful effects of methylglyoxal by increasing the activity of glyoxalase enzymes. Additionally, Si increased the expression of numerous genes involved in the detoxification of reactive oxygen species (e.g., OsCuZnSOD1, OsCaTB, OsGPX1, OsAPX1, OsGR2, and OsGSTU37) and methylglyoxal (e.g., OsGLYI-1 and OsGLYII-2). The findings supported that Si can be applied to plants to minimize the V availability to plant, and also induced V stress tolerance

Salicylic acid induces vanadium stress tolerance in rice by regulating the AsA-GSH cycle and glyoxalase system

Salicylic acid (SA) is a signaling molecule and behaves as an antioxidant that induces stress tolerance in plants against abiotic stress. The present study explored the rice seedling response to V stress and the role of SA in improving the V stress tolerance of rice seedlings. The rice seedlings were sown in Petri dishes and incubated in a climate-controlled chamber for 4 days without light for germination. After that, the rice seedlings were shifted into hydroponic solution and allowed to grow for 18 days in hydroponic solution. The roots of 21-day-old rice seedlings were pretreated with SA (200 μM) for 3 days, and exposed to V (35 mg L−1) stress for 7 days. After 7 days of V stress, rice seedlings were harvested to determine the root attributes, photosynthetic assimilation, reactive oxygen species (ROS), ascorbate-glutathione (AsA-GSH) pathway enzymes, antioxidant and glyoxalase enzyme activities, and plant growth parameters. The findings disclosed that pretreatment of rice seedlings with SA had a high SPAD index, chlorophyll pigment content, and photosynthetic assimilation resulted in better growth compared to non-SA-pretreated rice seedlings. Strikingly, SA sustains the V homeostasis by inhibiting the accumulation of V from rice root to shoot. Besides this, pretreatment of SA increased the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST), and ascorbate-glutathione (AsA-GSH) pathway enzymes, and also enhanced the ascorbate (AsA) and glutathione (GSH) level, and minimized the hydrogen peroxide (H2O2) and superoxide anion (O2-∙) of rice seedlings, by regulating the gene expression of antioxidant enzymes (OsCuZnSOD1, OsCaTB, OsGPX1, OsAPX1, OsGR2, and OsGSTU37). Furthermore, SA reduced methylglyoxal toxicity and enhanced glyoxalase enzyme activity by upregulating the genes expression of glyoxalase genes (OsGLYI-1 and OsGLYII-2) under V stress condition. Considering these findings demonstrated that SA may be utilized to reduce V availability to rice seedlings while also improving rice seedling growth and V stress resistance. Graphical abstract: [Figure not available: see fulltext.

Effect of vanadium on growth, photosynthesis, reactive oxygen species, antioxidant enzymes, and cell death of rice

Vanadium (V) as minor concentration is present in various plants and extensively found in soils. The current study was established to assess the response of rice seedlings to different V concentrations and also investigated its toxic effect on growth, photosynthetic assimilation, relative chlorophyll content, SPAD index, ion leakage, enzyme activities, hydrogen peroxide (H2O2), and cell death. The rice seeds were sown in Petri dishes for 8 days, and after that, rice seedlings were grown hydroponically in a climate-controlled growth chamber. After 15 days of V-treatment, antioxidant enzyme activities, H2O2, protein contents, photosynthetic assimilation, relative chlorophyll content, and cell death were determined by utilizing the Spectrophotometer (Lambda 25 UV/VIS Spectrophotometer), and V accumulation (roots and shoots) was determined by GFAAS (GTA 120). The obtained results showed that all V concentrations significantly decreased the biomass (dry and fresh) and root growth as a result of the reduction in total root length, root tips, root fork, root surface area, and root crossing, and V was more accumulated in roots than shoots. Besides this, enzymatic activities were significantly enhanced under V stress. The findings also confirmed that seedling exposed to V stress had lower tolerance indices, photosynthetic activity, and protein contents while the ion leakage was consistently increased by increasing the V concentrations. The viability of plant cells severely damaged in response to high V stress, and H2O2 induction might be responsible for cell death. Generally, all V doses had a drastic effect on enzyme activities and caused cell death of rice plans. Moreover, the current study demonstrated that V ≥ 35 mg L−1 caused damaging effects on rice plants

Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world’s largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60 years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ~30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death. The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death