S21 - Session O3 - Systemic resistances of banana as a potential tool to control of Fusarium oxysporum f. sp. cubense race 1

Authors: Jessica Mendoza Rodríguez , Nayanci Portal, Ermis Yanes Paz, Rayza Gonzalez Rodriguez, Monguy Ramon Santos, Alain Soler *

Banana is a fruit consumed by millions of people worldwide with a production of 150 millions tons mostly consumed in areas of production. The export production (about 20 millions tons) is based on Cavendish variety, but is jeopardized by a wilt disease caused by Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4). Integrated Pest Management strategies consist designing production systems of banana based on crop rotation and/or association with cover crops to restore ecosystem services such as organic matter content and turnover, disease suppression and regulation. The stimulation of systemic resistances to strengthen banana tolerance to pathogens in agroecosystems without pesticide is one of the strategies being considered. Firstly, in a study of the interaction banana with Foc - race 1, gene expression was measured after Foc - race1 extract was applied to leaves. Changes in the expression of genes involved signaling pathways and defenses were measured in susceptible and tolerant banana varieties after application of the extract of Foc - race1. Secondly, the direct interaction between banana and Foc - race 1 was used to evaluate a potential use of systemic resistances of banana to control Fusarium. Following inducer application, SA, ASM, or Met-Jasmonate, Foc race 1 was inoculated on banana vitroplants. Comparisons of expression of genes related to signaling pathways, SAR and ISR, were made on banana varieties susceptible or naturally tolerant to Foc - race 1 or/and Foc TR4. As a result of Foc - race1 extract application, significant changes in gene expression profiles of genes related to SAR signaling pathway (NPR1, PAL) and related to oxidative stress and defense (SOD, CAT, and PR1) were observed. Then, both stimulations of SAR and ISR reduced the incidence of Foc - race 1. SAR inducers were more effective than ISR inducer as demonstrated by the different types of markers, such as expression of symptoms, expression of PAL and NPR1 (SAR), as LOX, ACO, AOS, MYC2 (ISR) , and PR3, PR1 related to defenses, or SOD, PPO, POD, and CAT related to oxidative stress. The study demonstrated that SAR was a viable tool to help manage Fusarium wilt of bananas.