AUTHOR=Gunasinghe Niroshini , Barbetti Martin J. , You Ming Pei , Dehigaspitiya Prabuddha , Neate Stephen 

TITLE=Dimorphism in Neopseudocercosporella capsellae, an Emerging Pathogen Causing White Leaf Spot Disease of Brassicas

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2021.678231

DOI=10.3389/fcimb.2021.678231

ISSN=2235-2988

ABSTRACT=<p>White leaf spot pathogen: <italic>Neopseudocercosporella capsellae</italic> causes significant damage to many economically important Brassicaceae crops, including oilseed rape through foliar, stem, and pod lesions under cool and wet conditions. A lack of information on critical aspects of the pathogen’s life cycle limits the development of effective control measures. The presence of single-celled spores along with multi-celled conidia on cotyledons inoculated with multi-celled conidia suggested that the multi-celled conidia were able to form single-celled spores on the host surface. This study was designed to demonstrate <italic>N. capsellae</italic> morphological plasticity, which allows the shift between a yeast-like single-celled phase and the multi-celled hyphal phase. Separate experiments were designed to illustrate the pathogen’s morphological transformation to single-celled yeast phase from multi-celled hyphae or multi-celled macroconidia <italic>in-vitro</italic> and <italic>in-planta</italic>. Results confirmed the ability of <italic>N. capsellae</italic> to switch between two morphologies (septate hyphae and single-celled yeast phase) on a range of artificial culture media (<italic>in-vitro</italic>) or <italic>in-planta</italic> on the host surface before infection occurs. The hyphae-to-yeast transformation occurred through the production of two morphologically distinguishable blastospore (blastoconidia) types (meso-blastospores and micro-blastospores), and arthrospores (arthroconidia).</p>