SEARCH · PubMed Health

Results for “lamina joint”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2000

Loss of function of a rice brassinosteroid insensitive1 homolog prevents internode elongation and bending of the lamina joint.

Brassinosteroids (BRs) are plant growth-promoting natural products required for plant growth and development. Physiological studies have demonstrated that exogenous BR, alone or in combination with auxin, enhance bending of the lamina joint of rice. However, little is known about the function of endogenous BR in rice or other grass species. We report here the phenotypical and molecular characterization of a rice dwarf mutant, d61, that is less sensitive to BR compared to the wild type. We cloned a rice gene, OsBRI1, with extensive sequence similarity to that of the Arabidopsis BRI gene, which encodes a putative BR receptor kinase. Linkage analysis showed that the OsBRI1 gene is closely linked to the d61 locus. Single nucleotide substitutions found at different sites of the d61 alleles would give rise to amino acid changes in the corresponding polypeptides. Furthermore, introduction of the entire OsBRI1 coding region, including the 5' and 3' flanking sequences, into d61 plants complemented the mutation to display the wild-type phenotype. Transgenic plants carrying the antisense strand of the OsBRI1 transcript showed similar or even more severe phenotypes than those of the d61 mutants. Our results show that OsBRI1 functions in various growth and developmental processes in rice, including (1) internode elongation, by inducing the formation of the intercalary meristem and the longitudinal elongation of internode cells; (2) bending of the lamina joint; and (3) skotomorphogenesis.

Amino Acid Sequence↗

PubMed2003

A proteomics approach to investigating promotive effects of brassinolide on lamina inclination and root growth in rice seedlings.

The application of brassinolide (BL) to the lamina joint region of rice (Oryza sativa L., cv. Nipponbare) seedlings caused marked bending of laminae, and BL influenced rice root growth under intact conditions. A remarkable increase in lamina inclination at BL 1 microM and an evident increase in root elongation at BL 0.01 microM were observed compared with the control. A total of 786 and 508 proteins extracted from the lamina joint and root, respectively, were detected in images of two-dimensional polyacrylamide gel electrophoresis with isoelectric focusing or immobilized pH gradient tube gel, and 21 proteins changed by BL treatment were analyzed using a gas-phase protein sequencer and mass spectrometer. Proteins related to photosynthesis and stress tolerance were mainly found in the lamina joint and root, respectively. Advanced degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) large subunit was caused by both BL and ethylene. Calmodulin, which decreased in roots treated with BL, increased as a result of ethephon treatment. Proteins that showed homology to glutathione S-transferase (EC 2.5.1.18) increased with BL application in both the lamina joint and root. The results suggest that the physiological functions of these proteins detected using powerful proteome analysis are implicated in rice lamina inclination and/or root elongation triggered by BL.

Brassinosteroids↗

PubMed1995

The relationship between isthmic and degenerative spondylolisthesis and the configuration of the lamina and facet joints.

Advanced degenerative change in the facet joints leads to displacement of the vertebral body, and the configuration of facet joints and lamina is closely related to the development of degenerative spondylolisthesis. For this study 103 patients and 25 controls were examined with respect to the configuration of the lamina, anteroposterior diameter of the vertebral canal, interarticular distance, interlaminar distance, disc degeneration, and degree of arthritic changes of facet joint, all as shown of plain radiography, and facet angle, interfacet distance, and contour of the canal side of the inferior articular process and lamina, as shown on computed axial tomography. The results of this study showed that those patients with a narrow facet angle were more likely to have developed degenerative spondylolisthesis. If the sum of both facet angles was less than 77.9 degree, the risk of development of degenerative spondylolisthesis was 2.5 times higher than if the sum was greater than 77.9 degree. Those with type N lamina, detected on plain radiographs, were especially likely to have developed degenerative spondylolisthesis. This suggested that degenerative spondylolisthesis may be due to the less effective check mechanism preventing a vertebra from slipping forward on the vertebra below. We recommend fusion of the degenerated spinal segments when operation is considered in cases of acute facet angle with symptoms.

Adult↗

PubMed2006

A brassinolide-suppressed rice MADS-box transcription factor, OsMDP1, has a negative regulatory role in BR signaling.

The MADS-box transcription factor-encoding genes are expressed mainly during plant reproductive development, where they play important roles in controlling floral organ initiation and identity. Few previous reports have investigated the functions of MADS-box transcription factors expressed in vegetative tissues. Here we describe the functional characterization of a rice AG-like MADS-box protein, OsMDP1 (Oryza sativa MADS-domain-containing protein 1). A partial cDNA encoding a MADS-box domain was identified via high-throughput screening of rice brassinolide-regulated genes, and the full-length cDNA was subsequently isolated via screening of a cDNA library constructed from rice materials at tillering stage. Expression pattern analyses indicated that OsMDP1 is transcribed mainly in vegetative tissues, including the mature leaf, coleoptile, root-elongation zone, culm internode, and especially the joint region between the leaf blade and sheath. Further studies revealed that transcription of OsMDP1 is stimulated by darkness and suppressed by brassinolide treatment. OsMDP1 deficiency resulted in shortened primary roots, elongated coleoptiles and enhanced lamina joint inclinations. Moreover, transgenic plants showed hypersensitivities to exogenous brassinolide in terms of lamina joint inclination and coleoptile elongation. OsMDP1 deficiency resulted in enhanced expression of OsXTR1, which encodes xyloglucan endotransglycosylase, the cell-wall loosening enzyme necessary for cell elongation, and modulated expressions of multiple genes involved in cell signalling and gene transcription, indicating the key negative regulatory role of OsMDP1 in BR signalling.

Amino Acid Sequence↗

PubMed2003

A novel brassinolide-enhanced gene identified by cDNA microarray is involved in the growth of rice.

Brassinosteroids (BRs) are growth-promoting natural substances required for normal plant growth and development. To understand the molecular mechanism of BR action, a cDNA microarray containing 1265 rice genes was analyzed for expression differences in rice lamina joint treated with brassinolide (BL). A novel BL-enhanced gene, designated OsBLE2, was identified and cloned. The full-length cDNA is 3243 bp long, encoding a predicted polypeptide of 761 amino acid residues and nine possible transmembrane regions. OsBLE2 expression was most responsive to BL in the lamina joint and leaf sheath in rice seedlings. Besides, auxin and gibberellins also increased its expression. OsBLE2 expressed more, as revealed by in situ hybridization, in vascular bundles and root primordia, where the cells are actively undergoing division, elongation, and differentiation. Transgenic rice expressing antisense OsBLE2 exhibits various degrees of repressed growth. BL could not enhance its expression in transgenic rice expressing antisense BRI1, a BR receptor, indicating that BR signaling to the enhanced expression of OsBLE2 is through BRI1 . BL effect in the d1 mutant rice was much weaker than that in its wild-type control, indicating that heterotrimeric G protein may be a component of BRs signaling. These results suggest that OsBLE2 is involved in BL-regulated growth and development processes in rice.

Amino Acid Sequence↗

PubMed2025

Rice ETHYLENE RESPONSE FACTOR 101 increases leaf angle by upregulating BRASSINOSTEROID UPREGULATED 1.

The leaf angle (LA) is a critical component of plant architecture that directly influences photosynthetic efficiency and grain yield. In the present study, we found that ETHYLENE RESPONSE FACTOR 101 (OsERF101), an APETALA2/ethylene response factor, plays a role in LA formation. A null mutation in OsERF101 resulted in reduced LA, whereas transgenic plants overexpressing OsERF101 (OsERF101-OEs) exhibited increased LA. OsERF101 increased the development of the adaxial lamina joint (LJ). Transactivation assays and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis indicated that OsERF101 activated BRASSINOSTEROID UPREGULATED 1 (OsBU1) transcription by directly binding to its promoter. However, OsERF101 expression was suppressed by exogenous brassinosteroid (BR) treatment and elevated endogenous brassinolide (BL) levels during LJ development. Additionally, OsERF101 downregulated the expression of BR biosynthesis genes, including Brassinosteroid-deficient dwarf2 (OsBRD2) and CYP90B2/OsDWARF4, leading to reduced levels of endogenous BL, the most active BR, in OsERF101-OEs. These findings suggested that OsERF101 mediates a negative feedback loop that balances endogenous BR levels and signaling. Collectively, rice plants have evolved diverse regulatory mechanisms involving OsERF101 to tune LA formation and optimize plant architecture finely.

Oryza↗

PubMed1989

The configuration of the laminas and facet joints in degenerative spondylolisthesis. A clinicoradiologic study.

The configuratory variation of laminas and facet joints was discussed with reference to development of degenerative spondylolisthesis and its clinical symptoms. The authors have classified the configuration of laminas in the lower lumbar spine into three different types, (WI, W2, and N), based on the two characteristic features of the lamina: 1) whether or not the inferior articular processes are wider than the waist part of the lamina, and 2) whether or not the facet joint spaces can be recognized on plain anteroposterior (AP) radiographs. Types W1 and W2 laminas have the laterally prominent inferior articular processes, but the facet joint spaces are not visible on AP view in Type W1. Type N lamina has narrow inferior articular processes and its facet joint spaces can be recognized on AP view. Computed tomography (CT) scanning revealed that the direction of facet joints of Types W2 and N laminas was more sagittal than that of Type W1, and that all of Type N laminas with the narrow inferior articular processes have a sagittal facet. Type N lamina was rarely seen in the 257 controls, but was quite frequent in degenerative spondylolisthesis, 3.5% and 45.8%, respectively. Patients with Type N laminas were likely to show more severe clinical symptoms such as difficulty walking and neurologic deficits.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed2004

Molecular cloning and characterization of a novel brassinolide enhanced gene OsBLE1 in Oryza sativa seedlings.

Brassinosteroids (BRs) are plant steroids essential for normal growth and development. To gain insight into the molecular mechanism by which BRs regulate the growth and development of plants, it is necessary to identify and analyze more genes that are regulated by BRs. A novel brassinolide (BL)-enhanced gene designated OsBLE1, which was originally identified by using rice (Oryza sativa L.) cDNA microarray, was cloned and characterized. Its cDNA is 598 bp long, encoding a predicted polypeptide with 81 amino acid residues. Northern blots analysis revealed that OsBLE1 expression began to increase at 6 h and reached its maximum at 12 h after BL treatment. OsBLE1 expression was most responsive to BL in lamina joint in rice seedlings; besides, IAA and GA3 also enhanced its expression. OsBLE1 expressed mainly in active tissues such as vascular bundles and root primordial. Transgenic rice expressing antisense OsBLE1 exhibits various degrees of repressed growth. Results suggest that OsBLE1 might be involved in BL-regulated growth processes in rice seedlings.

Amino Acid Sequence↗

PubMed2000

Xylem-specific expression of wound-inducible rice peroxidase genes in transgenic plants.

A peroxidase gene, poxA, was isolated from a rice (Oryza sativa L.) genomic library. The gene consists of four exons whose combined sequences were identical to that of the prxRPA mRNA whose levels were dramatically stimulated by wounding as well as by treatment of rice shoots with ethephon or UV irradiation [H. Ito, F. Kimizuka, A. Ohbayashi, H. Matsui, M. Honma, A. Shinmyo, Y. Ohashi, A.B. Caplan, R.L. Rodriguez, Molecular cloning and characterization of two complementary DNAs encoding putative peroxidases from rice (Oryza sativa L.) shoots, Plant Cell Rep. 13 (1994) 361-366]. The temporal and spatial expression properties of the poxA gene promoter as well as that from a second related peroxidase gene, poxN, were analyzed in transgenic tobacco and rice plants using the uidA gene as a reporter. In transgenic tobacco, UV- and wound-responsive cis-elements were located within 144 bp from the translational start codon of the poxA gene. The poxN promoter, however, was inactive in the heterologous host as no significant GUS activity was evident. On the other hand, chimeric uidA genes containing 2.2 kb of the poxA promoter or 1.4 kb of poxN promoter were active in transgenic rice plants. Both peroxidase promoters directed GUS activities in a spatial and tissue specific manner coincident with the expression patterns exhibited by their mRNAs. Histochemical analysis of transgenic rice plants showed that both peroxidase genes are expressed in the vascular bundles of the shoot apex and lamina joint, and in xylem-parenchyma cells of the leaf blade and sheath.

Journal Article↗

PubMed2003

The OsTB1 gene negatively regulates lateral branching in rice.

Although the shoot apical meristem (SAM) is ultimately responsible for post-embryonic development in higher plants, lateral meristems also play an important role in determining the final morphology of the above-ground part. Axillary buds developing at the axils of leaves produce additional shoot systems, lateral branches. The rice TB1 gene (OsTB1) was first identified based on its sequence similarity with maize TEOSINTE BRANCHED 1 (TB1), which is involved in lateral branching in maize. Both genes encode putative transcription factors carrying a basic helix-loop-helix type of DNA-binding motif, named the TCP domain. The genetic locus of OsTB1 suggested that OsTB1 is a real counterpart of maize TB1. Transgenic rice plants overexpressing OsTB1 exhibited markedly reduced lateral branching without the propagation of axillary buds being affected. We also demonstrated that a rice strain carrying a classical morphological marker mutation, fine culm 1 (fc1), contain the loss-of-function mutation of OsTB1 and exhibits enhanced lateral branching. Expression of OsTB1, as examined with a putative promoter-glucuronidase (GUS) gene fusion, was observed throughout the axillary bud, as well as the basal part of the shoot apical meristem, vascular tissues in the pith and the lamina joint. Taking these data together, we concluded that OsTB1 functions as a negative regulator for lateral branching in rice, presumably through expression in axillary buds.

Amino Acid Sequence↗

PubMed2003

LAX and SPA: major regulators of shoot branching in rice.

The aerial architecture of plants is determined primarily by the pattern of shoot branching. Although shoot apical meristem initiation during embryogenesis has been extensively studied by molecular genetic approaches using Arabidopsis, little is known about the genetic mechanisms controlling axillary meristem initiation, mainly because of the insufficient number of mutants that specifically alter it. We identified the LAX PANICLE (LAX) and SMALL PANICLE (SPA) genes as the main regulators of axillary meristem formation in rice. LAX encodes a basic helix-loop-helix transcription factor and is expressed in the boundary between the shoot apical meristem and the region of new meristem formation. This pattern of LAX expression was repeatedly observed in every axillary meristem, consistent with our observation that LAX is involved in the formation of all types of axillary meristems throughout the ontogeny of a rice plant. Ectopic LAX expression in rice caused pleiotropic effects, including dwarfing, an altered pattern of stem elongation, darker color, bending of the lamina joint, absence of the midribs of leaves, and severe sterility.

Amino Acid Sequence↗

PubMed2003

A rice brassinosteroid-deficient mutant, ebisu dwarf (d2), is caused by a loss of function of a new member of cytochrome P450.

We characterized a rice dwarf mutant, ebisu dwarf (d2). It showed the pleiotropic abnormal phenotype similar to that of the rice brassinosteroid (BR)-insensitive mutant, d61. The dwarf phenotype of d2 was rescued by exogenous brassinolide treatment. The accumulation profile of BR intermediates in the d2 mutants confirmed that these plants are deficient in late BR biosynthesis. We cloned the D2 gene by map-based cloning. The D2 gene encoded a novel cytochrome P450 classified in CYP90D that is highly similar to the reported BR synthesis enzymes. Introduction of the wild D2 gene into d2-1 rescued the abnormal phenotype of the mutants. In feeding experiments, 3-dehydro-6-deoxoteasterone, 3-dehydroteasterone, and brassinolide effectively caused the lamina joints of the d2 plants to bend, whereas more upstream compounds did not cause bending. Based on these results, we conclude that D2/CYP90D2 catalyzes the steps from 6-deoxoteasterone to 3-dehydro-6-deoxoteasterone and from teasterone to 3-dehydroteasterone in the late BR biosynthesis pathway.

Amino Acid Sequence↗

PubMed2005

A novel cytochrome P450 is implicated in brassinosteroid biosynthesis via the characterization of a rice dwarf mutant, dwarf11, with reduced seed length.

We have characterized a rice (Oryza sativa) dwarf mutant, dwarf11 (d11), that bears seeds of reduced length. To understand the mechanism by which seed length is regulated, the D11 gene was isolated by a map-based cloning method. The gene was found to encode a novel cytochrome P450 (CYP724B1), which showed homology to enzymes involved in brassinosteroid (BR) biosynthesis. The dwarf phenotype of d11 mutants was restored by the application of the brassinolide (BL). Compared with wild-type plants, the aberrant D11 mRNA accumulated at higher levels in d11 mutants and was dramatically reduced by treatment with BL, implying that the gene is feedback-regulated by BL. Precise determination of the defective step(s) in BR synthesis in d11 mutants proved intractable because of tissue specificity and the complex control of BR accumulation in plants. However, 6-deoxotyphasterol (6-DeoxoTY) and typhasterol (TY), but not any upstream intermediates before these compounds, effectively restored BR response in d11 mutants in a lamina joint bending assay. Multiple lines of evidence together suggest that the D11/CYP724B1 gene plays a role in BR synthesis and may be involved in the supply of 6-DeoxoTY and TY in the BR biosynthesis network in rice.

Amino Acid Sequence↗

PubMed2005

The Rice brassinosteroid-deficient dwarf2 mutant, defective in the rice homolog of Arabidopsis DIMINUTO/DWARF1, is rescued by the endogenously accumulated alternative bioactive brassinosteroid, dolichosterone.

We have identified a rice (Oryza sativa) brassinosteroid (BR)-deficient mutant, BR-deficient dwarf2 (brd2). The brd2 locus contains a single base deletion in the coding region of Dim/dwf1, a homolog of Arabidopsis thaliana DIMINUTO/DWARF1 (DIM/DWF1). Introduction of the wild-type Dim/dwf1 gene into brd2 restored the normal phenotype. Overproduction and repression of Dim/dwf1 resulted in contrasting phenotypes, with repressors mimicking the brd2 phenotype and overproducers having large stature with increased numbers of flowers and seeds. Although brd2 contains low levels of common 6-oxo-type BRs, the severity of the brd2 phenotype is much milder than brd1 mutants and most similar to d2 and d11, which show a semidwarf phenotype at the young seedling stage. Quantitative analysis suggested that in brd2, the 24-methylene BR biosynthesis pathway is activated and the uncommon BR, dolichosterone (DS), is produced. DS enhances the rice lamina joint bending angle, rescues the brd1 dwarf phenotype, and inhibits root elongation, indicating that DS is a bioactive BR in rice. Based on these observations, we discuss an alternative BR biosynthetic pathway that produces DS when Dim/dwf1 is defective.

Amino Acid Sequence↗

PubMed2006

The rice SPINDLY gene functions as a negative regulator of gibberellin signaling by controlling the suppressive function of the DELLA protein, SLR1, and modulating brassinosteroid synthesis.

SPINDLY (SPY) encodes an O-linked N-acetylglucosamine transferase that is considered to be a negative regulator of gibberellin (GA) signaling through an unknown mechanism. To understand the function of SPY in GA signaling in rice, we isolated a rice SPINDLY homolog (OsSPY) and produced knockdown transgenic plants in which OsSPY expression was reduced by introducing its antisense or RNAi construct. In knockdown plants, the enhanced elongation of lower internodes was correlated with decreased levels of OsSPY expression, similar to the spindly phenotype of Arabidopsis spy mutants, suggesting that OsSPY also functions as a negative factor in GA signaling in rice. The suppressive function of OsSPY in GA signaling was supported by the findings that the dwarfism was partially rescued and OsGA20ox2 (GA20 oxidase) expression was reduced in GA-deficient and GA-insensitive mutants by the knockdown of OsSPY function. The suppression of OsSPY function in a GA-insensitive mutant, gid2, also caused an increase in the phosphorylation of a rice DELLA protein, SLR1, but did not change the amount of SLR1. This indicates that the function of OsSPY in GA signaling is not via changes in the amount or stability of SLR1, but probably involves control of the suppressive function of SLR1. In addition to the GA-related phenotypes, OsSPY antisense and RNAi plants showed increased lamina joint bending, which is a brassinosteroid-related phenotype, indicating that OsSPY may play roles both in GA signaling and in the brassinosteroid pathway.

Amino Acid Sequence↗

PubMedDate not supplied

The orientation of laminae and facet joints in the lower lumbar spine.

The relationship between the angulation of the facet joints and that of the caudad parts of the corresponding laminae in the transverse plane was investigated with computed tomography (CT) at the vertebral levels L3-L4, L4-L5, and L5-S1. At the level of L3-L4, both the facet joints and the caudad portions of the laminae tend toward a sagittal orientation, while at L5-S1 this is more toward the frontal plane. At the level of L4-L5, they occupy an intermediate position. A highly significant correlation between the orientation of these structures is demonstrated. The caudad parts of the laminae may be considered buttresses for the inferior articular processes of the same vertebra.

Biomechanical Phenomena↗

PubMed1979

[Radiographical and anatomical studies on the pathogenesis of degenerative spondylolisthesis (author's transl)].

In order to elucidate the causes of degenerative spondylolisthesis (D.S), the functional role of lumbar intervertebral joints and also laminae of the vertebral arch was studied by means of roentgenographic and also pathological exams. The inclination of the laminae of the vertebral arch and the intervertebral joints changed with age in accordance with statokinetic loading of the lumbar spine. In the group with increased lumbar lordosis at the upper level, movement of the 3rd and 4th lumbar vertebrae was great, accompanied by horizontal inclination of the laminae of the vertebral arch and the intervertebral joints and by osteoarthritic changes (O.A). This is similar to D.S. D.S is caused by abnormal spinal curvature and structural specificity of the lower limbs vertebrae, resulting in degeneration of the laminae of the vertebral arch and the intervertebral joints, changes in the inclination, decreased control of movement, and sliding of the vertebrae. Prodromal conditions resulting in the sliding of the vertebrae and in disc degeneration appear to be caused by D.S.

Adolescent↗

PubMed2006

Biomechanical analysis of cages for posterior lumbar interbody fusion.

Interbody fusions using intervertebral cages have become increasingly common in spinal surgery. Computational simulations were conducted in order to compare different cage designs in terms of their biomechanical interaction with the spinal structures. Differences in cage design and surgical technique may significantly affect the biomechanics of the fused spine segment, but little knowledge is available on this topic. In the present study, four 3D finite element models were developed, reproducing the human L4-L5 spinal unit in intact condition and after implantation of three different cage models. The intact model consisted of two vertebral bodies and relevant laminae, facet joints, main ligaments and disc. The instrumented models reproduced the post-operative conditions resulting after implant of the different cages. The three considered devices were hollow threaded titanium cages, the BAK (Zimmer Centerpulse, Warsaw, IN, USA), the Interfix and the Interfix Fly (both by Medtronic Sofamor Danek, Memphis, TN, USA). Simulations were run imposing various loading conditions, under a constant compressive preload. A great increase in the stiffness induced on the spinal segment by all cages was observed in all the considered loading cases. Stress distributions on the bony surface were evaluated and discussed. The differences observed between the biomechanics of the instrumented models were associated with the geometrical and surgical features of the devices.

Biomechanical Phenomena↗