Genome-Wide Identification of Bax Inhibitor (BI) Gene in Potato (Solanum tuberosum) and Response During Begomovirus Infection

Abstract

Bax Inhibitor (BI) protein plays a crucial role in regulating programmed cell death (apoptosis) in plants and is vital during biotic and abiotic stresses. In this study, a genome-wide analysis was performed to characterize the BI gene family in potato. Genome mining identified seven BI genes in potato, each on a distinct chromosome. Cis-regulatory element (CRE) analysis revealed that StBI genes may be involved in light, stress, developmental, and hormonal responses. All StBI genes contained the BI domain. RNA-seq expression data from various potato organs, sourced from online databases, indicated that all StBI and StBI7 genes respond to both biotic and abiotic stresses. Additionally, qRT-PCR-based expression profiling during begomovirus (Tomato Leaf Curl New Delhi Virus, ToLCNDV) infection showed low relative expression of StBI1 in infected samples. In contrast, StBI2, StBI4, StBI5, and StBI7 had high expression levels in infected plants. In virus-infected plants, chlorophyll content decreased, indicating impaired photosynthetic efficiency. Antioxidant activity increased, reflecting the activation of defense mechanisms against oxidative stress. This is the first report characterizing the S. tuberosum Bax inhibitor gene family and its expression against Begomovirus. These findings may aid in understanding the S. tuberosum Bax inhibitor gene family and lay the foundation for future cloning and functional studies.