Cloning of an ABC1-like Gene ZmABC1-10 and Its Responses to Cadmium and Other Abiotic Stresses in Maize (Zea mays L.)

Cadmium is a nonessential heavy metal that is extremely toxic to plants and animals. Previous studies have shown that several proteins associated with the Activity of the bc1 complex (ABC1) family participate in plant response to cadmium. An ABC1-like gene, ZmABC1-10, was cloned from maize (Zea mays L.). The full-length of cDNA was 2519 bp, which contained an open reading frame of 2250 bp encoding a membrane-binding protein with a predicted localization in the chloroplast. A promoter scan detected numerous cis-elements implicated in abiotic stress, light, and phytohormone responses. Expression profile analysis indicated most expression of this gene occurred in green tissues. Cadmium treatment revealed that expression of this gene could be induced and was correlated with plant development. In addition to cadmium, ZmABC1-10 expression was also affected by a broad range of abiotic factors, such as abscisic acid, H₂O₂, drought, and darkness. A total of 19 members of maize ABC1 family were identified with the B73 maize genomic sequence. Phylogenetic analysis using 148 ABC1 proteins from 8 representative species of plant kingdom revealed that divergence occurred and species-specific expansion contributed to the evolution of this family in plants. Collectively, ZmAbc1-10 is suggested to be a cadmium-responsive factor and may play potential roles in plant adaption to diverse abiotic stresses.