Genome-Wide Identification of Rice GSTs

GSTs were identified by keyword, domain name and HMMER searches of rice proteome available at Rice Genome Annotation Project [49 ] database using the Hidden Markov Model (HMM) profile (build 2.3.2) of GST_N domain (PF02798) downloaded from PFam. The presence of GST_N domain in individual protein was further confirmed by SMART analysis. Multiple sequence alignment analyses were performed using ClustalX (version 1.83) program. The GST genes present on duplicated chromosomal segments were identified by segmental genome duplication of rice available at RGAP with the maximum length distance permitted between collinear gene pairs of 500 kb. The GST genes separated by a maximum of five genes were identified as tandemly duplicated genes. The unrooted phylogenetic trees were constructed by neighbor-joining method and displayed using Treeview program. Putative conserved motifs were identified using MEME (version 4.1.0) program [50 ].