Environmental stresses can reduce crop yield and quality considerably. Plants protect cell metabolism in response to abiotic stresses at all stages of their life cycle, including seed production. As the production of vigorous seeds is important to both yield and crop growth, we analyzed causes of yield loss and reduced grain quality in staple crops exposed to environmental stresses such as drought and temperature extremes, with a focus on the remobilization of nutrients and water status during seed filling.
View Article and Find Full Text PDFSeed dormancy is one of the adaptive responses in the plant life cycle and an important agronomic trait. Reactive oxygen species (ROS) release seed dormancy and promote seed germination in several cereal crops; however, the key regulatory mechanism of ROS-mediated seed dormancy and germination remains controversial. Here, we focused on the relationship between hydrogen peroxide (a ROS) and abscisic acid (ABA) in dormant and non-dormant barley seeds.
View Article and Find Full Text PDFNADPH oxidase catalyzes the production of the superoxide anion (O2(-)), a reactive oxygen species (ROS), and regulates the germination of barley (Hordeum vulgare L.). Diphenyleneiodonium (DPI) chloride, an NADPH oxidase inhibitor, delayed barley germination, and exogenous H2O2 (an ROS) partially rescued it.
View Article and Find Full Text PDFReactive oxygen species (ROS) promote the germination of several seeds, and antioxidants suppress it. However, questions remain regarding the role and production mechanism of ROS in seed germination. Here, we focused on NADPH oxidases, which produce ROS.
View Article and Find Full Text PDFThe cereal aleurone layer is a secretory tissue that produces enzymes to hydrolyze the starchy endosperm during germination. We recently demonstrated that reactive oxygen species (ROS), produced in response to gibberellins (GA), promoted GAMyb expression, which induces α-amylase expression in barley aleurone cells. On the other hand, ROS levels increase during programmed cell death (PCD) in barley aleurone cells, and GAMyb is involved in PCD of these cells.
View Article and Find Full Text PDFHigh temperature reduces the grain quality of rice, a situation likely to become more frequent because of global warming. We studied the effects of high-temperature stress on grain quality of heat-tolerant cultivar 'Genkitsukushi' and heat-sensitive cultivar 'Tsukushiroman'. When day/night temperatures were 31/26 °C from heading until maturity, the grain quality of 'Genkitsukushi' was rated at the first inspection grade (high quality), whereas 'Tsukushiroman' showed a remarkable increase in the percentage of white immature kernels (low quality).
View Article and Find Full Text PDFA three-beam spectral domain optical coherence tomography system (OCT) whose center wavelength is 840 nm was developed. The three beams focus on fundus 3.1 mm apart from each other and are detected by a single line sensor.
View Article and Find Full Text PDFBackground And Aims: Despite their toxicity, reactive oxygen species (ROS) play important roles in plant cell signalling pathways, such as mediating responses to stress or infection and in programmed cell death, at lower levels. Although studies have indicated that hydrogen peroxide (H(2)O(2)) promotes seed germination of several plants such as Arabidopsis, barley, wheat, rice and sunflower, the role of H(2)O(2) in soybean seed germination is not well known. The aim of this study therefore was to investigate the relationships between ROS, plant hormones and soybean seed germination.
View Article and Find Full Text PDFReactive oxygen species (ROS) act as signal molecules for a variety of processes in plants. However, many questions about the roles of ROS in plants remain to be clarified. Here, we report the role of ROS in gibberellin (GA) and abscisic acid (ABA) signaling in barley (Hordeum vulgare) aleurone cells.
View Article and Find Full Text PDFIn higher plants, autophagy-related genes (ATGs) appear to play important roles in development, senescence, and starvation responses. Hormone signals underlying starvation-induced gene expression are involved in the expression of ATGs. An effect of starvation stress on the expression of ATGs and ethylene-related genes in young seedlings of soybean (Glycine max [L.
View Article and Find Full Text PDFTo ascertain the effect of exogenously applied hydrogen peroxide (H2O2) on drought stress, we examined whether the spraying of soybean leaves with H2O2 would alleviate the symptoms of drought stress. Pre-treatment by spraying leaves with H2O2 delayed foliar wilting caused by drought stress compared to leaves sprayed with distilled water (DW). Additionally, the relative water content of drought-stressed leaves pre-treated with H2O2 was higher than that of leaves pre-treated with DW.
View Article and Find Full Text PDFThe homeostasis of gibberellins (GAs) is maintained by negative-feedback regulation in plant cells. REPRESSION OF SHOOT GROWTH (RSG) is a transcriptional activator with a basic Leu zipper domain suggested to contribute GA feedback regulation by the transcriptional regulation of genes encoding GA biosynthetic enzymes. The 14-3-3 signaling proteins negatively regulate RSG by sequestering it in the cytoplasm in response to GAs.
View Article and Find Full Text PDFThe homeostasis of gibberellins (GAs) is maintained by negative feedback in plants. REPRESSION OF SHOOT GROWTH (RSG) is a tobacco (Nicotiana tabacum) transcriptional activator that has been suggested to play a role in GA feedback by the regulation of GA biosynthetic enzymes. The 14-3-3 signaling proteins negatively regulate RSG by sequestering it in the cytoplasm in response to GAs.
View Article and Find Full Text PDFHydrogen peroxide (H(2)O(2)) promotes seed germination of cereal plants and ascorbic acid which acts as antioxidant suppresses the germination of wheat seeds, but the role of H(2)O(2) scavenging on germination during seed maturation has not been demonstrated. We investigated relationship of germination, ascorbate, H(2)O(2) scavenging enzymes and sensitivity to ascorbic acid (AsA) maturing seeds of two typical wheat (Triticum aestivum L.) cultivars, cvs.
View Article and Find Full Text PDFSince 1997, we, the community pharmacists, have established this society, Aichi Prefecture Society for the Study of Pressure Ulcers Care, in order to furnish drug information about pressure ulcers care. Moist atmosphere is required for the healing of pressure ulcers. The moist environment that could be regulated depends on the physicochemical property of ointment bases.
View Article and Find Full Text PDFREPRESSION OF SHOOT GROWTH (RSG) is a tobacco (Nicotiana tabacum) transcriptional activator with a basic Leu zipper domain that regulates endogenous amounts of gibberellins (GAs) by the control of a GA biosynthetic enzyme. The 14-3-3 signaling proteins have been suggested to suppress RSG by sequestering it in the cytoplasm. Here, we show that RSG phosphorylation on Ser-114 is important for 14-3-3 binding.
View Article and Find Full Text PDFAs for pressure ulcers care, prevention is the most important approach. However, pressure ulcers, might develop despite enough care, depending on each person's physical condition. As for the treatment of pressure ulcers, maintenance of a moderately moist environment (60-70%) is quite important.
View Article and Find Full Text PDFAs for pressure ulcers care, prevention is the most important approach. However, pressure ulcers, might develop despite enough care, depending on each person's physical condition. As for the treatment of pressure ulcers, maintenance of a moderately moist environment (60-70%) is quite important.
View Article and Find Full Text PDFOn the basis of the genome sequence, the unicellular motile cyanobacterium Synechocystis sp. PCC 6803 harbors seven putative genes for eukaryotic-type protein kinase belonging to Pkn2 subfamily ( spkA approximately spkG). Previously, SpkA was shown to have protein kinase activity and to be required for cell motility.
View Article and Find Full Text PDFThe complete genome of the unicellular motile cyanobacterium Synechocystis sp. PCC 6803 harbors seven putative genes for a subfamily Pkn2 of the eukaryotic-type (or "Hanks-type") protein kinase. Previously, SpkA and SpkB were shown to have protein kinase activity and to be required for cell motility.
View Article and Find Full Text PDFMitogen-activated protein kinase (MAPK) pathways coordinate critical cellular responses to mitogens, stresses, and developmental cues. The coupling of MAPK kinase kinase (MAP3K) --> MAPK kinase (MEK) --> MAPK core pathways to cell surface receptors remains poorly understood. Recombinant forms of MAP3K MEK kinase 1 (MEKK1) interact in vivo and in vitro with the STE20 protein homologue germinal center kinase (GCK), and both GCK and MEKK1 associate in vivo with the adapter protein tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2).
View Article and Find Full Text PDFA cDNA clone encoding a Ca +-dependent protein kinase (DtCPK1) with a calculated molecular mass of 65,746 Da was isolated by sequential immuno- and hybridization-screening from a cDNA library of the halotolerant green alga, Dunaliella tertiolecta Butcher (Chlorophyceae). Primary structure analysis of DtCPK1 revealed a long variable domain preceding a catalytic domain, an autoinhibitory junction domain, and a C-terminal calmodulin-like domain containing 4 EF-hand motifs. Database searches showed that DtCPK1 has a high similarity to CCK1, a CDPK from the green alga, Chlamydomonas eugamentos Moewus.
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