Genome-Wide Survey and Expression Analysis of P1B-ATPases in Rice, Maize and Sorghum

P1B-type ATPase ion pumps that transport heavy metal ions across cellular membranes are essential for plant growth and development. To date, a genomic comparison overview of the family in rice, maize and sorghum is not yet available. In this study, a total of 31 heavy metal P1B-type ATPase (HMA) genes were identified, including 9 in rice, 11 each from maize and sorghum. They were classified into two distinct subfamilies based on their sequence composition and phylogenetic relationship. Four pairs of HMA genes were expanded via gene duplication with tandemly duplicated. Comprehensive analyses were performed to investigate the expression profiles of HMA genes in various tissues by using quantitative real-time PCR. Some HMA members exhibited abundant and tissue-specific expression patterns. Moreover, most of the genes were found to be differentially expressed under the Cu/Cd treatment. This study will facilitate further studies on P1B-type ATPase family and provide valuable hints for the functional validation in rice, maize and sorghum.