Over expression of anti-apoptotic gene in banana cv Rasthali enhances resistance against Fusarium oxysporum f. sp. cubense Race 1

Abstract

The most popular banana cv Rasthali was transformed with anti-apoptotic gene, AtBAG4 regulated with two different promoters viz., ZmBgl and ubiquitin to enhance the tolerance levels to Fusarium oxysporum f. sp. cubense Race 1 (FOC1). The differences in gene expression driven by two promoters revealed that stronger expression of AtBAG4 gene under the ubiquitin promoter suppressed the infection and spreading processes of FOC1 in transgenic banana under standard bioassay systems. Analysis using the real time PCR showed the varying levels of AtBAG4 gene expression under two promoters. It was evident that ZmBgl driven AtBAG4 lead to lower gene expression in leaves which correlated with lesser levels of resistance to FOC1. Constitutive expression of AtBAG4 under the control of ubiquitin promoter showed increased transgene transcripts which directly correlated with the enhanced tolerance against FOC1 from seedlings stage to active vegetative phases. This study reveals the importance of constitutive expression of anti-apoptotic gene showing enhanced tolerance against the most dreaded FOC1 in highly susceptible variety Rasthali.