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Seiichiro Kamisaka - One of the best experts on this subject based on the ideXlab platform.
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increase in the level of arabinoxylan hydroxycinnamate network in cell walls of wheat Coleoptiles grown under continuous hypergravity conditions
Physiologia Plantarum, 2005Co-Authors: Kouichi Soga, Seiichiro KamisakaAbstract:Changes in the amount and composition of cell wall constituents in response to continuous hypergravity stimuli were studied in wheat (Triticum aestivum L.) Coleoptiles. The lengths of Coleoptiles grown under hypergravity (300 g) conditions for 2-4 days from germination stage were 60-70% of those of 1 g control. However, the net amounts of hemicellulosic polysaccharides and cellulose in hypergravity-treated Coleoptiles increased progressively as much as those in the control Coleoptiles. As a result, their contents per unit length of Coleoptile largely increased under hypergravity conditions. In the hemicellulose fraction, the amounts of arabinose and xylose, the major components of the fraction, prominently increased in response to hypergravity. When hemicellulosic polysaccharides were separated into neutral and acidic polymers by an anion-exchange column, the amounts of the acidic fraction consisting of (glucurono)arabinoxylans were higher in hypergravity-treated Coleoptiles than in control Coleoptiles. The amounts of cell wall-bound ferulic acid and diferulic acid (DFA) increased dramatically in both 1 g control and hypergravity-treated Coleoptiles. Particularly, the amounts of DFA in hypergravity-treated Coleoptiles were significantly higher than those in control Coleoptiles during the incubation period. These results suggest that continuous hypergravity increases the rigid network structures via arabinoxylan-hydroxycinnamate cross-links within cell wall architecture in wheat Coleoptiles. These structures may have a load-bearing function and contribute to construct the stable cell wall against the gravitational force.
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increased molecular mass of hemicellulosic polysaccharides is involved in growth inhibition of maize Coleoptiles and mesocotyls under hypergravity conditions
Journal of Plant Research, 1999Co-Authors: Kouichi Soga, Keita Harada, Seiichiro KamisakaAbstract:mays L. cv. Cross Bantam T51) Coleoptiles and mesocotyls was suppressed by hypergravity at 30 g and above. Acceleration at 300 g significantly decreased the mechanical extensibility of cell walls of both organs. Hypergravity increased the amounts of hemicellulose and cellulose per unit length in mesocotyl walls, but not in Coleoptile walls. The weight-average molecular masses of hemicellulosic polysaccharides were also increased by hypergravity in both organs. On the other hand, the activities of β-glucanases extracted from Coleoptile and mesocotyl cell walls were decreased by hypergravity. These results suggest that the decreased activities of β-glucanases by hypergravity cause an increase in the molecular mass of hemicellulosic polysaccharides of both organs. The upshift of molecular mass of hemicellulosic polysaccharides as well as the thickening of cell walls under hypergravity conditions seems to be involved in making the cell wall mechanically rigid, thereby inhibiting elongation growth of maize Coleoptiles and mesocotyls.
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changes in cellular osmotic potential and mechanical properties of cell walls during light induced inhibition of cell elongation in maize Coleoptiles
Physiologia Plantarum, 1996Co-Authors: Mohammad Masud Parvez, Seiichiro KamisakaAbstract:The growth rate of maize (Zea mays L. cv. Cross Bantam T51) Coleoptiles in the dark was highest at the basal zone and decreased towards the tip. Growth was strongly inhibited by white fluorescent light (5 W m -2 ), especially in the basal zone of Coleoptiles. Light irradiation caused an increase in the values of stress-relaxation parameters, the minimum stress-relaxation time and the relaxation rate and a decrease in the extensibility (strain/stress) of the cell walls at all zones. In addition, during growth, the accumulation of osmotic solutes was strongly inhibited by white light irradiation, resulting in an increased osmotic potential. The influences of white light on the mechanical properties of the cell wall and the osmotic potential of the tissue sap were most prominent in the basal zone. Significant correlations were observed between the increment of Coleoptile length and the mechanical properties of the cell walls or the osmotic potential of the tissue sap and osmotic solutes content. Furthermore, light inhibited the outward bending of split Coleoptile segments. These facts suggest that white light inhibits elongation of maize Coleoptiles by modifying both the mechanical properties of the cell walls and cellular osmotic potential, which control the rate of water uptake.
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light induced increase in the contents of ferulic and diferulic acids in cell walls of avena Coleoptiles its relationship to growth inhibition by light
Physiologia Plantarum, 1994Co-Authors: Kensuke Miyamoto, Takayuki Hoson, Yoshio Masuda, Satomi Takeda, Junichi Ueda, Kazuko Ida, Seiichiro KamisakaAbstract:White fluorescent light (5 W m−2) inhibited Avena Coleoptile growth. Light caused in increase in minimum stress relaxation time and a decrease in extensibility (strain/load) of Coleoptile cell walls. Light increased the contents of ferulic acid (FA) and diferulic acid (DFA) ester-linked to the hemicellulose I in cell walls. These changes in the phenolic contents correlated with those of the mechanical properties of cell walls, suggesting that light stimulates the formation of DFA in hemicellulose I, making cell walls rigid, and thus results in growth inhibition. The ratio of DFA to FA was almost constant in the dark, but decreased in light, although it was almost constant in Oryza Coleoptiles either in the dark or in light (Tan et al. 1992). From this fact, it is speculated that in the light condition, the formation of DFA in cell walls is limited in the step of the peroxidase catalyzed coupling reaction to produce DFA, while in the dark it is limited in the step of the feruloylation of hemicellulose I.
Moritoshi Iino - One of the best experts on this subject based on the ideXlab platform.
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Circumnutation of rice Coleoptiles: its relationships with gravitropism and absence in lazy mutants.
Plant Cell and Environment, 2006Co-Authors: Takeshi Yoshihara, Moritoshi IinoAbstract:Although circumnutation occurs widely in higher plants, its mechanism is little understood. The idea that circumnutation is based on gravitropism has long been investigated, but the reported results have been controversial. We used dark-grown Coleoptiles of rice (Oryza sativa L.) to re-investigate this issue. The following results supported the existence of a close relationship between gravitropism and circumnutation: (1) circumnutation disappears on a horizontal clinostat; (2) circumnutation is interrupted by a gravitropic response and re-initiated at a definable phase after gravitropic curvature; (3) circumnutation can be re-established by submergence and a brief gravitropic stimulation in the Coleoptiles that have stopped nutating in response to red light; and (4) lazy mutants show no circumnutation. In spite of these results, however, there were cases in which gravitropism and circumnutation could be separated. Firstly, the non-circumnutating lazy Coleoptile showed nearly a wild-type level of gravitropic responsiveness in its upper half, although this part was an active site of both gravitropism and circumnutation in wild-type Coleoptiles. Secondly, Coleoptiles could nutate without overshooting the vertical when developing phototropic curvature. It is concluded that gravitropism influences, but it is not directly involved in the process of circumnutation. It is further suggested that a gravity signal, shared with gravitropism, contributes to the maintenance of circumnutation.
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circumnutation of rice Coleoptiles its occurrence regulation by phytochrome and relationship with gravitropism
Plant Cell and Environment, 2005Co-Authors: Takeshi Yoshihara, Moritoshi IinoAbstract:It has been found that Coleoptiles of dark-grown rice (Oryza sativa L.) seedlings undergo regular circumnutation in circular orbits with periods of about 180 min. Both clockwise and counter-clockwise movements were observed, but individual Coleoptiles continued to rotate only in one direction. Light-grown seedlings did not show circumnutation. In fact, dark-grown seedlings were found to cease circumnutating in response to a pulse of red light (R). This light-induced inhibition of circumnutation was demonstrated to involve both a FR-inducible very-low-fluence response, solely mediated by phytochrome A, and a FR-reversible low-fluence response, mediated by phytochrome B and/or C. The R-induced inhibition of circumnutation showed temporal agreement with the R-induced inhibition of Coleoptile growth, suggesting that the former results from the latter. However, about 25% of growth activity remained after R treatment, indicating that circumnutation is more specifically regulated by phytochrome. The R-treated Coleoptile showed gravitropism. Investigation of the growth differential for gravitropic curvature revealed that gravitropic responsiveness was rather enhanced by R. The results suggested that gravitropism is not a cause of circumnutation. It remained probable, however, that gravity perception is a part of the mechanism of circumnutation. It is speculated that the circumnutation investigated aids the seedling shoot in growing through the soil.
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The Rice Coleoptile PHOTOTROPISM1 Gene Encoding an Ortholog of Arabidopsis NPH3 Is Required for Phototropism of Coleoptiles and Lateral Translocation of Auxin
The Plant cell, 2004Co-Authors: Ken Haga, Ralf Neumann, Moritoshi IinoAbstract:We isolated a mutant, named Coleoptile phototropism1 (cpt1), from γ-ray–mutagenized japonica-type rice (Oryza sativa). This mutant showed no Coleoptile phototropism and severely reduced root phototropism after continuous stimulation. A map-based cloning strategy and transgenic complementation test were applied to demonstrate that a NPH3-like gene deleted in the mutant corresponds to CPT1. Phylogenetic analysis of putative CPT1 homologs of rice and related proteins indicated that CPT1 has an orthologous relationship with Arabidopsis thaliana NPH3. These results, along with those for Arabidopsis, demonstrate that NPH3/CPT1 is a key signal transduction component of higher plant phototropism. In an extended study with the cpt1 mutant, it was found that phototropic differential growth is accompanied by a CPT1-independent inhibition of net growth. Kinetic investigation further indicated that a small phototropism occurs in cpt1 Coleoptiles. This response, induced only transiently, was thought to be caused by the CPT1-independent growth inhibition. The 3H-indole-3-acetic acid applied to the Coleoptile tip was asymmetrically distributed between the two sides of phototropically responding Coleoptiles. However, no asymmetry was induced in cpt1 Coleoptiles, indicating that lateral translocation of auxin occurs downstream of CPT1. It is concluded that the CPT1-dependent major phototropism of Coleoptiles is achieved by lateral auxin translocation and subsequent growth redistribution.
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gravitropism of oat and wheat Coleoptiles dependence on the stimulation angle and involvement of autotropic straightening
Plant and Cell Physiology, 1997Co-Authors: Yutaka Tarui, Moritoshi IinoAbstract:Gravitropism of oat (A vena sativa L.) and wheat (Triticum aestivum L.) Coleoptiles was investigated in relation to the displacement angle or to the initially set stimulation angle (SA). We measured curvature rates at the early phase of curvature, before it was affected by the drop in SA resulting from the curvature response itself. The plot of the rates against the sines of initial SAs revealed similar curves for oats and wheat, which approached saturation as the sine increased to unity. The two species and previously analyzed rice [lino et al. (1996) Plant Cell Environ. 19: 1160] appeared to have similar gravisensitivities. Initial SAs below and over 90° yielded comparable rates when the sine values were the same, indicating that the extent of gravitropism is determined by the gravity component perpendicular to the organ's long axis. Long-term curvature kinetics at different SAs indicated that the net curvature rate dropped sharply before the tip reached the vertical position and then the tip approached the vertical slowly, with clear oscillatory movements in. the case of wheat. During this late curvature phase, the Coleoptile straightened gradually, although none of its parts had yet reached the vertical. When rotated on horizontal clinostats or displaced upwards to reduce SA in the late curvature phase, Coleoptiles bent in the opposite direction. These results demonstrated that autotropism counteracts gravitropism to straighten Coleoptiles.
Takayuki Hoson - One of the best experts on this subject based on the ideXlab platform.
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Amino Acid-Sugar Linkages in Rice Coleoptile
2016Co-Authors: Cell Walls, Takayuki Hoson, Shunji WadaAbstract:The nature of amino acid-sugar linkages in cell walls was investigated in a mono-cotyledonous tissue, rice Coleoptiles. The molar ratios of aspartic acid, threonine, and serine in cell walls were decreased by hydrazinolysis in Coleoptiles grown both on and under water. The molar ratios of threonine and serine were decreased also by a NaOH-NaBH4 treatment, while the alanine content was increased, and a-aminobutyric acid was not formed. The cell walls were treated with NaOH in the presence of NaB3H4, hydrolyzed, then divided into amino acid and sugar fractions. Two distinct radioactive peaks were detected in the thin-layer chromatography of the amino acid fractions. One was identified as alanine derived from glycosylated serine; the other was confirmed to be an oxidation product of glucosaminitol. There was just one 3H-labeled product in the sugar fractions, galactitol. These results suggest the presence of serine-O-galactose and asparagine-iV-iV-acetyl glucosamine linkages in rice Coleoptile cell walls. The existence of glucosamine linked to amino acids was further supported by the incorporation of 14G-glucosamine into cell walls. These linkages were also detected in the cell walls of a dicotyledonous tissue, Vicia epicotyls. Key words: Cell wall glycoprotein — ^-Elimination — Glucosamine — Glycosidic linkage — • Hydrazinolysis — Rice Coleoptiles. The structure of Hyp-GP contained in cell walls is only partially known (Ch
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temperature modulates the cell wall mechanical properties of rice Coleoptiles by altering the molecular mass of hemicellulosic polysaccharides
Physiologia Plantarum, 2003Co-Authors: Yukiko Nakamura, Kazuyuki Wakabayashi, Takayuki HosonAbstract:The present study was conducted to investigate the mechanism inducing the difference in the cell wall extensibility of rice (Oryza sativa L. cv. Koshihikari) Coleoptiles grown under various temperature (10-50 degrees C) conditions. The growth rate and the cell wall extensibility of rice Coleoptiles exhibited the maximum value at 30-40 degrees C, and became smaller as the growth temperature rose or dropped from this temperature range. The amounts of cell wall polysaccharides per unit length of Coleoptile increased in Coleoptiles grown at 40 degrees C, but not at other temperature conditions. On the other hand, the molecular size of hemicellulosic polysaccharides was small at temperatures where the cell wall extensibility was high (30-40 degrees C). The autolytic activities of cell walls obtained from Coleoptiles grown at 30 and 40 degrees C were substantially higher than those grown at 10, 20 and 50 degrees C. Furthermore, the activities of (1-->3),(1-->4)-beta-glucanases extracted from Coleoptile cell walls showed a similar tendency. When oat (1-->3),(1-->4)-beta-glucans with high molecular mass were incubated with the cell wall enzyme preparations from Coleoptiles grown at various temperature conditions, the extensive molecular mass downshifts were brought about only by the cell wall enzymes obtained from Coleoptiles grown at 30-40 degrees C. There were close correlations between the cell wall extensibility and the molecular mass of hemicellulosic polysaccharides or the activity of beta -glucanases. These results suggest that the environmental temperature regulates the cell wall extensibility of rice Coleoptiles by modifying mainly the molecular mass of hemicellulosic polysaccharides. Modulation of the activity of beta-glucanases under various temperature conditions may be involved in the alteration of the molecular size of hemicellulosic polysaccharides.
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light induced increase in the contents of ferulic and diferulic acids in cell walls of avena Coleoptiles its relationship to growth inhibition by light
Physiologia Plantarum, 1994Co-Authors: Kensuke Miyamoto, Takayuki Hoson, Yoshio Masuda, Satomi Takeda, Junichi Ueda, Kazuko Ida, Seiichiro KamisakaAbstract:White fluorescent light (5 W m−2) inhibited Avena Coleoptile growth. Light caused in increase in minimum stress relaxation time and a decrease in extensibility (strain/load) of Coleoptile cell walls. Light increased the contents of ferulic acid (FA) and diferulic acid (DFA) ester-linked to the hemicellulose I in cell walls. These changes in the phenolic contents correlated with those of the mechanical properties of cell walls, suggesting that light stimulates the formation of DFA in hemicellulose I, making cell walls rigid, and thus results in growth inhibition. The ratio of DFA to FA was almost constant in the dark, but decreased in light, although it was almost constant in Oryza Coleoptiles either in the dark or in light (Tan et al. 1992). From this fact, it is speculated that in the light condition, the formation of DFA in cell walls is limited in the step of the peroxidase catalyzed coupling reaction to produce DFA, while in the dark it is limited in the step of the feruloylation of hemicellulose I.
Philip J. Harris - One of the best experts on this subject based on the ideXlab platform.
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location of 1 3 and 1 3 1 4 β d glucans in vegetative cell walls of barley hordeum vulgare using immunogold labelling
New Phytologist, 2002Co-Authors: Jason A K Trethewey, Philip J. HarrisAbstract:Summary • (1 → 3),(1 → 4)-β-Glucans occur only in the cell walls of the family Poaceae (grasses and cereals) and related families, but little is known about their distribution among walls of different cell types or within walls. • The locations of (1 → 3)- and (1 → 3),(1 → 4)-β-glucans in the walls of the Coleoptile, first leaf and root tip of barley (Hordeum vulgare) seedlings were determined using immunogold labelling. • All the walls were labelled with the (1 → 3),(1 → 4)-β-glucan antibody, except those of the outer root cap cells. Labelling of the primary walls was heavy in the Coleoptile and leaf, but light or very light in the root tip. Two types of primary wall labelling occurred: in the Coleoptiles (except the walls of the epidermis and two layers of parenchyma under this) and in the leaf, labelling was throughout the walls; in the root tips, labelling was only adjacent to the plasma membrane. Small amounts of labelling occurred with the (1 → 3)-β-glucan antibody, mostly over plasmodesmata. Both antibodies labelled cell plates. • (1 → 3),(1 → 4)-β-Glucans occur widely in the cell walls of vegetative organs of the barley seedlings, including the walls of meristematic tissues.
Naoki Sakurai - One of the best experts on this subject based on the ideXlab platform.
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Growth Regulation in Dwarf Barley Coleoptiles by the Minor Cell Wall Components
2016Co-Authors: Naoki Sakurai, Yoshio Masuda, Masahiro Inouhe, Susumu KuraishiAbstract:Sugar compositions of cell walls of dark-grown Coleoptiles from 12 barley strains, 11 of which were coleoptilar semi-dwarf strains, were analyzed on days 2 and 3 after germination. Major wall components of the 12 strains were arabinose, xylose, and glucose in hemicellulose and cellulose; minor components were galactose and mannose. The sugar content of each wall component per unit length was not correlated to any growth parameters calculated from a logistic equation simulating Coleoptile growth, but the relative contents of galactose and mannose in relation to the total wall sugar content was correlated to the growth rate on day 3 and the growth continuing period. These facts suggest that growth of these 12 barley strains in the late growth stage is regulated by the minor wall components, galactose and mannose
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auxin induced elongation growth and expressions of cell wall bound exo and endo β glucanases in barley Coleoptiles
Plant and Cell Physiology, 2000Co-Authors: Toshihisa Kotake, Naoki Nakagawa, Kazuyoshi Takeda, Naoki SakuraiAbstract:When auxin stimulates rapid cell elongation growth of cereal Coleoptiles, it causes a degradation of 1,3:1,4-beta-glucan in hemicellulosic polysaccharides. We examined gene expressions of endo-1,3:1,4-beta-glucanase (EI) and exo-beta-glucanase (ExoII), of which optimum pH are about 5, and molecular distribution of hemicellulosic polysaccharides in barley (Hordeum vulgare L.) Coleoptile segments treated with or without IAA. IAA (10(-5) M) stimulated the gene expression of EI, while it did not affect that of ExoII. IAA induced gene expression of EI after 4 h and increased wall-bound glucanase activity after 8 h. The molecular weight distribution of hemicellulosic polysaccharides from Coleoptile cell walls was shifted to lower molecular weight region by 2 h of IAA treatment. Fusicoccin (10(-6) M) mimicked IAA-induced elongation growth and the decrease in molecular weight of hemicellulosic 1,3:1,4-beta-glucan of Coleoptiles in the first 4 h, but it did not promote elongation growth thereafter. These facts suggest that acidification of barley cell walls by IAA action enhances pre-existing cell wall-bound glucanase activity in the early first phase of IAA-induced growth and the late second phase involves the gene expression of EI by IAA.