scholarly journals Natural selection on traits and trait plasticity in Arabidopsis thaliana varies across competitive environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kattia Palacio-Lopez ◽  
Christian M. King ◽  
Jonathan Bloomberg ◽  
Stephen M. Hovick
Keyword(s):  
Arabidopsis Thaliana ◽  
Interspecific Competition ◽  
Flowering Phenology ◽  
Competitive Environment ◽  
Phenotypic Integration ◽  
Competitive Environments ◽  
Selection Processes ◽  
Delayed Flowering ◽  
Plastic Responses ◽  
Trait Correlation

AbstractInterspecific competition reduces resource availability and can affect evolution. We quantified multivariate selection in the presence and absence of strong interspecific competition using a greenhouse experiment with 35 natural accessions of Arabidopsis thaliana. We assessed selection on nine traits representing plant phenology, growth, and architecture, as well as their plasticities. Competition reduced biomass and fitness by over 98%, and plastic responses to competition varied by genotype (significant G × E) for all traits except specific leaf area (SLA). Competitive treatments altered selection on flowering phenology and plant architecture, with significant selection on all phenology traits and most architecture traits under competition-present conditions but little indication that selection occurred in the absence of competitors. Plasticity affected fitness only in competition-present conditions, where plasticity in flowering time and early internode lengths was adaptive. The competitive environment caused changes in the trait correlation structure and surprisingly reduced phenotypic integration, which helped explain some of the observed selection patterns. Despite this overall shift in the trait correlation matrix, genotypes with delayed flowering had lower SLA (thicker, tougher leaves) regardless of the competitive environment, a pattern we have not seen previously reported in the literature. Overall, our study highlights multiple ways in which interspecific competition can alter selective regimes, contributing to our understanding of variability in selection processes over space and time.

scholarly journals Fused Graphical Lasso Recovers Flowering Time Mutation Genes in Arabidopsis Thaliana

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 52
Author(s):  
Rajan Kapoor ◽  
Aniruddha Datta ◽  
Michael Thomson
Keyword(s):  
Arabidopsis Thaliana ◽  
Crop Improvement ◽  
Phenotypic Traits ◽  
The Novel ◽  
Model Plant ◽  
Graphical Lasso ◽  
Analysis Strategy ◽  
Model Plant Arabidopsis Thaliana ◽  
Beneficial Traits ◽  
Delayed Flowering

Conventional breeding approaches that focus on yield under highly favorable nutrient conditions have resulted in reduced genetic and trait diversity in crops. Under the growing threat from climate change, the mining of novel genes in more resilient varieties can help dramatically improve trait improvement efforts. In this work, we propose the use of the joint graphical lasso for discovering genes responsible for desired phenotypic traits. We prove its efficiency by using gene expression data for wild type and delayed flowering mutants for the model plant. Arabidopsis thaliana shows that it recovers the mutation causing genes LNK1 and LNK2. Some novel interactions of these genes were also predicted. Observing the network level changes between two phenotypes can also help develop meaningful biological hypotheses regarding the novel functions of these genes. Now that this data analysis strategy has been validated in a model plant, it can be extended to crop plants to help identify the key genes for beneficial traits for crop improvement.

The Effects of Production Performance Model and Competitive Environment of Hospital Systems

2013 ◽  
Vol 300-301 ◽  
pp. 1623-1627
Author(s):  
Ching Kuo Wei
Keyword(s):  
Performance Model ◽  
Production Performance ◽  
Competitive Environment ◽  
Data Envelopment ◽  
Hospital System ◽  
Department Of Health ◽  
Competitive Environments ◽  
Significant Difference ◽  
Efficiency Performance ◽  
Hospital Systems

This study investigated the efficiency performance of the production technology of the Department of Health (DOH)-affiliated hospital system in Taiwan in different competitive environments. This study used Data Envelopment Analysis (DEA) to analyze a total of 396 hospitals of different systems in Taiwan. The results indicated that, in terms of the internal competitive environment, the production performance of hospital Q was the best, while that of hospital N was the worst. This study also analyzed the production performance and scale of DOH-affiliated hospitals and provided hospitals with a direction for scale development. Finally, this study proposed suggestions on improvement direction for hospitals with poor production performance. As for external competitive environment, there is no significant difference in the average efficiency among various hospital systems. However, there are a lot to be improved in DOH-affiliated hospitals, especially in the aspect of technology efficiency. The improvement of technology efficiency should be more beneficial to the overall efficiency.

scholarly journals Flowering phenology in alpine grassland strongly responds to shifts in snowmelt but weakly to summer drought

Alpine Botany ◽  
2021 ◽  
Author(s):  
Maria Vorkauf ◽  
Ansgar Kahmen ◽  
Christian Körner ◽  
Erika Hiltbrunner
Keyword(s):  
Biotic Interactions ◽  
Flowering Phenology ◽  
Alpine Plants ◽  
Alpine Grassland ◽  
Summer Drought ◽  
Phenological Cycle ◽  
The Alps ◽  
Delayed Flowering ◽  
Photoperiod Sensitive ◽  
Species Specific

AbstractAlpine plants complete their seasonal phenological cycle during two to three snow-free months. Under climate change, snowmelt advances and the risk of summer droughts increases. Yet, photoperiodism may prevent alpine plants from benefiting from an earlier start of the growing season. To identify the drivers of flowering phenology in the seven main species of an alpine grassland, we experimentally shifted the snowmelt date through snow manipulations, and excluded precipitation during summer. With “time-to-event” models, we analysed the beginning of main flowering with respect to temperature sums, time after snowmelt, and calendar day (photoperiod). We identified two phenology types: four species tracking snowmelt dates directly or with a certain lag set by temperature sums, including the dominant sedge Carex curvula, Anthoxanthum alpinum Helictotrichon versicolor, and Trifolium alpinum, and three species tracking photoperiod: Geum montanum, Leontodon helveticus and Potentilla aurea. Photoperiodism did not act as daylength threshold but rather modulated the thermal sums at flowering. Hence, photoperiod delayed flowering after earlier snowmelt. The grass A. alpinum was the only one of seven species that clearly responded to drought by earlier and longer flowering. The remarkably high importance of snowmelt dates for both phenology types suggests an earlier onset of flowering in a warmer climate, particularly for non-photoperiod-sensitive species, with an increasing risk for freezing damages and potential disruptions of biotic interactions in the most frequent type of alpine grassland across the Alps. Consequentially, the distinct microclimate and species-specific responses to photoperiod challenge temperature-only based projections of climate warming effects on alpine plant species.

scholarly journals Managing Multiple Sources of Competitive Advantage in a Complex Competitive Environment

2013 ◽  
Vol 5 (2) ◽  
pp. 221-251
Author(s):  
Alexandre Howard Henry Lapersonne
Keyword(s):  
Competitive Advantage ◽  
Competitive Environment ◽  
Economic Rent ◽  
Multiple Sources ◽  
Dynamic Markets ◽  
Multiple Strategies ◽  
Competitive Environments ◽  
Framework Approach ◽  
The Subject ◽  
Historical Nature

The aim of this article is to review the literature on the topic of sustained and temporary competitive advantage creation, specifically in dynamic markets, and to propose further research possibilities. After having analyzed the main trends and scholars’ works on the subject, it was concluded that a firm which has been experiencing erosion of its core sources of economic rent generation, should have diversified its strategy portfolio in a search for new sources of competitive advantage, ones that could compensate for the decline of profits provoked by intensive competitive environments. This review concludes with the hypothesis that firms, who have decided to enter and manage multiple competitive environments, should have developed a multiple strategies framework approach. The management of this source of competitive advantage portfolio should have allowed persistence of a firm’s superior economic performance through the management of diverse temporary advantages lifecycle and through a resilient effect, where a very successful source of competitive advantage compensates the ones that have been eroded. Additionally, the review indicates that economies of emerging countries, such as the ones from the BRIC block, should present a more complex competitive environment due to their historical nature of cultural diversity, social contrasts and frequent economic disruption, and also because of recent institutional normalization that has turned the market into hypercompetition. Consequently, the study of complex competition should be appropriate in such environments.

scholarly journals FLOWERING PHENOLOGY AND SEXUAL ALLOCATION IN SINGLE-MUTATION LINEAGES OF ARABIDOPSIS THALIANA

Evolution ◽  
2005 ◽  
Vol 59 (5) ◽  
pp. 970-978 ◽  
Author(s):  
Angela M. Baker ◽  
Martin Burd ◽  
Kylie M. Climie
Keyword(s):  
Arabidopsis Thaliana ◽  
Flowering Phenology ◽  
Single Mutation

scholarly journals Spatiotemporal expression of FRIGIDA modulate flowering time in Arabidopsis thaliana

2018 ◽  
Author(s):  
Xiangxiang Kong ◽  
Jinjie Zhao ◽  
Landi Luo ◽  
Qian Chen ◽  
Guanxiao Chang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Flowering Time ◽  
Environmental Cues ◽  
The Novel ◽  
Spatiotemporal Expression ◽  
Embryo Stage ◽  
Novel Targets ◽  
Delayed Flowering ◽  
Fine Tune ◽  
Local Expression

AbstractFRIGIDA (FRI) as the major regulator of flowering time in Arabidopsis accessions can activate its target FLOWERING LOCUS C (FLC) to delay flowering before vernalization. Besides FLC, other FRI targets also exist in Arabidopsis. Although leaves sense environmental cues to modulate flowering time, it is not known if roots also regulate the floral transition. In this study, we investigated the spatiotemporal effect of FRI on flowering time. Local expression of FRI in the phloem and leaves activated FLC to delay flowering. Furthermore, we found that local expression of FRI in the roots also delayed flowering by activating other targets MADS AFFECTING FLOWERING4 (MAF4) and MAF5 in the roots. Graft and genetic experiments revealed that the spatial expression of FRI in the root might generate a mobile signal, which is transmitted from roots to shoot and antagonizes the FT signal to delay flowering. Specifically expressing FRI in the embryo efficiently delayed flowering, even expressing FRI as early as pro-embryo stage is enough to upregulate FLC expression to delay flowering. Together, our findings confirm the spatiotemporal effect of FRI on delaying flowering, and propose that root tissue also perceives the flowering signal to fine-tune the flowering time through MAF4/5 as novel targets of FRI.HighlightRoot FRIDIGA activated the novel targets MAF4/5 to delay flowering; Temporal expressing FRIGIDA at as early as pro-embryo stage is efficient to delay flowering.

scholarly journals CONCENTRATION INDICES IN ANALYSIS OF COMPETITIVE ENVIRONMENT: CASE OF RUSSIAN BANKING SECTOR

2017 ◽  
Vol 5 ◽  
pp. 458-464
Author(s):  
Polina Stazhkova ◽  
Tatyana Kotcofana ◽  
Alexander Protasov
Keyword(s):  
Russian Federation ◽  
Banking Sector ◽  
Market Concentration ◽  
Market Analysis ◽  
Monopoly Power ◽  
Competitive Environment ◽  
Analysis And Evaluation ◽  
Competitive Environments ◽  
The Russian Federation ◽  
Concentration Indices

This article is devoted to the analysis and evaluation of competitive environments by using some indicators of market concentration. An analysis was made of the key (main) concentration indices most often used in countries with developed market economies. The state of the competitive environment in the banking sector of the Russian Federation is estimated with the use of indices. The consistency of these indicators to the basic antitrust regulations was investigated. The authors show that in order to obtain reliable results each of the available methods of monopoly power detection requires a detailed market analysis.

scholarly journals Ribosomes act as cryosensors in plants

2020 ◽  
Author(s):  
Philip Anthony Wigge ◽  
David Guillaume-Schoepfer ◽  
Katja E Jaeger ◽  
Feng Geng ◽  
Fabrizio G Doccula ◽  
...  
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Transcription Factors ◽  
Cold Stress ◽  
Protein Translation ◽  
Free Calcium ◽  
Cold Temperatures ◽  
Stunted Growth ◽  
Subzero Temperatures ◽  
Delayed Flowering

Cold temperatures are a threat to temperate plants, and Arabidopsis thaliana has acquired an adaptive gene expression network controlled by CBF transcription factors. The CBFs are sufficient to enable plants to survive otherwise lethal subzero temperatures. Constitutive CBF expression causes delayed flowering and stunted growth, and plants have evolved the ability to restrict CBF expression to occur only in the cold. This allows plants to anticipate likely freezing events and selectively deploy cold tolerance. The mechanism by which cold stress is sensed is however unknown. Here we show that protein translation rates in plants are proportional to temperature, and reduced translation rates trigger a rise in intracellular free calcium that activates the CAMTA transcription factors, and these directly activate cold-induced gene expression.

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