Search Results - (Author, Cooperation:T. H. Ho)

2016-03-05

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-10-24

Nature Publishing Group (NPG)

2158-3188

Medicine

2018-06-30

The American Society for Microbiology (ASM)

0022-538X

1098-5514

Medicine

2018-11-02

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Modern-day plants are subjected to various biotic and abiotic stresses thereby limiting plant productivity and quality. It has previously been reported that the use of a strong constitutive 35S cauliflower mosaic virus (CaMV) promoter to drive the expression of Arabidopsis CBF1 in tomato improved tolerance to cold, drought and salt loading, at the expense of growth and yield under normal growth conditions. Hence in the present study, the suitability of expressing the Arabidopsis CBF1 driven by three copies of an ABA-responsive complex (ABRC1) from the barley HAV22 gene in order to improve the agronomic performance of the transgenic tomato plants was investigated. Northern blot analysis indicated that CBF1 gene expression was induced by chilling, water-deficit and salt treatment in the transgenic tomato plants. Under these tested stress conditions, transgenic tomato plants exhibited enhanced tolerance to chilling, water-deficit, and salt stress in comparison with untransformed plants. Under normal growing conditions the ABRC1-CBF1 tomato plants maintained normal growth and yield similar to the untransformed plants. The results demonstrate the promise of using ABRC1-CBF1 tomato plants in highly stressed conditions which will in turn benefit agriculture.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Abstract. A monoclonal antibody prepared against barley (Hordeum vulgare L., cv. Himalaya) nuclease (EC 3.1.30.2) was characterized with solid-state enzyme-linked immunosorbent assays and immuno-blotting. The antibody was specific for intracellular and secreted nuclease. Hormonal regulation of the synthesis and secretion of nuclease in isolated aleurone layers was investigated by immunoprecipitation of biosynthetically-labelled nuclease using polyclonal antibodies and by immunoblot analyses using the monoclonal antibody, respectively. Gibberellic acid (GA3) induced the de novo synthesis and secretion of nuclease in a time-and concentration-dependent manner. Nuclease was detected in aleurone layers incubated in 1 mmol m−3 GA3, after 24 h. The maximum rates of nuclease synthesis and secretion occurred 36–48 h after hormone treatment. A minimum concentration of 10−6 mol m−3 GA3 was required for nuclease synthesis and secretion, whereas the maximum rate of nuclease secretion occurred at concentrations of 10−5 mol m−3 and higher. In the presence of abscisic acid, the synthesis and secretion of nuclease from GA3-treated aleurone layers was almost completely inhibited. Based on these findings, the authors conclude that all nuclease within and secreted from aleurone layers treated with GA3 is the result of its de novo synthesis.

Electronic Resource

1399-3054

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The intracellular localization of an endonuclease (nuclease I) in barley aleurone responding to gibberellic acid was investigated by subcellular fractionation and immunocytochemistry with monoclonal and polyclonal antibodies. Organelle separations were performed with aleurone layers and protoplasts; immunefixations were carried out on protoplasts only. Nuclease was detected in fractions from isopycnic sucrose density gradients which were enriched in either endoplasmic reticulum or Golgi apparatus membranes. These two organelles were also labelled by the indirect immunogold method on thin sections. Intensive labelling of protein and developing vacuoles was observed. Therefore, as noted in other plants nuclease in barley is essentially a vacuolar enzyme.

Electronic Resource

0370-2693

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0370-2693

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1573-5028

aleurone layer ; embryo ; gene expression ; gibberellin ; Hordeum vulgare ; thionin

Springer Online Journal Archives 1860-2000

Biology

Abstract Gibberellins are noted for their ability to induce expression of genes, such as α-amylase, in the aleurone layers of cereals. However, a number of mRNA species in the mature imbibed aleurone cell of barley, such as a storage globulin (Heck et al., Mol Gen Genet 239: 209–218 1993), are simultaneously and specifically repressed by gibberellin. In a continuing effort to understand this effect, we report cloning and characterization of two additional cDNAs from barley designated pHvGS-1 and pcHth3 that have high corresponding mRNA levels in the mature imbibed aleurone but are repressed 10-fold or more within 24 h of treatment with gibberellic acid (GA3). The extent of repression was concentration dependent and maximally effective at 10-6 M GA3. Repression was also noted in the constitutive gibberellin response mutant, slender, in the absence of exogenous GA3. The antagonistic phytohormone, abscisic acid, had no effect or was weakly inductive of the steady-state levels of these mRNAs. During development of the seed, repressible mRNAs are present to different degrees in the maturing aleurone layer and embryo, but not in the starchy endosperm. Some repressible mRNA persists in the mature dry aleurone layer, but is degraded during imbibition, replenished by de novo transcription, and maintained at high steady-state levels until GA3 is perceived. Preliminary investigation suggests that repression is at least partly due to destabilization of the mRNAs which have estimated half-lives of 12 h or greater in the absence of GA3. pcHth3 encodes a member of the γ-thionin gene family located on chromosome 7. pHvGS-1 corresponds to a gene on chromosome 3 of unknown function.

Electronic Resource

1617-4623

Barley ; Embryo ; Aleurone ; Storage globulin ; Gibberellin

Springer Online Journal Archives 1860-2000

Biology

Abstract We report identification of a 2189 by cDNA clone from barley corresponding to a single-copy gene, Beg1 (Barley embryo globulin), on chromosome 4, which encodes a storage globulin. In barley, the major protein reserve in the aleurone layer belongs to the 7S globulin class of proteins found in many seeds. Electrophoretically and antigenically similar proteins are present in the barley embryo. Accumulation of Beg1 mRNA was noted beginning 15–20 days post-anthesis in both the aleurone layer and embryo of the developing barley grain but not in the starchy endosperm. A high level of Beg1 mRNA is also present in the mature imbibed aleurones, which can be repressed by treatment with gibberellic acid. This repressive effect of gibberellin on the levels of Beg1 mRNA is confirmed in the gibberellin response-constitutive mutant, slender, whose aleurone layers do not accumulate Beg1 mRNA even in the absence of applied gibberellic acid. The deduced primary translation product of the Beg1 mRNA is a 637 amino acid (72 kDa) protein with homology to maize embryo globulin 1 (GLB1) and a partial sequence of a wheat 7S globulin. The internal amino acid sequence of BEG1 closely matches the N-terminal sequence of isolated barley aleurone globulin. Seven imperfect tandem repeats of 16 amino acids each are present near the N-terminus of BEG1, which conform to the consensus HGEGEREEEXGRGRGR, and contribute to the observed unusual amino acid composition of this protein. A second, distinct barley globulin gene, Beg2, which is homologous to maize Glb2, was detected by Northern and Southern analysis. Beg-2 and Beg1 are regulated differently which may indicate variation in storage or utilization properties among the barley globulins.

Electronic Resource