Genome-wide Analysis of the CCCH Zinc-Finger Gene Family in Banana (Musa acuminata): An Insight Into Motif and Gene Structure Arrangement, Evolution and Salt Stress Responses

The CCCH zinc finger proteins contain a signature motif comprising of three cysteine and one histidine residues. Increasing evidence suggests that members of this large family regulate the transcription of genes that participate in plant growth and development as well as responses to environmental stresses including salt stress in plants. However, little is known about this gene family in banana (Musa acuminata), a tropical crop that is globally consumed and is highly sensitive to salt stress conditions. Here, we present the genome-wide identification of the CCCH Zinc-Finger (CCCH-ZF) gene family in banana. We identified 89 CCCH-ZFP (MaZFP) genes and evaluated their phylogenetic relationships. Our analysis showed that this gene family encodes proteins with variable lengths and highly conserved motif structures. Distribution mapping of this gene family revealed that MaZFP genes are unevenly dispersed on the 11 chromosomes with segmental duplication in 15 gene pairs, suggesting an important contribution of duplication in expansion of this gene family in banana. Expression analysis of four selected MaZFP genes in leaf and root tissues of banana showed temporal and spatial expression in response to salt stress conditions with high transcript accumulation in root tissue. The highest level of transcript was measured for MaZFP88 in root tissues sampled 24 h after treatment with 100 mM NaCl. The analysis presented here provides a valuable reference for future functional studies of MaZFP genes with the potential for use in developing salt-tolerant banana varieties.