A5084323594- Photosynthetic Processes and Mechanisms
- Light effects on plants
- Algal biology and biofuel production
- Plant Stress Responses and Tolerance
- Plant Gene Expression Analysis
- Photoreceptor and optogenetics research
- Genomics and Phylogenetic Studies
- Grit, Self-Efficacy, and Motivation
- Motivation and Self-Concept in Sports
- Education, Achievement, and Giftedness
- Microbial Community Ecology and Physiology
- Mitochondrial Function and Pathology
- Antioxidant Activity and Oxidative Stress
- Behavioral Health and Interventions
- Plant nutrient uptake and metabolism
- Lipid metabolism and biosynthesis
- Plant Molecular Biology Research
- Education and Learning Interventions
- Psychosocial Factors Impacting Youth
- Child and Adolescent Psychosocial and Emotional Development
- Protist diversity and phylogeny
- RNA and protein synthesis mechanisms
- Innovative Teaching and Learning Methods
- Porphyrin Metabolism and Disorders
- Marine and coastal ecosystems
Mitsubishi Chemical (Japan)
2025
Doshisha University
2014-2024
Tokyo University of Agriculture and Technology
2024
Hokkaido University
2014-2023
University of Human Environments
2022
Japan Science and Technology Agency
2004-2016
Sapporo Science Center
2015-2016
Kumamoto University
2016
Kagoshima University
1994-2015
University of Toyama
2010-2015
Abstract Chlorophyll degradation is an aspect of leaf senescence, which active process to salvage nutrients from old tissues. non-yellow coloring1 (nyc1) a rice (Oryza sativa) stay-green mutant in chlorophyll during senescence impaired. Pigment analysis revealed that not only chlorophylls but also light-harvesting complex II (LHCII)–bound carotenoids was repressed nyc1, most LHCII isoforms were selectively retained senescence. Ultrastructural nyc1 chloroplasts large and thick grana present...
Chlorophyll b is an ubiquitous accessory pigment in land plants, green algae, and prochlorophytes. Its biosynthesis plays a key role the adaptation to various light environments. We isolated six chlorophyll -less mutants by insertional mutagenesis using nitrate reductase or argininosuccinate lyase genes as tags examined rearrangement of mutant genomes. found that overlapping region nuclear genome was deleted all this encodes protein whose sequence similar those methyl monooxygenases. This...
Yellowing, which is related to the degradation of chlorophyll and chlorophyll-protein complexes, a notable phenomenon during leaf senescence. NON-YELLOW COLORING 1 (NYC1) in rice encodes membrane-localized short-chain dehydrogenase/reductase (SDR) that thought represent b reductase necessary for catalyzing first step degradation. Analysis nyc1 mutant, shows stay-green phenotype, revealed required light-harvesting complex II thylakoid grana Phylogenetic analysis further existence NYC1-LIKE...
Abstract Pheophytin a is an essential component of oxygenic photosynthetic organisms because the primary charge separation between chlorophyll and pheophytin first step in conversion light energy. In addition, to degradation. synthesized by extracting magnesium (Mg) from chlorophyll; enzyme Mg-dechelatase catalyzes this reaction. study, we report that Mendel's green cotyledon gene, STAY-GREEN (SGR), encodes Mg-dechelatase. The Arabidopsis thaliana genome has three SGR genes, SGR1, SGR2, LIKE...
Chlorophyll metabolism has been extensively studied with various organisms, and almost all of the chlorophyll biosynthetic genes have identified in higher plants. However, only gene for 3,8-divinyl protochlorophyllide a 8-vinyl reductase (DVR), which is indispensable monovinyl synthesis, not yet. In this study, we isolated an Arabidopsis thaliana mutant that accumulated divinyl instead by ethyl methanesulfonate mutagenesis. Map-based cloning resulted identification (AT5G18660) shows sequence...
The plastid plays a vital role in various cellular activities within plant cells including photosynthesis and other metabolic pathways. It is believed that the functional status of somehow monitored by nucleus to optimize expression genes encoding proteins. currently dominant model for plastid-derived signaling ("plastid signaling") proposes Mg-protoporphyrin IX (MgProto) negative signal represses wide range nuclear plastid-localized proteins when development inhibited. In this study, we...
The light-harvesting chlorophyll a/b-protein complex of photosystem II (LHCII) is the most abundant membrane protein in green plants, and its degradation a crucial process for acclimation to high light conditions recovery nitrogen (N) carbon (C) during senescence. However, molecular mechanism LHCII largely unknown. Here, we report that b reductase, which catalyzes first step degradation, plays central role degradation. When genes reductases NOL NYC1 were disrupted Arabidopsis thaliana, not...
Abstract The interconversion of chlorophyll a and b, referred to as the cycle, plays crucial role in processes greening, acclimation light intensity, senescence. cycle consists three reactions: conversions b by chlorophyllide oxygenase, 7-hydroxymethyl reductase, reductase. We identified which is last remaining unidentified enzyme from Arabidopsis thaliana genetic biochemical methods. Recombinant reductase converted using ferredoxin. Both sequence analyses showed that contains flavin adenine...
When conducting plant research, the measurement of photosynthetic pigments can provide basic information on physiological status a plant. High-pressure liquid chromatography (HPLC) is becoming widely used for this purpose because it provides an accurate determination variety simultaneously. This technique has drawback compared with conventional spectroscopic techniques, however, in that more prone to structural modification during extraction, thus potentially generating erroneous results....
Throughout the history of oxygen evolution, two types photosystem reaction centres (PSI and PSII) have worked in a coordinated manner. The evolving centre is an integral part PSII, extracts electron from water. PSI accepts electron, accumulates reducing power. Traditionally, PSII are thought to be spatially dispersed. Here, we show that about half PSIIs physically connected PSIs Arabidopsis thaliana. In PSI–PSII complex, excitation energy transferred efficiently between closely interacting...
Abstract Although seeds are a sink organ, chlorophyll synthesis and degradation occurs during embryogenesis in manner similar to that observed photosynthetic leaves. Some mutants retain after seed maturation, they disturbed storability. To elucidate the effects of retention on storability Arabidopsis (Arabidopsis thaliana), we examined non-yellow coloring1 (nyc1)/nyc1-like (nol) do not degrade properly. Approximately 10 times more was retained dry nyc1/nol mutant than wild-type seeds. The...
Despite the increasing number of studies examining correlates interest and boredom, surprisingly little research has focused on within-person fluctuations in these emotions, making it difficult to describe their situational nature.To address this gap literature, study conducted repeated measurements (12 times) a sample 158 undergraduate students using variety self-report assessments, examined relationships between task-specific perceptions (expectancy, utility, difficulty) boredom.This...
Abstract Increased grain yield will be critical to meet the growing demand for food, and could achieved by delaying crop senescence. Here, via quantitative trait locus (QTL) mapping, we uncover genetic basis underlying distinct life cycles senescence patterns of two rice subspecies, indica japonica . Promoter variations in Stay-Green ( OsSGR ) gene encoding chlorophyll-degrading Mg ++ -dechelatase were found trigger higher earlier induction , which accelerated cultivars. The -type promoter...
Oxygenation of pheophorbide a is key step in chlorophyll breakdown. Several biochemical studies have implicated that this was catalyzed by an iron-containing and ferredoxin-dependent monooxygenase, oxygenase (PaO). It has been proposed inhibition its activity arrests the breakdown leads to "stay-green" phenotype. We searched Arabidopsis genome for possible PaO-encoding gene hypothesized it homology known Rieske-type monooxygenase sequences. identified three such open reading frames, Tic55,...
With the increase in concentration of applied salicylic acid (SA), chlorophyll (Chl) content decreased significantly both wheat and moong seedlings. Chl a/b ratio only remained constant moong. On other hand, total carotenoid (Car) content, size xanthophyll pool, de-epoxidation rate increased with an SA plant species. Hence treatment may induce Car biosynthesis these species, but pool indicates that create oxidative stress degree which is different various plants.
Chlorophyll b is synthesized from chlorophyll a by the oxidation of methyl group on ring B tetrapyrrole to formyl group. Previously, we reported that chlorophyllide could be converted in isolated cucumber etioplasts indicating conversion a. To identify intermediate molecule, used barley instead cucumber. and an additional pigment were found after incubation with etioplasts. The has same retention time absorption spectrum as 7-hydroxymethyl chlorophyll, which hydroxymethyl b. Authentic was...
Plants acclimate to variations in light intensity by changing the antenna size of photosystems. This acclimation allows them undergo efficient photosynthesis and creates a protective strategy minimize photodamage. Chlorophyll b synthesis chlorophyllide oxygenase (CAO) is key regulatory step control size. Recently, we found that higher plant CAOs consist three domains (A, B, C domains) confirmed domain possesses catalytic function. To investigate function A domain, fused various combinations...