Bioinformatical study of Calcium/cation (CaCA) antiporters gene family in maize (Zea mays L.)

The Ca2+/cation antiporters (CaCA) superfamily proteins play vital function in Ca2+ ion homeostasis, which is an important event during development and defense response. In the present study, using related database, 14 CaCA genes were identified in the maize genome and classified according to their structural organization and evolutionary association with the identified CAX, CCX and MHX proteins. Most of the ZmCaCA proteins had two Na_Ca_ex domains. All of the identified genes had at least one functional motif and gene structure of each CaCA subgroup is highly conserved. In the prediction of reactive miRNAs relative to CaCA genes in maize, 33 different miRNA variants were identified that regulate the expression of 13 CaCA genes through cleavage or inhibition of translation. In addition, several cis-acting regulatory elements in ZmCaCA genes were found to be related to hormones stress responses. The variable expression of most ZmCaCA genes at different stages of development indicates their distinct role in development. Expression of these genes in abiotic stresses (cold, salt, and drought) indicates their role in stress response. The greatest high expression and down regulation of gene expression is related to CAX genes. The results of this study provide basic data about phylogeny and putative function of these genes for future studies on the role of CaCA genes in maize.