Ultrastructural Alterations in Fusarium sambucinum and Heterobasidion annosum Treated with Aluminum Chloride and Sodium Metabisulfite

Abstract

Aluminum chloride (AlCl(3)) and sodium metabisulfite (Na(2)S(2)O(5)) have received increasing attention as antifungal agents for the control of plant diseases. In an effort to understand their toxic action on fungi, ultrastructural changes and membrane damage in Fusarium sambucinum (Ascomycota) and Heterobasidion annosum (Basidiomycota) in response to salt exposure was investigated using transmission electron microscopy. Conidial membrane damage was quantified using SYTOX Green stain, which only enters altered membranes. The results showed that mortality of the conidia was generally closely associated with SYTOX stain absorption in F. sambucinum treated with Na(2)S(2)O(5) and in H. annosum treated with AlCl(3) or Na(2)S(2)O(5), suggesting that these salts cause membrane alterations. For both fungi, ultrastructural alterations in conidia treated with AlCl(3) and Na(2)S(2)O(5) included membrane retraction, undulation, and invagination. At higher concentrations or exposure periods to the salts, loss of membrane integrity, cytoplasmic leakage, and cell rupture were observed. Ultrastructural alterations and increased SYTOX stain absorption in salt-treated conidia appear consistent with a mode of action where AlCl(3) and Na(2)S(2)O(5) alter membrane integrity and permeability.

Antifungal activity and ultrastructural alterations in Pseudocercospora griseola treated with essential oils

“…It was observed that changes that occurred in the ultrastructure of this pathogen corroborate findings by several researchers in other pathosystems, as reported in (ROZWALKA et al, 2010;RASOOLI et al 2006;TIAN et al, 2012;AVIS et al, 2009). Scanning and transmission electron microscopy examinations reveal ultrastructural alterations in several compartments of the cell, such as plasma membrane, cytoplasm (swelling, shrivelling, vacuolations, leakage) and nucleus (SOYLU et al, 2006;SANTORO et al, 2007;TYAGI;MALIK, 2010, DAN et al, 2010.…”

Cellular damage induced by a sequential oxidative treatment on Penicillium digitatum

“…This membrane permeability causes a decrease in cell survival, which is in agreement with findings of other authors (Yaganza et al. 2004; Avis et al. 2009; Badosa et al.…”

“…We were able to demonstrate, using the Sytox Green dye, that SOT causes membrane disruption in conidia and hyphae of P. digitatum. This membrane permeability causes a decrease in cell survival, which is in agreement with findings of other authors (Yaganza et al 2004;Avis et al 2009;Badosa et al 2009). Interestingly, we found that incubations with either NaClO alone or with copper (a) Control conidia (without treatment) and (b) Conidia exposed to lethal sequential oxidative treatment (SOT).…”

Antifungal activity of aluminium‐containing salts against the development of carrot cavity spot and potato dry rot

“…Certainly, aluminium acetate, aluminium chloride and aluminium lactate were previously shown to decrease the in vitro mycelial growth and/or sporulation of Helminthosporium solani (Hervieux et al ., ), F . sambucinum and Heterobasidion annosum (Avis et al ., ). Spore germination and/or mycelial growth of F .…”