In plants, cytosolic and extracellular pH homeostasis are crucial for various physiological processes, including the uptake of macronutrients and micronutrients, cell elongation, cell expansion, and ...enzyme activity. Proton (H
+
) gradients and the membrane potential are generated by a H
+
pump consisting of an active primary transporter. Plasma membrane (PM) H
+
-ATPase, a PM-localized H
+
pump, plays a pivotal role in maintaining pH homeostasis in plant cells and extracellular regions. PM H
+
-ATPase activity is regulated by protein abundance and by post-translational modifications. Several stimuli have been found to activate the PM H
+
-ATPase through phosphorylation of the penultimate threonine (Thr) of the carboxy terminus. Light- and photosynthesis-induced phosphorylation of PM H
+
-ATPase are conserved phenomena among various plant species. In this work, we review recent findings related to PM H
+
-ATPase regulation in the photosynthetic tissues of plants, focusing on its mechanisms and physiological roles. The physiological roles of photosynthesis-dependent PM H
+
-ATPase activation are discussed in the context of nitrate uptake and cytoplasmic streaming in leaves.
Plasma membrane (PM) H
-ATPase is crucial for light-induced stomatal opening and phosphorylation of a penultimate residue, Thr948 (pen-Thr, numbering according to Arabidopsis AHA1) is required for ...enzyme activation. In this study, a comprehensive phosphoproteomic analysis using guard cell protoplasts from Vicia faba shows that both red and blue light increase the phosphorylation of Thr881, of PM H
-ATPase. Light-induced stomatal opening and the blue light-induced increase in stomatal conductance are reduced in transgenic Arabidopsis plants expressing mutant AHA1-T881A in aha1-9, whereas the blue light-induced phosphorylation of pen-Thr is unaffected. Auxin and photosynthetically active radiation induce the phosphorylation of both Thr881 and pen-Thr in etiolated seedlings and leaves, respectively. The dephosphorylation of phosphorylated Thr881 and pen-Thr are mediated by type 2 C protein phosphatase clade D isoforms. Taken together, Thr881 phosphorylation, in addition of the pen-Thr phosphorylation, are important for PM H
-ATPase function during physiological responses, such as light-induced stomatal opening in Arabidopsis thaliana.
Natural plutonium from supernovaeThe rapid neutron capture process (r-process) produces many of the heavy chemical elements, but the astrophysical settings where it occurs remain unclear. Leading ...candidates are neutron star mergers and some types of supernovae. Wallner et al. analyzed the plutonium content of a deep-sea crust sample, identifying a few dozen atoms of the r-process isotope plutonium- 244 that were delivered to Earth within the past few million years. There was a simultaneous signal of iron-60, which is known to be produced in supernovae. Comparing the ratios of these isotopes constrains the relative contributions of supernovae and neutron star mergers to r-process nucleosynthesis.Science, this issue p. 742Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust—iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.
After the nuclear accident in Fukushima Prefecture, Japan, in 2011, 137Caesium (Cs) contaminated nearby agricultural regions. Studies in these rice fields found that low K and high N fertilizer ...application enhanced Cs uptake in rice shoots. However, the influence of root and soil physics on these findings, as well as precise nutrient levels, remain to be clarified.
We sought to analyse these relationships utilizing hydroponically grown rice plants. The rice plants were subjected to various concentrations of K and N nutrient solutions. We measured Cs allocation within the plants and performed transcript analyses using root tissues.
Under low‐K conditions, low‐N plants accumulated less Cs in shoots and more in roots when compared to control‐N conditions, even though overall Cs uptake remained unchanged. Expression analyses of root mRNAs showed that low‐N plants accumulated reduced levels of OsAKT1 mRNA, encoding a K transporter. We also found a negative relationship between shoot Cs and K status in control‐N but not in low‐N conditions.
Our results suggest that the application of N shifts Cs from roots into the shoots and that OsAKT1 in root vascular tissues influences Cs allocation. In practice, fine tuning N/K application and targeted breeding of K transporters might mitigate Cs contamination in rice plants.
Low nitrogen environments reduce Cs accumulation in rice shoots.
Plasma membrane (PM) proton-translocating adenosine triphosphatase (H+-ATPase) is a pivotal enzyme for plant growth and development that acts as a primary transporter and is activated by ...phosphorylation of the penultimate residue, threonine, at the C-terminus. Small Auxin-Up RNA family proteins maintain the phosphorylation level via inhibiting dephosphorylation of the residue by protein phosphatase 2C-D clade. Photosynthetically active radiation activates PM H+-ATPase via phosphorylation in mesophyll cells of Arabidopsis thaliana, and phosphorylation of PM H+-ATPase depends on photosynthesis and photosynthesis-related sugar supplementation, such as sucrose, fructose and glucose. However, the molecular mechanism and physiological role of photosynthesis-dependent PM H+-ATPase activation are still unknown. Analysis using sugar analogs, such as palatinose, turanose and 2-deoxy glucose, revealed that sucrose metabolites and products of glycolysis such as pyruvate induce phosphorylation of PM H+-ATPase. Transcriptome analysis showed that the novel isoform of the Small Auxin-Up RNA genes, SAUR30, is upregulated in a light- and sucrose-dependent manner. Time-course analyses of sucrose supplementation showed that the phosphorylation level of PM H+-ATPase increased within 10 min, but the expression level of SAUR30 increased later than 10 min. The results suggest that two temporal regulations may participate in the regulation of PM H+-ATPase. Interestingly, a 15NO3- uptake assay in leaves showed that light increases 15NO3- uptake and that increment of 15NO3- uptake depends on PM H+-ATPase activity. The results opened the possibility of the physiological role of photosynthesis-dependent PM H+-ATPase activation in the uptake of NO3-. We speculate that PM H+-ATPase may connect photosynthesis and nitrogen metabolism in leaves.
Many researchers have confirmed the application of calcite precipitation method by urease enzyme induction as a potential soil improvement technique. However, this method needs an expensive ...investment due to the urease enzyme issue. The enzyme itself brings 90% of the total materials cost. It means that finding new inexpensive material for replacing the enzyme is considered essential for the development of this method. In this study, a potential material, which is soybean powder, was evaluated through several experimental tests. A comparison of urease activity value between EICP using soybean powder and commercial urease as a catalyst for hydrolysis of urea compound was made through a series of conductivity tests. It was found that EICP using soybean urease can be a potential alternative to a commercial product in terms of urease activity. The precipitation materials were analysed using a microscale test to analyses the minerals type. Besides, the reinforcing effect of EICP solution on soil specimens was evaluated by conducting unconfined compressive strength (UCS) test and acid leaching test. The results of the UCS test were indicated that the soybean powder is a potential material to be used in soil improvement technique.
Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types ...of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust-iron-60 (
Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (
Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of
Fe to Earth in the last 10 million years and accompanying lower quantities of
Pu. The
Pu/
Fe influx ratios are similar for both events. The
Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.
We analysed associations between exposure to nightlife businesses and severe acute respiratory syndrome coronavirus 2 PCR test results at a tertiary hospital in Tokyo between March and April 2020. A ...nightlife group was defined as those who had worked at or visited the businesses. We included 1517 individuals; 196 (12.9%) were categorised as the nightlife group. After propensity score matching, the proportion of positive PCR tests in the nightlife group was significantly higher than that in the non-nightlife group (nightlife, 63.8%; non-nightlife, 23.0%; P < 0.001). An inclusive approach to mitigate risks related to the businesses needs to be identified.
The extinct p-process nuclide 146Sm serves as an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its alpha -decay daughter 142Nd. Based on analyses of ...146Sm/147Sm alpha -activity and atom ratios, we determined the half-life of 146Sm to be 68 plus or minus 7 (1 sigma ) million years, which is shorter than the currently used value of 103 plus or minus 5 million years. This half-life value implies a higher initial 146Sm abundance in the early solar system, (146Sm/144Sm)0 = 0.0094 plus or minus 0.0005 (2 sigma ), than previously estimated. Terrestrial, lunar, and martian planetary silicate mantle differentiation events dated with 146Sm-142Nd converge to a shorter time span and in general to earlier times, due to the combined effect of the new 146Sm half-life and (146Sm/144Sm)0 values.
Summary
Stroke can be a cause of death, while in non‐fatal cases it is a common cause of various disabilities resulting from associated brain damage. However, whether a specific periodontal pathogen ...is associated with increased risk of unfavorable outcome after stroke remains unknown. We examined risk factors for unfavorable outcome following stroke occurrence, including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset (favorable = score 0 or 1; unfavorable = score 2–6). The associations of risk factors with unfavorable outcome, including serum titers of IgG antibodies to 16 periodontal pathogens, were examined. Logistic regression analysis showed that the initial National Institutes of Health stroke scale score odds ratio (OR) = 1·24, 95% confidence interval (CI) = 1·18–1·31, P < 0·001 and C‐reactive protein (OR = 1·29, 95% CI = 1·10–1·51, P = 0·002) were independently associated with unfavorable outcome after stroke. Following adjustment with those, detection of the antibody for Fusobacterium nucleatum ATCC 10953 in serum remained an independent predictor of unfavorable outcome (OR = 3·12, 95% CI = 1·55–6·29, P = 0·002). Determination of the antibody titer to F. nucleatum ATCC 10953 in serum may be useful as a predictor of unfavorable outcome after stroke.
We examined risk factors for unfavorable outcome following stroke occurrence including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset. Logistic regression analysis showed that detection of the antibody for F. nucleatum ATCC10953 in serum were independently associated with unfavorable outcome after stroke.
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