Microdochium bolleyi (Ascomycota: Xylariales): physiological characterization and structural features of its association with wheat.

ROTHEN C.P.; MIRANDA, V.; FRACCHIA S.; GODEAS A. M.; RODRIGUEZ, M.A.

BOLETíN DE LA SOCIEDAD ARGENTINA DE BOTáNICA

SOCIEDAD ARGENTINA DE BOTÁNICA

Año: 2018 vol. 53 p. 169 - 182

0373-580X

Plant roots can be asymptomaticaly colonized by fungi belonging to several taxa. Among them, the group defined as Dark Septate Endophytes (DSE) includes fungal species related to taxa of known pathogenic fungi. Microdochium bolleyi is considered a weak pathogen or even a non-pathogenic fungal species, which commonly colonizes wheat roots and other crops. It was previously considered as a potential biocontrol agent against aggressive soil-borne pathogens in cereal crops. In this study, we isolated a strain of M. bolleyi from wheat roots sampled in a crop field in Argentina, and characterized its abilities to grow in different carbon and nitrogen sources, produce indoles, solubilize phosphorus and several enzymatic activities were evaluated. In addition, resynthesis was performed under controlled conditions in order to characterize root fungal colonization under both, optical and transmission microscopy. The strain behaved as a DSE, colonizing wheat root parenchymal tissue, forming chlamysdospore inside parenchymal cells and root hairs, and poorly grew in carbon and nitrogen sources. The strain also synthesized indoles in in vitro culture, but did not show abilities to solubilize phosphorus. Only amylase activity was detected out of seven enzymatic activity measures. This fungus has great potential to be used as a bio-inoculant, however further studies are necessary to continue to elucidate its role in the association with wheat.