scholarly journals Adaptive diversification of growth allometry in the plant Arabidopsis thaliana

2018 ◽  
Vol 115 (13) ◽  
pp. 3416-3421 ◽  
Author(s):  
François Vasseur ◽  
Moises Exposito-Alonso ◽  
Oscar J. Ayala-Garay ◽  
George Wang ◽  
Brian J. Enquist ◽  
...  
Keyword(s):  
Growth Rate ◽  
Arabidopsis Thaliana ◽  
Abiotic Stress ◽  
Seed Production ◽  
Stress Resistance ◽  
Allometric Scaling ◽  
Hydrodynamic Resistance ◽  
Scaling Exponent ◽  
Scaling Exponents ◽  
Growth Scaling

Seed plants vary tremendously in size and morphology; however, variation and covariation in plant traits may be governed, at least in part, by universal biophysical laws and biological constants. Metabolic scaling theory (MST) posits that whole-organismal metabolism and growth rate are under stabilizing selection that minimizes the scaling of hydrodynamic resistance and maximizes the scaling of resource uptake. This constrains variation in physiological traits and in the rate of biomass accumulation, so that they can be expressed as mathematical functions of plant size with near-constant allometric scaling exponents across species. However, the observed variation in scaling exponents calls into question the evolutionary drivers and the universality of allometric equations. We have measured growth scaling and fitness traits of 451 Arabidopsis thaliana accessions with sequenced genomes. Variation among accessions around the scaling exponent predicted by MST was correlated with relative growth rate, seed production, and stress resistance. Genomic analyses indicate that growth allometry is affected by many genes associated with local climate and abiotic stress response. The gene with the strongest effect, PUB4, has molecular signatures of balancing selection, suggesting that intraspecific variation in growth scaling is maintained by opposing selection on the trade-off between seed production and abiotic stress resistance. Our findings suggest that variation in allometry contributes to local adaptation to contrasting environments. Our results help reconcile past debates on the origin of allometric scaling in biology and begin to link adaptive variation in allometric scaling to specific genes.

scholarly journals Adaptive diversification of growth allometry in the plant Arabidopsis thaliana

2018 ◽  
Author(s):  
François Vasseur ◽  
Moises Exposito-Alonso ◽  
Oscar Ayala-Garay ◽  
George Wang ◽  
Brian J. Enquist ◽  
...  
Keyword(s):  
Growth Rate ◽  
Arabidopsis Thaliana ◽  
Abiotic Stress ◽  
Seed Production ◽  
Allometric Scaling ◽  
Abiotic Stress Response ◽  
Scaling Exponents ◽  
Metabolic Scaling ◽  
Metabolic Scaling Theory ◽  
Growth Scaling

AbstractSeed plants vary tremendously in size and morphology. However, variation and covariation between plant traits may at least in part be governed by universal biophysical laws and biological constants. Metabolic Scaling Theory (MST) posits that whole-organismal metabolism and growth rate are under stabilizing selection that minimizes the scaling of hydrodynamic resistance and maximizes the scaling of resource uptake. This constrains variation in physiological traits and in the rate of biomass accumulation, so that they can be expressed as mathematical functions of plant size with near constant allometric scaling exponents across species. However, observed variation in scaling exponents questions the evolutionary drivers and the universality of allometric equations. We have measured growth scaling and fitness traits of 451 Arabidopsis thaliana accessions with sequenced genomes. Variation among accessions around the scaling exponent predicted by MST correlated with relative growth rate, seed production and stress resistance. Genomic analyses indicate that growth allometry is affected by many genes associated with local climate and abiotic stress response. The gene with the strongest effect, PUB4, has molecular signatures of balancing selection, suggesting that intraspecific variation in growth scaling is maintained by opposing selection on the trade-off between seed production and abiotic stress resistance. Our findings support a core MST prediction and suggest that variation in allometry contributes to local adaptation to contrasting environments. Our results help reconcile past debates on the origin of allometric scaling in biology, and begin to link adaptive variation in allometric scaling to specific genes.Significance statementAre there biological constants unifying phenotypic diversity across scales? Metabolic Scaling Theory (MST) predicts mathematical regularity and constancy in the allometric scaling of growth rate with body size across species. Here, we show that adaptation to climate in Arabidopsis thaliana is associated with local strains that substantially deviate from the values predicted by MST. This deviation can be linked to increased stress tolerance at the expense of seed production, and it occurs through selection on genes that are involved in abiotic stress response and that are geographically correlated with climatic conditions. This highlights the evolutionary role of allometric diversification and helps establish the physiological bases of plant adaptation to contrasting environments.

scholarly journals Kazantsev dynamo in turbulent compressible flows

2019 ◽  
Vol 475 (2223) ◽  
pp. 20180591 ◽  
Author(s):  
Marco Martins Afonso ◽  
Dhrubaditya Mitra ◽  
Dario Vincenzi
Keyword(s):  
Growth Rate ◽  
Reynolds Number ◽  
Critical Exponent ◽  
Compressible Flows ◽  
Critical Value ◽  
Magnetic Reynolds Number ◽  
Scaling Exponent ◽  
Scaling Exponents ◽  
Potential Part

We consider the kinematic fluctuation dynamo problem in a flow that is random, white-in-time, with both solenoidal and potential components. This model is a generalization of the well-studied Kazantsev model. If both the solenoidal and potential parts have the same scaling exponent, then, as the compressibility of the flow increases, the growth rate decreases but remains positive. If the scaling exponents for the solenoidal and potential parts differ, in particular if they correspond to typical Kolmogorov and Burgers values, we again find that an increase in compressibility slows down the growth rate but does not turn it off. The slow down is, however, weaker and the critical magnetic Reynolds number is lower than when both the solenoidal and potential components display the Kolmogorov scaling. Intriguingly, we find that there exist cases, when the potential part is smoother than the solenoidal part, for which an increase in compressibility increases the growth rate. We also find that the critical value of the scaling exponent above which a dynamo is seen is unity irrespective of the compressibility. Finally, we realize that the dimension d  = 3 is special, as for all other values of d the critical exponent is higher and depends on the compressibility.

GROWTH OF PERCOLATED Ag NANOSTRUCTURES ON Si(111)-(7 × 7) SURFACES

2011 ◽  
Vol 10 (01n02) ◽  
pp. 123-127
Author(s):  
D. K. GOSWAMI ◽  
A. PAL
Keyword(s):  
Statistical Analysis ◽  
Surface Morphology ◽  
Room Temperature ◽  
Atomic Layer ◽  
Atomic Scale ◽  
Growth Exponent ◽  
Scanning Tunneling ◽  
Scaling Exponent ◽  
Scaling Exponents ◽  
Growth Scaling

Growth of Ag nanostructures on Si (111)-7 × 7 surfaces has been investigated at the atomic scale regime by studying the evolution of nanoscale surface morphology with Ag coverage. Ag growth on Si (111)-7 × 7 surfaces at room temperature showed a strongly preferential height with even atomic layer thick flat top percolated islands. Here we report that the roughness scaling exponent α and growth scaling exponents β associated with such electronic growth mode are determined by statistical analysis of rough surfaces obtained from scanning tunneling micrograph images of Ag nanostructures grown on Si (111)-7 × 7 surfaces. Observed roughness and growth exponent for this system are 0.82±0.02 and 0.45±0.04, respectively.

scholarly journals Effects of AtSPS on the Growth and Development of Arabidopsis thaliana under Abiotic Stress

2021 ◽  
pp. 39-44
Author(s):  
Bao-Zhen Zhao ◽  
Yang Yu ◽  
Zhi Yang ◽  
Qi Ding ◽  
Na Cui
Keyword(s):  
Arabidopsis Thaliana ◽  
Abiotic Stress ◽  
Plant Growth ◽  
Stress Resistance ◽  
Growth And Development ◽  
Soluble Sugar ◽  
Test Material ◽  
Insertion Mutant ◽  
Plant Growth And Development ◽  
Dna Insertion

Aims: SPS (Sucrose phosphate synthase) participates in plant growth and yield formation, and plays an important role in plant stress resistance. This study used T-DNA insertion mutant of AtSPS in Arabidopsis as test material. The growth indexes and soluble sugar contents of Arabidopsis thaliana under salt stress, osmotic stress and low temperature stress were determined, which laid the foundation for further understanding the mechanism of SPS in plant growth and development and abiotic stress resistance. Study Design: In order to analyze the mechanism of SPS in plant growth and development and abiotic stress resistance, this study used T-DNA insertion mutant of AtSPS in Arabidopsis as test material. The growth indexes and soluble sugar contents of Arabidopsis thaliana under salt stress, osmotic stress and low temperature stress were determined. Place and Duration of Study: College of Biological Science and Technology, between December 2020 and May 2021. Methodology: The contents of soluble sugar in tomato fruits were measured with HPLC (High performance liquid chromatography). The growth indexes were determined. Results: The results showed that AtSPS played positive regulation roles in seed germination and seedling growth of Arabidopsis thaliana. However, under abiotic stress conditions, AtSPS mutant increased the contents of soluble sugar, suggesting that Arabidopsis thaliana seedlings might improve resistance through osmotic regulating substances. Conclusion: AtSPS played positive regulation roles in seed germination and seedling growth of Arabidopsis. Meanwhile, AtSPS mutant increased the contents of soluble sugar to increase resistance of Arabidopsis under abiotic stresses, and the growth and development were blocked, suggesting that SPS was negative regulatory element to resist abiotic stress.

Maize similar to RCD1 gene induced by salt enhances Arabidopsis thaliana abiotic stress resistance

2018 ◽  
Vol 503 (4) ◽  
pp. 2625-2632 ◽  
Author(s):  
Xiaoyu Li ◽  
Yunjian Xu ◽  
Fang Liu ◽  
Manli Zhao ◽  
Yi Sun ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Abiotic Stress ◽  
Stress Resistance

scholarly journals Characterizing Growth and Form of Fractal Cities with Allometric Scaling Exponents

2010 ◽  
Vol 2010 ◽  
pp. 1-22 ◽  
Author(s):  
Yanguang Chen
Keyword(s):  
Fractal Dimension ◽  
Allometric Scaling ◽  
Fractal Dimensions ◽  
Scaling Exponent ◽  
Allometric Growth ◽  
Scaling Exponents ◽  
Scaling Invariance ◽  
Spatial Features ◽  
Limited Scale ◽  
Different Dimensions

Fractal growth is a kind of allometric growth, and the allometric scaling exponents can be employed to describe growing fractal phenomena such as cities. The spatial features of the regular fractals can be characterized by fractal dimension. However, for the real systems with statistical fractality, it is incomplete to measure the structure of scaling invariance only by fractal dimension. Sometimes, we need to know the ratio of different dimensions rather than the fractal dimensions themselves. A fractal-dimension ratio can make an allometric scaling exponent (ASE). As compared with fractal dimension, ASEs have three advantages. First, the values of ASEs are easy to be estimated in practice; second, ASEs can reflect the dynamical characters of system's evolution; third, the analysis of ASEs can be made through prefractal structure with limited scale. Therefore, the ASEs based on fractal dimensions are more functional than fractal dimensions for real fractal systems. In this paper, the definition and calculation method of ASEs are illustrated by starting from mathematical fractals, and, then, China's cities are taken as examples to show how to apply ASEs to depiction of growth and form of fractal cities.

Role of melatonin in UV‐B signaling pathway and UV‐B stress resistance in Arabidopsis thaliana

2020 ◽  
Vol 44 (1) ◽  
pp. 114-129
Author(s):  
Jing‐Wen Yao ◽  
Zheng Ma ◽  
Yan‐Qin Ma ◽  
Ying Zhu ◽  
Meng‐Qi Lei ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Signaling Pathway ◽  
Stress Resistance

scholarly journals Biological scaling in green algae: the role of cell size and geometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helena Bestová ◽  
Jules Segrestin ◽  
Klaus von Schwartzenberg ◽  
Pavel Škaloud ◽  
Thomas Lenormand ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Internal Diffusion ◽  
Scaling Exponent ◽  
Power Scaling ◽  
Nutrient Distribution ◽  
Metabolic Scaling ◽  
Key Factor ◽  
Size And Morphology

AbstractThe Metabolic Scaling Theory (MST), hypothesizes limitations of resource-transport networks in organisms and predicts their optimization into fractal-like structures. As a result, the relationship between population growth rate and body size should follow a cross-species universal quarter-power scaling. However, the universality of metabolic scaling has been challenged, particularly across transitions from bacteria to protists to multicellulars. The population growth rate of unicellulars should be constrained by external diffusion, ruling nutrient uptake, and internal diffusion, operating nutrient distribution. Both constraints intensify with increasing size possibly leading to shifting in the scaling exponent. We focused on unicellular algae Micrasterias. Large size and fractal-like morphology make this species a transitional group between unicellular and multicellular organisms in the evolution of allometry. We tested MST predictions using measurements of growth rate, size, and morphology-related traits. We showed that growth scaling of Micrasterias follows MST predictions, reflecting constraints by internal diffusion transport. Cell fractality and density decrease led to a proportional increase in surface area with body mass relaxing external constraints. Complex allometric optimization enables to maintain quarter-power scaling of population growth rate even with a large unicellular plan. Overall, our findings support fractality as a key factor in the evolution of biological scaling.

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