Project description:Suitability of CATMA for the analysis of the transcriptome of Thellungiella halophila - flower/leaf transcriptomic comparison in Arabidopsis and Thellungiella. adt09-01_thellungiella - thelungiella
Project description:Suitability of CATMA for the analysis of the transcriptome of Thellungiella halophila - flower/leaf transcriptomic comparison in Arabidopsis and Thellungiella. adt09-01_thellungiella - thelungiella 2 dye-swap - CATMA arrays
Project description:Thellungiella, an Arabidopsis-related halophyte, is an emerging model species for studies designed to elucidate molecular mechanisms of abiotic stress tolerance. Using a cDNA microarray containing 3628 unique sequences derived from previously reported libraries of stress-induced cDNAs of the Yukon ecotype of Thellungiella, we obtained transcript profiles of its response to drought, cold, high salinity and re-watering after drought. A total of 153 transcripts were found to be significantly differentially regulated under the conditions studied. Only six of these genes responded to all three stresses of drought, cold and salinity. Unlike in Arabidopsis, there were relatively few transcript changes in response to high salinity in this halophyte. Furthermore, drought responsive-transcripts in Thellungiella provided a link between the down-regulation of defense-related transcripts and the increase of endogenous abscisic acid during drought. This antagonistic interaction between drought and biotic stress response may potentially be beneficial for survival under drought stress. Intriguingly, changes of transcript abundance in response to cold implicate the involvement of jasmonic acid in the cold acclimation of Thellungiella. Taken together, our results provide useful starting points for more in depth analysis of Thellungiella’s extreme stress tolerance. Keywords: Abiotic stress response
Project description:Arabidopsis thaliana is not particularly stress tolerant and may lack protective mechanisms required to survive extreme environmental conditions. Thellungiella salsuginea has therefore attracted increasing interest as an alternative plant model species that possesses high tolerance of various abiotic stresses. While the T. salsuginea genome has recently been sequenced, its annotation is still far from complete and, due to the low number of ESTs available, evidence for actual transcriptional activity is lacking for most genes. ESTs were generated from a non-normalized and a normalized library synthesized from RNA pooled from plant samples from different developmental stages and grown under abiotic stress conditions. The ESTs of Thellungiella was sequenced by 454 pyrosequencing method. More than 1 million sequence reads were assembled into 42,810 unigenes, approximately 50% of which could be functionally annotated. From this sequence information, we constructed a 44k Agilent oligonucleotide microarray. A comparison of same-species and cross-species hybridization results showed the superior performance of the newly designed array for Thellungiella samples. In addition, the array was validated in a cold acclimation experiment that used the appropriately adapted MapMan software for analysis and visualization. To examine the quality of the Thellungiella array and to assess whether hybridization results from a dedicated array are superior to cross-species hybridization using the Arabidopsis array from the same manufacturer, we performed reciprocal array hybridizations. In this experiment, RNA from the Yukon accession of Thellungiella and RNA from the Col-0 accession of Arabidopsis were both hybridized on the Agilent Thellungiella and Arabidopsis expression arrays. For both species, RNA was extracted from acclimated and non-acclimated plants from three independent biological replicates.
Project description:The overall objective was to document transcriptomic changes in the guard cells of Thellungiella salsuginea under short (1x) - and long-term (3x) saline growth conditions. For that. microarray analysis was performed using a 60-mer oligonucleotide probe array from Agilent (44 K, design number 031554, Santa Clara, CA, USA). It was clearly observed that salt salinity alters the transcriptomic landscape of Thellungiella guard cells. However, changes in gene expression were evident under 3x saline growth conditions compared to non-saline conditions. Similarly, more GO terms were significantly enriched in differentially expressed guard cell genes of 3x salt than 1x salt treated plants.
Project description:Background: Thellungiella salsuginea is an important model plant due to its natural tolerance to abiotic stresses including salt, cold, and water deficits. Microarray and metabolite profiling have shown that Thellungiella undergoes stress-responsive changes in transcript and organic solute abundance when grown under controlled environmental conditions. However, few reports assess the capacity of plants to display stress-responsive traits in natural habitats where concurrent stresses are the norm. Results: To determine whether stress-responsive changes observed in cabinet-grown plants are recapitulated in the field, we analyzed leaf transcript and metabolic profiles of Thellungiella growing in its native Yukon habitat during two years of contrasting meteorological conditions. We found 673 genes showing differential expression between field and unstressed, chamber-grown plants. There were comparatively few overlaps between genes expressed under field and cabinet treatment-specific conditions. Only 20 of 99 drought-responsive genes were expressed both in the field during a year of low precipitation and in plants subjected to drought treatments in cabinets. There was also a general pattern of lower abundance among metabolites found in field plants relative to control or stress-treated plants in growth cabinets. Nutrient availability may explain some of the observed differences. For example, proline accumulated to high levels in cold and salt-stressed cabinet-grown plants but proline content was, by comparison, negligible in plants at a saline Yukon field site. We show that proline accumulated in a stress-responsive manner in Thellungiella plants salinized in growth cabinets and in salt-stressed seedlings when nitrogen was provided at 1.0 mM. In seedlings grown on 0.1 mM nitrogen medium, the proline content was low while carbohydrates increased. The relatively higher content of sugar-like compounds in field plants and seedlings on low nitrogen media suggests that Thellungiella shows metabolic plasticity in response to environmental stress and that resource availability can influence the expression of stress tolerance traits under field conditions. Conclusion: Comparisons between Thellungiella plants responding to stress in cabinets and in their natural habitats showed differences but also overlap between transcript and metabolite profiles. The traits in common offer potential targets for improving crops that must respond appropriately to multiple, concurrent stresses.
Project description:Arabidopsis thaliana is not particularly stress tolerant and may lack protective mechanisms required to survive extreme environmental conditions. Thellungiella salsuginea has therefore attracted increasing interest as an alternative plant model species that possesses high tolerance of various abiotic stresses. While the T. salsuginea genome has recently been sequenced, its annotation is still far from complete and, due to the low number of ESTs available, evidence for actual transcriptional activity is lacking for most genes. ESTs were generated from a non-normalized and a normalized library synthesized from RNA pooled from plant samples from different developmental stages and grown under abiotic stress conditions. The ESTs of Thellungiella was sequenced by 454 pyrosequencing method. More than 1 million sequence reads were assembled into 42,810 unigenes, approximately 50% of which could be functionally annotated. From this sequence information, we constructed a 44k Agilent oligonucleotide microarray. A comparison of same-species and cross-species hybridization results showed the superior performance of the newly designed array for Thellungiella samples. In addition, the array was validated in a cold acclimation experiment that used the appropriately adapted MapMan software for analysis and visualization.
Project description:Background: Thellungiella salsuginea is an important model plant due to its natural tolerance to abiotic stresses including salt, cold, and water deficits. Microarray and metabolite profiling have shown that Thellungiella undergoes stress-responsive changes in transcript and organic solute abundance when grown under controlled environmental conditions. However, few reports assess the capacity of plants to display stress-responsive traits in natural habitats where concurrent stresses are the norm. Results: To determine whether stress-responsive changes observed in cabinet-grown plants are recapitulated in the field, we analyzed leaf transcript and metabolic profiles of Thellungiella growing in its native Yukon habitat during two years of contrasting meteorological conditions. We found 673 genes showing differential expression between field and unstressed, chamber-grown plants. There were comparatively few overlaps between genes expressed under field and cabinet treatment-specific conditions. Only 20 of 99 drought-responsive genes were expressed both in the field during a year of low precipitation and in plants subjected to drought treatments in cabinets. There was also a general pattern of lower abundance among metabolites found in field plants relative to control or stress-treated plants in growth cabinets. Nutrient availability may explain some of the observed differences. For example, proline accumulated to high levels in cold and salt-stressed cabinet-grown plants but proline content was, by comparison, negligible in plants at a saline Yukon field site. We show that proline accumulated in a stress-responsive manner in Thellungiella plants salinized in growth cabinets and in salt-stressed seedlings when nitrogen was provided at 1.0 mM. In seedlings grown on 0.1 mM nitrogen medium, the proline content was low while carbohydrates increased. The relatively higher content of sugar-like compounds in field plants and seedlings on low nitrogen media suggests that Thellungiella shows metabolic plasticity in response to environmental stress and that resource availability can influence the expression of stress tolerance traits under field conditions. Conclusion: Comparisons between Thellungiella plants responding to stress in cabinets and in their natural habitats showed differences but also overlap between transcript and metabolite profiles. The traits in common offer potential targets for improving crops that must respond appropriately to multiple, concurrent stresses. A custom cDNA mcroarray was used for transcript profiling. Cauline leaves from individual plants collected at a Yukon, Canada field site were used in this study. Three samples were obtained in 2003 (Field 2003 A, B and C) and three harvested in 2005 (Field 2005 A, B and D). Cauline leaves from 12 week old chamber grown plants served as controls. For each microarray experiment a technical replicate (dye swap) was performed resulting in a total of 12 hybridizations.