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1. Effects of drying methods on plant lipid compounds and bulk isotopic compositions

   https://doi.org/10.1002/rcm.8900  

   Suh, Yeon Jee ; Diefendorf, Aaron F. ( August 2020 , Rapid Communications in Mass Spectrometry)

   Plant lipid biomarkers, such as plant waxes and terpenoids, and the stable isotopic composition of bulk leaves are widely used in both modern and paleoclimate studies for tracking vegetation and climate. However, the effects of different drying methods on the preservation of plant lipid biomarkers and the stable isotopic compositions of leaves are less explored. Here, we investigated various drying methods for the measurement of plant lipid concentrations and bulk leaf isotopic compositions.

   Leaves from four tree species (Acer rubrum,Pinus sylvestris,Platanus occidentalis, andTaxodium distichum) were collected and dried using air, an oven, a freeze‐dryer, and a microwave. We compared concentrations of leaf waxes and terpenoids and carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic compositions of leaves by different drying methods.

   The air, oven, freeze‐dryer, and microwave drying methods did not affect lipid concentrations significantly, and only a few homologues differed (38.1% or 41.8 μg/g on average) possibly due to biological variations or enhanced extraction efficiencies. The δ¹³C values were not affected by drying methods, whereas the δ¹⁵N values in oven‐dried leaves in some species were higher by 0.2–0.7‰ than those obtained by other methods. Though small, we attribute these patterns to loss of leaf compounds with lower isotope ratios during oven‐drying.

   Based on our results, each drying technique yielded equivalent results for all plant wax and terpenoid concentrations and bulk leaf δ¹³C values; however, oven‐drying modified the δ¹⁵N values.

    

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2. Morphological Analysis of Size and Shape ( MASS ): An integrative software program for morphometric analyses of leaves

   https://doi.org/10.1002/aps3.11288  

   Chuanromanee, Tya S. ; Cohen, James I. ; Ryan, Gillian L. ( September 2019 , Applications in Plant Sciences)

   Morphometric analysis is a common approach for comparing and categorizing botanical samples; however, completing a suite of analyses using existing tools may require a multi‐stage, multi‐program process. To facilitate streamlined analysis within a single program, Morphological Analysis of Size and Shape (MASS) for leaves was developed. Its utility is demonstrated using exemplar leaf samples fromAcer saccharum,Malus domestica, andLithospermum.

   Exemplar samples were obtained from across a single tree (Acer saccharum), three trees in the same species (Malus domestica), and online, digitized herbarium specimens (Lithospermum).MASSwas used to complete simple geometric measurements of samples, such as length and area, as well as geometric morphological analyses including elliptical Fourier and Procrustes analyses. Principal component analysis (PCA) of data was also completed within the same program.

   MASSis capable of making desired measurements and analyzing traditional morphometric data as well as landmark and outline data.

   UsingMASS, differences were observed among leaves of the three studied taxa, but only inMalus domesticawere differences statistically significant or correlated with other morphological features. In the future,MASScould be applied for analysis of other two‐dimensional organs and structures.MASSis available for download athttps://github.com/gillianlynnryan/MASS.

    

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3. Transcriptome analyses of leaf architecture in Sansevieria support a common genetic toolkit in the parallel evolution of unifacial leaves in monocots

   https://doi.org/10.1002/pld3.511  

   Golenberg, Edward M. ; Popadić, Aleksandar ; Hao, Weilong ( August 2023 , Plant Direct)

   Planar structures dramatically increase the surface‐area‐to‐volume ratio, which is critically important for multicellular organisms. In this study, we utilize naturally occurring phenotypic variation among threeSansivieriaspecies (Asperagaceae) to investigate leaf margin expression patterns that are associated with mediolateral and adaxial/abaxial development. We identified differentially expressed genes (DEGs) between center and margin leaf tissues in two planar‐leaf speciesSansevieria subspicataandSansevieria trifasciataand compared these with expression patterns within the cylindrically leavedSansevieria cylindrica. TwoYABBYfamily genes, homologs ofFILAMENTOUS FLOWERandDROOPING LEAF, are overexpressed in the center leaf tissue in the planar‐leaf species and in the tissue of the cylindrical leaves. As mesophyll structure does not indicate adaxial versus abaxial differentiation, increased leaf thickness results in more water‐storage tissue and enhances resistance to aridity. This suggests that the cylindrical‐leaf inS. cylindricais analogous to the central leaf tissue in the planar‐leaf species. Furthermore, the congruence of the expression patterns of theseYABBYgenes inSansevieriawith expression patterns found in other unifacial monocot species suggests that patterns of parallel evolution may be the result of similar solutions derived from a limited developmental toolbox.

    

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4. Assessing the factors influencing natural regeneration patterns in the diverse, multi‐cohort, and managed forests of Maine, USA

   https://doi.org/10.1111/jvs.12433  

   Bose, Arun_K ; Weiskittel, Aaron ; Wagner, Robert_G ; Kuehne, Christian ; Michalet, ed., Richard ( June 2016 , Journal of Vegetation Science)

   What are the primary biotic and abiotic factors driving composition and abundance of naturally regenerated tree seedlings across forest landscapes of Maine? Do seedling species richness (SR) and density (SD) decrease with improved growing conditions (climate and soil), but increase with increased diversity of overstorey composition and structure? Does partial harvesting disproportionately favour relative dominance of shade‐intolerant hardwoods (PIHD) over shade‐tolerant softwoods (PTSD)?

   Forest landscapes across the diverse eco‐regions and forest types of Maine,USA.

   This study usedUSDAForest Service Forest Inventory Analysis permanent plots (n = 10 842), measured every 5 yr since 1999. The best models for each response variable (SR,SD,PIHDandPTSD) were developed based onAICand biological interpretability, while considering 35 potential explanatory variables incorporating climate, soil, site productivity, overstorey structure and composition, and past harvesting.

   Mean annual temperature was the most important abiotic factor, whereas overstorey tree size diversity was the most important biotic factor forSRandSD. Both mean annual temperature and overstorey tree size diversity had a curvilinear relationship withSRandSD. Average overstorey shade tolerance and percentage tolerant softwood basal area in the overstorey were the top predictor variables ofPIHDandPTSD,respectively. Partial harvesting favouredPIHDbut notPTSD.

   This is one of the first studies to comprehensively evaluate a number of factors influencing naturally established tree seedlings at a broad landscape scale in the Northern Forest region of the easternUSAand Canada. Despite limitations associated with relatively small plot size, large seedling size class and lack of direct measurements of light, water and nutrients, this study documents the influence of these factors amid high variability associated with patterns of natural regeneration. The curvilinear relationship between mean annual temperature withSRandSDsupports the argument that species richness and abundance usually have unimodal relationships with productivity indicators, whereas the curvilinear relationship between overstorey tree size diversity andSRandSDsuggest that moderate overstorey diversity incorporates multiple species as well as higher seedling individuals.

    

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5. Extensive allopolyploidy in the neotropical genus Lachemilla (Rosaceae) revealed by PCR ‐based target enrichment of the nuclear ribosomal DNA cistron and plastid phylogenomics

   https://doi.org/10.1002/ajb2.1253  

   Morales‐Briones, Diego F. ; Tank, David C. ( March 2019 , American Journal of Botany)

   Polyploidy has been long recognized as an important force in plant evolution. Previous studies had suggested widespread occurrence of polyploidy and the allopolyploid origin of several species in the diverse neotropical genusLachemilla(Rosaceae). Nonetheless, this evidence has relied mostly on patterns of cytonuclear discordance, and direct evidence from nuclear allelic markers is still needed.

   Here we usedPCRtarget enrichment in combination with high throughput sequencing to obtain multiple copies of the nuclear ribosomal (nr)DNAcistron and 45 regions of the plastid genome (cpDNA) from 219 accessions representing 48 species ofLachemillaand to explore the allopolyploid origin of species in this group.

   We were able to identify multiple nrDNAribotypes and establish clear evidence of allopolyploidy in 33 species ofLachemilla, showing that this condition is common and widespread in the genus. Additionally, we found evidence for three autopolyploid species. We also established multiple, independent origins of several allopolyploid species. Finally, based solely on the cpDNAphylogeny, we identified that the monotypic genusFarinopsisis the sister group ofLachemillaand allied genera within subtribe Fragariinae.

   Our study demonstrates the utility of the nuclear ribosomalDNAcistron to detect allopolyploidy when concerted evolution of this region is not complete. Additionally, with a robust chloroplast phylogeny in place, the direction of hybridization events can be established, and multiple, independent origins of allopolyploid species can be identified.

    

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