Encodes a P-Type ATPase, a Novel Gene for Cadmium Accumulation and Tolerance in Barley ( L.).

The identification of gene(s) that are involved in Cd accumulation/tolerance is vital in developing crop cultivars with low Cd accumulation. We developed a doubled haploid (DH) population that was derived from a cross of Suyinmai 2 (Cd-sensitive) × Weisuobuzhi (Cd-tolerant) to conduct quantitative trait loci (QTL) mapping studies. We assessed chlorophyll content, traits that are associated with development, metal concentration, and antioxidative enzyme activity in DH population lines and parents under control and Cd stress conditions. A single QTL, designated as , was identified on chromosome 7H that was linked to shoot Cd concentration; explained 17% of the phenotypic variation. Comparative genomics, map-based cloning, and gene silencing were used in isolation, cloning, and functional characterization of the candidate gene. A novel gene , being related to shoot Cd concentration, was identified from . Sequence comparison indicated that carried seven domains with an N-glycosylation motif. is predominantly expressed in shoots. Subcellular localization verified that HvPAA1 is located in plasma membrane. The silencing of resulted in growth inhibition, greater Cd accumulation, and a significant decrease in Cd tolerance. We conclude is a novel plasma membrane-localized ATPase that contributes to Cd tolerance and accumulation in barley. The results provide us with new insights that may aid in the screening and development of Cd-tolerant and low-Cd-accumulation crops.