A novel gene silencing strategy based on tobacco rattle virus in Hibiscus mutabilis

Hibiscus mutabilis L. is a popular regional characteristic plant in China, cultivated for its attractive flower colors, extended bloom time, and medicinal properties. To enhance molecular breeding and gene function studies, we conducted transcriptome analysis and identified valuable genes in previous research. Nonetheless, the current inefficient and labor-intensive transformation techniques have hindered their applications. Virus-induced gene silencing (VIGS) provides a precise and effective strategy for post-transcriptional down-regulation of endogenous gene expression.

We investigated the performance of tobacco rattle virus (TRV) as a tool for targeting and silencing the gene encoding the protein involved in chloroplast development, cloroplastos alterados 1 (altered chloroplast; CLA1), of H. mutabilis through Agrobacterium tumefaciens-mediated infiltration.

By effectively suppressing the CLA1 gene associated with chloroplast development in H. mutabilis via the TRV-VIGS system, we have illustrated the inaugural implementation of VIGS in this species. Quantitative RT-PCR proved that HmCLA1 expression in agro-infiltrated plants was lower than in the mock-infiltrated (mock) and the control (CK) plants. Phenotypic observations corroborated the albino phenotype in leaves following successful HmCLA1 silencing.

Our study showcases TRV-VIGS as a potential gene silencing tool for H. mutabilis, facilitating functional genomics studies and molecular breeding efforts in this species.