Biology subjects

Lupatelli, C. A.

Publications and source records attributed to Lupatelli, C. A..

3 recordsLinked to original sources

bioRxiv2026

Potassium modulates Phytophthora zoospore motility and flagellar beating through dose-dependent effects

Biflagellate zoospores are critical agents in the spread of Phytophthora spp., plant pathogens causing major agronomic and economic losses worldwide. These motile cells navigate soil water films toward plant roots using taxis triggered by environmental cues. Here, we investigate how potassium modulates zoospore motility by analyzing trajectory and flagellar beating parameters across KCl concentrations. Using high-speed imaging, we apply kymograph analysis and Fourier transform of the cell body direction over time to quantify flagellar dynamics, while low-speed imaging provides trajectory characteristics. Our results demonstrate that increasing potassium concentration significantly reduces swimming speed while enhancing directional changes. We establish a direct correlation between altered swimming speed and changes in flagellar beating parameters. Our findings indicate that potassium differentially affects anterior and posterior flagella beating. Furthermore, potassium exerts multiple effects, influencing beat amplitude, wave propagation speed and direction- change frequency. This reveals potassium as a key modulator of zoospore motility, triggering a shift from exploratory swimming to confined, reoriented movement. By uncovering the biomechanical responses of zoospores to potassium, this study advances our understanding of how surrounding signals regulate pathogen dispersal in the environment.

biophysics↗

bioRxiv2026

Aphid Salivary MIF Modulates Plant Programmed Cell Death and DNA Damage Response and Interacts with SOG1

The establishment of aphid-plant interaction involves the secretion of a salivary MIF protein. Morphological analyses revealed that aphid MpMIF1 prevents plant cell death, protects organelles from stress, and may promote plant cellular recovery. Co-expression of aphid MpMIF1 and the cell death inducer Npp1 revealed that MpMIF1 modulates autophagy-related genes ATG7/BECLIN1, impair plant senescence regulator ATAF1 and regulate apoptosis-like via Caspase-3-like activity. This effect on multiple-cell death pathways helps to maintain cellular homeostasis during aphid infection. Investigations on DNA Damage Response (DDR) signaling pathways demonstrated that aphid MpMIF1 reduces {gamma}H2A.X phosphorylation, maintains activity of the DNA repair protein RAD51 and stabilizes cell cycle checkpoint expression WEE1 under genotoxic stress. Therefore, MpMIF1 actively participates to the maintenance of a functional DDR. Finally, we showed that aphid MpMIF1 physically interacts with SOG1, a functional analog of animal p53 and central regulator of DDR, cell cycle arrest and programmed cell death in plants. These findings establish MpMIF1 as a key regulator of plant cell death during aphid-plant interactions and highlight its potential as a biotechnological tool for protecting major crops against aphid infection.

plant biology↗

bioRxiv2025

Membrane Proteome of Phytophthora parasitica Zoospores: How Does Sensing Occur?

Phytophthora plant pathogens rely on motile biflagellated zoospores to efficiently locate and colonise host tissues. While rhizospheric signals guiding zoospore movement toward roots are known, the protein composition of membranes mediating these responses remains unclear. Here, we used liquid chromatography with tandem mass spectrometry (LC-MS/MS) and proteomic data mining to analyse membrane fractions from the flagella and cell bodies of Phytophthora parasitica zoospores. Major classes of membrane proteins (receptors, transporters and enzymes) were identified and their subcellular distribution between flagella and cell bodies quantified. Immunolocalization revealed that while most membrane proteins are evenly distributed, a subset localizes to the flagella, suggestive of specialized roles in sensing and movement regulation, particularly for sterol recruitment and ion flux variations. These findings advance our understanding of protein-mediated dispersal and host targeting by zoospores and support the hypothesis that zoospores use polarized signal perception mechanisms for environmental sensing and movement.

microbiology↗