Eucalyptus grandis
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PROVIDER: PRJNA153359 | ENA |
REPOSITORIES: ENA
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Project description:The loss of rooting capability following the transition from the juvenile to the mature phase is a known phenomenon in woody plant development. Eucalyptus grandis was used here as a model system to study the differences in gene expression between juvenile and mature cuttings. RNA was prepared from the base of the two types of cuttings before root induction and hybridized to a DNA microarray of E. grandis. In juvenile cuttings, 363 transcripts were specifically upregulated, enriched in enzymes of oxidation/reduction processes. In contrast, in mature cuttings, 245 transcripts were specifically upregulated, enriched in transcription factors involved in the regulation of secondary metabolites. A gene encoding for nitrate reductase (NIA), an enzyme that is known to be involved in nitric oxide (NO) production, was among the genes that were upregulated in juvenile cuttings. Concomitantly, a transient burst of NO upon excision was higher in juvenile cuttings than in mature ones. Treatment with a NO donor improved rooting of both juvenile and mature cuttings. A single NIA gene was found in the newly released E. grandis genome sequence, the cDNA of which was isolated, overexpressed in Arabidopsis plants and shown to increase NO production. Therefore, higher levels of NIA in E. grandis juvenile cuttings might lead to their better ability to produce NO and form adventitious roots. The Arabidopsis transgenic plants did not exhibit significantly increased lateral or adventitious roots, suggesting that spatial and temporal rather than a constitutive increase in NO is favorable for root formation.
2012-10-16 | GSE36317 | GEO
Project description:The loss of rooting capability following the transition from the juvenile to the mature phase is a known phenomenon in woody plant development. Eucalyptus grandis was used here as a model system to study the differences in gene expression between juvenile and mature cuttings. RNA was prepared from the base of the two types of cuttings before root induction and hybridized to a DNA microarray of E. grandis. In juvenile cuttings, 363 transcripts were specifically upregulated, enriched in enzymes of oxidation/reduction processes. In contrast, in mature cuttings, 245 transcripts were specifically upregulated, enriched in transcription factors involved in the regulation of secondary metabolites. A gene encoding for nitrate reductase (NIA), an enzyme that is known to be involved in nitric oxide (NO) production, was among the genes that were upregulated in juvenile cuttings. Concomitantly, a transient burst of NO upon excision was higher in juvenile cuttings than in mature ones. Treatment with a NO donor improved rooting of both juvenile and mature cuttings. A single NIA gene was found in the newly released E. grandis genome sequence, the cDNA of which was isolated, overexpressed in Arabidopsis plants and shown to increase NO production. Therefore, higher levels of NIA in E. grandis juvenile cuttings might lead to their better ability to produce NO and form adventitious roots. The Arabidopsis transgenic plants did not exhibit significantly increased lateral or adventitious roots, suggesting that spatial and temporal rather than a constitutive increase in NO is favorable for root formation. E. grandis seedlings were grown from seeds to the age of 6-7 months. The seedlings were pruned either at 10-15 cm or at 150-200 cm above the ground. The newly developed shoots were used as cuttings. To induce rooting, auxin (6000 ppm of K-IBA), was applied by quick dipping (20 sec). Stem cuttings taken from low-pruned seedlings were found to be easy-to root, exhibiting 45% rooting after 14 days and 60% after 35 days. These cuttings were defined as juvenile (RNA from two biological replicates was extracted). In contrast, stem cuttings taken from high pruned seedlings, barely rooted (5%) after 35 days, and were defined as mature (RNA from two biological replicates was extracted). The two biological replicates was used to dye swap experimental design.
2012-10-16 | E-GEOD-36317 | biostudies-arrayexpress
Project description:Rooting capability is one of the economically traits lost during the juvenile to mature phase change in woody plants. A comprehensive microarray analysis was performed to compare the profiles of gene expression in juvenile and mature cuttings from E. grandis, either auxin treated or untreated on days, 0, 1, 3, 6, 9 and 12 post excision. At the end of the experiment, root primordia were observed only in auxin treated juvenile cuttings. Clustering the expression profiles revealed that the time after excision contributed to expression differences more than the age or auxin. Maximum differences contributed by the age and auxin occurred on day 6 which correlated with the kinetics of root primordia formation. These included genes related to the microtubules (MTs) system. Therefore, expression of 42 transcripts annotated as tubulin or MTs associated proteins (MAPs) was validated in the same RNA samples. The results suggest developmental and auxin regulation of MTs. To determine the relevance to adventitious root (AR) formation, subtle perturbations to MTs were performed with trifluralin during induction. While juvenile cuttings were not affected, improved rooting was obtained in mature cuttings. Taken together it suggests that specific MTs remodeling is required for AR formation in E. grandis.
2015-05-01 | GSE57375 | GEO
Project description:Background: The change from juvenile to mature phase in woody plants is often accompanied by a gradual loss of rooting ability, as well as by reduced microRNA (miR) 156 and increased miR172 expression. Results: We characterized the population of miRNAs of Eucalyptus grandis and compared by Northern blot the gradual reduction in miR156 and increase in miR172 expression during development to the loss of rooting ability. Forty known and eight novel miRNAs were discovered and their predicted targets are listed. The expression pattern of nine miRNAs was determined during adventitious root formation in juvenile and mature cuttings. While the expression levels of miR156 and miR172 were inverse in juvenile and mature tissues, no mutual relationship was found between high miR156 expression and rooting ability, or high miR172 expression and loss of rooting ability. This is shown both in E. grandis and also in E. brachyphylla, in which explants that underwent rejuvenation in tissue culture conditions were also examined. Conclusions: It is suggested that in these Eucalyptus species, there is no correlation between the switch of miR156 with miR172 expression in the stems and the loss of rooting ability. Examination of microRNA in seedlings of Eucalyptus grandis
2014-10-01 | E-GEOD-58367 | biostudies-arrayexpress
Project description:Rooting capability is one of the economically traits lost during the juvenile to mature phase change in woody plants. A comprehensive microarray analysis was performed to compare the profiles of gene expression in juvenile and mature cuttings from E. grandis, either auxin treated or untreated on days, 0, 1, 3, 6, 9 and 12 post excision. At the end of the experiment, root primordia were observed only in auxin treated juvenile cuttings. Clustering the expression profiles revealed that the time after excision contributed to expression differences more than the age or auxin. Maximum differences contributed by the age and auxin occurred on day 6 which correlated with the kinetics of root primordia formation. These included genes related to the microtubules (MTs) system. Therefore, expression of 42 transcripts annotated as tubulin or MTs associated proteins (MAPs) was validated in the same RNA samples. The results suggest developmental and auxin regulation of MTs. To determine the relevance to adventitious root (AR) formation, subtle perturbations to MTs were performed with trifluralin during induction. While juvenile cuttings were not affected, improved rooting was obtained in mature cuttings. Taken together it suggests that specific MTs remodeling is required for AR formation in E. grandis. mRNA samlpes from mature and juvenile Eucalyptus sections immediately after cutting served as contorls. The rest of the samples were mature and juvenile sections, treated of not treated with Auxin, 1, 3, 6, 9 and 12 days after the prunning. At each time point, a loop design was performed consisting of a juvenile untreated vs. mature untreated array, a matrue untreated vs. mature auxin treated array, a matrue auxin treated vs. juvenile auxin treated array, and a juvenile auxin treated vs. juvenile untreated array. additional arrays connected between these loops, and between them and the time 0 controls. Most conditions had 3 replicates, but mature-untreated-day1 had 4 replicates, and three conditions had 2 replicates each: Juvenile-auxin-treated-day1, juvenile-untreated-day6, and mature-auxin-treated-day9.
2015-05-01 | E-GEOD-57375 | biostudies-arrayexpress
Project description:Background: The change from juvenile to mature phase in woody plants is often accompanied by a gradual loss of rooting ability, as well as by reduced microRNA (miR) 156 and increased miR172 expression. Results: We characterized the population of miRNAs of Eucalyptus grandis and compared by Northern blot the gradual reduction in miR156 and increase in miR172 expression during development to the loss of rooting ability. Forty known and eight novel miRNAs were discovered and their predicted targets are listed. The expression pattern of nine miRNAs was determined during adventitious root formation in juvenile and mature cuttings. While the expression levels of miR156 and miR172 were inverse in juvenile and mature tissues, no mutual relationship was found between high miR156 expression and rooting ability, or high miR172 expression and loss of rooting ability. This is shown both in E. grandis and also in E. brachyphylla, in which explants that underwent rejuvenation in tissue culture conditions were also examined. Conclusions: It is suggested that in these Eucalyptus species, there is no correlation between the switch of miR156 with miR172 expression in the stems and the loss of rooting ability.
2014-10-01 | GSE58367 | GEO
Project description:The gene expression profiles of the differentiating xylem of 91 Eucalyptus grandis backcross individuals were characterized following a loop design (Churchill, G.A. Nat Genet. 2002 Dec;32 Suppl:490-5). In this design, RNA from genotype 1666 (labeled with Cy5) was hybridized with RNA from genotype 1667 (labeled with Cy3) on the first slide(GEO accession number GSM7637); the same genotype 1667 (now labeled with Cy5) was compared with genotype 1669 (Cy3) on the second slide (GSM7638), and so on. The loop was completed when genotype 1666 (Cy3) was contrasted to individual 1796 (Cy3) on slide GSM7727. Therefore, 91 individuals (genotypes) from the E. grandis backcross population were analyzed in two replicates, one with RNA labeled with Cy3 and the other with Cy5. Keywords = Eucalyptus, xylem, microarray Keywords: ordered
2003-07-16 | GSE502 | GEO
Project description:The gene expression profiles of the differentiating xylem of 91 Eucalyptus grandis backcross individuals were characterized following a loop design (Churchill, G.A. Nat Genet. 2002 Dec;32 Suppl:490-5). In this design, RNA from genotype 1666 (labeled with Cy5) was hybridized with RNA from genotype 1667 (labeled with Cy3) on the first slide(GEO accession number GSM7637); the same genotype 1667 (now labeled with Cy5) was compared with genotype 1669 (Cy3) on the second slide (GSM7638), and so on. The loop was completed when genotype 1666 (Cy3) was contrasted to individual 1796 (Cy3) on slide GSM7727. Therefore, 91 individuals (genotypes) from the E. grandis backcross population were analyzed in two replicates, one with RNA labeled with Cy3 and the other with Cy5. Keywords = Eucalyptus, xylem, microarray
2010-06-05 | E-GEOD-502 | biostudies-arrayexpress
Project description:In order to pinpoint the most differentially expressed genes between Eucalyptus grandis leaf blades and vascular (xylem) tissues as well as between E. grandis and Eucalyptus globulus xylem tissues, a total number of nine 50mer-oligoprobes covering the length of each one of 21,432 unique sequences derived from the Genolyptus EST dataset were synthesized “on-chip” in duplicate, randomly distributed in two blocks of each slide. Probes were also synthesized from ten cDNA sequences encoding known human proteins as negative controls, totaling 21,442 sequences. Leaves and xylem samples were taken from two E. grandis clonal trees, i.e., both derived from the same matrix tree and harboring the same genotype. Two additional xylem samples were collected from two other E. grandis clonal trees of a different genotype, as well as from two E. globulus clonal trees. Therefore, ten cDNA samples and ten identical chips were produced at Roche NimbleGen for the microarray assays, with a total number of 385,956 features per slide. Besides the discovery of differentially expressed genes between leaf and xylem, we wanted to test the validity of the assumed “technical” and “biological duplicates” since all trees were field-grown and four years-old in age.
2011-12-31 | GSE31696 | GEO
Project description:Background: Eucalyptus species and interspecific hybrids exhibit valuable growth and wood properties that make them a highly desirable commodity. However, these trees are challenged by a wide array of biotic stresses during their lifetimes. The Eucalyptus grandis reference genome sequence provides a resource to study pest and pathogen defence mechanisms in long-lived woody plants. E. grandis trees are generally susceptible to Chrysoporthe austroafricana, a causal agent of stem cankers on eucalypts. The aim of this study was to characterize the defence response of E. grandis against C. austroafricana. Results: Hormone profiling of susceptible and moderately resistant clonal E. grandis genotypes indicated a reduction in salicylic acid and gibberellic acid levels at 3 days post inoculation. We hypothesized that these signaling pathways may facilitate resistance. To further investigate other defence mechanisms at this time point, transcriptome profiling was performed. This revealed that cell wall modifications and response to oxidative stress form part of the defence responses common to both genotypes, whilst changes in the hormone signaling pathways may contribute to resistance. Additionally the expression of selected candidate defence response genes was induced earlier in moderately resistant trees than in susceptible trees, supporting the hypothesis that a delayed defence response may occur in the susceptible interaction. Conclusion: The ability of a host to fine-tune its defence responses is crucial and the responses identified in this study extends our understanding of plant defence, gained from model systems, to woody perennials.
2015-04-03 | GSE67554 | GEO