Identification of Nitrogen-Fixing Bradyrhizobium Associated With Roots of Field-Grown Sorghum by Metagenome and Proteome Analyses

Sorghum (Sorghum bicolor) is cultivated worldwide for food, bioethanol, and fodder production. Although nitrogen fixation in sorghum has been studied since the 1970s, N2-fixing bacteria have not been widely examined in field-grown sorghum plants because the identification of functional diazotrophs depends on the culture method used. The aim of this study was to identify functional N2-fixing bacteria associated with field-grown sorghum by using “omics” approaches. Four lines of sorghum (KM1, KM2, KM4, and KM5) were grown in a field in Fukushima, Japan. The nitrogen-fixing activities of the roots, leaves, and stems were evaluated by acetylene reduction and 15N2-feeding assays. The highest nitrogen-fixing activities were detected in the roots of lines KM1 and KM2 at the late growth stage. Bacterial cells extracted from KM1 and KM2 roots were analyzed by metagenome, proteome, and isolation approaches and their DNA was isolated and sequenced. Nitrogenase structural gene sequences in the metagenome sequences were retrieved using two nitrogenase databases. Most sequences were assigned to nifHDK of Bradyrhizobium species, including non-nodulating Bradyrhizobium sp. S23321 and photosynthetic B. oligotrophicum S58T. Amplicon sequence and metagenome analysis revealed a relatively higher abundance (2.9–3.6%) of Bradyrhizobium in the roots. Proteome analysis indicated that three NifHDK proteins of Bradyrhizobium species were consistently detected across sample replicates. By using oligotrophic media, we purified eight bradyrhizobial isolates. Among them, two bradyrhizobial isolates possessed 16S rRNA and nif genes similar to those in S23321 and S58T which were predicted as functional diazotrophs by omics approaches. Both free-living cells of the isolates expressed N2-fixing activity in a semi-solid medium according to an acetylene reduction assay. These results suggest that major functional N2-fixing bacteria in sorghum roots are unique bradyrhizobia that resemble photosynthetic B. oligotrophicum S58T and non-nodulating Bradyrhizobium sp. S23321. Based on our findings, we discuss the N2-fixing activity level of sorghum plants, phylogenetic and genomic comparison with diazotrophic bacteria in other crops, and Bradyrhizobium diversity in N2 fixation and nodulation

A patient with sustained ventricular tachycardia : identification of a responder to amiodarone using signal-averaged electrocardiogram

A75-year-old man suffered sustained ventricular tachycardia with syncopal attack. Ventricular tachycardias appeared repeatedly, and an electrical defibrillator was used after an anti-arrhythmic drug, such as lidocaine or mexiletine, proved ineffective. The tachycardias had multiple origins, and the signal-averaged electrocardiogram (SAECG) showed ventricular late potential before the administration of amiodarone. After administration, the filtered QRS and duration of the late potential increased, but the recurrence of tachycardias was suppressed. The reason for this is thought to be that amiodarone blocked the sodium channel and delayed conduction, consequently blocking reentry, because amiodaron has antiarrhymic properties with a prolongation of refractoriness and minimal effect on conduction velocity in ventricular myocardium, and inhibits sympathetic activity, and blocks L-type calcium channel besides the depression of the fast sodium channel. In this case, SAECG predicted to some degree whether or not this patient’s ventricular tachycardia would respond to amiodarone

ジュウショウ シンフゼン カンジャ ニオケル サンソ リョウホウ ト Adaptive-servo ventilator ノ コウカ ノ ケントウ ハイドウミャクセイ ハイコウケツアツ ニ トモナウ ウシンフゼン ニ タイシテ ノ Adaptive-servo ventilator ノ コウカ

Pulmonary arterial hypertension（PAH）, including idiopathic or connective tissue diseaserelated PAH is very poor prognosis. Recently it has been reported that Adaptive-servo ventilator（ASV）is useful device for improving congestive heart failure compared with oxygen therapy however, it has not been clear whether ASV is useful not only in congestive heart failure but also in PAH patients. We experienced a drug therapy-resistant PAH patient, whose subjective symptom and pulmonary arterial pressure were ameliorated by ASV. We also found that ASV was also effective on improving subjective symptoms and on decreasing pulmonary arterial pressure in ６patients with PAH. These findings suggest that ASV is a useful and new device in patients with drug therapy-resistant PAH

Decoding Plant–Environment Interactions That Influence Crop Agronomic Traits

To ensure food security in the face of increasing global demand due to population growth and progressive urbanization, it will be crucial to integrate emerging technologies in multiple disciplines to accelerate overall throughput of gene discovery and crop breeding. Plant agronomic traits often appear during the plants’ later growth stages due to the cumulative effects of their lifetime interactions with the environment. Therefore, decoding plant–environment interactions by elucidating plants’ temporal physiological responses to environmental changes throughout their lifespans will facilitate the identification of genetic and environmental factors, timing and pathways that influence complex end-point agronomic traits, such as yield. Here, we discuss the expected role of the life-course approach to monitoring plant and crop health status in improving crop productivity by enhancing the understanding of plant–environment interactions. We review recent advances in analytical technologies for monitoring health status in plants based on multi-omics analyses and strategies for integrating heterogeneous datasets from multiple omics areas to identify informative factors associated with traits of interest. In addition, we showcase emerging phenomics techniques that enable the noninvasive and continuous monitoring of plant growth by various means, including three-dimensional phenotyping, plant root phenotyping, implantable/injectable sensors and affordable phenotyping devices. Finally, we present an integrated review of analytical technologies and applications for monitoring plant growth, developed across disciplines, such as plant science, data science and sensors and Internet-of-things technologies, to improve plant productivity