The first cavefish in the Dinaric Karst?Cave colonization made possible by phenotypic plasticity in Telestes karsticus

Cave animals are an excellent model system for studying adaptive evolution.At present,however,little is known about the mechanisms that enable surface colonizers to survive in the challenging environment of caves.One possibility is that these species have the necessary genetic background to respond with plastic changes to the pressures of underground habitats.To gain insight into this process,we conducted a comparative study with the fish species Telestes karsticus,which occurs in a hydrological system consisting of an interconnected stream and a cave.Results showed that T.karsticus resided year-round and spawned in Sušik cave,making it the first known cavefish in the Dinaric Karst.Cave and surface populations differed in morphological and physiological characteristics,as well as in patterns of gene expression without any evidence of genetic divergence.To test whether observed trait differences were plastic or genetic,we placed adult fish from both populations under light/dark or constant dark conditions.Common laboratory conditions erased all morphometric differences between the two morphs,suggesting phenotypic plasticity is driving the divergence of shape and size in wild fish.Lighter pigmentation and increased fat deposition exhibited by cave individuals were also observed in surface fish kept in the dark in the laboratory.Our study also revealed that specialized cave traits were not solely attributed to developmental plasticity,but also arose from adult responses,including acclimatization.Thus,we conclude that T.karsticus can adapt to cave conditions,with phenotypic plasticity playing an important role in the process of cave colonization.

Phenotypic plasticity in the monoclonal marbled crayfish is associated with very low genetic diversity but pronounced epigenetic diversity

Clonal organisms are particularly useful to investigate the contribution of epigenetics to phenotypic plasticity,because confounding effects of genetic variation are negligible.In the last decade,the apomictic parthenogenetic marbled crayfish,Procambarus virginalis,has been developed as a model to investigate the relationships between phenotypic plasticity and genetic and epigenetic diversity in detail.This crayfish originated about 30 years ago by autotriploidy from a single slough crayfish Procambarus fallax.As the result of human releases and active spreading,marbled crayfish has established numerous populations in very diverse habitats in 22 countries from the tropics to cold temperate regions.Studies in the laboratory and field revealed considerable plasticity in coloration,spination,morphometric parameters,growth,food preference,population structure,trophic position,and niche width.Illumina and PacBio whole-genome sequencing of marbled crayfish from representatives of 19 populations in Europe and Madagascar demonstrated extremely low genetic diversity within and among populations,indicating that the observed phenotypic diversity and ability to live in strikingly different environments are not due to adaptation by selection on genetic variation.In contrast,considerable differences were found between populations in the DNA methylation patterns of hundreds of genes,suggesting that the environmentally induced phenotypic plasticity is mediated by epigenetic mechanisms and corresponding changes in gene expression.Specific DNA methylation fingerprints persisted in local populations over successive years indicating the existence of epigenetic ecotypes,but there is presently no information as to whether these epigenetic signatures are transgenerationally inherited or established anew in each generation and whether the recorded phenotypic plasticity is adaptive or nonadaptive.

Modeling the influence of phenotypic plasticity on maize hybrid performance

Phenotypic plasticity,the ability of an individual to alter its phenotype in response to changes in the environment,has been proposed as a target for breeding crop varieties with high environmental fitness.Here,we used phenotypic and genotypic data from multiple maize(Zea mays L.)populations to mathematically model phenotypic plasticity in response to the environment(PPRE)in inbred and hybrid lines.PPRE can be simply described by a linear model in which the two main parameters,intercept a and slope b,reflect two classes of genes responsive to endogenous(class A)and exogenous(class B)signals that coordinate plant development.Together,class A and class B genes contribute to the phenotypic plasticity of an individual in response to the environment.We also made connections between phenotypic plasticity and hybrid performance or general combining ability(GCA)of yield using 30 F_(1) hybrid populations generated by crossing the same maternal line with 30 paternal lines from different maize heterotic groups.We show that the parameters a and b from two given parental lines must be concordant to reach an ideal GCA of F_(1) yield.We hypothesize that coordinated regulation of the two classes of genes in the F_(1) hybrid genome is the basis for high GCA.Based on this theory,we built a series of predictive models to evaluate GCA in silico between parental lines of different heterotic groups.

Genetic interrogation of phenotypic plasticity informs genome-enabled breeding in cotton

Phenotypic plasticity, or the ability to adapt to and thrive in changing climates and variable environments, is essential for developmental programs in plants. Despite its importance, the genetic underpinnings of phenotypic plasticity for key agronomic traits remain poorly understood in many crops. In this study, we aim to fill this gap by using genome-wide association studies to identify genetic variations associated with phenotypic plasticity in upland cotton (Gossypium hirsutum L.). We identified 73 additive quantitative trait loci (QTLs), 32 dominant QTLs, and 6799 epistatic QTLs associated with 20 traits. We also identified 117 additive QTLs, 28 dominant QTLs, and 4691 epistatic QTLs associated with phenotypic plasticity in 19 traits. Our findings reveal new genetic factors, including additive, dominant, and epistatic QTLs, that are linked to phenotypic plasticity and agronomic traits. Meanwhile, we find that the genetic factors controlling the mean phenotype and phenotypic plasticity are largely independent in upland cotton, indicating the potential for simultaneous improvement. Additionally, we envision a genomic design strategy by utilizing the identified QTLs to facilitate cotton breeding. Taken together, our study provides new insights into the genetic basis of phenotypic plasticity in cotton, which should be valuable for future breeding.

Role of phenotypic plasticity in morphological differentiation between watersnake populations

An individual’s morphology is shaped by the environmental pressures it experiences,and the resulting morphological response is the culmination of both genetic factors and environmental(non-genetic)conditions experienced early in its life(i.e.phenotypic plasticity).The role that phenotypic plasticity plays in shaping phenotypes is important,but evidence for its influence is often mixed.We exposed female neonate diamond-backed watersnakes(Nerodia rhombifer)from populations experiencing different prey-size regimes to different feeding treatments to test the influence of phenotypic plasticity in shaping trophic morphology.We found that snakes in a large-prey treatment from a population frequently encountering large prey exhibited a higher growth rate in body size than individuals in a small-prey treatment from the same population.This pattern was not observed in snakes from a population that regularly encounters small prey.We also found that regardless of treatment,snakes from the smallprey population were smaller at birth than snakes from the large-prey population and remained so throughout the study.These results suggest that the ability to plastically respond to environmental pressures may be populationspecific.These results also indicate a genetic predisposition towards larger body sizes in a population where large prey items are more common.

Significance of differential allelic expression in phenotypic plasticity and evolutionary potential of microbial eukaryotes

Background:Differential allelic expression(DAE)plays a key role in the regularion of many biological processes,and it may also play a role in adaptive evolution.Recently,environment-dependent DAE has been observed in species of marine phytoplankton,and most remarkably,alleles that showed the highest level of DAE also showed the fastest rate of evolution.Methods:To better understand the role of DAE in adaptive evolution and phenotypic plasticity,we developed a 2-D cellular automata model“DAEsy-World”that builds on the classical Daisyworld model.Results:Simulations show that DAE delineates the evolution of alternative alleles of a gene,enabling the two alleles to adapt to different environmental conditions and sub-functionalize.With DAE,the build-up of genetic polymorphisms within genes is driven by positive selection rather than strict neutral evolution,and this can enhance phenotypic plasticity.Moreover,in sexually reproducing organisms,DAE also increased the standing genetic variation,augmenting a species’adaptive evolutionary potential and ability to respond to fluctuating and/or changing conditions(cf,genetic assimilation).We furthermore show that DAE is likely to evolve in fluctuating environmental conditions.Conclusions:DAE increases the adaptive evolutionary potential of both sexual and asexually reproducing organisms,and it may affect the pattern of nucleotide substitutions of genes.

Leaf phenotypic variation in natural populations of Carpinus tschonoskii in China

Carpinus tschonoskii Maxim.exhibits rich leaf phenotypic variation and various leaf shapes,but few studies show why leaf phenotypic traits have such a large variation.Basic morphological markers may provide guidance for studying plant genetic variation and species protection and utilization.To study leaf phenotypic variations and the relationship between variation characteristics and climatic and geographical factors,phenotypic traits among natural populations were investigated.Results revealed that leaf phenotypes varied significantly among and within populations.Some populations had higher phenotypic diversity,while others had lower phenotypic diversity.Among the phenotypic traits,leaf area and petiole length had the most variation.Leaf index and primary lateral veins were the most stable phenotypes,which may be important reference indexes for phenotype identification in field investigations.There was a strong consistency between leaf phenotypic traits and geographical location.Plants in high latitudes tend to have longer leaves,and plants in low temperatures tend to have longer leaves and larger leaf perimeter.In addition,plants in areas with less rainfall have longer petioles.The 13 populations of C.tschonoskii can be divided into four branches by cluster analysis,and the results show a good relationship with the geographical location of each population.Additionally,some populations geographically isolated also had unique leaf phenotypes.

Causal Analysis Between Rice Growth and Cadmium Accumulation and Transfer under Arbuscular Mycorrhizal Inoculation

Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF.

Fate of rubber bush (Calotropis procera (Aiton) W. T. Aiton) in adversary environment modulated by microstructural and functional attributes

Calotropis procera(Aiton)W.T.Aiton,belonging to the family Apocynaceae,is C3 evergreen plant species in arid and semi-arid areas of the Punjab Province,Pakistan.It grows in a variety of habitats like salt affected and waterlogged area,desert/semi-desert,roadside,wasteland,graveyard,forest,crop field,coastline,and river/canal bank.A total of 12 populations growing in different ecological regions were sampled to evaluate their growth,physio-biochemical,and anatomical responses to specific environmental condition.Population adapted to desert/semi-desert showed vigorous growth(plant height,shoot length,and number of leaves),enhanced photosynthetic level(chlorophyll a,chlorophyll b,carotenoids,and total chlorophyll),and apparent anatomical modifications such as increased stem radius,cuticle thickness,storage parenchyma tissues(cortex and pith),and vascular bundles in stems,while the maximum of midrib and lamina thickness,epidermal cells,cuticle thickness,cortical proportion,abaxial stomatal density,and its area in leaves.There was high plasticity in structural and functional features of these populations,which enable them to survive and tolerate under such hot and dry desert environment.Population of saline areas exhibited very critical modifications to sustain under salt prone environment.At physiological level,it possesses the maximum amount of organic osmolytes(glycine betaine and proline)and antioxidants(superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)),while at anatomical level,it showed intensive sclerification,large phloem region(inner and outer),pith parenchyma cells,and metaxylem vessels in stems and leaves.The population of dry mountains showed very distinctive features,such as increased shoot ionic contents(K+and Ca2+),collenchyma and sclerenchyma thickness in stems,trichomes size,and numerous small stomata on abaxial surface of leaves.It is concluded that no definite or precise single character can be taken as a yardstick for adjudging the biomass production in this rubber bush weed population.

A highly effective incubation strategy enhanced the urban bird hatch success

Urbanization is currently considered one of the most rapid types of global environmental change.Urban habitats are biotically and abiotically different from their rural areas,i.e.,the ambient temperature,predator,and food availability.These novel challenges create new selection pressures,which allow one to investigate ecoevolutionary responses to contemporary environmental change.A total of 118 breeding nests were monitored for nest predation in both urban and rural areas from 2018 to 2020.We used environmental factors from urban and rural areas and behavioral data from 439 Chinese Blackbird(Turdus mandarinus)valid incubation days to understand the impact of urbanization on the incubation behavior of blackbirds and its adaptation mechanism to the urban environment.Cities have warmer ambient temperatures and lower predation pressures than rural areas.Urban blackbirds chose the incubation strategy with shorter and more bouts,while rural blackbirds selected the incubation strategy with longer and fewer bouts.The plasticity of incubation behavior of urban blackbirds was higher than that of rural areas,and the range of egg temperature was also higher than that of rural areas.In addition,incubation temperature and the number of bouts per day were the key factors affecting the day survival rate of blackbirds,and the hatching rate of urban blackbirds was higher than that of rural blackbirds.Our results provide evidence for behavioral shifts in blackbirds during adaptation to urbanization and support the central role of behavioral adaptation in the successful colonization of new environments by wildlife.These help us understand the behavioral characteristics required for wildlife to live in cities and the urban adaptors faced environmental pressures.

Complex genetic architecture underlying the plasticity of maize agronomic traits

Phenotypic plasticity is the ability of a given genotype to produce multiple phenotypes in response to changing environmental conditions.Understanding the genetic basis of phenotypic plasticity and establishing a predictive model is highly relevant to future agriculture under a changing climate.Here we report findings on the genetic basis of phenotypic plasticity for 23 complex traits using a diverse maize population planted at five sites with distinct environmental conditions.We found that latituderelated environmental factors were the main drivers of across-site variation in flowering time traits but not in plant architecture or yield traits.For the 23 traits,we detected 109 quantitative trait loci(QTLs),29 for mean values,66 for plasticity,and 14 for both parameters,and 80%of the QTLs interacted with latitude.The effects of several QTLs changed in magnitude or sign,driving variation in phenotypic plasticity.We experimentally validated one plastic gene,ZmTPS14.1,whose effect was likely mediated by the compensation effect of ZmSPL6 from a downstream pathway.By integrating genetic diversity,environmental variation,and their interaction into a joint model,we could provide site-specific predictions with increased accuracy by as much as 9.9%,2.2%,and 2.6%for days to tassel,plant height,and ear weight,respectively.This study revealed a complex genetic architecture involving multiple alleles,pleiotropy,and genotype-byenvironment interaction that underlies variation in the mean and plasticity of maize complex traits.It provides novel insights into the dynamic genetic architecture of agronomic traits in response to changing environments,paving a practical way toward precision agriculture.

Plant hormesis and Shelford’s tolerance law curve

Shelford’s law of tolerance is illustrated by a bell-shaped curve depicting the relationship between environmental factor/factors’intensity and its favorability for species or populations.It is a fundamental basis of ecology when considering the regularities of environment impacts on living systems,and applies in plant biology,agriculture and forestry to manage resistance to environmental limiting factors and to enhance productivity.In recent years,the concept of hormesis has been increasingly used to study the dose-response relationships in living organisms of different complexities,including plants.This requires the need for an analysis of the relationships between the hormetic dose-response model and the classical understanding of plant reactions to environments in terms of Shelford’s law of tolerance.This paper analyses various dimensions of the relationships between the hormetic model and Shelford’s tolerance law curve under the influence of natural environmental factors on plants,which are limiting for plants both in deficiency and excess.The analysis has shown that Shelford’s curve and hormetic model do not contradict but instead complement each other.The hormetic response of plants is localized in the stress zone of the Shelford’s curve when adaptive mechanisms are disabled within the ecological optimum.At the same time,in a species range,the ecological optimum is the most favorable combination of all or at least the most important environmental factors,each of which usually deviates slightly from its optimal value.Adaptive mechanisms cannot be completely disabled in the optimum,and hormesis covers optimum and stress zones.Hormesis can modify the plant tolerance range to environmental factors by preconditioning and makes limits of plant tolerance to environmental factors flexible to a certain extent.In turn,as a result of tolerance range evolution,quantitative characteristics of hormesis(width and magnitude of hormetic zone)as well as the range of stimulating doses,may significantly differ in various plant species and even populations and intra-population groups,including plants at different development stages.Using hormetic preconditioning for managing plant resistance to environmental limiting factors provides an important perspective for increasing the productivity of woody plants in forestry.

Influences of fisheries management measures on biological characteristics of threadfin bream(Nemipterus virgatus)in the Beibu Gulf,South China Sea

Long-term variations in population structure,growth,mortality,length at median sexual maturity,and exploitation rate of threadfin bream(Nemipterus virgatus)are reported based on bottom trawl survey data collected during 1960-2012 in the Beibu Gulf,South China Sea.Laboratory-based analyses were conducted on 16791 individuals collected quarterly in eight different sampling years.Average body length,estimated asymptotic length,and percentage of large individuals have decreased significantly with the growth of marine catch and fishing power,indicating individual miniaturization of this fish species.Estimated exploitation rates indicate that the N.virgatus stock in the Beibu Gulf was moderately exploited in 1960 and 1962 and overexploited after 1992.This stock was taking a good turn in status in 2012,with the lowest exploitation rate since 1992 and ceased downward trend in length indexes.These results suggest that management measures to reduce fishing pressure may have a positive influence on the biological characteristics of this commercial fish species.Biological characteristics of most commercial fish species have phenotypic plasticity and might change over years in response to fisheries management.Therefore,attentions should be paid on variations in fish biological characteristics,when evaluating the effectiveness of current measures to control the total catch for all fisheries.

Growth and production characters of elymus cylindricus in different shortening heading time

Ramet modules in a certain population differ in terms of functions,which accounts for different contributions of the same ramets.Shortening heading time brings about different contributions of such modules.Ramets heading one after another were treated as a continuum in respective cohorts of Elymus cylindricus aged two.The reproductive ramets that head earlier were marked with tags every four days during the whole heading stage from the beginning to the end,after which all the labeled ramets at the maturity period were gathered.The results showed that,the height and biomass of ramets,the length and biomass of inflorescences,percentage of inflorescence length to ramet height,percentage of inflorescence biomass to ramet biomass,the number and biomass of seeds,seed-setting rate,and percentage of seed biomass to ramet biomass declined with the increasing intensity of heading time shortening as displayed with linear or quadratic function.Ramet characteristics weakened remarkably when shortened heading time added up to 17 days.The biomass distribution in relation to inflorescence and seed maintain a stable rate at the early heading stage and dwindled quickly at the near-end stage,but the biomass of ramets remain constant throughout the entire heading stage.The ramets with earlier heading time make greater contribution to the survival of population than the shortened heading time in this species of bunchgrass.

The ecological context of bilateral symmetry of organ and organisms

A particular phenotype is generated through numerous networks of interactions from within the cell to the whole ecosystem. The level of the environmental noise and the ability of a given genotype to render different phenotypes under different environmental conditions, called phenotypic plasticity, determine survival or death at individual and/or population level. It is important to highlight that non-lethal environmental changes are important for generating genetic variability and promoting biological adaptations. However, when the level of environmental noise starts to be stressed, the developmental stability (DS) of the organism can be perturbed. The DS has been analysed through the symmetry deviations in organs or organisms with bilateral structure. The symmetry deviations occur due to inability to contain disorders from environmental or endogenous conditions during its development. This deviation is called fluctuating asymmetry (FA) when is a non-directional deviation in the symmetry of a bilateral structure normally distributed in a population. Low FA has been associated with greater DS. The analysis of FA has often been used to measure the effects of environmental perturbations. In this review, I discuss the concept of plant stress and phenotypic plasticity connecting both to the generation of an asymmetry phenotype, highlighting the usefulness of FA as an indicator of the level of stress which the organism is subjected to. Further, although this review explores mainly the connection between FA and stress in plants, the ecological context of symmetry in animals and plant-insect interaction is also discussed. Finally, I provided some methodologies used to detect symmetry variations in organs or organisms with bilateral structure.

Maternal low protein diet induces persistent expression changes in metabolic genes in male rats

BACKGROUND Perinatal exposure to a poor nutritional environment predisposes the progeny to the development of metabolic disease at the adult age,both in experimental models and humans.Numerous adaptive responses to maternal protein restriction have been reported in metabolic tissues.However,the expression of glucose/fatty acid metabolism-related genes in adipose tissue and liver needs to be described.AIM To evaluate the metabolic impact of perinatal malnutrition,we determined malnutrition-associated gene expression alterations in liver and adipose tissue.METHODS In the present study,we evaluated the alterations in gene expression of glycolytic/Krebs cycle genes(Pyruvate dehydrogenase kinase 4 and citrate synthase),adipogenic and lipolytic genes and leptin in the adipose tissue of offspring rats at 30 d and 90 d of age exposed to maternal isocaloric low protein(LP)diet throughout gestation and lactation.We also evaluated,in the livers of the same animals,the same set of genes as well as the gene expression of the transcription factors peroxisome proliferator-activated receptor gamma coactivator 1,forkhead box protein O1 and hepatocyte nuclear factor 4 and of gluconeogenic genes.RESULTS In the adipose tissue,we observed a transitory(i.e.,at 30 d)downregulation of pyruvate dehydrogenase kinase 4,citrate synthase and carnitine palmitoyl transferase 1b gene expression.Such transcriptional changes did not persist in adult LP rats(90 d),but we observed a tendency towards a decreased gene expression of leptin(P=0.052).The liver featured some gene expression alterations comparable to the adipose tissue,such as pyruvate dehydrogenase kinase 4 downregulation at 30 d and displayed other tissue-specific changes,including citrate synthase and fatty acid synthase upregulation,but pyruvate kinase downregulation at 30 d in the LP group and carnitine palmitoyl transferase 1b downregulation at 90 d.These gene alterations,together with previously described changes in gene expression in skeletal muscle,may account for the metabolic adaptations in response to maternal LP diet and highlight the occurrence of persistent transcriptional defects in key metabolic genes that may contribute to the development of metabolic alterations during the adult life as a consequence of perinatal malnutrition.CONCLUSION We conclude that perinatal malnutrition relays long-lasting transcriptional alterations in metabolically active organs,i.e.,liver and adipose tissue.

Heritability of early growth traits and their plasticity in 14 woody species of Chinese subtropical forest

Aims Genetic variation in plant traits represents the raw material for future adaptive evolution.Its extent can be estimated as heritability based on the performance of experimental plants of known relatedness,such as maternal half-sib seed families.While there is considerable heritability information for herbaceous plants and commercially important trees,little is known for woody species of natural subtropical forest.Moreover,it is open whether heritability is higher for species with r-or K-strategies,for more common species with larger distribution ranges than for rarer ones,or for populations closer to the centres of distributional ranges.Methods For 14 woody species in Chinese subtropical forest,we collected 13-38 maternal seed families,assessed seed size,grew replicates of each seed family in one more and one less benign nursery environment and measured stem diameter and plant height after 7 months.Important findings For the different species,plants grew 1.8-8.1 times taller in the more benign environment.For all 14 species,variation between seed families(and thus heritability)was significant(with very few exceptions at the P<0.001 level)for seed size and for stem diameter and plant height in both nurseries.Moreover,significant seed family by nursery interactions for stem diameter and plant height for all species(P<0.001)indicated significant heritability for plasticity in these traits.Multiple regression analysis suggests that heritabilities were higher for species with higher age at reproduction and higher wood density(traits indicating a K strategy)but also for species with higher specific leaf area(a trait rather indicating an r strategy).Furthermore,heritabilities were higher for species with larger range sizes,while there was no significant relationship between heritabilities and the distance of the study area to the range margins of our study species.In conclusion,the detected large heritability estimates suggest considerable potential for the evolution of plant performance and its plasticity for trees of subtropical forest.Moreover,our study shows that the simple method of comparing plants of different maternal seed families is valuable to address evolutionary ecological questions for so far understudied species.

Plant responses to simulated warming and drought:a comparative study of functional plasticity between congeneric mid and high elevation species

Aims Effects of climate change,especially changes in temperatures and precipitation patterns,are particularly pronounced in alpine regions.In response,plants may exhibit phenotypic plasticity in key functional traits allowing short-term adjustment to novel conditions.However,little is known about the degree of pheno-typic plasticity of high elevation species relative to mid elevation congeners.Methods We transplanted 14 herbaceous perennial species from high eleva-tion into two common gardens(1050 and 2000 m.a.s.l.)in the Swiss Alps,and we examined plastic responses in key functional traits to changes in temperature and soil water availability.This design was replicated with 14 congeneric species from mid elevation to assess if the degree of phenotypic plasticity differs between mid and high elevation species.Survival was assessed across two growing seasons,while aboveground biomass and specific leaf area(SLA)were measured after the first growing season,and biomass alloca-tion to belowground and reproductive structures after the second.Moreover,a phenotypic plasticity index was calculated for the func-tional traits to compare the degree of plasticity between mid and high elevation species.Important Findings Aboveground biomass was higher in mid elevation species relative to high elevation congeners in all treatments,yet decreased for both with elevation and drought.Similarly,SLA decreased with elevation and drought.Root mass fraction(RMF)was generally higher in high ele-vation species,and decreased with drought at the lower site.Drought increased the allocation to reproductive structures,especially when plants were grown at their elevation of origin.Interestingly,no differ-ence was found in the degree of phenotypic plasticity averaged across mid and high elevation species for any of the studied functional traits.These results indicate that phenotypic plasticity in the focal traits did not depend on the elevation of origin of the species.Plasticity was not related to environmental heterogeneity,nor constrained by selective pressures at high elevation.However,both species groups showed a remarkable capacity for short-term acclimation to a prospective cli-mate through rapid adjustments in key functional traits.

Major ascaroside pheromone component asc-C5 influences reproductive plasticity among isolates of the invasive species pinewood nematode

Pheromones are communication chemicals and regulatory signals used by animals and represent unique tools for organisms to mediate behaviors and make“decisions”to maximize their fitness.Phenotypic plasticity refers to the innate capacity of a species to tolerate a greater breadth of environmental conditions across which it adapts to improve its survival,reproduction,and fitness.The pinewood nematode,Bursaphelenchus xylophilus,an invasive nematode species,was accidentally introduced from North America into Japan,China,and Europe;however,few studies have investigated its pheromones and phenotypic plasticity as a natural model.Here,we demonstrated a novel phenomenon,in which nematodes under the condition of pheromone presence triggered increased reproduction in invasive strains(JP1,JP2,CN1,CN2,EU1,and EU2),while it simultaneously decreased reproduction in native strains(US1 and US2).The bidirectional effect on fecundity,mediated by presence/absence of pheromones,is henceforth termed pheromone-regulative reproductive plasticity(PRRP).We further found that synthetic ascaroside asc-C5(ascr#9),the major pheromone component,plays a leading role in PRRP and identified 2 candidate receptor genes,Bxydaf-38 and Bxysrd-10,involved in perceiving asc-C5.These results suggest that plasticity of reproductive responses to pheromones in pinewood nematode may increase its fitness in novel environments following introduction.This opens up a new perspective for invasion biology and presents a novel strategy of invasion,suggesting that pheromones,in addition to their traditional roles in chemical signaling,can influence the reproductive phenotype among native and invasive isolates.In addition,this novel mechanism could broadly explain,through comparative studies of native and invasive populations of animals,a potential underlying factor behind of the success of other biological invasions.

Master of one trade:Arbutus unedo relies on plasticity to persist under habitats differing in water availability

Aims the limited water supply in the Mediterranean Basin will be exacerbated in the immediate future as result of severe drought events.thus,the study of the intraspecific variability in functional traits of plant species is important,because such variability modulates species’responses.Here,we aimed to analyse the variability in plasticity of physiological and structural traits of Arbutus unedo L.in response to water availability and to determine whether the levels of phenotypic plasticity varied in plants of different provenances.Methods We kept two sets of plants under contrasted water regimes(high water and low water)and calculated a phenotypic plasticity index to determine the plastic response to water stress.We compared the response among kind of traits and provenance.We also per-formed analysis of variance to assess the trait and provenance effect.Important Findings We found that biomass and key physiological traits decrease under drought conditions,while the water use efficiency increased.Plasticity differed between groups of traits,being higher in structural and gas exchange parameters,but the provenance did not account for signifi-cant variation in plasticity.A.unedo has evolved a‘good saver’strat-egy,involving decreasing growth and water use-when this resource is unavailable-together with the dissipation of excess of radiation that it cannot process.the homogeneous response between provenances may be the result of a canalization event.this strategy,based on a high degree of plasticity,is a probable determining factor in the success of the species over its wide range of environmental conditions and will be critical to withstand the ongoing environmental changes.