Global monitoring of autumn gene expression within and among populations of Sitka spruce
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ABSTRACT:
ORGANISM(S): Picea sitchensis Picea
PROVIDER: GSE8370 | GEO | 2008/06/01
SECONDARY ACCESSION(S): PRJNA101399
REPOSITORIES: GEO
Similar Datasets
Project description:Cold acclimation in conifers is a complex process, the timing and extent of which reflects local adaptation and varies widely along latitudinal gradients for many temperate and boreal tree species. In spite of their ecological and economic importance, little is known about the global changes in gene expression that accompany autumn cold acclimation in conifers. Using three populations of Sitka spruce (Picea sitchensis) spanning the species range, and a Picea cDNA microarray with 21,840 unique elements, we monitored within and among-population gene expression during the fall. Microarray data were validated for selected genes using real-time PCR. Similar numbers of genes were significantly two-fold upregulated (1,257) and downregulated (967) between late summer and early winter. Among those upregulated were dehydrins, pathogenesis-related/antifreeze genes, carbohydrate and lipid metabolism genes, and genes involved in signal transduction and transcriptional regulation. Among-population microarray hybridizations at early and late autumn time points revealed substantial variation in the autumn transcriptome, some of which may reflect local adaptation. Our results demonstrate the complexity of cold acclimation in conifers, highlight similarities and differences to cold tolerance in annual plants, and provide a solid foundation for functional and genetic studies of this important adaptive process in conifers. Keywords: Time course Foliage for RNA extraction was obtained from four-year-old Sitka spruce seedlings, which were grown from seed collected across the species range in a raised-bed outdoor common garden in Vancouver, BC, Canada (49º N) (Mimura and Aitken, 2007, Heredity). Needle tissues from current year upper lateral shoots, separated from stem and bark tissue, were collected at five time points between late summer and early winter, 2004. Three populations were chosen for sampling: Valdez, Alaska, USA (61º N) (AK), Prince Rupert, British Columbia, Canada (54º N) (BC) and Redwood, California, USA (41º N) (CA) (Figure 1a). Needle samples (~1g) were taken from eight individuals in the BC population on each of the five dates (Aug. 30, Oct. 18, Nov. 24, Dec. 1, and Dec. 13). Eight individuals from the AK and CA populations were also sampled on the second and fourth dates, as well as eight additional individuals from the BC population. Tissues were flash frozen in an N2 vapor tank immediately upon collection, and subsequently stored at -80°C until processing. To decrease the effects of biological variance among individual seedlings within populations, equal amounts of foliar tissue were pooled from four individuals prior to RNA extraction. Two pools were collected at each time point for each population, and total RNA was extracted following a previously published protocol (Kolosova et al., 2004). Slides were scanned and spot intensity quantified using ImaGene software (BioDiscovery, Inc., El Segundo, CA). To correct for background intensity, the lowest 10% of median foreground intensities was subtracted from the median foreground intensities. Data were then normalized by variance stabilizing normalization (VSN) to compensate for nonlinearity of intensity distributions (Huber et al., 2002). To identify significant changes in gene expression, a linear mixed-effects model was fit to the normalized intensities in the Cy3 and Cy5 channels of the 32 microarray slides. The model contained an adjustment for dye bias, an array effect indicating which Cy5/Cy3 pair was on each array, a treatment effect indicating sample population and time point, and a random effect to adjust for repeated measures on the same biological sample (Kerr et al., 2000). P-values were computed for each gene-by-treatment effect and Q-values were calculated to adjust for the false discovery rate (FDR) (Storey & Tibshirani, 2003).
2008-05-31 | E-GEOD-8370 | biostudies-arrayexpress
Project description:During cold acclimation plants increase their freezing tolerance in response to low non-freezing temperatures. This is accompanied by many physiological, biochemical and molecular changes that have been extensively investigated. In addition, many cold acclimated plants become more freezing tolerant during exposure to mild, non-damaging sub-zero temperatures. There is hardly any information available about the molecular basis of this adaptation. However, Arabidopsis thaliana is among the species that acclimate to sub-zero temperatures. This makes it possible to use the molecular and genetic tools available in this species to identify components of sub-zero signal transduction and acclimation. Here, we have used microarrays and a qRT-PCR primer platform covering 1880 genes encoding transcription factors to monitor changes in gene expression in the accessions Columbia-0, Rschew and Tenela during the first three days of sub-zero acclimation at -3°C. The results indicate that gene expression during sub-zero acclimation follows a tighly controlled time-course. Especially AP2/EREBP and WRKY transcription factors may be important regulators of sub-zero acclimation, although the CBF signal transduction pathway seems to be less important during sub-zero than during cold acclimation. Globally, we estimate that approximately 5% of all Arabidopsis genes are regulated during sub-zero acclimation. Particularly photosynthesis-related genes were down-regulated and genes belonging to the functional classes of cell wall biosynthesis, hormone metabolism and RNA regulation of transcription were up-regulated. Collectively, these data provide the first global analysis of gene expression during sub-zero acclimation and allow the identification of candidate genes for forward and reverse genetic studies into the molecular mechanisms of sub-zero acclimation. We used whole genome microarrays to monitor changes in gene expression in the Arabidopsis thaliana accessions Columbia-0, Rschew and Tenela during three days of acclimation to sub-zero temperature at -3°C after cold acclimation
2014-03-12 | GSE55835 | GEO
Project description:Stress acclimation is an effective mechanism that plants acquired for adaption to dynamic environmental conditions. After undergoing cold acclimation, plants become more tolerant to cold stress. In order to understand the mechanism of cold acclimation, we performed a systematic, comprehensive study of cold response and acclimation in Cassava (Manihot esculenta), a staple crop and major food source in the tropical regions of the world. We profiled mRNA genes and small-RNA species, using next generation sequencing, and performed an integrative analysis of the transcriptome and microRNAome of Cassava across the normal condition, a moderate cold stress at 14°C, a harsh stress at 4°C after cold acclimation at 14°C, and a cold shock from 24°C to 4°C. Two results from the analysis were striking. First, the moderate stress and cold shock, despite a difference of 10°C between the two, triggered comparable degrees of perturbation to the transcriptome; in contrary, further harsh stress after cold acclimation resulted in a much smaller degree of transcriptome variation. Second and more importantly, about two thirds of the up- or down-regulated genes after moderate stress reversed their expression to down- or up-regulation, respectively, under harsh stress after cold acclimation, resulting in a genome-wide rewiring of regulatory networks. MicroRNAs, which are key post-transcriptional gene regulators, were major players in this massive rewiring of genetic circuitry. Further, a function enrichment analysis of the perturbed genes revealed that cold acclimation helped the plant to develop immunity to further harsh stress by exclusively inducing genes with functions of nutrient reservoir; in contrast, many genes with functions of viral reproduction were induced by cold shock. Our study revealed, for the first time, the molecular basis of stress acclimation in plants, and shed lights on the role of microRNA gene regulation in cold response and acclimation in Euphorbia.
2014-08-18 | GSE52176 | GEO
Project description:During cold acclimation plants increase their freezing tolerance in response to low non-freezing temperatures. This is accompanied by many physiological, biochemical and molecular changes that have been extensively investigated. In addition, many cold acclimated plants become more freezing tolerant during exposure to mild, non-damaging sub-zero temperatures. There is hardly any information available about the molecular basis of this adaptation. However, Arabidopsis thaliana is among the species that acclimate to sub-zero temperatures. This makes it possible to use the molecular and genetic tools available in this species to identify components of sub-zero signal transduction and acclimation. Here, we have used microarrays and a qRT-PCR primer platform covering 1880 genes encoding transcription factors to monitor changes in gene expression in the accessions Columbia-0, Rschew and Tenela during the first three days of sub-zero acclimation at -3°C. The results indicate that gene expression during sub-zero acclimation follows a tighly controlled time-course. Especially AP2/EREBP and WRKY transcription factors may be important regulators of sub-zero acclimation, although the CBF signal transduction pathway seems to be less important during sub-zero than during cold acclimation. Globally, we estimate that approximately 5% of all Arabidopsis genes are regulated during sub-zero acclimation. Particularly photosynthesis-related genes were down-regulated and genes belonging to the functional classes of cell wall biosynthesis, hormone metabolism and RNA regulation of transcription were up-regulated. Collectively, these data provide the first global analysis of gene expression during sub-zero acclimation and allow the identification of candidate genes for forward and reverse genetic studies into the molecular mechanisms of sub-zero acclimation. We used whole genome microarrays to monitor changes in gene expression in the Arabidopsis thaliana accessions Columbia-0, Rschew and Tenela during three days of acclimation to sub-zero temperature at -3°C after cold acclimation Plants from Arabidopsis thaliana accessions Columbia-0, Rschew and Tenela were cold acclimated at 4°C for two weeks. Detached leaves were then sub-zero acclimated at -3°C for 8 h, 1 d or 3 d at -3°C. Leaves of cold acclimated plants and sub-zero acclimated leaves were collected for RNA extraction and hybridization on Affymetrix ATH1 microarrays in order to explore temporal transcriptome changes during sub-zero acclimation. For each sample total RNA was isolated from a pool of three leaves from three different plants. The experiment was performed in three idenpendent biological replicates.
2014-03-12 | E-GEOD-55835 | biostudies-arrayexpress
Project description:Plants in temperate regions have evolved mechanisms to survive sudden temperature drops. Previous reports have indicated that the cold acclimation mechanism is light-dependent and does not fully operate under a low light intensity. In these studies, plants were grown under a long-day photoperiod and were more sensitive to freezing stress. However, winter annuals like Arabidopsis thaliana Col-0 germinate in the fall, overwinter as rosettes, and therefore must acclimate under short photoperiods and low irradiance. The role of light intensity was analysed in plants grown under a short-day photoperiod at the growth stage 1.14. Plants were acclimated at 4 °C for seven days under 100 and 20 μmol m-2s-1 PPFD for control and limited-light conditions, respectively. All cold acclimated plants accumulated molecular markers reportedly associated with acquired freezing tolerance, including proline, sucrose, CBFs, and COR gene protein products dehydrins and low-temperature-responsive proteins LTIs. Observed changes indicated that low PPFD did not inhibit the cold acclimation process, and the freezing stress experiment confirmed similar survival rates. The molecular analysis found distinct PPFD-specific adaptation mechanisms that were manifested in contrasting content of anthocyanins, cytokinin conjugates, abundances of proteins forming photosystems, and enzymes of protein, energy, and ROS metabolism pathways. Finally, this study led to the identification of putative proteins and metabolite markers correlating with susceptibility to freezing stress of non-acclimated plants grown under low PPFD. Our data show that Arabidopsis plants grown under short-day photoperiod can be fully cold-acclimated under limited light conditions, employing standard and PPFD-specific pathways.
2021-07-08 | PXD025234 | Pride
Project description:White pine weevil is a major pest of conifers in North America, especially for Spruce trees. Constitutive defenses are important in understanding defense mechanisms because they constitute the initial barrier to attacks by weevils and other pests. Resistant and susceptible trees exhibit constitutive differences in spruce. To improve our knowledge of their genetic basis, we compared the constitutive expression levels of 17,825 genes between 20 resistant and 20 susceptible trees in interior spruce (Picea glauca).
2011-11-28 | GSE27476 | GEO
Project description:Jojoba (Simmondsia chinensis) is a new semi- arid, oil- producing industrial crop that has attracted much attention in recent years. Low temperature is one of the major environmental stress that impairs plant growth and development. To better understand the molecular mechanisms of cold stress adaptation and acclimation of jojoba plants, a quantitative proteomic analysis using iTRAQ technology was conducted to detect the effects of cold stress on protein expression profiles in jojoba seedlings. Our work provided useful infomation for understanding the cold stress response and cold acclimation in jojoba.
2019-11-11 | PXD007063 | Pride
Project description:Coping of evergreen conifers of boreal forests with freezing temperatures on bright winter days puts the photosynthetic machinery in great risk of oxidative damage. To survive harsh winter conditions, conifers have evolved a unique but poorly characterised photoprotection mechanism, a sustained form of non-photochemical quenching (sustained NPQ). Here we focused on functional properties and underlying molecular mechanisms related to the development of sustained NPQ in Norway spruce (Picea abies). Data was collected during four consecutive years (2016-19) from trees growing in sun and shade habitats. When day temperatures dropped below -4°C, specific N-terminally triply phosphorylated LHCB1 isoform (3p-LHCII) and phosphorylated PSBS (p-PSBS) were detected in the thylakoid membrane. Development of sustained NPQ coincided with the highest level of 3p-LHCII and p-PSBS, occurring after prolonged combination of bright winter days and temperature close to -10°C. Artificial induction of both the sustained NPQ and recovery from naturally induced sustained NPQ provided information on differential dynamics and light-dependence of 3p-LHCII and p-PSBS accumulation and dephosphorylation as essential prerequisites of sustained NPQ. Data obtained collectively suggest three novel components related to sustained NPQ in spruce. (i) Freezing temperatures induce 3p-LHCII accumulation independently of light, which is suggested to initiate de-stacking of appressed thylakoid membranes due to increased electrostatic repulsion of adjacent membranes. (ii) p-PSBS accumulation is both light- and temperature-dependent and closely linked to the initiation of sustained NPQ, which (iii) in concert with PSII photoinhibition is likely to trigger sustained NPQ in spruce.
2020-07-27 | PXD018941 | Pride
Project description:Molecular mechanisms for phenological traits in boreal conifers related to altitudinal adaptation
| PRJDB4238 | ENA