Project description:Waterlogging is a major abiotic stress causing oxygen depletion and carbon dioxide accumulation in the rhizosphere. Barley is more susceptible to waterlogging stress than other cereals. To gain a better understanding of the effect of waterlogging stress in barley, we carried out a genome-wide gene expression analysis in roots of Yerong and Deder2 barley genotypes under waterlogging and control (well-watered) conditions by RNA-Sequencing, using Illumina HiSeq™ 4000 platform.
Project description:NILs containing five parental lines, three wild barley genotypes ssp. spontaneum: HID 4 (A), Iraq; HID 64 (B), Turkey; and HID 369 (C), Israel, one ssp. agriocrithon: HID 382(D)) and cv. Morex (ssp. vulgare, USA). Purpose: Variant calling to identifie markers associated with a awn length QTL on the distal part of chromosome 7HL
Project description:Senescence is the last developmental phase of plant tissues, plant organs and, in the case of monocarpic senescence, entire plants. In monocarpic crops such as barley, it leads to massive remobilization of nitrogen (primarily from degradation of photosynthetic proteins) and other nutrients to developing seeds. Senescence has therefore a major impact on both yield and seed/grain quality. To further investigate this process, a proteomic comparison of flag leaves of late-senescing barley variety ‘Karl’ and a near-isogenic early-senescing line, ‘10_11’, was performed at 14 and 21 days past anthesis, using both two-dimensional gel-based and label-free quantitative mass spectrometry-based (‘shotgun’) proteomic techniques. Overall, this approach identified >9,000 barley proteins, and one-third of them were quantified. Analysis focused on proteins that were significantly (P-value ≤0.05; difference ≥1.5-fold) upregulated in early-senescing line ‘10_11’ as compared to ‘Karl’, as these may be functionally important for the senescence process. Many proteins in this group, including several membrane and intracellular receptors, glucanases, enzymes with possible roles in cuticle modification, classical pathogenesis-related proteins, membrane transporters and proteins involved in DNA repair, have likely or putative functions in plant pathogen defense. Additionally, several proteases and elements of the ubiquitin-proteasome system were upregulated in line ‘10_11’; these proteins may be involved in nitrogen remobilization, and in the regulation of both senescence and plant defense reactions. Together, our data shed new light, at the protein level, on the importance of plant defense reactions during senescence, on senescence regulation, and possibly on crosstalk between senescence regulation and plant-pathogen interaction.
Project description:Effect of high grain protein locus on barley grain protein accumulation. Gene expression levels were analysed in Karl, a low grain protein variety with its near-isogenic line 10_11(has high grain protein locus, chromosome 6)using Barley1 22k affymetrix chip. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Aravind Jukanti. The equivalent experiment is BB53 at PLEXdb.]
Project description:On average less than 1% of the total phosphorous present in soils is available to plants, making phosphorous one of the most limiting macronutrients for crop productivity worldwide. The aim of this work was to isolate and select phosphate solubilizing bacteria (PSB) from the barley rhizosphere, which has other growth promoting traits and can increase crop productivity. A total of 104 different bacterial isolates were extracted from the barley plant rhizosphere. In this case, 64 strains were able to solubilize phosphate in agar plates. The 24 strains exhibiting the highest solubilizing index belonged to 16 different species, of which 7 isolates were discarded since they were identified as putative phytopathogens. The remaining nine strains were tested for their ability to solubilize phosphate in liquid medium and in pot trials performed in a greenhouse. Several of the isolated strains (Advenella mimigardefordensis, Bacillus cereus, Bacillus megaterium and Burkholderia fungorum) were able to significantly improve levels of assimilated phosphate, dry weight of ears and total starch accumulated on ears compared to non-inoculated plants. Since these strains were able to increase the growth and productivity of barley crops, they could be potentially used as microbial inoculants (biofertilizers).
Project description:Gene expression in plastids of higher plants is dependent on two different transcription machineries, a plastid-encoded bacterial-type RNA polymerase (PEP) and a nuclear-encoded phage-type RNA polymerase (NEP), which recognize distinct types of promoters. The division of labor between PEP and NEP during plastid development and in mature chloroplasts is unclear due to a lack of comprehensive information on promoter usage. Here we present a thorough investigation into the distribution of PEP and NEP promoters within the plastid genome of barley (Hordeum vulgare L). Using a novel differential RNA sequencing approach, which discriminates between primary and processed transcripts, we obtained a genome-wide map of transcription start sites in plastids of mature first leaves. PEP-lacking plastids of the albostrians mutant allowed for the unambiguous identifications of NEP promoters. We observed that the chloroplast genome contains many more promoters than genes. According to our data, most genes (including genes coding for photosynthesis proteins) have both PEP and NEP promoters. We also detected numerous transcription start sites within operons indicating transcriptional uncoupling of genes in polycistronic gene clusters. Moreover, we mapped many transcription start sites in intergenic regions, as well as opposite to annotated genes demonstrating the existence of numerous non-coding RNA candidates.
Project description:The phytohormones auxin and cytokinin control development and maintenance of plant meristems and stem cell systems. Fluorescent protein reporter lines that monitor phytohormone controlled gene expression programmes have been widely used to study development and differentiation in the model species Arabidopsis, but equivalent tools are still missing for the majority of crop species. Barley (Hordeum vulgare) is the fourth most abundant cereal crop plant, but knowledge on these important phytohormones in regard to the barley root and shoot stem cell niches is still negligible. We have now analysed the role of auxin and cytokinin in barley root meristem development, and present fluorescent protein reporter lines that allow to dissect auxin and cytokinin signalling outputs in vivo. We found that application of either auxin or cytokinin to barley seedlings negatively impacts root meristem growth. We further established a barley cytokinin reporter, TCSnew, which revealed significant cytokinin signalling in the stele cells proximal to the QC, and in the differentiated root cap cells. Application of exogenous cytokinin activated signalling in the root stem cell niche. Commonly employed auxin reporters DR5 or DR5v2 failed to respond to auxin in barley. However, analysis of putative auxin signalling targets barley PLETHORA1 (HvPLT1) is expressed in a similar pattern as its orthologue AtPLT1 from Arabidopsis, i.e. in the QC and the surrounding cells. Furthermore, the PINFORMED1 (HvPIN1) auxin efflux carrier was found to be expressed in root and shoot meristems, where it polarly localized to the plasma membrane. HvPIN1 expression is negatively regulated by cytokinin and its intracellular localisation is sensitive to brefeldinA (BFA). With this study, we provide the first fluorescent reporter lines as a tool to study auxin and cytokinin signalling and response pathways in barley.
Project description:Gene expression in plastids of higher plants is dependent on two different transcription machineries, a plastid-encoded bacterial-type RNA polymerase (PEP) and a nuclear-encoded phage-type RNA polymerase (NEP), which recognize distinct types of promoters. The division of labor between PEP and NEP during plastid development and in mature chloroplasts is unclear due to a lack of comprehensive information on promoter usage. Here we present a thorough investigation into the distribution of PEP and NEP promoters within the plastid genome of barley (Hordeum vulgare L). Using a novel differential RNA sequencing approach, which discriminates between primary and processed transcripts, we obtained a genome-wide map of transcription start sites in plastids of mature first leaves. PEP-lacking plastids of the albostrians mutant allowed for the unambiguous identifications of NEP promoters. We observed that the chloroplast genome contains many more promoters than genes. According to our data, most genes (including genes coding for photosynthesis proteins) have both PEP and NEP promoters. We also detected numerous transcription start sites within operons indicating transcriptional uncoupling of genes in polycistronic gene clusters. Moreover, we mapped many transcription start sites in intergenic regions, as well as opposite to annotated genes demonstrating the existence of numerous non-coding RNA candidates. dRNA-seq analysis of total RNA from green and white plastids of the barley mutant line albostrians
Project description:The effect of elevated atmospheric CO2 concentration [CO2 ] on the diversity and composition of the prokaryotic community inhabiting the rhizosphere of winter barley (Hordeum vulgare L.) was investigated in a field experiment, using open-top chambers. Rhizosphere samples were collected at anthesis (flowering stage) from six chambers with ambient [CO2 ] (approximately 400 ppm) and six chambers with elevated [CO2 ] (700 ppm). The V4 region of the 16S rRNA gene was PCR-amplified from the extracted DNA and sequenced on an Illumina MiSeq instrument. Above-ground plant biomass was not affected by elevated [CO2 ] at anthesis, but plants exposed to elevated [CO2 ] had significantly higher grain yield. The composition of the rhizosphere prokaryotic communities was very similar under ambient and elevated [CO2 ]. The dominant taxa were Bacteroidetes, Actinobacteria, Alpha-, Gamma-, and Betaproteobacteria. Elevated [CO2 ] resulted in lower prokaryotic diversity in the rhizosphere, but did not cause a significant difference in community structure.