Variation and Adaptive Role of Seed Dormancy in Some Annual Grassland Species

1982 ◽  
Vol 143 (1) ◽  
pp. 101-106 ◽  
Author(s):  
S. K. Jain
Keyword(s):  
Seed Dormancy ◽  
Grassland Species ◽  
Annual Grassland ◽  
Adaptive Role

Adaptive Role of Lipids in Algae under Metal Ions Impact (a Review)

2018 ◽  
Vol 54 (6) ◽  
pp. 78-93
Author(s):  
V. V. Grubinko ◽  
O. I. Bodnar ◽  
A. I. Lutsiv ◽  
G. B. Viniarska
Keyword(s):  
Metal Ions ◽  
Adaptive Role

Role of ethylene and proteolytic N‐degron pathway in the regulation of Arabidopsis seed dormancy

2021 ◽  
Author(s):  
Xu Wang ◽  
Malaika Maraya Gomes ◽  
Christophe Bailly ◽  
Eiji Nambara ◽  
Françoise Corbineau
Keyword(s):  
Seed Dormancy ◽  
Arabidopsis Seed

scholarly journals Risky Politics? Associations between Adolescent Risk Preference and Political Engagement

2019 ◽  
Author(s):  
Benjamin Oosterhoff
Keyword(s):  
Risk Preference ◽  
Political Engagement ◽  
Political Interest ◽  
Government Officials ◽  
Adolescent Risk ◽  
Future Data ◽  
Monitoring The Future ◽  
Nationally Representative ◽  
Adaptive Role

This study examined associations among adolescent risk preference and political engagement using nationally representative Monitoring the Future data from high school seniors (N=109,574; modal age=18 years) spanning 1976-2014. Greater risk preference was associated with greater past voting, donating to a campaign, writing government officials, boycotting, and protesting. Greater risk preference was associated with higher future intentions to boycott and protest, but lower intentions to donate to or volunteer for a campaign. In general, associations between risk preference and political engagement became stronger with higher levels of political interest. Results highlight the importance of considering the adaptive role of adolescent risk preference and suggest that political engagement may be a constructive outlet for youth who pursue or are comfortable taking risks.

Regulation of seed dormancy by abscisic acid and DELAY OF GERMINATION 1

2015 ◽  
Vol 25 (2) ◽  
pp. 82-98 ◽  
Author(s):  
Bas J.W. Dekkers ◽  
Leónie Bentsink
Keyword(s):  
Abscisic Acid ◽  
Seed Dormancy ◽  
Plant Hormone ◽  
Complex Trait ◽  
Hormone Interactions ◽  
Physiological Dormancy ◽  
Recent Developments ◽  
Radicle Emergence ◽  
Dormancy Induction

AbstractPhysiological dormancy has been described as a physiological inhibiting mechanism that prevents radicle emergence. It can be caused by the embryo (embryo dormancy) as well as by the structures that cover the embryo. One of its functions is to time plant growth and reproduction to the most optimal season and therefore, in nature, dormancy is an important adaptive trait that is under selective pressure. Dormancy is a complex trait that is affected by many loci, as well as by an intricate web of plant hormone interactions. Moreover, it is strongly affected by a multitude of environmental factors. Its induction, maintenance, cycling and loss come down to the central paradigm, which is the balance between two key hormonal regulators, i.e. the plant hormone abscisic acid (ABA), which is required for dormancy induction, and gibberellins (GA), which are required for germination. In this review we will summarize recent developments in dormancy research (mainly) in the model plant Arabidopsis thaliana, focusing on two key players for dormancy induction, i.e. the plant hormone ABA and the DELAY OF GERMINATION 1 (DOG1) gene. We will address the role of ABA and DOG1 in relation to various aspects of seed dormancy, i.e. induction during seed maturation, loss during dry seed afterripening, the rehydrated state (including dormancy cycling) and the switch to germination.

Gene loss and gain in the evolution of the vertebrates

Development ◽  
1994 ◽  
Vol 1994 (Supplement) ◽  
pp. 155-161
Author(s):  
Frank H. Ruddle ◽  
Kevin L. Bentley ◽  
Michael T. Murtha ◽  
Neil Risch
Keyword(s):  
Hox Genes ◽  
Gene Loss ◽  
Biological Function ◽  
Hox Gene ◽  
Step Process ◽  
Gene Expansion ◽  
Multiple Clusters ◽  
Adaptive Role ◽  
Hox Clusters

Homeobox cluster genes (Hox genes) are highly conserved and can be usefully employed to study phyletic relationships and the process of evolution itself. A phylogenetic survey of Hox genes shows an increase in gene number in some more recently evolved forms, particularly in vertebrates. The gene increase has occurred through a two-step process involving first, gene expansion to form a cluster, and second, cluster duplication to form multiple clusters. We also describe data that suggests that non-Hox genes may be preferrentially associated with the Hox clusters and raise the possibility that this association may have an adaptive biological function. Hox gene loss may also play a role in evolution. Hox gene loss is well substantiated in the vertebrates, and we identify additional possible instances of gene loss in the echinoderms and urochordates based on PCR surveys. We point out the possible adaptive role of gene loss in evolution, and urge the extension of gene mapping studies to relevant species as a means of its substantiation.

The time when the “Tomte” of evolution was playing with time

2001 ◽  
Vol 24 (2) ◽  
pp. 287-287
Author(s):  
Giorgio M. Innocenti
Keyword(s):  
Developmental Plasticity ◽  
Brain Structures ◽  
Developmental Constraints ◽  
Developmental Mechanisms ◽  
Differential Expansion ◽  
High Degree ◽  
Adaptive Role

Developmental constraints presumably had a major role in channeling evolution. In particular, developmental mechanisms may have coordinated the evolution of neocortex with that of other brain structures. However, the rules determining the differential expansion of different cortical territories remain to be determined as well as the adaptive role of cortical expansion versus that of the structures it is connected to. The high degree of developmental plasticity of neocortex was probably the key to its successful evolution.

scholarly journals Distribution of seed dormancy classes across a fire-prone continent: effects of rainfall seasonality and temperature

2020 ◽  
Author(s):  
Justin C Collette ◽  
Mark K J Ooi
Keyword(s):  
Seed Dormancy ◽  
Critical Role ◽  
Fire Regimes ◽  
Common Species ◽  
Functional Responses ◽  
Stochastic Disturbance ◽  
Climate Gradients ◽  
Selective Pressures ◽  
Rainfall Seasonality

Abstract Background and Aims Different seed dormancy classes control the timing of germination via different cues. The ecological dissimilarities between classes therefore suggest that they are likely to be subject to different selective pressures, and that species within each class will have diverse functional responses. We aimed to investigate this by assessing how variation in the distribution of dormancy classes is correlated with regional environmental factors, in particular rainfall seasonality and temperature. Additionally, we compare the relative proportions of species with physiological (PD) or physical (PY) dormancy to assess whether dormancy class influences their ability to persist under different rainfall seasonality regimes. Methods Dormancy class was assigned for 3990 species from 281 genera occurring across two climate regions, with either winter or aseasonal rainfall, across temperate fire-prone Australia. All regions have similar vegetation and fire regimes. Using a Bayesian framework, we compared the distribution of dormancy classes across temperature and rainfall climate gradients, for threatened and common species. Key Results A high dormant:non-dormant species ratio highlighted the critical role of dormancy across our study regions. Critically, species showing PD were more likely to be threatened in aseasonal rainfall climate regions. Conclusions Our results support the assumption that dormancy is favoured in environments with stochastic disturbance

Sign in / Sign up

Export Citation Format

Share Document