Identification and Characterization of Two Paralogous Plastid Terminal Oxidase Genes in Soybean

Xin Sun, Tao Lei, Jun-Bo Du, Wen-Yu Yang
2015 International Journal of Agriculture and Biology  
Plastid terminal oxidase (PTOX) is a plastoquinol oxidase, which plays several important roles in plants. Previous studies suggested that PTOX is encoded by a single gene with only one copy in higher plants. Here we report the identification of two possible paralogous PTOX genes on different chromosomes of soybean, both of which are highly homologous to known PTOX genes in other species. These two paralogs have quite different introns and nearly the same exons and were predicted to encode
more » ... ted to encode membrane protein with chloroplast transit peptide. The deduced PTOX protein encoded by both paralogs were proposed to be functional, since the existence of highly conserved amino acid sites necessary for a typical PTOX, including six iron-binding sites and Exon 8 domain. Moreover, soybean PTOX also exhibit clear sequence similarity to alternative oxidase (AOX). Organ-specific expression analysis showed high transcript levels of soybean PTOX in stems, leaves and flowers, while the levels in pods and roots were relatively low. In addition, a light-inducible character was also suggested for soybean PTOX in the present study.
doi:10.17957/ijab/15.0051 fatcat:fg6gep32vncftgsh5l5cd2vfem