Cloning and characterization of auxin efflux carrier genes EcPIN1a and EcPIN1b from finger millet Eleusine coracana L.

Auxin signaling events in plants play important role in developmental regulation as well as gravitropic responses and plays crucial role in the development of root, lateral root and root hairs. The gene that is known to be most important in the development of root, lateral root and root hairs is commonly known as auxin efflux carrier (PIN). Being commonly known as orphan plant, the genome sequence of Eleusine coracana is not known yet, and hence it was very difficult to conduct advanced research in root development in this plant. As PIN gene plays crucial role in root development, to have some advanced study we proposed to clone the PIN genes from E. coracana. We cloned two PIN genes in E. coracana and named them as EcPIN1a and EcPIN1b. The coding sequence (CDS) of EcPIN1a was 1779 bp and EcPIN1b was 1788 bp long that encodes for 593 and 596 amino acids, respectively. In-silico analysis shows the presence of transmembrane domain in EcPIN1a and EcPIN1b protein. Multiple sequence alignment of EcPIN1a and EcPIN1b protein shows the presence of several conserved motifs. Phylogenetic analysis of EcPIN1a and EcPIN1b grouped with the PIN gene of monocot plant Oryza sativa. This shows that EcPIN genes were monocot specific, and closely match with the PIN genes of O. sativa. The transcript analysis of EcPIN1a gene in leaf tissue shows gradual up-regulation from 7th to 28th days of developmental time period while the transcript level was found to be lower in root tissue. The transcript abundance of EcPIN1b was not detected. Gradual up-regulation of EcPIN1a gene in developmental stages signifies its important role in root development in E. coracana.