RT journal article
T1 Alternaria alternata Isolated from Infected Pears (Pyrus communis) in Italy Produces Non-Host Toxins and Hydrolytic Enzymes as Infection Mechanisms and Exhibits Competitive Exclusion against Botrytis cinerea in Co-Infected Host Fruits
A1 Castaldi, Stefany
A1 García Zorrilla, Jesús
A1 Petrillo, Claudia
A1 Russo, Maria Teresa
A1 Ambrosino, Patrizia
A1 Masi, Marco
A1 Cimmino, Alessio
A1 Isticato, Rachele
A2 Química Orgánica
K1 Alternaria alternata
K1 pear pathogens
K1 enzymatic activities
K1 toxins
K1 necrotic activity
K1 Botrytis cinerea
K1 competitive exclusion
K1 multi-infection
AB Alternaria alternata is one of the most devastating phytopathogenic fungi. This microorganismcauses black spots in many fruits and vegetables worldwide, generating significant post-harvestlosses. In this study, an A. alternata strain, isolated from infected pears (Pyrus communis) harvested inItaly, was characterized by focusing on its pathogenicity mechanisms and competitive exclusion inthe presence of another pathogen, Botrytis cinerea. In in vitro assays, the fungus produces strong enzymaticactivities such as amylase, xylanase, and cellulase, potentially involved during the infection.Moreover, it secretes four different toxins purified and identified as altertoxin I, alteichin, alternariol,and alternariol 4-methyl ether. Only alteichin generated necrotic lesions on host-variety pears,while all the compounds showed moderate to slight necrotic activity on non-host pears and othernon-host fruit (lemon, Citrus limon), indicating they are non-host toxins. Interestingly, A. alternata hasshown competitive exclusion to the competitor fungus Botrytis cinerea when co-inoculated in hostand non-host pear fruits, inhibiting its growth by 70 and 65%, respectively, a result not observed in apreliminary characterization in a dual culture assay. Alteichin and alternariol 4-methyl ether testedagainst B. cinerea had the best inhibition activity, suggesting that the synergism of these toxins andenzymatic activities of A. alternata are probably involved in the competitive exclusion dynamics inhost and non-host pear fruits.
PB MDPI
SN 2309-608X
YR 2023
FD 2023
LK http://hdl.handle.net/10498/32036
UL http://hdl.handle.net/10498/32036
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026