Overexpression of MusaVicilin Gene for Disease Resistance in Banana

Abstract

Banana Xanthomonas wilt (BXW) disease, caused by Xanthomonas vasicola pv. musacearum, is a major constraint to banana production in East and Central Africa. All cultivated banana varieties are susceptible, with the wild progenitor Musa balbisiana being the only known source of complete resistance. Limitations in classical breeding have prompted the exploration of molecular genetic tools, such as genetic modification, to develop resistant cultivars. Comparative transcriptomic analyses revealed a five-fold upregulation of MusaVicilin gene in M. balbisiana (BB genome) compared to the BXW- susceptible Pisang Awak when challenged with the pathogen, suggesting its role in defense. This study investigated whether constitutive overexpression of the MusaVicilin gene cloned from M. balbisiana could enhance resistance to BXW in the susceptible Sukali Ndiizi cultivar (AAB genome). Transgenic events were developed with the MusaVicilin gene under the control of the constitutive CaMV 35S promoter. These events exhibited enhanced disease resistance compared with non-transgenic control plants. The overexpression of MusaVicilin highlights its potential as a candidate gene for engineering resistance to BXW in susceptible cultivars. Moreover, MusaVicilin could serve as a valuable component in gene stacking strategies aimed at developing durable, disease-resistant banana varieties.