Bipolaris sorokiniana, a cereal pathogen of global concern: cytological and molecular approaches towards better control‡

Abstract

Summary Bipolaris sorokiniana (teleomorph Cochliobolus sativus ) is the causal agent of common root rot, leaf spot disease, seedling blight, head blight, and black point of wheat and barley. The fungus is one of the most serious foliar disease constraints for both crops in warmer growing areas and causes significant yield losses. High temperature and high relative humidity favour the outbreak of the disease, in particular in South Asia's intensive ‘irrigated wheat–rice’ production systems. In this article, we review the taxonomy and worldwide distribution, as well as strategies to counteract the disease as an emerging threat to cereal production systems. We also review the current understanding of the cytological and molecular aspects of the interaction of the fungus with its cereal hosts, which makes B. sorokiniana a model organism for studying plant defence responses to hemibiotrophic pathogens. The contrasting roles of cell death and H 2O2 generation in plant defence during biotrophic and necrotrophic fungal growth phases are discussed.

A novel late embryogenesis abundant protein and peroxidase associated with black point in barley grains

“…Black point of barley and wheat grains has historically been associated with fungal colonisation of the grain [2][3][4][5]. However, evidence of fungal association with black point is often contradictory within the literature.…”

“…[4] and Bipolaris sorokiniana [5]. However, studies describing these associations have also isolated fungi from healthy grains.…”

The endophytic fungus Piriformospora indica reprograms barley to salt-stress tolerance, disease resistance, and higher yield

“…In axenic culture, P. indica did not exhibit antifungal activity to F. culmorum or C. sativus (data not shown), indicating that the protective potential of the endophytic fungus does not rely on antibiosis. These results show that P. indica exerts beneficial activity against two major cereal pathogens that cause enormous worldwide economic losses (30).…”

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.…”