Plant Physiol Biochem. 2025 Jun 19. pii: S0981-9428(25)00708-9. [Epub ahead of print]227 110180
Mitochondrial calcium uniporters (MCUs) play a crucial role in calcium transport, signaling, and homeostasis, which is vital for plant growth, development, and stress responses. In this study, we identified 17 TaMCU genes classified into seven homoeologous groups with conserved gene architecture in the bread wheat genome. The structural analysis revealed the presence of MCU domain, DVME motif, transmembrane helices, and various key amino acid residues, which are conserved across all TaMCU proteins. Each TaMCU protein consisted of a mitochondrial targeting peptide and predicted to be localized in the mitochondria. The phylogenetic and synteny analyses provided insights into their evolutionary diverged and conserved nature. Cis-regulatory element analysis suggested that TaMCU genes are involved in abiotic stress responses, involving key transcription factors such as MYB, MBS, W-box, and ERF. Protein-protein interaction study suggested that TaMCUs interact with other mitochondrial and stress-related proteins, such as MICU, PHB, and FREE1. Additionally, six miRNAs related to plant development and stress-response such as miR5384-3p, tae-miR5050 etc., exhibited interactions with a few TaMCU transcripts. RNA-seq expression profiling revealed differential expression of various TaMCU genes in tissue developmental stages and under various stress conditions. qRT-PCR under salinity and drought treatments confirmed the involvement of TaMCU1-D, TaMCU3-A, and TaMCU5-B genes in these stress conditions. These findings provide insights into the potential roles of TaMCU genes and suggest their future applications in the development of abiotic stress-resilient crop plants.
Keywords: Abiotic stress; Bread wheat; Drought; Mitochondrial calcium uniporters; Salinity