scholarly journals Adaptive divergence in transcriptome response to heat and acclimation in Arabidopsis thaliana plants from contrasting climates.

2016 ◽  
Author(s):  
Nana Zhang ◽  
Elizabeth Vierling ◽  
Stephen Tonsor
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
High Temperature ◽  
Expression Patterns ◽  
High Elevation ◽  
Adaptive Divergence ◽  
Gene Expression Patterns ◽  
Direct Exposure ◽  
Small Hsps

Phenotypic variation in stress response has been widely observed within species. This variation is an adaptive response to local climates and is controlled by gene sequence variation and especially by variation in expression at the transcriptome level. Plants from contrasting climates are thus expected to have different patterns in gene expression. Acclimation, a pre-exposure to sub-lethal temperature before exposing to extreme high temperature, is an important adaptive mechanism of plant survival. We are interested to evaluate the gene expression difference to heat stress for plants from contrasting climates and the role of acclimation in altering their gene expression pattern. Natural Arabidopsis thaliana plants from low elevation mediterranean and high elevation montane climates were exposed to two heat treatments at the bolting stage: a) 45 oC: a direct exposure to 45oC heat; b) 38/45 oC: an exposure to 45oC heat after a 38oC acclimation treatment. Variation in overall gene expression patterns was investigated. We also explored gene expression patterns for Hsp/Hsf pathway and reactive oxygen species (ROS) pathway. In both heat treatments, high elevation plants had more differentially expressed (DE) genes than low elevation plants. In 45 oC, only Hsp/Hsf pathway was activated in low elevation plants; both Hsp/Hsf and ROS pathways were activated in high elevation plants. Small Hsps had the highest magnitude of change in low elevation plants while Hsp70 and Hsp90 showed the largest magnitude of fold in high elevation plants. In 38/45 oC, Hsp/Hsf and ROS pathways were activated in both low and high elevation plants. Low elevation plants showed up-regulation in all Hsps, especially small Hsps; high elevation plants showed down-regulation in all Hsps. Low elevation and high elevation also adopted different genes in the ROS pathway. We also observed genes that shifted expression in both low and high elevation plants but with opposite directions of change. This study indicates that low and high elevation plants have evolved adaptive divergence in heat stress response. The contrasting patterns of temperature variation in low and high elevation sites appears to have played a strong role in the evolution of divergent patterns to high temperature stress, both pre-acclimation and direct exposure gene expression responses.

scholarly journals Contrasting avoidance - tolerance in heat stress response from thermally contrasting climates in Arabidopsis thaliana

2016 ◽  
Author(s):  
Nana Zhang ◽  
Philip Carlucci ◽  
Joshua Nguyen ◽  
Jai-W Hayes-Jackson ◽  
Stephen Tonsor
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
High Temperature ◽  
Elevation Gradient ◽  
Branch Length ◽  
High Elevation ◽  
Tissue Temperature ◽  
Adaptive Divergence ◽  
Leaf Angle ◽  
Heat Stress Response

Plants ameliorate heat stress by avoiding heat loading, reducing tissue temperature through evaporative cooling, and/or through tolerance, i.e. maintaining function at high temperature. Here Arabidopsis thaliana natural populations from two ends of an elevation gradient in NE Spain were used to ask: do plants from contrasting climates 1) show genetically based differences in heat stress damage and 2) adopt different avoidance-tolerance patterns? Four low- and four high-elevation populations were repeatedly exposed to high temperature (45oC) in a growth chamber at bolting stage. High temperature induced 23% more inflorescence branches, 25% longer total reproductive branch length, and 12% less root dry mass, compared with control. However summed fruit length, hence fitness, decreased by 15%, populations did not differ significantly in fitness reduction. High elevation populations showed more avoidance, i.e. lower rosette temperature at 45oC. Low elevation populations showed more tolerance, maintaining relatively higher photosynthetic rate at 45oC. Avoidance was associated with high transpiration rate and flat rosette leaf angle. Tolerance was negatively associated with heat shock protein 101 (Hsp101) and salicylic acid (SA) accumulation. The divergent avoidance tolerance patterns for populations from thermally contrasting climates may indicate both constraints on the evolution and contrasting adaptive divergence regulated by local climates.

scholarly journals Arabidopsis sepals: A model system for the emergent process of morphogenesis

2021 ◽  
Vol 2 ◽  
Author(s):  
Adrienne H. K. Roeder
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Cell Division ◽  
Slow Growth ◽  
Expression Patterns ◽  
Giant Cells ◽  
Model System ◽  
Gene Expression Patterns ◽  
Emergent Properties ◽  
Correct Size

Abstract During development, Arabidopsis thaliana sepal primordium cells grow, divide and interact with their neighbours, giving rise to a sepal with the correct size, shape and form. Arabidopsis sepals have proven to be a good system for elucidating the emergent processes driving morphogenesis due to their simplicity, their accessibility for imaging and manipulation, and their reproducible development. Sepals undergo a basipetal gradient of growth, with cessation of cell division, slow growth and maturation starting at the tip of the sepal and progressing to the base. In this review, I discuss five recent examples of processes during sepal morphogenesis that yield emergent properties: robust size, tapered tip shape, laminar shape, scattered giant cells and complex gene expression patterns. In each case, experiments examining the dynamics of sepal development led to the hypotheses of local rules. In each example, a computational model was used to demonstrate that these local rules are sufficient to give rise to the emergent properties of morphogenesis.

Microarray data uncover the genome-wide gene expression patterns in response to heat stress in rice post-meiosis panicle

2014 ◽  
Vol 57 (6) ◽  
pp. 327-336 ◽  
Author(s):  
Xianwen Zhang ◽  
Hairong Xiong ◽  
Ailing Liu ◽  
Xiaoyun Zhou ◽  
Yan Peng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Microarray Data ◽  
Expression Patterns ◽  
Gene Expression Patterns ◽  
Genome Wide ◽  
Genome Wide Gene Expression

scholarly journals Variation in Coral Thermotolerance Across a Pollution Gradient Erodes as Coral Symbionts Shift to More Heat-Tolerant Genera

2021 ◽  
Vol 8 ◽  
Author(s):  
Melissa S. Naugle ◽  
Thomas A. Oliver ◽  
Daniel J. Barshis ◽  
Ruth D. Gates ◽  
Cheryl A. Logan
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Phenotypic Plasticity ◽  
Environmental Changes ◽  
Expression Patterns ◽  
Pollution Level ◽  
Gene Expression Patterns ◽  
Polluted Sites ◽  
Baseline Levels ◽  
Heat Tolerant

Phenotypic plasticity is one mechanism whereby species may cope with stressful environmental changes associated with climate change. Reef building corals present a good model for studying phenotypic plasticity because they have experienced rapid climate-driven declines in recent decades (within a single generation of many corals), often with differential survival among individuals during heat stress. Underlying differences in thermotolerance may be driven by differences in baseline levels of environmental stress, including pollution stress. To examine this possibility, acute heat stress experiments were conducted on Acropora hyacinthus from 10 sites around Tutuila, American Samoa with differing nutrient pollution impact. A threshold-based heat stress assay was conducted in 2014 and a ramp-hold based assay was conducted in 2019. Bleaching responses were measured by assessing color paling. Endosymbiont community composition was assessed at each site using quantitative PCR. RNA sequencing was used to compare differences in coral gene expression patterns prior to and during heat stress in 2019. In 2014, thermotolerance varied among sites, with polluted sites holding more thermotolerant corals. These differences in thermotolerance correlated with differences in symbiont communities, with higher proportions of heat-tolerant Durusdinium found in more polluted sites. By 2019, thermotolerance varied less among sites, with no clear trend by pollution level. This coincided with a shift toward Durusdinium across all sites, reducing symbiont community differences seen in 2014. While pollution and symbiont community no longer could explain variation in thermotolerance by 2019, gene expression patterns at baseline levels could be used to predict thermotolerance thresholds. These patterns suggest that the mechanisms underlying thermotolerance shifted between 2014 and 2019, though it is possible trends may have also been affected by methodological differences between heat stress assays. This study documents a shift in symbiont community over time and captures potential implications of that shift, including how it affects variation in thermotolerance among neighboring reefs. This work also highlights how gene expression patterns could help identify heat-tolerant corals in a future where most corals are dominated by Durusdinium and symbiont-driven thermotolerance has reached an upper limit.

Gene expression patterns in blood predict future severe endpoints in community acquired pneumonia

Pneumologie ◽  
2018 ◽  
Vol 72 (S 01) ◽  
pp. S8-S9
Author(s):  
M Bauer ◽  
H Kirsten ◽  
E Grunow ◽  
P Ahnert ◽  
M Kiehntopf ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
Community Acquired Pneumonia ◽  
Gene Expression Patterns
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