scholarly journals Diverse strategies link growth rate and competitive ability in phytoplankton responses to changes in CO2 levels

2019 ◽  
Author(s):  
Sinead Collins ◽  
C. Elisa Schaum
Keyword(s):  
Growth Rate ◽  
Specific Energy ◽  
Competitive Ability ◽  
Energy Allocation ◽  
Maximum Energy ◽  
Growth Strategies ◽  
Primary Producers ◽  
Data Archiving ◽  
Organismal Biology ◽  
Co2 Levels

AbstractAquatic microbial primary producers exist in genetically variable populations, but are often studied as single lineages. However, the properties of lineages grown alone often fail to predict the composition of microbial assemblages. We demonstrate that different lineages of a marine picoplankter have unique growth strategies, and that they modulate their lineage growth rate in the presence of other lineages. This explains why growth rates of lineages in isolation do not reliably predict the lineage composition of assemblages. The diversity of growth strategies observed are consistent with lineage-specific energy-allocation that depends on social milieu. Since lineage growth is only one of many traits determining fitness in natural assemblages, we propose that in all but the poorest quality environments where allocating maximum energy to growth is the only viable strategy, we should expect intraspecific variation in growth strategies, with more strategies possible in ameliorated environments, such as high CO2 for many marine picoplankton. This emphasizes the importance of understanding and accounting for basic organismal biology in our models of aquatic primary producers.Data archivingShould this manuscript be accepted, data will be archived at Pangea, and the DOI be included at the end of the article

scholarly journals Growth strategies of a model picoplankter depend on social milieu and p CO 2

2021 ◽  
Vol 288 (1955) ◽  
pp. 20211154
Author(s):  
Sinead Collins ◽  
C. Elisa Schaum
Keyword(s):  
Growth Rate ◽  
Specific Energy ◽  
Growth Rates ◽  
Microbial Growth ◽  
Resource Competition ◽  
Maximum Growth ◽  
Energy Allocation ◽  
Diverse Populations ◽  
Growth Strategies ◽  
Social Milieu

Phytoplankton exist in genetically diverse populations, but are often studied as single lineages (single strains), so that interpreting single-lineage studies relies critically on understanding how microbial growth differs with social milieu, defined as the presence or absence of conspecifics. The properties of lineages grown alone often fail to predict the growth of these same lineages in the presence of conspecifics, and this discrepancy points towards an opportunity to improve our understanding of the factors that affect lineage growth rates. We demonstrate that different lineages of a marine picoplankter modulate their maximum lineage growth rate in response to the presence of non-self conspecifics, even when resource competition is effectively absent. This explains why growth rates of lineages in isolation do not reliably predict their growth rates in mixed culture, or the lineage composition of assemblages under conditions of rapid growth. The diversity of growth strategies observed here are consistent with lineage-specific energy allocation that depends on social milieu. Since lineage growth is only one of many traits determining fitness in natural assemblages, we hypothesize that intraspecific variation in growth strategies should be common, with more strategies possible in ameliorated environments that support higher maximum growth rates, such as high CO 2 for many marine picoplankton.

scholarly journals Bacterial Quorum Sensing Stabilizes Cooperation by Optimizing Growth Strategies

2016 ◽  
Vol 82 (22) ◽  
pp. 6498-6506 ◽  
Author(s):  
Eric L. Bruger ◽  
Christopher M. Waters
Keyword(s):  
Growth Rate ◽  
Quorum Sensing ◽  
Experimental Evidence ◽  
Fundamental Problem ◽  
Growth Yield ◽  
Cellular Growth ◽  
Growth Strategies ◽  
High Cell ◽  
Content Type ◽  
Cell Densities

ABSTRACTCommunication has been suggested as a mechanism to stabilize cooperation. In bacteria, chemical communication, termed quorum sensing (QS), has been hypothesized to fill this role, and extracellular public goods are often induced by QS at high cell densities. Here we show, with the bacteriumVibrio harveyi, that QS provides strong resistance against invasion of a QS defector strain by maximizing the cellular growth rate at low cell densities while achieving maximum productivity through protease upregulation at high cell densities. In contrast, QS mutants that act as defectors or unconditional cooperators maximize either the growth rate or the growth yield, respectively, and thus are less fit than the wild-type QS strain. Our findings provide experimental evidence that regulation mediated by microbial communication can optimize growth strategies and stabilize cooperative phenotypes by preventing defector invasion, even under well-mixed conditions. This effect is due to a combination of responsiveness to environmental conditions provided by QS, lowering of competitive costs when QS is not induced, and pleiotropic constraints imposed on defectors that do not perform QS.IMPORTANCECooperation is a fundamental problem for evolutionary biology to explain. Conditional participation through phenotypic plasticity driven by communication is a potential solution to this dilemma. Thus, among bacteria, QS has been proposed to be a proximate stabilizing mechanism for cooperative behaviors. Here, we empirically demonstrate that QS inV. harveyiprevents cheating and subsequent invasion by nonproducing defectors by maximizing the growth rate at low cell densities and the growth yield at high cell densities, whereas an unconditional cooperator is rapidly driven to extinction by defectors. Our findings provide experimental evidence that QS regulation prevents the invasion of cooperative populations by QS defectors even under unstructured conditions, and they strongly support the role of communication in bacteria as a mechanism that stabilizes cooperative traits.

scholarly journals Trusting the hand that feeds: microbes evolve to anticipate a serial transfer protocol as individuals or collectives

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Bram van Dijk ◽  
Jeroen Meijer ◽  
Thomas D. Cuypers ◽  
Paulien Hogeweg
Keyword(s):  
Growth Rate ◽  
In Silico ◽  
High Growth ◽  
Growth Cycle ◽  
High Growth Rate ◽  
Divergent Evolution ◽  
High Yield ◽  
Growth Strategies ◽  
Serial Transfer ◽  
Transfer Protocol

Abstract Background Experimental evolution of microbes often involves a serial transfer protocol, where microbes are repeatedly diluted by transfer to a fresh medium, starting a new growth cycle. This has revealed that evolution can be remarkably reproducible, where microbes show parallel adaptations both on the level of the phenotype as well as the genotype. However, these studies also reveal a strong potential for divergent evolution, leading to diversity both between and within replicate populations. We here study how in silico evolved Virtual Microbe “wild types” (WTs) adapt to a serial transfer protocol to investigate generic evolutionary adaptations, and how these adaptations can be manifested by a variety of different mechanisms. Results We show that all WTs evolve to anticipate the regularity of the serial transfer protocol by adopting a fine-tuned balance of growth and survival. This anticipation is done by evolving either a high yield mode, or a high growth rate mode. We find that both modes of anticipation can be achieved by individual lineages and by collectives of microbes. Moreover, these different outcomes can be achieved with or without regulation, although the individual-based anticipation without regulation is less well adapted in the high growth rate mode. Conclusions All our in silico WTs evolve to trust the hand that feeds by evolving to anticipate the periodicity of a serial transfer protocol, but can do so by evolving two distinct growth strategies. Furthermore, both these growth strategies can be accomplished by gene regulation, a variety of different polymorphisms, and combinations thereof. Our work reveals that, even under controlled conditions like those in the lab, it may not be possible to predict individual evolutionary trajectories, but repeated experiments may well result in only a limited number of possible outcomes.

scholarly journals Genotype-specific relationships among phosphorus use, growth and abundance in Daphnia pulicaria

2017 ◽  
Vol 4 (12) ◽  
pp. 170770 ◽  
Author(s):  
Ryan E. Sherman ◽  
Priyanka Roy Chowdhury ◽  
Kristina D. Baker ◽  
Lawrence J. Weider ◽  
Punidan D. Jeyasingh
Keyword(s):  
Growth Rate ◽  
Ecological Stoichiometry ◽  
Competitive Ability ◽  
Nutrient Content ◽  
Nutrient Supply ◽  
P Limitation ◽  
Poor Predictor ◽  
Nutrient Use ◽  
P Content ◽  
Stoichiometric Models

The framework ecological stoichiometry uses elemental composition of species to make predictions about growth and competitive ability in defined elemental supply conditions. Although intraspecific differences in stoichiometry have been observed, we have yet to understand the mechanisms generating and maintaining such variation. We used variation in phosphorus (P) content within a Daphnia species to test the extent to which %P can explain variation in growth and competition. Further, we measured 33 P kinetics (acquisition, assimilation, incorporation and retention) to understand the extent to which such variables improved predictions. Genotypes showed significant variation in P content, 33 P kinetics and growth rate. P content alone was a poor predictor of growth rate and competitive ability. While most genotypes exhibited the typical growth penalty under P limitation, a few varied little in growth between P diets. These observations indicate that some genotypes can maintain growth under P-limited conditions by altering P use, suggesting that decomposing P content of an individual into physiological components of P kinetics will improve stoichiometric models. More generally, attention to the interplay between nutrient content and nutrient-use is required to make inferences regarding the success of genotypes in defined conditions of nutrient supply.

Littleseed Canarygrass (Phalaris minor) and Short-spiked Canarygrass (Phalaris brachystachys) Interference in Wheat and Barley

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 560-565 ◽  
Author(s):  
Catherine G. Afentouli ◽  
I. G. Eleftherohorinos
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Competitive Ability ◽  
Field Experiments ◽  
Wheat Yield ◽  
Time Study ◽  
Stages Of Growth ◽  
Removal Time ◽  
Panicle Number ◽  
Dry Conditions

Field experiments were established in Greece from 1990 to 1993 to study the effect of littleseed and short-spiked canarygrass density on wheat and barley yield, as well as the influence of littleseed canarygrass removal time on wheat yield. Competitive ability of both canarygrass species in wheat was similar, though littleseed canarygrass showed faster growth rate and formed more panicles than short-spiked canarygrass. Grain yield of wheat was not significantly affected by the presence of 76 plants m−2 of either canarygrass species, but it was reduced by 36 to 39% by the presence of 304 canarygrass plants m−2. None of the canarygrass species at any density had any effect on grain yield of wheat when cold and dry conditions prevailed during the early stages of growth. Grain yield of barley was not affected by any density of either canarygrass species. Growth and consequently panicle number of both canarygrass species were severely reduced by the interference of barley. The littleseed canarygrass removal time study indicated that emergence of this weed was completed by the middle of February. Grain yield of wheat grown with 150 littleseed canarygrass plants m−2 was not affected even when these plants were removed early in April. However, the presence of these canarygrass plants until harvest reduced grain yield of wheat by 23 to 28%.

Accumulation of Persistent Pollutants in Normal and Dwarfed Arctic Char (Salvelinus alpinus sp. complex)

1993 ◽  
Vol 50 (12) ◽  
pp. 2574-2580 ◽  
Author(s):  
Johan Hammar ◽  
Per Larsson ◽  
Maris Klavins
Keyword(s):  
Growth Rate ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Individual Growth ◽  
The Arctic ◽  
Growth Strategies ◽  
Sympatric Populations ◽  
Fast Growing ◽  
Persistent Pollutants ◽  
Slow Growing

Two extreme growth fractions of introgressed sympatric populations of the Arctic char (Salvelinus alpinus) species complex from Lake Blåsjön, northern Sweden, were sampled for individual concentrations of persistent pollutants originating from atmospheric deposition. Slow growing char (dwarfs) had significantly higher levels of SPCB (sum of PCB congeners found) and p,p-DDE (dominating DDT-compound) than fast growing char (normals). Besides demonstrating a highly divergent growth pattern the introgressed populations also inhabit a great range of depths, and the seasonal food consumption rates may differ between extreme growth fractions, although the same major invertebrates (introduced Mysis relicta and Pallasea quadrispinosa) are consumed over the year. However, of the life history parameters differing in late spring, individual growth rate was the most important factor explaining the variation in the levels of the pollutants studied. The results support the hypothesis of a biomass "dilution" of pollutants in fish, illustrated by lower levels in fast growing char and higher levels in the slow-growing dwarfs. Individuals with alternative growth strategies in sympatric conspecific communities thus provide unique opportunities to study growth rate as a variable influencing levels of persistent pollutants in fish.

Trade-Off between Interspecific Competitive Ability and Growth Rate in Bacteria

Ecology ◽  
1990 ◽  
Vol 71 (2) ◽  
pp. 645-650 ◽  
Author(s):  
Yasushi Kurihara ◽  
Shuichi Shikano ◽  
Masahiko Toda
Keyword(s):  
Growth Rate ◽  
Competitive Ability ◽  
Trade Off
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