The cost of movement: assessing energy expenditure in a long-distant ectothermic migrant under climate change.

Migration is an energetically taxing phenomenon as animals move across vast, heterogeneous landscapes where the cost of transport is impacted by permissible ambient conditions. In this study, we assessed the energetic demands of long-distance migration in a multigenerational ectothermic migrant, the monarch butterfly (Danaus plexippus). We tested the hypotheses that temperature-dependent physiological processes reduce energy reserves faster during migration than previously estimated, and that increasing climatic temperatures resulting from the climate crisis will intensify baseline daily energy expenditure. First, we reared monarchs under laboratory conditions to assess energy and mass conversion from fifth instar to adult stages, as a baseline for migratory adult mass and ontogenetic shifts in metabolic rate from larvae to adult. Then, using historical tag-recapture data, we estimated the movement propensity and migratory pace of autumn migrants using computer simulations and subsequently calculated energy expenditure. Finally, we estimated the energy use of monarchs based on these tag-recapture data and used this information to estimate daily energy expenditure over a 57 year period. We found support for our two hypotheses, noting that incorporating standard metabolic rate into estimates of migratory energy expenditure shows higher energy demand and that daily energy expenditure has been gradually increasing over time since 1961. Our study shows the deleterious energetic consequences under current climate change trajectories and highlights the importance of incorporating energetic estimates for understanding migration by small, ectothermic migrants.

Genetic potential for changes in breeding systems: Predicted and observed trait changes during artificial selection for male and female allocation in a gynodioecious species.

PREMISE: Evolution of separate sexes from hermaphroditism often proceeds through gynodioecy, but genetic constraints on this process are poorly understood. Genetic (co-)variances and between-sex genetic correlations were used to predict evolutionary responses of multiple reproductive traits in a sexually dimorphic gynodioecious species, and predictions were compared with observed responses to artificial selection. METHODS: Schiedea (Caryophyllaceae) is an endemic Hawaiian lineage with hermaphroditic, gynodioecious, subdioecious, and dioecious species. We measured genetic parameters of Schiedea salicaria and used them to predict evolutionary responses of 18 traits in hermaphrodites and females in response to artificial selection for increased male (stamen) biomass in hermaphrodites or increased female (carpel, capsule) biomass in females. Observed responses over two generations were compared with predictions in replicate lines of treatments and controls. RESULTS: In only two generations, both stamen biomass in hermaphrodites and female biomass in females responded markedly to direct selection, supporting a key assumption of models for evolution of dioecy. Other biomass traits, pollen and ovule numbers, and inflorescence characters important in wind pollination evolved indirectly in response to selection on sex allocation. Responses generally followed predictions from multivariate selection models, with some responses unexpectedly large due to increased genetic correlations as selection proceeded. CONCLUSIONS: Results illustrate the power of artificial selection and utility of multivariate selection models incorporating sex differences. They further indicate that pollen and ovule numbers and inflorescence architecture could evolve in response to selection on biomass allocation to male versus female function, producing complex changes in plant phenotype as separate sexes evolve.

Multilocus phylogenetic inference in subfamily Chlorogaloideae and related genera of Agavaceae - informing questions in taxonomy at multiple ranks.

A series of taxonomic questions at the subfamilial, generic, and intrageneric levels have remained within subfamily Chlorogaloideae s.s. (comprising Camassia, Chlorogalum, Hastingsia, and Schoenolirion) and relatives in Agavaceae. We present the first phylogenetic hypotheses focused on Chlorogaloideae that are based on multiple independent loci and include a wide sampling of outgroups across Agavaceae. In addition to chloroplast regions ndhF and trnL-trnF, we used nrDNA ITS for phylogenetic inference. Incomplete concerted evolution of the latter is indicated by intra-individual site polymorphisms for nearly half of the individuals. Comparisons of four coding and analysis methods for these characters indicate that the region remains phylogenetically informative. Our results confirm that Chlorogaloideae s.s. is not monophyletic, due to the close relationship of Schoenolirion with Hesperaloe and Hesperoyucca, as well as the likely sister relationship between Hesperocallis and core Chlorogaloideae (Camassia, Chlorogalum, and Hastingsia). Chlorogalum is also not monophyletic, being divided with strong support into vespertine and diurnal clades. This study produced the first phylogenetic hypotheses across Hesperaloe, allowing initial tests of several taxonomic disagreements within this genus. Our results reveal the lack of cohesion of H. funifera, indicating that H. funifera ssp. funifera may be more closely related to H. campanulata than to H. funifera ssp. chiangii (=H. chiangii). With potential gene flow between many members of Hesperaloe and a possible hybrid origin for H. campanulata, the genetic relationships within this genus appear complex. Further population-level investigation of many of the taxa in Chlorogaloideae s.l. would benefit our understanding of the evolution and taxonomy of these groups; Camassia and Hastingsia are the current focus of ongoing study.

Long-term effects of a tornado: Impacts on woody native vegetation and invasive Amur honeysuckle (Lonicera maackii) in an urban forest.

As tornados become increasingly common with global climate change, recovery of the woody vegetation in temperate forests is imperative to maintain an intact ecosystem. In many urbanized landscapes, invasive species are also increasing and could interfere with natural recovery from environmental disturbance. We quantified the impact and 17-year recovery from a major tornado in a temperate deciduous forest. We used vegetational surveys in southwestern Ohio at the Harris M. Benedict Nature Preserve, where approximately a third of this site was damaged by a tornado in 1999. Plots were established in the tornado-damaged area and the nearby undisturbed forest to examine forest recovery of trees/saplings, shrubs and vines, and tree seedlings during 2003, 2006, 2010, and 2016/2017. The number of tree saplings, shrubs, and vines increased immediately after the tornado, but then declined by 2010, relative to the undisturbed forest. Forest tree recruitment was lower in tornado-damaged sites with fewer tree seedlings, but more saplings. Tree diversity was also affected by Agrilus planipennis (Emerald Ash borer) which targeted native ash trees within this time period. Despite an initial increase in shrubs and vines in the damaged area, the diversity and density of shrubs approached equality in both sites by 2016. Most shrubs in both sites were the invasive Lonicera maackii (Amur honeysuckle). In tornado sites, honeysuckle thinned out over time, leaving larger shrubs with greater mean basal diameter compared to the undisturbed forest. Other woody invasive species were also more prevalent in the damaged area, but increased in number in both locations by 2017. The forest has the capability to begin to recover from the initial tornado, but its future composition may differ from its initial trajectory due to invasive species, loss of ash trees, and anthropogenic impacts within the urban landscape.

Measure for measure: comparing morphological and biomass traits for sex allocation in two gynodioecious species.

PREMISE OF THE STUDY: Sex allocation models assume male and female traits are measured in a common currency, allocation traits show heritability, and tradeoffs between investment in the two sexual functions occur. The potential for model predictions and genetic parameters to depend on the currency used is not well understood, despite frequent use of measures not in a common currency. • METHODS: We analyzed the relationship between common currency (biomass of carpels, seeds, and stamens) measures and morphological measures (numbers of ovules, seeds, and pollen) in Schiedea salicaria (12-13% females) and S. adamantis (39% females), two closely related gynodioecious species. Additionally, we compared heritabilities and genetic correlations for male and female allocation between these two types of measures. • KEY RESULTS: Ovule, seed, and pollen number show greater sexual dimorphism in S. adamantis than in S. salicaria. Most but not all morphological traits and analogous biomass traits are highly correlated with a linear relationship. Narrow-sense heritabilities based on the two methods are often similar, but higher for ovule number than carpel mass and lower for anther number than stamen mass in S. adamantis. Neither trait type shows negative genetic correlations between male and female function. • CONCLUSIONS: Both trait types show greater sexual dimorphism in S. adamantis, and significant heritabilities suggest that morphological traits will continue to evolve with breeding system changes. Although most relationships between morphological and biomass traits are linear, curvilinear relationships for two traits suggest that caution is warranted if morphological and common currency traits are used interchangeably in fitness gain curves.

Improving culture initiation of mature oak shoots through use of silver thiosulfate.

Premise: Of the approximately 430 species of oaks (Quercus spp.) that have been assessed, 31% are threatened with extinction and in need of safeguarding. However, oak seeds cannot be seed banked, and thus rely on alternative strategies such as in vitro culture for ex situ conservation. One challenge to this approach is low culture initiation rates. Our objective was to identify factors that may improve the establishment of shoot cultures in vitro using new growth collected from mature trees. Methods: Shoot cuttings were harvested from individuals of five different oak species (Q. alba, Q. bicolor, Q. macrocarpa, Q. muehlenbergii, and Q. palustris). Shoots were cultured onto medium with or without 50 µM silver thiosulfate (STS), a known inhibitor of the stress hormone ethylene. Cultures were grown for one month, at which point shoots were assessed for survival. Results: Shoot survival was significantly greater in shoots cultured on medium containing STS compared to the control group, with the overall survival rate increasing from 65% to 73%. Discussion: Increasing the survival rate of newly established cultures is important in ensuring that material collected from endangered species has the best chance for survival, which is critical for successful ex situ conservation.

Research inequity in the plant sciences.

Do all plant biologists worldwide have equal access to novel methods, enabling them to be equally productive, publish, and receive credit for their research? Or does reduced access to cutting-edge techniques in countries with lower financial resources create an inequity for researchers located there? Such disparities and biases do exist within our discipline and must be addressed if we are to move forward as a more just society. Applications in Plant Sciences has taken steps to address this important issue of research inequity, as outlined below. We now call upon the entire botanical community-researchers, editors and reviewers, funding agencies, and publishers-to work together toward a more equitable environment for all researchers around the world.

A laboratory-based study examining the properties of silk fabric to evaluate its potential as a protective barrier for personal protective equipment and as a functional material for face coverings during the COVID-19 pandemic.

The worldwide shortage of single-use N95 respirators and surgical masks due to the COVID-19 pandemic has forced many health care personnel to use their existing equipment for as long as possible. In many cases, workers cover respirators with available masks in an attempt to extend their effectiveness against the virus. Due to low mask supplies, many people instead are using face coverings improvised from common fabrics. Our goal was to determine what fabrics would be most effective in both practices. Under laboratory conditions, we examined the hydrophobicity of fabrics (cotton, polyester, silk), as measured by their resistance to the penetration of small and aerosolized water droplets, an important transmission avenue for the virus causing COVID-19. We also examined the breathability of these fabrics and their ability to maintain hydrophobicity despite undergoing repeated cleaning. Laboratory-based tests were conducted when fabrics were fashioned as an overlaying barrier for respirators and when constructed as face coverings. When used as material in these two situations, silk was more effective at impeding the penetration and absorption of droplets due to its greater hydrophobicity relative to other tested fabrics. We found that silk face coverings repelled droplets in spray tests as well as disposable single-use surgical masks, and silk face coverings have the added advantage over masks such that they can be sterilized for immediate reuse. We show that silk is a hydrophobic barrier to droplets, can be more breathable than other fabrics that trap humidity, and are re-useable via cleaning. We suggest that silk can serve as an effective material for making hydrophobic barriers that protect respirators, and silk can now be tested under clinical conditions to verify its efficacy for this function. Although respirators are still the most appropriate form of protection, silk face coverings possess properties that make them capable of repelling droplets.

The frontier of data discoverability: Why we need to share our data.

We are now in an era where sharing and making data widely accessible are not only expected within many disciplines, but also required by federal granting agencies and many scientific journals. In addition, there are practical reasons why authors should deposit their data into permanent data repositories: (1) it prevents data loss due to accidents, theft, or death of the researcher; (2) it enables published research to be reproduced by others; (3) publications associated with accessible data sets can have higher citation rates; (4) deposited data sets are increasingly recognized for scholarly recognition and professional advancement; and (5) stored and accessible data can be used in the future for projects that are unanticipated today. Applications in Plant Sciences requires that data underlying its articles be publicly accessible as a condition of publication to promote the continued advancement of the field of plant biology.

Does particulate matter along roadsides interfere with plant reproduction? A comparison of effects of different road types on Cichorium intybus pollen deposition and germination.

The roadside habitat can be challenging for plants, which must maintain normal biological processes despite an influx of airborne pollutants. While the effects of many gases on plants have been quantified, the impacts of particulate pollutants have been relatively less studied. This is especially true of field experiments where particle dispersion may be influenced by meteorology and roadway use. We examined chicory (Cichorium intybus L.) along roadsides in the Cincinnati, Ohio metropolitan area to assess particulate influence on plant pollination through stigmatic clogging. We compared flowers collected from plants situated along interstates, U.S. highways, state highways, and county roads as these different road-types vary in motor vehicle usage and thus should have varying levels of particulate deposition on flowers. We examined floral stigmas for total particulates, total pollen, and percentage of pollen tube germination to determine whether particulates may interfere with early reproductive processes. Our results suggest that there was minimal variation of particulate matter found on chicory stigmas among road-types. Furthermore, the deposition of particulates on stigmas based on road-type did not show a strong link to variation in pollen deposition and pollen germination. There was also no significant relationship between total particulate levels and pollen germination rates across all road types. Future studies should investigate other plant species that may be more sensitive to roadside pollution, such as economically important crops. Locations in which vehicle use is increasing and where pollutants are not regulated strictly should also be examined as the effects of airborne particulates in early plant reproduction would be expected to be more substantial in these areas.

An empirical review: Characteristics of plant microsatellite markers that confer higher levels of genetic variation.

During microsatellite marker development, researchers must choose from a pool of possible primer pairs to further test in their species of interest. In many cases, the goal is maximizing detectable levels of genetic variation. To guide researchers and determine which markers are associated with higher levels of genetic variation, we conducted a literature review based on 6782 genomic microsatellite markers published from 1997-2012. We examined relationships between heterozygosity (H e or H o) or allele number (A) with the following marker characteristics: repeat type, motif length, motif region, repeat frequency, and microsatellite size. Variation across taxonomic groups was also analyzed. There were significant differences between imperfect and perfect repeat types in A and H e. Dinucleotide motifs exhibited significantly higher A, H e, and H o than most other motifs. Repeat frequency and motif region were positively correlated with A, H e, and H o, but correlations with microsatellite size were minimal. Higher taxonomic groups were disproportionately represented in the literature and showed little consistency. In conclusion, researchers should carefully consider marker characteristics so they can be tailored to the desired application. If researchers aim to target high genetic variation, dinucleotide motif lengths with large repeat frequencies may be best.

A Bayesian Approach to Inferring Rates of Selfing and Locus-Specific Mutation.

We present a Bayesian method for characterizing the mating system of populations reproducing through a mixture of self-fertilization and random outcrossing. Our method uses patterns of genetic variation across the genome as a basis for inference about reproduction under pure hermaphroditism, gynodioecy, and a model developed to describe the self-fertilizing killifish Kryptolebias marmoratus. We extend the standard coalescence model to accommodate these mating systems, accounting explicitly for multilocus identity disequilibrium, inbreeding depression, and variation in fertility among mating types. We incorporate the Ewens sampling formula (ESF) under the infinite-alleles model of mutation to obtain a novel expression for the likelihood of mating system parameters. Our Markov chain Monte Carlo (MCMC) algorithm assigns locus-specific mutation rates, drawn from a common mutation rate distribution that is itself estimated from the data using a Dirichlet process prior model. Our sampler is designed to accommodate additional information, including observations pertaining to the sex ratio, the intensity of inbreeding depression, and other aspects of reproduction. It can provide joint posterior distributions for the population-wide proportion of uniparental individuals, locus-specific mutation rates, and the number of generations since the most recent outcrossing event for each sampled individual. Further, estimation of all basic parameters of a given model permits estimation of functions of those parameters, including the proportion of the gene pool contributed by each sex and relative effective numbers.

APPS's stance on self-plagiarism: Just say no.

Should authors be able to reuse the same text in multiple papers without citing the earlier source? Known as self-plagiarism, this practice is strongly discouraged in Applications in Plant Sciences (APPS) because it violates professional standards, is potentially deceptive, and lacks originality. The most frequent form of self-plagiarism in APPS submissions is text recycling, which depending on the extent and location of copied text, has consequences ranging from authors being required to rewrite duplicated text or add citations, to automatic rejection of a manuscript without review. Ultimately, avoidance of self-plagiarism will result in original articles that improve upon, and do not simply replicate, the existing literature.

Changing technologies offer new opportunities in the plant sciences(1.).

The plant sciences are now facing an unprecedented time in our history in which technology is advancing at a rapid pace, creating a wide variety of novel opportunities for our field. Applications in Plant Sciences is a new source for sharing exciting and innovative applications of new technologies that have the potential to propel plant research forward into the future.

Why vouchers matter in botanical research.

What is a voucher and why is it important in research? As a preserved specimen of an identified taxon deposited in a permanent and accessible storage facility, the voucher serves as the supporting material for published studies of the taxon and ensures that the science is repeatable. Vouchers are crucial in authenticating the taxonomy of an organism, as a tool for identifying localities of the taxon, and for additional taxonomic, genetic, ecological, and/or environmental research.

Development of 16 microsatellite markers within the Camassia (Agavaceae) species complex and amplification in related taxa.

PREMISE OF THE STUDY: The North American genus Camassia is an ecologically important group whose variability and evolution are little understood, being influenced by hybridization and geographic isolation. We developed microsatellite markers to investigate patterns of gene flow, population structure, and taxonomic relationships within this group. • METHODS AND RESULTS: Using a traditional approach with biotin-labeled probes, we developed 16 microsatellite primers in three species of Camassia: C. howellii, C. leichtlinii, and C. quamash. The number of alleles per locus averaged 3.94 per species, and levels of heterozygosity ranged from 0.000 to 1.00 and 0.033 to 0.917 for observed and expected heterozygosities, respectively. All primers amplified to varying extents in additional species (C. angusta, C. cusickii, C. scilloides) and in putative species in a related genus (Hastingsia alba, H. atropurpurea, H. bracteosa, H. serpentinicola). • CONCLUSIONS: These microsatellite markers exhibit variation and are useful for ongoing studies of integrative taxonomy and population differentiation within this species complex.

An efficient technique for primer development and application that integrates fluorescent labeling and multiplex PCR.

PREMISE OF THE STUDY: Development of genetic markers can be costly and time-consuming, especially when multiple primer pairs are fluorescently labeled. This step was streamlined by combining two techniques in the same PCR reaction: (1) custom-labeling of primers by the investigator and (2) multiplexing multiple primers together in the same reaction. • METHODS AND RESULTS: This technique was successfully used to develop microsatellite markers in several plant species. Microsatellites amplified with this multiplexing process were identical to those generated from PCR using individual primer pairs and with traditional methods using a priori labeled fluorescent primers. Tests of PCR cycling programs revealed that conditions recommended for the commercial kit generated stronger fragment peaks than the previously recommended cycling protocol. • CONCLUSIONS: This technique is an efficient and economical way to fluorescently label multiple microsatellite primers in the same reaction. It is also applicable to other markers used in PCR amplification of genetic material.