Shoot tip tissue: Tall Mokka vs Typica.
Ontology highlight
ABSTRACT:
ORGANISM(S): Coffea arabica
SUBMITTER: Ratnesh Singh
PROVIDER: E-GEOD-31179 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The closely related Coffea arabica cultivars ‘Tall Mokka’ and ‘Typica’, with excellent flavor, but differing distinctively in the size of aerial organs, branching pattern and branch numbers. Differential gene expression analysis of shoot tips of arabica coffee cultivars 'Tall Mokka' and 'Typica' were done using Potato cDNA microarray as cross-species platform. Using cross-species microarray hybridization, we identified a prolyl oligopeptidase (CaPOP) gene as differentially expressed between the shoot tips of ‘Tall Mokka’ and ‘Typica’. Isolation and sequencing of POP genes from coffee identified three paralogs, CaPOP1, CaPOP2 and CaPOP3. All three genes were present in both cultivars, which suggest that differences in the expression of CaPOP are caused by factor(s) regulating the transcription of CaPOPs. CaPOP1 differs in sequence from CaPOP2 primarily in having two large deletions in the promoter region. CaPOP genes are homologous to arabidopsis At1g20380, encoding a post-proline cleaving enzyme that acts on substrates shorter than 30 amino acids. Ectopic expression of CaPOP1 under its native promoter in transgenic arabidopsis resulted in more secondary branches than in the wild type. This is the first study to successfully isolate CaPOP genes and characterize their expression in the developing tissues of coffee. This study also identified a novel role for prolyl oligopeptidase in control of branching.
2011-08-04 | GSE31179 | GEO
Project description:Multiple transcription factors regulate B cell commitment, which coordinates with myeloid–erythroid lineage differentiation. One such factor, NF-kB, has long been speculated to regulate early B cell development; however, this issue remains controversial. IKKa is required for splenic B cell maturation, but not for bone marrow (BM) B cell development. Here, we unexpectedly found defective BM B cell development and an increased myeloid–erythroid lineages in kinase-dead IKKa (KA/KA) knock-in mice. Markedly increased cytosolic p100, an NF-kB2 inhibitory form, and reduced nuclear NF-kB p65, RelB, p50, and p52, as well as IKKa, was observed in KA/KA splenic and BM B cells. Several B- and myeloid–erythroid-cell regulators, including Pax5, were deregulated in KA/KA BM B cells. Using fetal liver and BM congenic transplants, and IKKa deletion from early hematopoietic cells in mice, this defect was identified as B cell intrinsic and as an early event during hematopoiesis. Re-expression of IKKa, Pax5, or combined NF-kB molecules promoted B cell development, but repressed myeloid–erythroid cell differentiation in KA/KA BM B cells. Together, these results demonstrate that IKKa regulates B-lineage commitment via combined canonical and noncanonical NF-kB transcriptional activity to target Pax5 expression during hematopoiesis.
2011-07-02 | GSE30363 | GEO
Project description:IKKa, a major regulator of noncanonical and canonical NF-kB pathways, is essential for B-lymphocyte maturation and secondary lymph organ formation. No evidence of IKKa regulating early B cell development currently exists. Here we found reduced pre-pro-B and pro-B cells but increased myeloid-erythroid lineages in the bone marrow (BM) of knockin mice expressing reduced and kinase-dead IKKa (KA/KA). The KA/KA BM cells recaptured their defects in wild-type recipients and KA/KA fetal liver displayed reduced B cells but increased progenitors. IKKa inactivation impaired both NF-kB pathways and deregulated expression of many genes required for early B cell commitment and hematopoiesis, including downregulated Pax5, IRF4, and Ikaros expression, but increased C/EBPa, GATA1, and Stat3 levels. Reintroduced combined NF-kB components, Pax5, and IKKa promoted BM B cell differentiation and repressed myeloid-erythroid lineages. Our studies revealed a new function of IKKa in a coordinated development process of B-lineage and erythroid-myeloid lineages during hematopoiesis via multiple pathways. Microarray analysis was performed on RNA isolated from the BM of B220+ cells isolated from 4-week old WT and KA/KA mice using affymetrix mouse 430 2.0 array chip, containing 45,000 genes, at the Laboratory of Molecular Technology SAIC-Frederick. Data were normalized, and log2 transformations were generated using Partek software (St. Louis, MO, USA).
2011-07-02 | E-GEOD-30363 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 μmol mol-1 h and in 2006 69.0 μmol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and five dye-swaps for each of sun and shade leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios.
2011-10-20 | E-GEOD-17413 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 μmol mol-1 h and in 2006 69.0 μmol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and five dye-swaps for each of sun and shade leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios.
2011-10-20 | E-GEOD-17411 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 μmol mol-1 h and in 2006 69.0 μmol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and two dye-swaps for shade leaves, and three microarrays and two dye-swaps for sun leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios.
2011-10-20 | E-GEOD-17419 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 μmol mol-1 h and in 2006 69.0 μmol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and five dye-swaps for each of sun and shade leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios.
2011-10-20 | E-GEOD-17418 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 μmol mol-1 h and in 2006 69.0 μmol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and five dye-swaps for each of sun and shade leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios.
2011-10-20 | E-GEOD-17417 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 ?mol mol-1 h and in 2006 69.0 ?mol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and five dye-swaps for each of sun and shade leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios. The following Sample is missing from this submission: Sun leaves, rep.5 (non-dye-swap)
2011-10-20 | E-GEOD-17414 | biostudies-arrayexpress
Project description:Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavarian). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA-levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two additional transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. The study was carried out at the Kranzberger Forst research site (near Freising, Germany: 48°25’08’’N, 11°39’41’””E, 485m (Pretzsch et al., 1998) in a mixed 60-year old stand (closed canopy) with about 30m high European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. Free-air ozone fumigation started in May 2000 at double the ambient ozone concentrations with a cut-off at 150 nl l-1 (Werner and Fabian, 2002), thereby avoiding acute damage to the leaves. The ozone concentrations were measured at four heights within the fumigated space and were additionally monitored with 200 passive samplers (Werner and Fabian, 2002). In 2005 the AOT40 value under twice ambient ozone was 64.3 μmol mol-1 h and in 2006 69.0 μmol mol-1 h. Detailed ozone concentration data over the growing seasons have been reported elsewhere (Gielen et al., 2007; Kitao et al., 2009). Sun and shade leaves from 60-year-old European beech trees were harvested in a total of 8 sampling campaigns in 2005 and 2006. Using scaffolding, five leaves of sun crown (height of about 25 m) and five shade (height of about 19 m) leaves were taken from each of five control and ozone-treated trees. The sampling was carried out in May, June, August, and September of 2005 and in June, August, September and October of 2006. To avoid diurnal effects, the samples were always taken around 11 a.m. For each tree, the four leaves (sun or shade) were combined, frozen in liquid nitrogen and stored at -80 °C until RNA isolation. For one time point we had five microarrays and five dye-swaps for each of sun and shade leaves. The probes of the trees under ambient ozone were labelled with Cy3 and probes of the trees under 2x ambient were labelled with Cy5. For every pair of trees a dye control were carried out, where the control trees were labelled with Cy5 and the ozone-treated one with Cy3. For statistical analysis a coefficient of variation about all microarrays of one time point was calculated using Acuity 4.0 microarray informatics software [Axon Instruments]. We used only those spots that had a coefficient of variation < 50 and were present on at least half of identical slides. The ozone-changed transcript level of genes were expressed in the median values as log2 ratios. The following Samples are missing from this submission: Sun leaves, rep.2 (non-dye-swap) Sun leaves, rep.2 (dye-swap) Sun leaves, rep.3 (non-dye-swap) Sun leaves, rep.4 (non-dye-swap)
2011-10-20 | E-GEOD-17416 | biostudies-arrayexpress