Isolation and characterization of axi 1 (auxin independent) gene from pisum sativum

In this study, axi 1 gene was isolated from Pisum sativum and the effects of this gene on cortical cell division during nodule initiation was searched. Southern blotting results showed that axi 1 gene (auxin independence) is controlled by 1 or small gene families. The nucleotide sequences from Pisum sativum axi 1 gene were compared with the nucleotide sequences of Arabidopsis thaliana axi 1 gene. Based on this data, 71.918 % homology between nucleotide sequences and 80.588 % homology between petide sequences were determined. The nucleotide sequences from Pisum sativum axi 1 gene were also compared with the nucleotide sequences of Nicotiana tabacum axi 1 gene. This data have shown that 82.111 % homology between nucleotide sequences and 82.111 % homology between peptide sequences exist. Root and nodule samples were taken from pea seedlings 24 hours, 48 hours, 6 days and 10 days after inoculation with Rhizobium leguminosarum PRE strain. Using digdNTP in-situ hybridisation, location of the axi 1 gene expression in root and nodule tissues were identified. The results showed that in root tissues inoculated with Rhizobia, axi 1 gene is expressed on the phloem tissue of vascular bundle. In the 10 -days old nodule tissues, the gene expression was found in the phloem tissue, around the nodule bundle and nodule meristematic region Key Words : Pisum sativum, axi 1 gene, auxin, auxin independent