Epoxycarotenoid cleavage by NCED5 fine-tunes ABA accumulation and affects seed dormancy and drought tolerance with other NCED family members

Carotenoid cleavage, catalyzed by the 9-cis-epoxycarotenoid dioxygenase (NCED) constitutes a key step in the regulation of ABA biosynthesis. In Arabidopsis, this enzyme is encoded by five genes. NCED3 has been shown to play a major role in the regulation of ABA synthesis in response to water deficit, whereas NCED6 and NCED9 have been shown to be essential for the ABA production in the embryo and endosperm that imposes dormancy. Reporter gene analysis was carried out to determine the spatiotemporal pattern of NCED5 and NCED9 gene expression. GUS activity from the NCED5 promoter was detected in both the embryo and endosperm of developing seeds with maximal staining after mid-development. NCED9 expression was found at early stages in the testa outer integument layer 1, and after mid-development in epidermal cells of the embryo, but not in the endosperm. In accordance with its temporal- and tissue-specific expression, the phenotypic analysis of nced5 nced6 nced9 triple mutant showed the involvement of the NCED5 gene, together with NCED6 and NCED9, in the induction of seed dormancy. In contrast to nced6 and nced9, however, nced5 mutation did not affect the gibberellin required for germination. In vegetative tissues, combining nced5 and nced3 mutations reduced vegetative growth, increased water loss upon dehydration, and decreased ABA levels under both normal and stressed conditions, as compared with nced3. NCED5 thus contributes, together with NCED3, to ABA production affecting plant growth and water stress tolerance.     

Quantitative detection of methylated SOCS-1, a tumor suppressor gene, by a modified protocol of quantitative real time methylation-specific PCR using SYBR green and its use in early gastric cancer detection

Although methylation-specific PCR (MSP) is a sensitive technique in the detection of DNA hypermethylation, it is not quantitative. Here we described a modified PCR protocol to quantify methylated SOCS-1 gene by real time MSP using SYBR green, which involves an additional PCR step after the 72 degrees C extension step. This modified protocol is also useful in the quantitative detection of methylated SOCS-1 gene in serum samples of gastric cancer patients.     

Physical mapping of three fruit ripening genes：Endopolygalacturonase,ACC oxidase and ACC synthase from apple（Malus x domestica） in an apple rootstock A106（Malus sieboldii

The apple rootstock,A106(Malus sieboldii),had 17 bivalents in pollen mother cells at meiotic metaphase 1,and 17 chromosomes in a haploid pollen cell.Karyotypes were prepared from root-tip cells with 2n=34 chromosomes,Seven out of 82 karyotypes(8.5%) showed one pari of satellites at the end of the short arm of chromosome 3.C-bands were shown on 6 pairs of chromosomes 2,4,6,8,14,and 16 near the telomeric regions of short arms.Probes for three ripening-related genes from Malus x domestica:endopolygalacturonase(EPG,0.6kb),ACC oxidase(1.2kb),and ACC synthase(2kb)were hybridized in situ to metaphase chromosomes of A106.Hybridization sites for the EPG gene were observed on the long arm of chromosome 14 in 15 out of 16 replicate spreads and proximal to the centromere of chromosomes 6 and 11.For the ACC oxidase gene,hylridization sites were observed in the telomeric region of the short arm of chromosomes 5 and 11 in 87% and 81% of 16 spreads respectively,proxiaml to the centromere of chromosome 1 in 81% of the spreads,and on the long arm of chromosome 13 in 50% of the spreads. Physical mapping of three fruit ripening genes in an apple rootstock A106.Twenty five spreads were studied for the ACC synthase gene and hybridization sites were observed in the telomeric region of the short arm of chromosome 12 in 96% of the spreads.chromosomes 9 and 10 in 76% of the spreads,and chromosome 17 in 56% of the spreads.     

Comparison of the Morphology Development of Polymer–Fullerene and Polymer–Polymer Solar Cells during Solution‐Shearing Blade Coating

In this work, the detailed morphology studies of polymer poly(3‐hexylthiophene‐2,5‐diyl) (P3HT):fullerene(PCBM) and polymer(P3HT):polymer naphthalene diimide thiophene (PNDIT) solar cell are presented to understand the challenge for getting high performance all‐polymer solar cells. The in situ X‐ray scattering and optical interferometry and ex situ hard and soft X‐ray scattering and imaging techniques are used to characterize the bulk heterojunction (BHJ) ink during drying and in dried state. The crystallization of P3HT polymers in P3HT:PCBM bulk heterojunction shows very different behavior compared to that of P3HT:PNDIT BHJ due to different mobilities of P3HT in the donor:acceptor glass. Supplemented by the ex situ grazing incidence X‐ray diffraction and soft X‐ray scattering, PNDIT has a lower tendency to form a mixed phase with P3HT than PCBM, which may be the key to inhibit the donor polymer crystallization process, thus creating preferred small phase separation between the donor and acceptor polymer.     

Isolation and characterization of streptomycin-resistant mutants in Nicotiana plumbaginifolia

Summary Streptomycin-resistant colonies were isolated from protoplast cultures of haploid Nicotiana plumbaginifolia based on their ability to green in medium containing 1 mg/ml streptomycin sulfate. The frequency of resistant colonies was 0.9×10^–5 in nonmutagenized culture, and increased ten-fold following treatment of culture with 10 g/ml N-methyl-N-nitro-N-nitrosoguanidine. Of a total of 52 resistant clones isolated, 2 gave rise to haploid, 15 to diploid, and 3 to tetraploid plants upon transfer of calli to differentiation medium. Leaf-segment and protoplast assays showed that all diploid regenerates were resistant to streptomycin but sensitive to chloramphenicol, kanamycin, lincomycin, neomycin, and spectinomycin. Plants in most diploid clones were fertile and able to set seeds when self-fertilized and crossed reciprocally to wild-type plants. Inheritance of streptomycin resistance was studied in the diploid clones and, without exception, the resistance was transmitted maternally. Comparative studies of the ultrastructure of organelles and protein synthesis in isolated chloroplasts between wild-type and resistant clones in the presence of streptomycin suggest that streptomycin resistance is controlled by chloroplasts.     

Multi-proxy analysis of waterlogged preserved Late Neolithic canine excrements

Vegetation History and Archaeobotany - Multi-proxy analysis of the coprolites which were found during excavations at two Late Neolithic (fourth millennium bc) pile-dwelling sites (Črnelnik and...     

Introduction and expression of foreign DNA in isolated spinach chloroplasts by electroporation

An electroporation-mediated method for the study of foreign gene expression within chloroplasts has been developed. The chloroplast expression vector pHD203-GUS, which consists of coding regions for β-glucuronidase (GUS) and chloramphenicol acetyltransferase (CAT) separated by a double psbA promoter fragment from pea (in opposite orientation) was electroporated into spinach chloroplasts and the transient gene expression was examined. Conditions for the expression of the reporter genes have been optimized. Both CAT and GUS activities were detected in chloroplasts electroporated with pHD203-GUS, but not with nuclear expression vector pBI221 or negative control pUC18. No GUS activity was detected when pHD203-GUS was electroporated into spinach protoplasts. Dot immunoblot analysis using anti-GUS antibody confirmed the existence of GUS protein in chloroplasts electroporated with chloroplast-specific vector but not the negative controls, excluding the possibilities of endogenous GUS or bacterial contamination. The expression of GUS protein in treated chloroplasts was further confirmed by Western blot analysis.