Satoshi Ohkubo

Tohoku University | Tohokudai · Graduate School of Life Sciences

Enhancing leaf photosynthetic capacity is essential for improving yield of rice ( Oryza sativa L.). The exploitation of natural genetic variation is a promising approach to enhance photosynthetic capacity, as well as molecular engineering approaches. However, genetic resources have yet to be efficiently used in breeding programs, partially due to t...

In rice (Oryza sativa L.), leaf sheaths enhance stem strength and lodging resistance. However, little is known about the factors that affect varietal differences and changes over time regarding leaf sheath reinforcement. In the present study, the morphological and physiological traits that are presumed to be related to leaf sheath reinforcement wer...

Introduction Plant cell walls play an important role in providing physical strength and defence against abiotic stress. Rice brittle culm (bc) mutants are a strength-decreased mutant because of abnormal cell walls, and it has been reported that the causative genes of bc mutants affect cell wall composition. However, the metabolic alterations in eac...

We report the 3.5-Mb draft genome sequence of the cyanobacterium Synechococcus sp. strain Nb3U1, which was isolated from a microbial mat sample collected from Nakabusa Hot Spring, Nagano, Japan.

It is generally believed that rice landraces with long culms are susceptible to lodging, and have not been utilized for breeding to improve lodging resistance. However, little is known about the structural culm strength of landraces and their beneficial genetic loci. Therefore, in this study, genome-wide association studies (GWAS) were performed us...

Symbiosis between organisms influences their evolution via adaptive changes in genome architectures. Immunity of soybean carrying the Rj2 allele is triggered by NopP (type III secretion system [T3SS]-dependent effector), encoded by symbiosis island A (SymA) in B. diazoefficiens USDA122. This immunity was overcome by many mutants with large SymA del...

How genetic variations affect gene expression dynamics of field-grown plants remains unclear. Expression quantitative trait loci (eQTL) analysis is frequently used to find genomic regions underlying gene expression polymorphisms. This approach requires transcriptome data for the complete set of the QTL mapping population under the given conditions....

Leaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO 2 assimilation rate ( A ) of two elite ri...

Leaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO 2 assimilation rate ( A ) of two elite ri...

Plants in the field experience dynamic changes of sunlight rather than steady-state irradiation. Therefore, increasing the photosynthetic rate of an individual leaf under fluctuating light is essential for improving crop productivity. The high-yielding indica rice (Oryza sativa L.) cultivar Takanari is considered a potential donor of photosynthesis...

Microbial community structure reflects the surrounding natural environment and changes to that environment. Although the subsurface at 5–100 m depth is important for human activities and there are potential risks of environmental pollution in this region, there have been only a few reports of subsurface microbial community structures in terrestrial...

Over the past 20 years, researchers have developed increasingly sophisticated genome information and analytical platforms for rice (Oryza sativa) genetic research. The genetic controls of source capacity include photosynthesis capacity, leaf senescence, canopy architecture, and translocation. Details of these controls have been gradually elucidated...

Leaves within crop canopies experience variable light over the course of a day, which greatly affects photosynthesis and crop productivity. Little is known about the mechanisms of the photosynthetic response to fluctuating light and their genetic control. Here, we examined gas exchange, metabolite levels, and chlorophyll fluorescence during photosy...

Organisms respond to the fluctuations in field environments differently throughout their lives depending on their genetic variations. However, how such genetic variations affect environmental responses of organisms under field conditions, that is, the genotype × environment interaction (G×E), remains unclear. In the present study, we developed a me...

Acquisition of additional photosynthetic pigments enables photosynthetic organisms to survive in particular niches. To reveal the ecological significance of chlorophyll (Chl) f, we investigated the distribution of Chl and cyanobacteria within two microbial mats. In a 7-mm-thick microbial mat beneath the running water of the Nakabusa hot spring, Jap...

Global warming and urbanization together with development of subsurface infrastructures (e.g. subways, shopping complexes, sewage systems, and Ground Source Heat Pump (GSHP) systems) will likely cause a rapid increase in the temperature of relatively shallow groundwater reservoirs (subsurface thermal pollution). However, potential effects of a subs...

In this review, we described the biological characteristics of a cyanobacterium Acaryochloris marina and a unicellular cyanobacterium strain KC1 and the possible photosynthetic systems of the cells based on the physicochemical properties of chlorophylls. Strain KC1 as well as Acaryochloris spp. in addition to Halomiclonema hongdechloris should cont...

The diversity of cyanobacterial species within the coralloid roots of an individual and populations of Cycas revoluta was investigated based on 16S rRNA gene sequences. Sixty-six coralloid roots were collected from nine natural populations of cycads on Kyushu and the Ryukyu Islands, covering the entire distribution range of the species. Approximate...

Acaryochloris spp. are unique cyanobacteria which contain chlorophyll d as the predominant pigment. The phylogenetic diversity of Acaryochloris spp. associated with 7 Prochloron- or Synechocystis-containing didemnid ascidians and 1 Synechococcus-containing sponge obtained from the coast of the Republic of Palau was analyzed; we established a PCR pr...

Although analyses of chlorophyll d (Chl d)-dominated oxygenic photosystems have been conducted since their discovery 12 years ago, Chl d distribution in the environment and quantitative importance for aquatic photosynthesis remain to be investigated. We analyzed the pigment compositions of surface sediments and detected Chl d and its derivatives fr...

A molecular method for detecting the epiphyte community on marine macroalgae was developed by using PCR-denaturing gradient gel electrophoresis. Selective amplification of 16S rRNA gene fragments from either cyanobacteria or algal plastids improved the detection of minor epiphytes. Two phylotypes of Acaryochloris, a chlorophyll d-containing cyanoba...