The life cycle of the smut fungus Moesziomyces penicillariae is adapted to the short-cycle of the host, Pennisetum glaucum.

Autor: Diagne-Leye G; Laboratoire de Biotechnologies des Champignons-LBC, Département de Biologie Végétale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop-UCAD, Dakar, Sénégal., Sare IC, Martinez Y, Fall-Ndiaye MA, Sabbagh SK, Ba AT, Roux CP
Jazyk: angličtina
Zdroj: Fungal biology [Fungal Biol] 2013 May; Vol. 117 (5), pp. 311-8. Date of Electronic Publication: 2013 Mar 23.
DOI: 10.1016/j.funbio.2013.03.002
Abstrakt: Moesziomyces penicillariae (Brefield) Vànky is a basidiomycete fungus responsible for smut disease on pearl millet, an important staple food in the sub-Sahelian zone. We revisited the life cycle of this fungus. Unlike other Ustilaginales, mating of sporidia was never observed and monoclonal cultures of monokaryotic sporidia were infectious in the absence of mating with compatible partner. These data argued for an atypical monokaryotic diploid cell cycle of M. penicillariae, where teliospores only form solopathogenic sporidia. After inoculation of monoclonal solopathogenic strains on spikelets, the fungus infects the ovaries and induces the folding of the micropilar lips, as observed during early pollination steps. The infected embryo then becomes disorganized and the fungus invades peripheral ovary tissues before sporulating. We evaluated the systemic growth abilities of the fungus. After root inoculation, mycelium was observed around and inside the roots. As argued by transmission electron microscopy (TEM) observations and polymerase chain reaction (PCR) detection using specific primers for M. penicillariae, the fungus can grow from roots to the caulinar meristems. In spite of this systemic growth, no sori were formed on the varieties of pearl millet tested after root inoculation. All together, these data suggest that the reduced life cycle of M. penicillariae--i.e. dispersal of 'ready to infect' solopathogenic sporidia, floral infection--is an adaptation to the aetiology of this disease to short-cycle pearl millet varieties from the sub-Sahel.
(Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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