COMPLETE CHLOROPLAST GENOME SEQUENCE AND PHYLOGENETIC RELATIONSHIPS OF SOME ACANTHOIDEAE SPECIES (ACANTHACEAE)
ID: 613 / 275
Proposed Symposium Title: COMPLETE CHLOROPLAST GENOME SEQUENCE AND PHYLOGENETIC RELATIONSHIPS OF SOME ACANTHOIDEAE SPECIES (ACANTHACEAE)
Samaila S. Yaradua
Affiliations: Department of Biology, Umaru Musa Yaradua University, Katsina, Nigeria.
The plastid genomes of Acanthoidea were sequenced and compared with plastome of other sequenced Acanthoideae species to characterize the plastomes, identify the simple sequence repeats (SSRs), detect variations among the cp genomes and to infer their phylogenetic relationships. The plastome was assembled from the whole genome sequences using NOVOPlasty.The cp genomes of the species ranged from 149, 717 bp to 152,217 bp in length with GC and AT contents of 38.3 and 61.7 % respectively and have a quadripartite and circular structure, the genome constitutes of a pair of inverted repeats (IRa and IRb) which are separated by large single copy (LSC) and small single copy (SSC). A total of 131 genes were identified in the genomes, comprising of 80 protein-coding genes, 30 tRNA and 4 rRNA; 113 are unique, 18 were duplicated in IR regions. The analysis of long repeat showed all types of repeats were present in the plastomes and palindromic has the highest frequency. A total number of 98 SSR were also identified in the cp genome of B. prionitis and J. flava of which majority were mononucleotide A/T. Genome comparative analysis among the plastomes revealed that the IRs regions are more conserved than large single copy and small single copy. In addition, high variation is observed in the noncoding region than the coding. The genes, ndhF and ycf1 are located at the border junction of the small single copy region and IRb region of all the plastome. The sequence divergence analysis indicates that the following genes undergo positive selection (atpF, petD, psbZ, rpl20, petB, rpl16, rps16, rpoC, rps7, rpl32 and ycf3). Phylogenetic analysis indicated sister relationship between Ruellieae and Justcieae. In addition, Barleria, Justicia and Ruellia are paraphyletic, suggesting that Justiceae, Ruellieae, Andrographideae and Barlerieae should be treated as tribes.