Biology subjects

Jellen, E.

Publications and source records attributed to Jellen, E..

3 recordsLinked to original sources

bioRxiv2025

Leaf shape modulates climate trait relationships in the wild species Chenopodium hircinum (Amaranthaceae)

Understanding how leaf morphology mediates plant responses to environmental variation is essential for predicting species adaptability under climate change. In this study, we investigated natural variation in leaf shape and associated functional- physiological traits (FPTs) across populations of Chenopodium hircinum grown in a common garden. We found that leaf shape strongly correlates with the climatic conditions of population provenance, while functional and physiological traits are independently associated with morphology rather than directly with climate. Landmark-based morphometric analysis revealed that the second principal component, distinguishing deeply lobed from rounded leaves, is significantly linked to key traits such as leaf mass per unit area (LMA) and stomatal conductance. These relationships suggest that morphology mediates a functional continuum between resource-use strategies. Notably, within-population phenotypic variation accounted for much of the observed trait diversity, underscoring the role of individual-level phenotypic plasticity in shaping ecological function. Our results challenge traditional views on the thermoregulatory role of leaf lobation and highlight morphology as a central axis of adaptation. This work advances understanding of trait integration in response to environmental heterogeneity and suggests that plasticity in leaf shape and function may enhance resilience of C. hircinum across its native range.

plant biology↗

bioRxiv2024

A pangenome and pantranscriptome of hexaploid oat

Oat grain is a traditional human food rich in dietary fiber that contributes to improved human health. Interest in the crop has surged in recent years owing to its use as the basis for plant-based milk analogs. Oat is an allohexaploid with a large, repeat-rich genome that was shaped by subgenome exchanges over evolutionary timescales. In contrast to many other cereal species, genomic research in oat is still at an early stage, and surveys of structural genome diversity and gene expression variability are scarce. Here, we present annotated chromosome-scale sequence assemblies of 33 wild and domesticated oats along with an atlas of gene expression across six tissues of different developmental stages in 23 accessions. We describe the interplay of gene expression diversity across subgenomes, accessions and tissues. Gene loss in the hexaploid is accompanied by compensatory up-regulation of the remaining homeologs, but this process is constrained by subgenome divergence. Chromosomal rearrangements have significantly impacted recent oat breeding. A large pericentric inversion associated with early flowering explains distorted segregation on chromosome 7D and a homeologous sequence exchange between chromosomes 2A and 2C in a semidwarf mutant has risen to prominence in Australian elite varieties. The oat pangeome will promote the adoption of genomic approaches to understanding the evolution and adaptation of domesticated oats and will accelerate their improvement.

genomics↗

bioRxiv2024

LEAF SHAPE OF QUINOA WILD ANCESTOR CHENOPODIUM HIRCINUM IN A GEOGRAPHIC CONTEXT

PremiseIntraspecific variation in plant traits, such as leaf morphology, offers insights into local adaptation and the ecological niche breadth of species. Chenopodium hircinum, the wild ancestor of quinoa, is widely distributed across various ecoregions in Argentina. A detailed comparative analysis of leaf morphology across 23 populations covering its entire distribution was conducted to understand patterns of intraspecific variation along geographic gradients. Materials and MethodsUsing 104 leaves from these populations, leaf shapes were described through shape, landmarks, and Fourier descriptors. Both univariate and multivariate analyses were employed to evaluate variations among and within populations and to link leaf shape patterns with climatic and geographical variables at the sites of origin. ResultsA significant variability in leaf shapes was found across all ecoregions, with marked integration among populations. While landmark-based and Fourier analyses differentiated populations, shape descriptors introduced complexity in identification. Leaf morphology varied widely, from rounded and toothed to sharply lobed, with prominent lobes located at the base or middle of the leaf. The key environmental factors influencing leaf shape, particularly lobulation and relative positioning, were mean annual temperature and altitude. ConclusionsThe findings suggest that in C. hircinum, leaf shape variability goes beyond the simple lobed vs. entire dichotomy and is shaped by environmental temperatures. Leaf morphology and margin traits are primarily governed by the relative position of the lobes, which are strongly correlated with the mean temperature at the populations origin. This convergence across different ecoregions highlights the need for further research to explore the functional significance of such variation.

plant biology↗