Biology subjects

Bezvoda, R.

Publications and source records attributed to Bezvoda, R..

3 recordsLinked to original sources

bioRxiv2026

Endogenous and environmentally modulated leaf shape plasticity in Boquila trifoliolata: how good is the evidence for mimicry?

Reports that the South American climbing vine Boquila trifoliolata modifies its leaf shape to mimic leaves of its host plant have raised considerable attention. Boquila leaf development was proposed to reflect visual inputs perceived in an unknown manner. However, the very existence of Boquila leaf shape mimicry remains inconclusive, since the reported observations are open to alternative explanations. We performed an initial quantitative characterization of leaf shape variability in glasshouse-cultured clonal Boquila plants grown without close host contact, and attempted to reproduce the leaf shape mimicry phenomenon under controlled culture conditions using live olive (Olea europaea) plants, artificial (decoy) olive or artificial ivy plants as supports. While we found leaves of variable shape (including those resembling ivy leaves) both in plants grown without host contact and in those climbing on live or decoy hosts, we did not observe any link between leaf shape and host presence or character. Instead, the leaf shape appears to be affected by environmental conditions including the season. Although our study was limited to a single Boquila genotype and an ecologically unrealistic host selection, our observations suggest that the alleged mimicry might originate from unintentional misinterpretation of intrinsic discontinuous leaf shape plasticity in field observations.

plant biology↗

bioRxiv2025

The Tonoplast Topology Index - a new metric for describing vacuole organization

BackgroundThe plant vacuole arises by orchestrated interplay of membrane trafficking, cytoskeletal rearrangements and a variety of signalling pathways. In the root, the characteristic large central vacuole develops by endomembrane reorganization occurring mainly in the transition zone. The vacuoles bounding membrane - the tonoplast - can be visualized in vivo using fluorescent protein markers, allowing for quantitative analysis of confocal microscopy images. Tonoplast organization can thus serve as a sensitive indicator of changes to any of the processes involved in vacuole biogenesis. The Vacuolar Morphology Index (VMI) is widely accepted as a quantitative measure of vacuole structure. However, this metric has two drawbacks - it only reflects the size of the largest vacuolar compartment (missing therefore possible differences in the organization of smaller compartments), and its determination is labor intensive, limiting its use on large datasets. ResultsWe developed an alternative metric for describing vacuole organization, named the Tonoplast Topology Index (TTI), which overcomes the above-mentioned shortcomings of the VMI. We compared the performance of our protocol with VMI on a simulated dataset and on real data. To validate the methods performance, we used it to confirm the previously reported differences in vacuole shape and size between Arabidopsis thaliana roots grown on the surface of an agar medium compared to those embedded inside the agar. Both VMI and TTI could efficiently detect the relatively subtle changes in vacuole organization depending on the position of the root in the agar, and provided correlated results. However, only TTI produced data with close to normal value distribution, simplifying subsequent statistical evaluation. ConclusionsWe present the protocol for TTI determination as a two-stage semi-automated procedure involving microscopic image analysis employing an ImageJ macro and subsequent processing of numeric data in the Jupyter Notebook environment, together with benchmarking image data. Since this implementation is freeware-based, platform-independent and (relatively) user-friendly, we hope it will find its use as a high throughput, added value alternative to the VMI metric.

plant biology↗

bioRxiv2024

A genome-wide association screen for genes affecting leaf trichome development and epidermal metal accumulation in Arabidopsis

To identify novel genes engaged in plant epidermal development, we characterized the phenotypic variability of rosette leaf epidermis of 310 sequenced Arabidopsis thaliana accessions, focusing on trichome shape and distribution, compositional characteristics of the trichome cell wall, and histologically detectable metal ion distribution. Some of these traits correlated with climate parameters of ourq accessions locations of origin, suggesting environmental selection. A novel metal deposition pattern in stomatal guard cells was observed in some accessions. Subsequent GWAS analysis identified 1546 loci with protein sequence-altering SNPs associated with one or more traits, including 5 genes with previously reported relevant mutant phenotypes and 80 additional genes with known or predicted roles in relevant developmental and cellular processes. Some candidates, including GFS9/TT9, exhibited environmentally correlated allele distribution. Several large gene families, namely DUF674, DUF784, DUF1262, DUF1985, DUF3741, cytochrome P450, receptor-like kinases, Cys/His-rich C1 domain proteins and formins were overrepresented among the candidates for various traits, suggesting epidermal development-related functions. A possible participation of formins in guard cell metal deposition was supported by observations in available loss of function mutants. Screening of candidate gene lists against the STRING interactome database uncovered several predominantly nuclear protein interaction networks with possible novel roles in epidermal development.

plant biology↗