Differential regulation of jasmonic acid pathways in resistant (Calcutta 4) and susceptible (Williams) banana genotypes during the interaction with Pseudocercospora fijiensis

One of the main biosecurity problems facing banana crops is black Sigatoka disease, caused by the fungus Pseudocercospora fijiensis. Disease control is achieved mainly by chemical sprays and generates more than 50% of the costs of production, with a trend to increase due to the rapid resistance that the fungus acquires to the main fungicide molecules. Thus, it is very important to acquire information on the molecular mechanisms of the plant–pathogen interactions in this pathosystem as a way to help design future control strategies. Hormonal plant responses of banana genotypes susceptible and resistant to P. fijiensis were identified and analysed in this work by transcriptomic (RNA‐Seq and RT‐qPCR) and metabolomic studies (ultraperformance liquid chromatography‐mass spectroscopy). Differentially expressed genes related to signal transduction and biosynthesis pathways of jasmonic acid (JA) and ethylene (ET) were identified in the resistant variety Calcutta 4 during the early stage of interaction with P. fijiensis. Metabolomic analysis corroborated the induction of metabolites related to JA and ET pathways during the first 72 hr post‐inoculation. Observed results are evidence that signalling via JA/ET could be key in the activation of defence response signals in the resistant variety Calcutta 4. In black Sigatoka‐resistant banana cv. Calcutta 4, jasmonic acid and ethylene signalling and biosynthesis pathways are induced early after infection with Pseudocercopora fijiensis, indicating a key role in activation of defences.