Genetic Characteristics and Metabolic Interactions between Pseudocercospora fijiensis and Banana: Progress toward Controlling Black Sigatoka

Abstract

The international importance of banana and severity of black Sigatoka disease have led to extensive investigations into the genetic characteristics and metabolic interactions between the Dothideomycete Pseudocercospora fijiensis and its banana host. P. fijiensis was shown to have a greatly expanded genome compared to other Dothideomycetes, due to the proliferation of retrotransposons. Genome analysis suggests the presence of dispensable chromosomes that may aid in fungal adaptation as well as pathogenicity. Genomic research has led to the characterization of genes and metabolic pathways involved in pathogenicity, including: secondary metabolism genes such as PKS10-2, genes for mitogen-activated protein kinases such as Fus3 and Slt2, and genes for cell wall proteins such as glucosyl phosphatidylinositol (GPI) and glycophospholipid surface (Gas) proteins. Studies conducted on resistance mechanisms in banana have documented the role of jasmonic acid and ethylene pathways. With the development of banana transformation protocols, strategies for engineering resistance include transgenes expressing antimicrobial peptides or hydrolytic enzymes as well as host-induced gene silencing (HIGS) targeting pathogenicity genes. Pseudocercospora fijiensis has been identified as having high evolutionary potential, given its large genome size, ability to reproduce both sexually and asexually, and long-distance spore dispersal. Thus, multiple control measures are needed for the sustainable control of black Sigatoka disease.

Gene Expression, Histology and Histochemistry in the Interaction between Musa sp. and Pseudocercospora fijiensis

“…Research on plant-fungal interactions from the biochemical and histological perspective has helped improve the understanding of the mechanisms that drive the infectious process [ 84 ]. In addition, the development of an effective control of the disease does not depend only on extensive knowledge of the fungal life cycle, and it is of paramount importance to know and understand which resistance mechanisms are used by the host [ 10 ]. Thus, histological and histochemical studies allowed the characterization of the process of infection with black Sigatoka in the cultivars studied, and it was possible to observe the production of waxes, calcium oxalate and compounds produced in response to infection by the pathogen.…”

“…Despite the large scale of banana production, this crop is constantly affected by abiotic and biotic factors that directly affect fruit production, including water deficit and temperature extremes, as well as pests and diseases [ 4 ]. The main biotic factors affecting banana include bacterial wilt [ 5 ], nematodes [ 6 ], Fusarium wilt [ 7 ], yellow Sigatoka [ 8 ] and black Sigatoka [ 9 , 10 ]. Black Sigatoka is thought to have the greatest economic impact since the incidence of this fungus in banana-producing regions has increased significantly in recent years, partly due to climate changes that have made the temperature and humidity conditions favorable for the germination and growth of fungal spores [ 11 ].…”

New Insights into Chemical and Biological Properties of Funicone-like Compounds

“…Funicones are one of the classes of fungal secondary metabolites for which very limited assessments have been carried out in this regard so far. Most of the producing species are not established pathogens of crops, with the exception of Pseudocercospora (= Mycosphaerella ) fijiensis , a vermistatin producer that is known as the agent of black sigatoka disease of banana [ 72 ]. However, this is a leaf pathogen that is not known to spread to fruit, implying that it is unlikely that bananas can be contaminated with vermistatin.…”

Does Abiotic Host Stress Favour Dothideomycete-Induced Disease Development?

“…Taken together, these results suggest that the light effect cannot be explained solely by the action of juglone in the plant. The role played by juglone in the interactions between P. fijiensis and banana has been reviewed in this issue by Noar et al [164].…”