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Magnesium (Mg) homeostasis is critical for maintaining many biological processes, but little information is available to comprehend the molecular mechanisms regulating Mg concentration in rice (Oryza sativa). To make up for the lack of information, we aimed to identify mutants defective in Mg homeostasis through a forward genetic approach. As a result of the screening of 2,825 M2 seedlings mutated by ion-beam irradiation, we found a rice mutant that showed reduced Mg content in leaves and slightly increased Mg content in roots. Radiotracer 28Mg experiments showed that this mutant, named low-magnesium content 1 (LMGC1), has decreased Mg2+ influx in the root and Mg2+ translocation from root to shoot. Consequently, LMGC1 is sensitive to the low Mg condition and prone to develop chlorosis in the young mature leaf. The MutMap method identified a 7.4-kbp deletion in the LMGC1 genome leading to a loss of two genes. Genome editing using CRISPR-Cas9 further revealed that one of the two lost genes, a gene belonging to the RanBP2-type zinc-finger family that we named RanBP2-TYPE ZINC FINGER1 (OsRZF1), was the causal gene of the low Mg phenotype. OsRZF1 is a nuclear protein and may have a fundamental role in maintaining Mg homeostasis in rice plants.

Quantum simulation is one of the key applications of quantum computing, which accelerates research and development in the fields such as chemistry and material science. The recent development of noisy intermediate-scale quantum (NISQ) devices urges the exploration of applications without the necessity of quantum error correction. In this paper, we propose an efficient method to simulate quantum dynamics driven by a static Hamiltonian on NISQ devices, named subspace variational quantum simulator (SVQS). SVQS employs the subspace-search variational quantum eigensolver (SSVQE) to find a low-lying eigensubspace and extends it to simulate dynamics within the subspace with lower overhead compared to the existing schemes. We experimentally simulate the time-evolution operator in a low-lying eigensubspace of a hydrogen molecule. We also define the subspace process fidelity as a measure between two quantum processes in a subspace. The subspace time evolution mimicked by SVQS shows the subspace process fidelity of $0.88$-$0.98$.

Magnesium (Mg) homeostasis is critical for maintaining many biological processes, but little information is available to comprehend the molecular mechanisms regulating Mg concentration in rice (Oryza sativa). To make up for the lack of information, we aimed to identify mutants defective in Mg homeostasis through a forward genetic approach. As a result of the screening of about 3,000 M2 seedlings mutated by ion-beam irradiation, we found a rice mutant that showed reduced Mg content in leaves and slightly increased Mg content in roots. Radiotracer 28Mg experiments showed that this mutant, named low magnesium content 1 (LMGC1), has decreased Mg2+ influx in the root and Mg2+ translocation from root to shoot. The MutMap method identified 7.4 kbp deletion in the LMGC1 genome leading to a loss of two genes. Genome editing using CRISPR-Cas9 further revealed that one of the two lost genes, a gene belonging to RanBP2-type zinc finger family, was the causal gene of the low-Mg phenotype. Considering this gene, named OsRZF1, has never been reported to be involved in ion transport, the phenotype of LMGC1 would be associated with a novel mechanism of Mg homeostasis in plants.

In the phloem, various solutes such as photosynthates, mineral nutrients, or toxic elements move from the source organs to sinks. One of them is the root. While this process may mediate significant quantities of solutes delivered to the root, it is unclear how the solutes are distributed along the root axis. To elucidate the distributing pattern of solutes, we visually analyzed the movement of solutes in Arabidopsis roots using a radioisotope imaging technique. The distribution patterns fell into four different groups: (1) root tip accumulation for 14C-photosynthates, 28Mg2+, 32PO43-, and 35SO42-; (2) homogenous distribution along the root axis for 42K+ and 137Cs+; (3) no detectable accumulation in the root for 45Ca2+ and 59Fe2+; and (4) transient accumulation in the root for 22Na+. The latter phenomenon was explored in more detail using Arabidopsis knockout mutants lacking functional sodium efflux transporter SOS1 (operating as Na+/H+ exchanger). By utilizing a non-invasive microelectrode MIFE ion flux measuring technique, we found that Na+ efflux was active in the mature root zone of wild-type Arabidopsis plants but not in root apex as initially thought, and that in sos1 mutants lacking functional Na+/H+ exchangers, shoot-derived 22Na+ remained in the root. These findings challenge the notion that Na+ exclusion via SOS1 is confined to the root apex and demonstrates the power of combining the radioisotope imaging technique and the MIFE ion flux measuring technique to study the kinetics of ion transport in the root and root-to-shoot communication.

Phosphorus (P) is an essential macronutrient for plant growth. In deciduous trees, P is remobilized from senescing leaves and stored in perennial tissues during winter for further growth. Annual internal recycling and accumulation of P are considered an important strategy to support the vigorous growth of trees. However, the pathways of seasonal re-translocation of P and the molecular mechanisms of this transport have not been clarified. Here we show the seasonal P re-translocation route visualized using real-time radioisotope imaging and the macro- and micro-autoradiography. We analysed the seasonal re-translocation P in poplar (Populus alba. L) cultivated under 'a shortened annual cycle system', which mimicked seasonal phenology in a laboratory. From growing to senescing season, sink tissues of

Background Human epidermal growth factor 2 (HER2) is a potential driver oncogene. Although HER2-targeted precision therapy has been tested in non-small cell lung cancer (NSCLC), the demographic characteristics of HER2-positive NSCLC have not been systematically defined. Methods Patients with pathologically confirmed stage IIIB/IV or recurrent NSCLC, Eastern Cooperative Oncology Group performance status 0 to 2, were prospectively registered. HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assays were performed to screen patients. HER2 mutations were identified by using direct gene sequencing. The aim of this study was to clarify the frequency, characteristics, and outcome of HER2-positive NSCLC. HER2 was defined as positive if the tumor harbored IHC3+, IHC2+/FISH+, or exon 20 insertion mutations. Results Of the 1,126 tumors screened, 34 (3.0%) were IHC3+, and 34 (3.0%) were IHC2+/FISH+. Among the 724 epidermal growth factor receptor wild-type tumors, 21 (2.9%) were HER2-mutant tumors, including A775-G776insYVMA (n = 15). Interestingly, the IHC3+ tumors and mutant tumors were entirely exclusive. Female patients had HER2-mutant tumors more frequently, whereas both IHC3+ and IHC2+/FISH+ tumors were detected more often in male subjects and smokers. Patients with an HER2-aberrant tumor had a significantly worse prognosis than those with epidermal growth factor receptor-positive and anaplastic lymphoma kinase-positive tumors, possibly due to the low proportion that received HER2-targeted therapies (n = 15 [26%]) and low response rates of 0% and 14% in patients with HER2-overexpressing and HER2-mutant tumors, respectively. Conclusions This prospective large-scale cohort study is the first to show comprehensively the frequency and clinical demographic characteristics of those with HER2-positive advanced lung tumors in detail, providing critical historical data for future drug development against HER2-positive NSCLC. Future treatment strategies would be developed stratified according to the types of HER2 aberrations. Trial Registry UMIN Registration No. 000017003; URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000019691

Simultaneous expression of multiplex guide RNAs (gRNAs) is valuable for knockout of multiple genes and also for effective disruption of a gene by introducing multiple deletions. We developed a method of Tetraplex-guide Tandem for construction of cosmids containing four and eight multiplex gRNA-expressing units in one step utilizing lambda in vitro packaging. Using this method, we produced an adenovirus vector (AdV) containing four multiplex-gRNA units for two double-nicking sets. Unexpectedly, the AdV could stably be amplified to the scale sufficient for animal experiments with no detectable lack of the multiplex units. When the AdV containing gRNAs targeting the H2-Aa gene and an AdV expressing Cas9 nickase were mixed and doubly infected to mouse embryonic fibroblast cells, deletions were observed in more than 80% of the target gene even using double-nicking strategy. Indels were also detected in about 20% of the target gene at two sites in newborn mouse liver cells by intravenous injection. Interestingly, when one double-nicking site was disrupted, the other was simultaneously disrupted, implying that two genes in the same cell may simultaneously be disrupted in the AdV system. The AdVs expressing four multiplex gRNAs could offer simultaneous knockout of four genes or two genes by double-nicking cleavages with low off-target effect.

Spatial (3D) image construction from imaging plate (IP) images and the development of the microautography (MAR) method were presented. A rice grain was sliced every 5 μm, IP images were taken for successive slices, and the series of 2D images acquired by an IP were used to construct 3D images. In the case of 109Cd and 137Cs, the spatial distributions in the grain showed that the concentrations increased at the surface of the grain during the maturing process.

In the case of root movement, a very interesting phenomenon was found using the Super-HARP camera, which enabled the visualization of root movement in the dark.Although the first data on plants show that the harmful effect is growth inhibition, the first effect of the toxicity was to stop the rotation movement of the roots before growth inhibition occurred.When there was a chemical change in the environment, although the circumnutation of the root tip ceased, the root was able to elongate, and it was interesting that after a while the root movement resumed. In the case of a rice root, one round of movement of the rice root tip showed a constant time of approximately 50 minutes. However, this movement ceased when Al ion was supplied. The time needed for resuming the movement of the root tip was dependent on the Al ion concentration. It is not known what triggers the resumption of the movement of the root tip.

For the first stage of the study of the elements, the distribution of the element within the plant tissue was presented employing neutron activation analysis (NAA). Since NAA allows nondestructive analysis of the elements in the sample, this is the only method to measure the absolute amount of elements in the sample.The results showed that the element-specific profile varied throughout the whole plant, and this distribution tendency remained similar throughout development. There were many junctions of element-specific concentrations between the tissues, suggesting barriers to the movement of the elements. Generally, heavy elements tended to accumulate in roots, except for Mn and Cr. Of the elements measured, Ca and Mg showed changes in concentration with the circadian rhythm. Since the amount of the element in a plant reflects the features of the soil where the plant grows, multielement analysis of the plant could specify the site of the agricultural products produced.Before addressing the development of a real-time RI imaging system (RRIS), the production of RIs for essential elements for plant nutrition, 28Mg and 42K, is presented. The reason why concentrating on RIs is because when we examine the history of plant research, physiological research on the elements without available radioisotopes has not been well developed. For example, the boron (B) transporter was recently found and the study of B in plants is far behind compared to the other elements.Therefore, we developed a preparation method for elements whose available RIs were not previously employed in plant research, 28Mg and 42K. They are the radioisotopes we prepared and a root absorption study using 28Mg as a tracer is presented as an example. It was found that the orientation of Mg transfer was different according to the site of the root where Mg was absorbed. The specific role of Mg has not yet been clarified by florescent imaging because the overwhelming amount of Ca makes it difficult to distinguish Mg and Ca.

Our first target was water, namely, how to obtain a water-specific image nondestructively. Using a neutron beam, we could visualize water-specific images of plants, including roots and flowers, which were never shown before. Each image suggested the plant-specific activity related to water.We briefly present how to acquire the image and what kind of water image is taken by neutron beam irradiation. We present a variety of plant samples, such as flowers, seeds, and wood disks. It was noted that neutrons could visualize the roots imbedded in soil without uprooting. When a spatial image of the root imbedded in soil was created from many projection images, the water profile around the root was analyzed. Then, fundamental questions were raised, such as whether plants are absorbing water solution or water vapor from the soil, because there was always a space adjacent to the root surface and hardly any water solution was visualized there. The roots are in constant motion during growth, known as circumnutation, and it is natural that the root tip is always pushing the soil aside to produce space for the root to grow. If the roots are absorbing water vapor, then the next question is about metals. Are the roots absorbing metal vapor? Since we tended to employ water culture to study the physiological activity of plants, the physiological study of the plants growing in soil was somewhat neglected. Later, when we could develop a system to visualize the movement of element absorption in a plant, there was a clear difference in element absorption between water culture and soil culture.

MAR was developed to increase the resolution of the image for the sliced plant sample. This revised MAR method showed the detailed distribution of 137Cs accumulation in embryos, which indicated that the plumule and radicle, which grow as a meristem of a root or shoot, were protected from the accumulation of heavy elements. Because of daguerreotype imaging, MAR is now hardly used, and the film emulsion is not available. Here, this method was essentially recreated with a revised processing method for both sample preparation and imaging process.

We developed an imaging method utilizing the available RIs. We developed two types of real-time RI imaging systems (RRIS), one for macroscopic imaging and the other for microscopic imaging. The principle of visualization was the same, converting the radiation to light by a Cs(Tl)I scintillator deposited on a fiber optic plate (FOS). Many nuclides were employed, including 14C, 18F, 22Na, 28Mg, 32P 33P, 35S, 42K, 45Ca, 48V, 54Mn, 55Fe, 59Fe, 65Zn, 86Rb, 109Cd, and 137Cs.Since radiation can penetrate the soil as well as water, the difference between soil culture and water culture was visualized. 137Cs was hardly absorbed by rice roots growing in soil, whereas water culture showed high absorption, which could provide some reassurance after the Fukushima Nuclear Accident and could indicate an important role of soil in firmly adsorbing the radioactive cesium.28Mg and 42K, whose production methods were presented, were applied for RRIS to visualize the absorption image from the roots. In addition to 28Mg and 42K, many nuclides were applied to image absorption in the roots. Each element showed a specific absorption speed and accumulation pattern. The image analysis of the absorption of Mg is presented as an example. Through successive images of the element absorption, phloem flow in the aboveground part of the plant was analyzed. The element absorption was visualized not only in the roots but also in the leaves, a basic study of foliar fertilization.In the case of the microscopic imaging system, a fluorescence microscope was modified to acquire three images at the same time: a light image, fluorescent image, and radiation image. Although the resolution of the image was estimated to be approximately 50 μm, superposition showed the expression site of the transporter gene and the actual 32P-phosphate absorption site to be the same in Arabidopsis roots.

We targeted not only the elements we can supply to the nutrient solution but also carbon dioxide gas to visualize the fixation process and the movement of assimilated carbon in a plant. This is another highlight of our study using real-time RI imaging systems (RRIS). The interesting result was that the route of assimilated carbon was different depending on where the fixation took place. In Arabidopsis, most of the metabolites after photosynthesis were transferred to the tip of the main internode and roots when 14CO2 gas was fixed and photosynthates were produced at rosette leaves, whereas most of the metabolites moved to the tip of the branch internode and hardly moved down to the roots when 14CO2 gas was supplied to the aboveground parts of the plant other than rosette leaves. Interestingly, it was possible to visualize and trace which tissue performed the fixation of 14CO2 gas, i.e., carbon could be traced from the fixation site in tissue to tissue formation. However, especially in the case of 14C imaging, image analysis should be carefully performed because of the self-absorption of the β-rays in tissue. To image 14CO2 gas fixation in larger samples, approximately 50 cm in height, a plastic scintillator was introduced, and the assimilation process of the gas was visualized for rice and maize.

Magnesium (Mg) is essential for many biological processes in plant cells, and its deficiency causes yield reduction in crop systems. Low Mg status reportedly affects photosynthesis, sucrose partitioning and biomass allocation. However, earlier physiological responses to Mg deficiency are scarcely described. Here, we report that Mg deficiency in Arabidopsis thaliana first modified the mineral profile in mature leaves within 1 or 2 days, then affected sucrose partitioning after 4 days, and net photosynthesis and biomass production after 6 days. The short-term Mg deficiency reduced the contents of phosphorus (P), potassium, manganese, zinc and molybdenum in mature but not in expanding (young) leaves. While P content decreased in mature leaves, P transport from roots to mature leaves was not affected, indicating that Mg deficiency triggered retranslocation of the mineral nutrients from mature leaves. A global transcriptome analysis revealed that Mg deficiency triggered the expression of genes involved in defence response in young leaves., SCOPUS: ar.j, info:eu-repo/semantics/published

The identification and SAR development of a series of negative allosteric modulators of the GABA

Phosphorus (P) is an essential macronutrient for plant growth. In deciduous trees, P is remobilized from senescing leaves and stored in perennial tissues during winter for further growth. Annual internal recycling and accumulation of P is considered an important strategy to support vigorous growth of trees. However, the pathways of seasonal re-translocation of P and the molecular mechanisms of this transport have not been clarified. Here we show the seasonal P re-translocation route visualized using the real-time radioisotope imaging and the macro- and micro-autoradiography. We analyzed the seasonal re-translocation P in poplar (Populus alba. L) cultivated under “a shortened annual cycle system”, which mimicked seasonal phenology in a laboratory. From growing to senescing season, sink tissues of 32P and/or 33P shifted from young leaves and the apex to the lower stem and roots. The radioisotope P re-translocated from a leaf was stored in phloem and xylem parenchyma cells and redistributed to new shoots after dormancy. Seasonal expression profile of phosphate transporters (PHT1, PHT5 and PHO1 family) was obtained in the same system. Our results reveal the seasonal P re-translocation routes at the organ and tissue levels and provide a foothold for elucidating its molecular mechanisms.

To explore the possibilities of a near-term intermediate-scale quantum algorithm and long-term fault-tolerant quantum computing, a fast and versatile quantum circuit simulator is needed. Here, we introduce Qulacs, a fast simulator for quantum circuits intended for research purpose. We show the main concepts of Qulacs, explain how to use its features via examples, describe numerical techniques to speed-up simulation, and demonstrate its performance with numerical benchmarks., Comment: 34 pages, 12 figures

Supplemental material, DS_10.1177_0022034520901731 for Functional Analysis of PTH1R Variants Found in Primary Failure of Eruption by E. Izumida, T. Suzawa, Y. Miyamoto, A. Yamada, M. Otsu, T. Saito, T. Yamaguchi, K. Nishimura, M. Ohtaka, M. Nakanishi, K. Yoshimura, K. Sasa, R. Takimoto, R. Uyama, T. Shirota, K. Maki and R. Kamijo in Journal of Dental Research

Quantum computational chemistry is a potential application of quantum computers that is expected to effectively solve several quantum-chemistry problems, particularly the electronic structure problem. Quantum computational chemistry can be compared to the conventional computational devices. This review comprehensively investigates the applications and overview of quantum computational chemistry, including a review of the Hartree-Fock method for quantum information scientists. Quantum algorithms, quantum phase estimation, and variational quantum eigensolver, have been applied to the post-Hartree-Fock method., Comment: 31 pages, 6 figures

Since plants live on inorganic elements, absorbing ions from roots and transferring them to each tissue in a plant is an essential activity. However, little is known about the movement of the elements or water in plant tissue. Though fluorescent imaging is now overwhelmingly used at the microscopic level in biology, especially to visualize chemicals or organelles in a cell, radioisotope imaging has become one of the important methods for human imaging in the medical field. In the case of plant studies, however, real-time radioisotope imaging is little-known among plant researchers. The author has developed radioisotope imaging systems using various radioisotopes to study living plant activity, both for elements and for water. Here we review the real-time radioisotope imaging methods we developed, and show new aspects of plant physiology discovered by live imaging.

This study investigated the effect of Cs-137 absorbed from the upper part (surface of leaves and husk) of rice plants and its accumulation in grains. Cesium-137 content in brown rice plants sprayed with Cs-137 onto the plant surface before ear emergence, flowering, and grain filling stages were 5, 109, and 76 Bq/kg, respectively. Comparison of Cs-137 concentration between mature and immature grains revealed that brown rice can easily absorb Cs-137 at the beginning of grain filling.

Using the real-time radioisotope imaging system (RRIS), we present the carbon dioxide gas fixation process of a soybean plant applying the 14C-labeled gas. When 14CO2 gas was supplied to the selected mature leaf, the fixed carbon, photosynthate, was transferred and accumulated to the younger leaves preferentially within 24 h. When 14CO2 gas was supplied to the younger leaves, fixed carbon was hardly moved. In the case of the pods, fixed 14CO2 gas in the leaf was preferentially transferred to the closest pod.

We updated real-time radioisotope imaging system (RRIS) to study photosynthate movement in a large-size plant. Earlier, we used a CsI (Tl) scintillator attached to a fiber optic plate (FOS) to convert radiation into light. However, the scintillator size was fixed as 10 cm × 10 cm, which was too small to observe the entire plant. Moreover, the high cost of FOS makes it hard for other researchers to introduce the system in their facilities. Here, we investigated six types of low-priced plastic scintillators, and demonstrated the movement of 14C-labeled photosynthates in a living plant using the most efficient scintillator instead of FOS.

Contamination of agricultural products by resuspended matter remains a concern in the highly contaminated areas. Radiocesium concentration of spinach cultivated with non-contaminated soil was low in the decontaminated areas, but high in the contaminated areas. The washed plants had relatively lower radiocesium concentration than the unwashed plants. Furthermore, the plants cultivated closer to the ground surface tended to have a higher radiocesium concentration than those cultivated farther from the ground. Therefore, it can be concluded that radiocesium found in the spinach leaves derived from resuspended matter in the air. With further analysis, radiocesium in the resuspended matter was confirmed to be present as particles.

The Mg2+ uptake system in Arabidopsis roots is Gd3+- and Fe2+-sensitive, and responds to a changing Mg2+ concentration within 1 h with the participation of AtMRS2 transporters. Magnesium (Mg2+) absorption and the mechanism regulating its activity have not been clarified yet. To address these issues, it is necessary to reveal the characteristics of Mg2+ uptake in roots. Therefore, we first investigated the Mg2+ uptake characteristics in roots of 1-week-old Arabidopsis plants using 28Mg. The Mg2+ uptake system in roots was up-regulated within 1 h in response to the low Mg2+ condition. This induction was inhibited in Arabidopsis “mitochondrial RNA splicing 2/magnesium transport” mutants atmrs2-4/atmgt6 and atmrs2-7/atmgt7, while the expression of AtMRS2-4/AtMGT6 and AtMRS2-7/AtMGT7 genes in the Arabidopsis wild-type was not responsive to Mg2+ conditions. In addition, the Mg deficiency-induced Mg2+ uptake system was shut-down within 5 min when Mg2+ was resupplied to the environment. An inhibition study showed that the constitutive mechanism functioning in Mg2+ uptake under Mg2+ sufficient conditions was sensitive to a number of divalent and trivalent cations, particularly Gd3+ and Fe2+, but not to K+.

Magnesium deficiency can cause starch accumulation, photosynthesis inhibition and senescence particularly in young mature leaves. This study was performed to identify the initial process leading to leaf senescence under Mg deficiency. Gene expression in the young leaf was analyzed at days 2, 4, 5 of Mg deficiency using microarray analysis, and several Fe responsive genes were identified. Therefore, the effect of lowering Fe supply on gene expression and oxidative stress under Mg deficiency was evaluated. Transcriptome analysis revealed that 7 of the 30 most upregulated genes and 11 of the 30 most downregulated genes were Fe-responsive. Particularly, the upregulation of OsFER2 and downregulation of OsMIR and OsIRO2 hinted at the induction of excess Fe stress under Mg deficiency. Both lowering of Fe concentration in Mg-free solutions and resupply of Mg without modifying Fe concentrations at day 4 rescued leaves from senescence by inhibiting oxidative stress and normalising the expression of Fe-responsive genes. Meanwhile, Fe content was equal between control, Mg-deficient and Mg-resupplied plants. Mg shortage can induce excess Fe stress, which in turn causes oxidative stress before inhibition of photosynthesis. It is proposed that Mg deficiency disrupts a mechanism for storing toxic Fe ions into the vacuole in the expanding young leaf cells.

Aims Magnesium deficiency can cause starch accumulation, photosynthesis inhibition and senescence particularly in young mature leaves. This study was performed to identify the initial process leading to leaf senescence under Mg deficiency. Methods Gene expression in the young leaf was analyzed at days 2, 4, 5 of Mg deficiency using microarray analysis, and several Fe responsive genes were identified. Therefore, the effect of lowering Fe supply on gene expression and oxidative stress under Mg deficiency was evaluated. Results Transcriptome analysis revealed that 7 of the 30 most upregulated genes and 11 of the 30 most downregulated genes were Fe-responsive. Particularly, the upregulation of OsFER2 and downregulation of OsMIR and OsIRO2 hinted at the induction of excess Fe stress under Mg deficiency. Both lowering of Fe concentration in Mg-free solutions and resupply of Mg without modifying Fe concentrations at day 4 rescued leaves from senescence by inhibiting oxidative stress and normalising the expression of Fe-responsive genes. Meanwhile, Fe content was equal between control, Mg-deficient and Mg-resupplied plants. Conclusion Mg shortage can induce excess Fe stress, which in turn causes oxidative stress before inhibition of photosynthesis. It is proposed that Mg deficiency disrupts a mechanism for storing toxic Fe ions into the vacuole in the expanding young leaf cells.