The cytotoxic properties of a plant lipid transfer protein involve membrane permeabilization of target cells.
OBJECTIVE
To determine whether Ha-AP10, a member of the plant lipid transfer proteins (LTPs) family produces a direct cytotoxic effect on fungal cells mediated by membrane permeabilization. LTPs can inhibit fungal growth and are considered members of the ubiquitous class of antimicrobial peptides. However, the way they exert their effects on target cells is not yet understood.


RESULTS
Viability assays demonstrate that Ha-AP10 acts as a fungicidal compound but no harmful effect is observed on plant cells. Liposome leakage assays show that the protein induces a moderate release of fluorescent probes encapsulated in model membranes, indicating its ability to interact with phospholipids. Using a fluorescent indicator of damage at the membrane level, we demonstrate that Ha-AP10 is able to induce the permeabilization of intact fungal spores in a dose-dependent manner.


CONCLUSIONS
The results presented here demonstrate the permeabilization of fungal spores caused by Ha-AP10.


CONCLUSIONS
To our knowledge, this is the first demonstration of fungal membrane damage by an LTP, giving a clue to elucidate the basis of its antimicrobial properties.
Regente
M C
MC
Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina. mregente@mdp.edu.ar
Giudici
A M
AM
Villalaín
J
J
de la Canal
L
L
D000935:Antifungal Agents / Q000633:toxicity*; D052179:Antigens, Plant; D023181:Antimicrobial Cationic Peptides / Q000633:toxicity*; D002352:Carrier Proteins / Q000633:toxicity*; D002462:Cell Membrane / Q000187:drug effects; D002463:Cell Membrane Permeability; D005456:Fluorescent Dyes / Q000032:analysis / Q000378:metabolism; D005670:Fusarium / Q000187:drug effects; D006368:Helianthus / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D010940:Plant Proteins / Q000633:toxicity*; D013172:Spores, Fungal / Q000166:cytology
D000935:Antifungal Agents; D052179:Antigens, Plant; D023181:Antimicrobial Cationic Peptides; D002352:Carrier Proteins; D005456:Fluorescent Dyes; C500581:Ha-AP10 protein, Helianthus annuus; D008081:Liposomes; D010940:Plant Proteins; C511920:lipid transfer proteins, plant