Loss of function of MusaPUB genes in banana can provide enhanced resistance to bacterial wilt disease

Abstract

Plants deploy a sophisticated defense mechanism against pathogens through pattern recognition receptors (PRRs) and resistance (R) proteins, activating pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). E3 ubiquitin ligases, notably U-box types like PUB22 and PUB23, modulate PTI by suppressing immune responses. The role of MusaPUB22/23 in immunity against Xanthomonas campestris pv. musacearum (Xcm), the cause of banana Xanthomonas wilt (BXW) in East Africa, was investigated by knocking out these genes in the BXW-susceptible 'Sukali Ndiizi' cultivar. Confirmed edited events demonstrated enhanced resistance against Xcm without compromising growth. Suppressed MusaPUB22/23 expression upon Xcm infection in the pub22/23 events underscored their negative immune regulation role. The enhanced expression of defense-related genes in edited events indicates improved immunity. This study showcases MusaPUB22/23 knockout as a promising strategy against BXW, addressing a crucial agricultural issue in East Africa while unraveling plant immunity regulation and paving the way for disease-resistant crop engineering targeting PUB genes.