A reference genome of Commelinales provides insights into the commelinids evolution and global spread of water hyacinth (Pontederia crassipes).

Commelinales belongs to the commelinids clade, which also comprises Poales that includes the most important monocot species, such as rice, wheat, and maize. No reference genome of Commelinales is currently available. Water hyacinth (Pontederia crassipes or Eichhornia crassipes), a member of Commelinales, is one of the devastating aquatic weeds, although it is also grown as an ornamental and medical plant. Here, we present a chromosome-scale reference genome of the tetraploid water hyacinth with a total length of 1.22 Gb (over 95% of the estimated size) across 8 pseudochromosome pairs. With the representative genomes, we reconstructed a phylogeny of the commelinids, which supported Zingiberales and Commelinales being sister lineages of Arecales and shed lights on the controversial relationship of the orders. We also reconstructed ancestral karyotypes of the commelinids clade and confirmed the ancient commelinids genome having 8 chromosomes but not 5 as previously reported. Gene family analysis revealed contraction of disease-resistance genes during polyploidization of water hyacinth, likely a result of fitness requirement for its role as a weed. Genetic diversity analysis using 9 water hyacinth lines from 3 continents (South America, Asia, and Europe) revealed very closely related nuclear genomes and almost identical chloroplast genomes of the materials, as well as provided clues about the global dispersal of water hyacinth. The genomic resources of P. crassipes reported here contribute a crucial missing link of the commelinids species and offer novel insights into their phylogeny.

Transcriptional heterogeneity of catabolic genes on the plasmid pCAR1 causes host-specific carbazole degradation.

To elucidate why plasmid-borne catabolic ability differs among host bacteria, we assessed the expression dynamics of the Pant promoter on the carbazole-degradative conjugative plasmid pCAR1 in Pseudomonas putida KT2440(pCAR1) (hereafter, KTPC) and Pseudomonas resinovorans CA10. The Pant promoter regulates the transcription of both the car and ant operons, which are responsible for converting carbazole into anthranilate and anthranilate into catechol, respectively. In the presence of anthranilate, transcription of the Pant promoter is induced by the AraC/XylS family regulator AntR, encoded on pCAR1. A reporter cassette containing the Pant promoter followed by gfp was inserted into the chromosomes of KTPC and CA10. After adding anthranilate, GFP expression in the population of CA10 showed an unimodal distribution, whereas a small population with low GFP fluorescence intensity appeared for KTPC. CA10 has a gene, antRCA, that encodes an iso-functional homolog of AntR on its chromosome. When antRCA was disrupted, a small population with low GFP fluorescence intensity appeared. In contrast, overexpression of pCAR1-encoded AntR in KTPC resulted in unimodal expression under the Pant promoter. These results suggest that the expression of pCAR1-encoded AntR is insufficient to ameliorate the stochastic expression of the Pant promoter. Raman spectra of single cells collected using deuterium-labeled carbazole showed that the C-D Raman signal exhibited greater variability for KTPC than CA10. These results indicate that heterogeneity at the transcriptional level of the Pant promoter due to insufficient AntR availability causes fluctuations in the pCAR1-borne carbazole-degrading capacity of host bacterial cells.IMPORTANCEHorizontally acquired genes increase the competitiveness of host bacteria under selective conditions, although unregulated expression of foreign genes may impose fitness costs. The "appropriate" host for a plasmid is empirically known to maximize the expression of plasmid-borne traits. In the case of pCAR1-harboring Pseudomonas strains, P. resinovorans CA10 exhibits strong carbazole-degrading capacity, whereas P. putida KT2440 harboring pCAR1 exhibits low degradation capacity. Our results suggest that a chromosomally encoded transcription factor affects transcriptional and metabolic fluctuations in host cells, resulting in different carbazole-degrading capacities as a population. This study may provide a clue for determining appropriate hosts for a plasmid and for regulating the expression of plasmid-borne traits, such as the degradation of xenobiotics and antibiotic resistance.

Mitochondrial-targeting effector RsIA_CtaG/Cox11 in Rhizoctonia solani AG-1 IA has two functions: plant immunity suppression and cell death induction mediated by a rice cytochrome c oxidase subunit.

Rhizoctonia solani AG-1 IA causes a necrotrophic rice disease and is a serious threat to rice production. To date, only a few effectors have been characterized in AG-1 IA. We previously identified RsIA_CtaG/Cox11 and showed that infiltration of the recombinant protein into rice leaves caused disease-like symptoms. In the present study, we further characterized the functionality of RsIA_CtaG/Cox11. RsIA_CtaG/Cox11 is an alternative transcript of cytochrome c oxidase copper chaperone Cox11 that starts from the second AUG codon, but contains a functional secretion signal peptide. RNA interference with RsIA_CtaG/Cox11 reduced the pathogenicity of AG-1 IA towards rice and Nicotiana benthamiana without affecting its fitness or mycelial morphology. Transient expression of the RsIA_CtaG/Cox11-GFP fusion protein demonstrated the localization of RsIA_CtaG/Cox11 to mitochondria. Agro-infiltration of RsIA_CtaG/Cox11 into N. benthamiana leaves inhibited cell death by BAX and INF1. In contrast to rice, agro-infiltration of RsIA_CtaG/Cox11 did not induce cell death in N. benthamiana. However, cell death was observed when it was coinfiltrated with Os_CoxVIIa, which encodes a subunit of cytochrome c oxidase. Os_CoxVIIa appeared to interact with RsIA_CtaG/Cox11. The cell death triggered by coexpression of RsIA_CtaG/Cox11 and Os_CoxVIIa is independent of the leucine-rich repeat receptor kinases BAK1/SOBIR1 and enhanced the susceptibility of N. benthamiana to AG-1 IA. Two of the three evolutionarily conserved cysteine residues at positions 25 and 126 of RsIA_CtaG/Cox11 were essential for its immunosuppressive activity, but not for cell death induction. This report suggests that RsIA_CtaG/Cox11 appears to have a dual role in immunosuppression and cell death induction during pathogenesis.

Optimal left ventricular diameter measurement in subjects with sigmoid septum: comparison with three-dimensional left ventricular volume.

BACKGROUND: The purpose of this study was to determine the most appropriate measurement of left ventricular (LV) end-diastolic diameter for subjects with the sigmoid septum (SS) by measuring the LV end-diastolic diameter at the base and mid-ventricle and by examining the relationship between these measurements and the three-dimensional (3D) echocardiographic LV end-diastolic volume. METHODS: In 91 patients who underwent echocardiography for screening cardiovascular abnormalities, the aorto-septal angle (ASA) was measured as an index of the sigmoid septum. LV end-diastolic diameter was measured at the base and mid-ventricular level (DDbase and DDmid, respectively), and their average value was calculated (DDavg). By using 3D echocardiography, LV end-diastolic volume (EDV3D) was measured. RESULTS: Among 91 patients, 48 patients had narrow ASA (< 120 degrees) and were divided into the sigmoid septum (SS) group, and the remaining 43 patients were divided into the non-SS group. In the SS group, all DDbase, DDmid, and DDavg were significantly correlated with EDV3D (r = 0.59, 0.80, and 0.76, respectively), and the correlation coefficient between DDbase and EDV3D was significantly lower than that between DDmid and EDV3D (p < 0.01). On the other hand, in the non-SS group, all DDbase, DDmid, and DDavg were significantly correlated with EDV3D (r = 0.77, 0.85, and 0.84, respectively), and the correlation coefficient between DDbase and EDV3D was statistically comparable to that between DDmid and EDV3D (p = 0.12). ASA was significantly correlated with the difference of DDmid minus DDbase (r = - 0.71, p < 0.001). CONCLUSIONS: In patients with SS, DDmid and DDavg were well reflected the 3D echocardiographic LV end-diastolic volume.

Chemical screening of inhibitors specific for MdDOX-Co that cause an apple columnar tree-shape.

MdDOX-Co, the ectopic expression of which is considered to cause the apple columnar tree shape, belongs to the 2-oxoglutarate-dependent dioxygenase (2ODD) family. It adds a hydroxyl group to position 12 of gibberellins (GAs). However, the 2ODD enzymes related to GA biosynthesis and catabolism are phylogenetically distinct from MdDOX-Co. Thus, it is possible that substrates other than GAs exist in MdDOX-Co. To identify the previously unidentified substrate(s) of MdDOX-Co, we searched for MdDOX-Co-specific inhibitors. Chemical screening using gas chromatography-mass spectrometry was performed to investigate the effects of 2400 compounds that inhibited the catalytic reaction of MdDOX-Co, but not the catabolic reaction of GA 2-oxidase, an enzyme involved in GA catabolism. By applying two positive compounds in Arabidopsis, a chemical 3-((2-chloro-6-fluorobenzyl)thio)-5,7-dimethyl-5H-pyrazolo[3,4-e][1,4,2]dithiazine-1,1-dioxide designated as TPDD that did not inhibit GA biosynthesis was selected. The structure-activity relationships among the TPDD analogs were also obtained.

Characterization of diterpene synthase genes in Brachypodium distachyon, a monocotyledonous model plant, provides evolutionary insight into their multiple homologs in cereals.

Gibberellins are diterpenoid phytohormones that regulate plant growth, and are biosynthesized from a diterpene intermediate, ent-kaurene, which is produced from geranylgeranyl diphosphate via ent-copalyl diphosphate (ent-CDP). The successive 2 cyclization reactions are catalyzed by 2 distinct diterpene synthases, ent-CDP synthase (ent-CPS) and ent-kaurene synthase (KS). Various diterpene synthase genes involved in specialized metabolism were likely created through duplication and neofunctionalization of gibberellin-biosynthetic ent-CPS and KS genes in crops. Brachypodium distachyon is a monocotyledonous species that is a model plant in grasses. We herein found 1 ent-CPS gene homolog BdCPS and 4 tandemly arrayed KS-like genes BdKS1, KSL2, KSL3, and KSL4 in the B. distachyon genome, a simpler collection of paralogs than in crops. Phylogenetic and biochemical analyses showed that BdCPS and BdKS1 are responsible for gibberellin biosynthesis. BdKSL2 and BdKSL3 are suggested to be involved in specialized diterpenoid metabolism. Moreover, we restored KS activity of BdKSL2 through amino acid substitution.

Difference in the ligand affinity among redundant plant hormone receptors of rice OsCOI1a/1b/2-OsJAZs.

(3R, 7S)-jasmonoyl-L-isoleucine (JA-Ile) is a lipid-derived plant hormone that regulates plant responses, including biotic/abiotic stress adaptation. In the plant cells, JA-Ile is perceived by COI1-JAZ co-receptor by causing protein-protein interaction between COI1 and JAZ proteins to trigger gene expressions. In this study, we focused on Oryza sativa, a model monocot and an important crop, with 45 possible OsCOI-OsJAZ co-receptor pairs composed of three OsCOI homologs (OsCOI1a, OsCOI1b, and OsCOI2) and 15 OsJAZ homologs. We performed fluorescein anisotropy and pull-down assays to examine the affinity between JA-Ile and OsCOI1a/1b/2-OsJAZ1-15 co-receptor pairs. The results revealed a remarkable difference in the modes of ligand perception by OsCOI1a/1b and OsCOI2. Recently, the unique function of OsCOI2 in some of the JA-responses were revealed. Our current results will lead to the possible development of OsCOI2-selective synthetic ligand.

BSR1, a Rice Receptor-like Cytoplasmic Kinase, Positively Regulates Defense Responses to Herbivory.

Crops experience herbivory by arthropods and microbial infections. In the interaction between plants and chewing herbivores, lepidopteran larval oral secretions (OS) and plant-derived damage-associated molecular patterns (DAMPs) trigger plant defense responses. However, the mechanisms underlying anti-herbivore defense, especially in monocots, have not been elucidated. The receptor-like cytoplasmic kinase Broad-Spectrum Resistance 1 (BSR1) of Oryza sativa L. (rice) mediates cytoplasmic defense signaling in response to microbial pathogens and enhances disease resistance when overexpressed. Here, we investigated whether BSR1 contributes to anti-herbivore defense responses. BSR1 knockout suppressed rice responses triggered by OS from the chewing herbivore Mythimna loreyi Duponchel (Lepidoptera: Noctuidae) and peptidic DAMPs OsPeps, including the activation of genes required for biosynthesis of diterpenoid phytoalexins (DPs). BSR1-overexpressing rice plants exhibited hyperactivation of DP accumulation and ethylene signaling after treatment with simulated herbivory and acquired enhanced resistance to larval feeding. As the biological significance of herbivory-induced accumulation of rice DPs remains unexplained, their physiological activities in M. loreyi were analyzed. The addition of momilactone B, a rice DP, to the artificial diet suppressed the growth of M. loreyi larvae. Altogether, this study revealed that BSR1 and herbivory-induced rice DPs are involved in the defense against chewing insects, in addition to pathogens.

Do Tapping and Massaging during Tourniquet Application Promote Dilation of Forearm Cutaneous Veins? A Pilot Quasi-Experimental Study.

Successful insertion of a peripheral intravenous catheterization requires that veins be sufficiently dilated. This study aimed to clarify the venous dilation effect of including tapping or massaging to the application of a tourniquet at the cutaneous veins of healthy adults' forearms. This was a quasi-experimental study of 30 healthy adult volunteers. Each participant underwent all three venous dilation procedures, which included the tourniquet application (Control condition), the tourniquet application and tapping the participant's forearm (Tapping condition), as well as the tourniquet application combined with massaging the participant's forearm (Massage condition). To clarify the venous dilation effects, venous indices were measured, namely the venous diameter (mm), depth (mm), and palpation score. After applying all venous dilation procedures, the venous diameter and palpation score significantly increased. However, no significant difference was observed between the control condition and each intervention condition. The depth in the control and tapping conditions decreased significantly in contrast to the Massage condition. Moreover, a subgroup (nine participants with a venous diameter less than 3 mm after the control condition) had similar results. This study found that additional tapping or massaging after tourniquet application could be less effective in promoting dilation in the forearm veins of healthy adults. Future studies should examine the efficacy and effectiveness of venous dilation in a wide target population while considering intervention methods.

Usefulness of the pulmonary venous flow waveform for assessing left atrial stiffness.

PURPOSE: This study investigated the novel non-invasive left atrial (LA) stiffness parameter using pulmonary venous (PV) flow measurements and the clinical usefulness of the novel LA stiffness parameter. METHODS: We retrospectively analyzed 237 patients who underwent right heart catheterization and echocardiography less than one week apart. From the pulmonary artery wedge pressure waveform, the difference between x-descent and v-wave (ΔP) was measured. Using the echocardiographic biplane method of disks, the difference between LA maximum volume and that just before atrial contraction (ΔVMOD) was calculated, and the ΔP/ΔVMOD was calculated as a standard LA stiffness index. From the PV flow waveform, the peak systolic velocity (S), peak diastolic velocity (D), and minimum velocity between them (R) were measured, and S/D, S/R, and D/R were calculated. From the speckle tracking echocardiography-derived time-LA volume curve, the difference between LA maximum volume and that just before atrial contraction (ΔVSTE) was measured. Each patient's prognosis was investigated until three years after echocardiography. RESULTS: Among the PV flow parameters, D/R was significantly correlated with ΔP (r = 0.62), and the correlation coefficient exceeded that between S/D and ΔP (r = - 0.39) or S/R and ΔP (r = 0.14). The [D/R]/ΔVSTE was significantly correlated with ΔP/ΔVMOD (r = 0.61). During the follow-up, 37 (17%) composite endpoints occurred. Kaplan-Meier analysis showed that patients with [D/R]/ΔVSTE greater than 0.13 /mL were at higher risk of cardiac events. CONCLUSION: The [D/R]/ΔVSTE was useful for assessing LA stiffness non-invasively and might be valuable in the prognostic evaluation of patients with cardiac diseases.

Determinants of exercise capacity in patients with heart failure without left ventricular hypertrophy.

BACKGROUND: Determinants of exercise intolerance in a phenotype of heart failure with preserved ejection fraction (HFpEF) with normal left ventricular (LV) structure have not been fully elucidated. METHODS: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 44 HFpEF patients without LV hypertrophy. Exercise capacity was determined by peak oxygen consumption (peak VO2). Doppler-derived cardiac output (CO), transmitral E velocity, systolic (LV-s') and early diastolic mitral annular velocities (e'), systolic pulmonary artery (PA) pressure (SPAP), tricuspid annular plane systolic excursion (TAPSE), and peak systolic right ventricular (RV) free wall velocity (RV-s') were measured at rest and exercise. E/e' and TAPSE/SPAP were used as an LV filling pressure parameter and RV-PA coupling, respectively. RESULTS: During exercise, CO, LV-s', RV-s', e', and SPAP were significantly increased (p < 0.05 for all), whereas E/e' remained unchanged and TAPSE/SPAP was significantly reduced (p < 0.001). SPAP was higher and TAPSE/SPAP was lower at peak exercise in patients showing lower-half peak VO2. In univariable analyses, LV-s' (R = 0.35, p = 0.022), SPAP (R = -0.40, p = 0.008), RV-s' (R = 0.47, p = 0.002), and TAPSE/SPAP (R = 0.42, p = 0.005) were significantly correlated with peak VO2. In multivariable analyses, not only SPAP, but also TAPSE/SPAP independently determined peak VO2 even after the adjustment for clinically relevant parameters. CONCLUSIONS: In HFpEF patients without LV hypertrophy, altered RV-PA coupling by exercise could be associated with exercise intolerance, which might not be caused by elevated LV filling pressure.

Genome Editing Reveals Both the Crucial Role of OsCOI2 in Jasmonate Signaling and the Functional Diversity of COI1 Homologs in Rice.

Jasmonic acid (JA) regulates plant growth, development and stress responses. Coronatine insensitive 1 (COI1) and jasmonate zinc-finger inflorescence meristem-domain (JAZ) proteins form a receptor complex for jasmonoyl-l-isoleucine, a biologically active form of JA. Three COIs (OsCOI1a, OsCOI1b and OsCOI2) are encoded in the rice genome. In the present study, we generated mutants for each rice COI gene using genome editing to reveal the physiological functions of the three rice COIs. The oscoi2 mutants, but not the oscoi1a and oscoi1b mutants, exhibited severely low fertility, indicating the crucial role of OsCOI2 in rice fertility. Transcriptomic analysis revealed that the transcriptional changes after methyl jasmonate (MeJA) treatment were moderate in the leaves of oscoi2 mutants compared to those in the wild type or oscoi1a and oscoi1b mutants. MeJA-induced chlorophyll degradation and accumulation of antimicrobial secondary metabolites were suppressed in oscoi2 mutants. These results indicate that OsCOI2 plays a central role in JA response in rice leaves. In contrast, the assessment of growth inhibition upon exogenous application of JA to seedlings of each mutant revealed that rice COIs are redundantly involved in shoot growth, whereas OsCOI2 plays a primary role in root growth. In addition, a co-immunoprecipitation assay showed that OsJAZ2 and OsJAZ5 containing divergent Jas motifs physically interacted only with OsCOI2, whereas OsJAZ4 with a canonical Jas motif interacts with all three rice COIs. The present study demonstrated the functional diversity of rice COIs, thereby providing clues to the mechanisms regulating the various physiological functions of JA.

Iron Induces Resistance Against the Rice Blast Fungus Magnaporthe oryzae Through Potentiation of Immune Responses.

Iron is an essential nutrient required for plant growth and development. The availability of iron might also influence disease resistance in plants. However, the molecular mechanisms involved in the plant response to iron availability and immunity have been investigated separately from each other. In this work, we found that exposure of rice plants to high iron enhances resistance to infection by the fungal pathogen Magnaporthe oryzae, the causal agent of blast disease. RNA-Seq analysis revealed that blast resistance in iron-treated rice plants was associated with superinduction of defense-related genes during pathogen infection, including Pathogenesis-Related genes. The expression level of genes involved in the biosynthesis of phytoalexins, both diterpene phytoalexins and the flavonoid phytoalexin sakuranetin, was also higher in iron-treated plants compared with control plants, which correlated well with increased levels of phytoalexins in these plants during M. oryzae infection. Upon pathogen infection, lipid peroxidation was also higher in iron-treated plants compared with non-treated plants. We also show that M. oryzae infection modulates the expression of genes that play a pivotal role in the maintenance of iron homeostasis. Histochemical analysis of M. oryzae-infected leaves revealed colocalization of iron and reactive oxygen species in cells located in the vicinity of fungal penetration sites (e.g. appressoria) in rice plants that have been exposed to iron. Together these findings support that ferroptosis plays a role in the response of iron-treated rice plants to infection by virulent M. oryzae. Understanding interconnected regulations between iron signaling and immune signaling in rice holds great potential for developing novel strategies to improve blast resistance in rice.

Evaluation of two semi-supervised learning methods and their combination for automatic classification of bone marrow cells.

Differential bone marrow (BM) cell counting is an important test for the diagnosis of various hematological diseases. However, it is difficult to accurately classify BM cells due to non-uniformity and the lack of reproducibility of differential counting. Therefore, automatic classification systems have been developed in which deep learning is used. These systems requires large and accurately labeled datasets for training. To overcome this, we used semi-supervised learning (SSL), in which learning proceeds while labeling. We used three methods: self-training (ST), active learning (AL), and a combination of these methods, and attempted to automatically classify 16 types of BM cell images. ST involves data verification, as in AL, before adding them to the training dataset (confirmed self-training: CST). After 25 rounds of CST, AL, and CST + AL, the initial number of training data increased from 425 to 40,518; 3682; and 47,843, respectively. Accuracies for the test data of 50 images for each cell type were 0.944, 0.941, and 0.976, respectively. Data added with CST or AL showed some imbalances between classes, while CST + AL exhibited fewer imbalances. We suggest that CST + AL, when combined with two SSL methods, is efficient in increasing training data for the development of automatic BM cells classification systems.

Secreted Glycosyltransferase RsIA_GT of Rhizoctonia solani AG-1 IA Inhibits Defense Responses in Nicotiana benthamiana.

Anastomosis group AG-1 IA of Rhizoctonia solani Khün has a wide host range and threatens crop production. Various glycosyltransferases secreted by phytopathogenic fungi play an essential role in pathogenicity. Previously, we identified a glycosyltransferase RsIA_GT (AG11A_09161) as a secreted protein-encoding gene of R. solani AG-1 IA, whose expression levels increased during infection in rice. In this study, we further characterized the virulence function of RsIA_GT. It is conserved not only in Basidiomycota, including multiple anastomosis groups of R. solani, but also in other primary fungal taxonomic categories. RsIA_GT possesses a signal peptide (SP) for protein secretion, and its functionality was proven using yeast and Nicotiana benthamiana. The SP-truncated form of RsIA_GT (RsIA_GT(ΔS)) expressed in Escherichia coli-induced lesion-like phenotype in rice leaves when applied to punched leaves. However, Agrobacterium-mediated transient expressions of both the full-length RsIA_GT and RsIA_GT(ΔS) did not induce cell death in N. benthamiana leaves. Instead, only RsIA_GT(ΔS) suppressed the cell death induced by two reference cell death factors BAX and INF1 in N.benthamiana. RsIA_GT(ΔS)R154A D168A D170A, a mutant RsIA_GT(ΔS) for the glycosyltransferase catalytic domain, still suppressed the BAX- or INF1-induced cell death, suggesting that the cell death suppression activity of RsIA_GT(ΔS) would be independent from its enzymatic activity. RsIA_GT(ΔS) also suppressed the H2O2 production and callose deposition and showed an effect on the induction of defense genes associated with the expression of BAX and INF1. The transient expression of RsIA_GT(ΔS) in N. benthamiana enhanced the lesion area caused by R. solani AG-1 IA. The secreted glycosyltransferase, RsIA_GT, of R. solani AG-1 IA is likely to have a dual role in virulence inside and outside of host cells.

Transcriptional response of a target plant to benzoxazinoid and diterpene allelochemicals highlights commonalities in detoxification.

BACKGROUND: Plants growing in proximity to other plants are exposed to a variety of metabolites that these neighbors release into the environment. Some species produce allelochemicals to inhibit growth of neighboring plants, which in turn have evolved ways to detoxify these compounds. RESULTS: In order to understand how the allelochemical-receiving target plants respond to chemically diverse compounds, we performed whole-genome transcriptome analysis of Arabidopsis thaliana exposed to either the benzoxazinoid derivative 2-amino- 3H-phenoxazin-3-one (APO) or momilactone B. These two allelochemicals belong to two very different compound classes, benzoxazinoids and diterpenes, respectively, produced by different Poaceae crop species. CONCLUSIONS: Despite their distinct chemical nature, we observed similar molecular responses of A. thaliana to these allelochemicals. In particular, many of the same or closely related genes belonging to the three-phase detoxification pathway were upregulated in both treatments. Further, we observed an overlap between genes upregulated by allelochemicals and those involved in herbicide detoxification. Our findings highlight the overlap in the transcriptional response of a target plant to natural and synthetic phytotoxic compounds and illustrate how herbicide resistance could arise via pathways involved in plant-plant interaction.

The α- and ß-Subunit Boundary at the Stem of the Mushroom-Like α3ß3-Type Oxygenase Component of Rieske Non-Heme Iron Oxygenases Is the Rieske-Type Ferredoxin-Binding Site.

Cumene dioxygenase (CumDO) is an initial enzyme in the cumene degradation pathway of Pseudomonas fluorescens IP01 and is a Rieske non-heme iron oxygenase (RO) that comprises two electron transfer components (reductase [CumDO-R] and Rieske-type ferredoxin [CumDO-F]) and one catalytic component (α3ß3-type oxygenase [CumDO-O]). Catalysis is triggered by electrons that are transferred from NAD(P)H to CumDO-O by CumDO-R and CumDO-F. To investigate the binding mode between CumDO-F and CumDO-O and to identify the key CumDO-O amino acid residues for binding, we simulated docking between the CumDO-O crystal structure and predicted model of CumDO-F and identified two potential binding sites: one is at the side-wise site and the other is at the top-wise site in mushroom-like CumDO-O. Then, we performed alanine mutagenesis of 16 surface amino acid residues at two potential binding sites. The results of reduction efficiency analyses using the purified components indicated that CumDO-F bound at the side-wise site of CumDO-O, and K117 of the α-subunit and R65 of the ß-subunit were critical for the interaction. Moreover, these two positively charged residues are well conserved in α3ß3-type oxygenase components of ROs whose electron donors are Rieske-type ferredoxins. Given that these residues were not conserved if the electron donors were different types of ferredoxins or reductases, the side-wise site of the mushroom-like structure is thought to be the common binding site between Rieske-type ferredoxin and α3ß3-type oxygenase components in ROs. IMPORTANCE We clarified the critical amino acid residues of the oxygenase component (Oxy) of Rieske non-heme iron oxygenase (RO) for binding with Rieske-type ferredoxin (Fd). Our results showed that Rieske-type Fd-binding site is commonly located at the stem (side-wise site) of the mushroom-like α3ß3 quaternary structure in many ROs. The resultant binding site was totally different from those reported at the top-wise site of the doughnut-like α3-type Oxy, although α3-type Oxys correspond to the cap (α3 subunit part) of the mushroom-like α3ß3-type Oxys. Critical amino acid residues detected in this study were not conserved if the electron donors of Oxys were different types of Fds or reductases. Altogether, we can suggest that unique binding modes between Oxys and electron donors have evolved, depending on the nature of the electron donors, despite Oxy molecules having shared α3ß3 quaternary structures.

Lateral transfers lead to the birth of momilactone biosynthetic gene clusters in grass.

Momilactone A, an important plant labdane-related diterpenoid, functions as a phytoalexin against pathogens and an allelochemical against neighboring plants. The genes involved in the biosynthesis of momilactone A are found in clusters, i.e., momilactone A biosynthetic gene clusters (MABGCs), in the rice and barnyardgrass genomes. In addition, we know little about the origin and evolution of MABGCs. Here, we integrated results from comprehensive phylogeny and comparative genomic analyses of the core genes of MABGC-like clusters and MABGCs in 40 monocot plant genomes, providing convincing evidence for the birth and evolution of MABGCs in grass species. The MABGCs found in the PACMAD clade of the core grass lineage (including Panicoideae and Chloridoideae) originated from a MABGC-like cluster in Triticeae (BOP clade) via lateral gene transfer (LGT) and followed by recruitment of MAS1/2 and CYP76L1 genes. The MABGCs in Oryzoideae originated from PACMAD through another LGT event and lost CYP76L1 afterwards. The Oryza MABGC and another Oryza diterpenoid cluster c2BGC are two distinct clusters, with the latter originating from gene duplication and relocation within Oryzoideae. Further comparison of the expression patterns of the MABGC genes between rice and barnyardgrass in response to pathogen infection and allelopathy provides novel insights into the functional innovation of MABGCs in plants. Our results demonstrate LGT-mediated origination of MABGCs in grass and shed lights into the evolutionary innovation and optimization of plant biosynthetic pathways.

Aerial (+)-borneol modulates root morphology, auxin signalling and meristematic activity in Arabidopsis roots.

One of the characteristic aspects of odour sensing in humans is the activation of olfactory receptors in a slightly different manner in response to different enantiomers. Here, we focused on whether plants showed enantiomer-specific response similar to that in humans. We exposed Arabidopsis seedlings to methanol (control) and (+)- or (-)-borneol, and found that only (+)-borneol reduced the root length. Furthermore, the root-tip width was more increased upon (+)-borneol exposure than upon (-)-borneol exposure. In addition, root-hair formation was observed near the root tip in response to (+)-borneol. Auxin signalling was strongly reduced in the root tip following exposure to (+)-borneol, but was detected following exposure to (-)-borneol and methanol. Similarly, in the root tip, the activity of cyclin B1:1 was detected on exposure to (-)-borneol and methanol, but not on exposure to (+)-borneol, indicating that (+)-borneol inhibits the meristematic activity in the root. These results partially explain the (+)-borneol-specific reduction in the root length of Arabidopsis. Our results indicate the presence of a sensing system specific for (+)-borneol in Arabidopsis.

Clinical Utility of Superior Vena Cava Flow Velocity Waveform Measured from the Subcostal Window for Estimating Right Atrial Pressure.

BACKGROUND: The superior vena cava (SVC) flow velocity waveform from the supraclavicular window reflects right atrial pressure (RAP) status. Recent guidelines have stated that the subcostal window is an alternative view for recording SVC flow, but the validity of this approach remains unclear. The aim of this study was to determine the usefulness of SVC flow evaluation from the subcostal window for estimating RAP. METHODS: Differences in SVC flow characteristics between opposite approaches were examined in 38 healthy adults. In 115 patients with cardiovascular diseases who underwent cardiac catheterization and echocardiography within 48 hours, the ratio of peak systolic to diastolic forward SVC flow (SVC-S/D) was measured, and the diagnostic ability of SVC-S/D for elevated RAP was tested. A validation cohort was used to confirm the diagnostic ability of SVC-S/D in 48 patients who underwent both cardiac catheterization and echocardiography within 24 hours. In 59 patients in the derivation and validation cohorts, the relationship between SVC flow and RAP was compared between the opposite windows. RESULTS: Both systolic and diastolic SVC flow velocities were higher in the subcostal than in the supraclavicular approach, and effect of position change on subcostal SVC-S/D was smaller than that on supraclavicular SVC-S/D in healthy adults. Measurement of SVC-S/D from the subcostal window was feasible in 98 patients (85%). RAP was inversely correlated with SVC-S/D (r = -0.50, P < .001) and was an independent determinant of SVC-S/D after adjustment for right ventricular systolic function (ß = -0.48, P < .001). A cutoff value of 1.9 for SVC-S/D showed 85% sensitivity and 74% specificity in identifying elevated RAP. Additionally, SVC-S/D showed an incremental diagnostic value combined with inferior vena cava size and collapsibility (P = .006). When a cutoff value of SVC-S/D < 1.9 was applied to the validation cohort, it showed acceptable accuracy of 72% and incremental diagnostic value combined with inferior vena cava parameters (P = .033). SVC-S/D from the subcostal window correlated better with RAP than that from the supraclavicular window (P < .001, Meng's test). CONCLUSIONS: Measurement of SVC flow velocity from the subcostal window was feasible, and SVC-S/D from the subcostal window could be an additive parameter for estimating RAP.