Early Events in the Fusarium verticillioides -Maize Interaction Characterized by Using a Green Fluorescent Protein-Expressing Transgenic Isolate

Abstract

The infection of maize by Fusarium verticillioides can result in highly variable disease symptoms ranging from asymptomatic plants to severe rotting and wilting. We produced F. verticillioides green fluorescent proteinexpressing transgenic isolates and used them to characterize early events in the F. verticillioides-maize interaction that may affect later symptom appearance. Plants grown in F. verticillioides-infested soil were smaller and chlorotic. The fungus colonized all of the underground parts of a plant but was found primarily in lateral roots and mesocotyl tissue. In some mesocotyl cells, conidia were produced within 14 to 21 days after infection. Intercellular mycelium was detected, but additional cells were not infected until 21 days after planting. At 25 to 30 days after planting, the mesocotyl and main roots were heavily infected, and rotting developed in these tissues. Other tissues, including the adventitious roots and the stem, appeared to be healthy and contained only a small number of hyphae. These results imply that asymptomatic systemic infection is characterized by a mode of fungal development that includes infection of certain tissues, intercellular growth of a limited number of fungal hyphae, and reproduction of the fungus in a few cells without invasion of other cells. Development of visibly rotted tissue is associated with massive production of fungal mycelium and much less organized growth.

Tagging target genes of the MAT1-2-1 transcription factor in Fusarium verticillioides (Gibberella fujikuroi MP-A)

“…F. verticillioides, a heterothallic fungus (teleomorph: Gibberella moniliformis; synonymous names Fusarium moniliforme, Gibberella fujikuroi mating population A) was selected for this study due to its economic importance. This fungus that occurs globally and is one of the most commonly reported fungal species infecting maize (Oren et al 2003), producing fumonisins, a well known group of mycotoxins that cause human and animal diseases (Nelson et al 1993;Moretti et al 1997;Marasas 2001). Moreover, F. verticillioides is member of a species complex that contains both sexual and asexual species of agronomic importance (O'Donnell et al 1998).…”

Microdochium nivale (Fr., Samuels & Hallett): cytological analysis of the infection process in triticale (×Triticosecale Wittm.)

“…Such data were published, for instance, in the case of the maize infection caused by Fusarium verticillioides (Oren et al 2003) or Bipolaris sorokiniana (Kumar et al 2002), infection of wheat caused by Fusarium culmorum, F. graminearum and M. nivale (Clement and Parry 1998;Jackowiak et al 2005;Kang et al 2007). However, the infection development initiated from spores differs from the process induced by M. nivale mycelium, which is the main source of infection in winter conditions (Tronsmo et al 2001).…”

“…The papers mainly illustrate infection initiated by fungal spores and the literature describing the cytological analysis of the infection in cereals is fragmentary (Clement and Parry 1998;Kumar et al 2002;Oren et al 2003;Jackowiak et al 2005;Kang et al 2007). There is no cytological data describing the infection caused by mycelial inoculum of M. nivale, including the early phases of pathogenesis.…”

Response of AtNPR1-expressing cotton plants to Fusarium oxysporum f. sp. vasinfectum isolates

“…The protoplast preparation and transformation were carried out as described (Hohn and Desjardins 1992;Oren et al 2003) with minor modifications. A few blocks of Fov11 from potato dextrose agar culture were inoculated in 100 ml potato dextrose broth and grown for 10 days on a rotary shaker at 25°C at 150 rpm.…”