Isolation, characterization and immunolocalization of a seed dominant CaM from finger millet (Eleusine coracana L. Gartn.) for studying its functional role in differential accumulation of calcium in developing grains.
To understand the exceptional high grain calcium accumulation in finger millet grains, a calmodulin (CaM) gene that is strongly expressed during developing spikes of high grain calcium genotype was further characterized. Using 5'-3' RACE, the full-length CaM open reading frame (ORF) was isolated and the deduced protein sequence showed the presence of four characteristic EF motifs. Phylogenetic analysis showed that the finger millet CaM (Eleusine coracana calmodulin [EcCaM]) was identical to the rice CaM 1-1. Southern hybridization showed the presence of at least four copies of CaM gene that might be located on different regions of the finger millet "AABB" genome. Immunodetection using monospecific polyclonal anti-EcCaM antibodies revealed that EcCaM is localized in the embryo and aleurone layer and accumulates in higher amounts in high grain calcium genotype compared to the low grain calcium genotype. Furthermore, in silico analysis showed that EcCaM interacts with aquaporin which indicates that calcium is probably delivered to developing spike via mass flow of water. These results indicate that higher expression of CaM might cause greater stimulation of the downstream calcium transport machinery operative in the aleurone layer leading to the higher calcium accumulation in the grains of high grain calcium genotype.
Department of Molecular Biology and Genetic Engineering, College of Basic Sciences and Humanities, GB Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263 145, India, anilkumar.mbge@gmail.com.
Anil
A
Kumar
Neelofar
N
Mirza
Tara
T
Charan
Netrapal
N
Sharma
Vikram Singh
VS
Gaur
D020816:Amino Acid Motifs; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002523:Edible Grain; D031748:Eleusine / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018628:Gene Dosage; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D005838:Genotype; D017136:Ion Transport; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D025941:Protein Interaction Mapping; D012639:Seeds / Q000235:genetics* / Q000378:metabolism
D020346:Aquaporins; D002147:Calmodulin; D010940:Plant Proteins; D002118:Calcium