Abstract:
Nod inducing gene (NIG) families plays a crucial role in several stages of biological
nitrogen fixation which includes flavonoids exudation from roots and perception on
rhizobacteria, phosphorylation cascade of protein kinases, node genes expression in
rhizobacteria, node proteins causing root hair curling and nodule formation. Nod inducing
genes characterization has not been performed in Arachis hypogaea except for some
nodulation inducing genes in other legumes. In this study, we performed a genome-wide
analysis of NIG family in Arachis hypogaea followed by phylogenetic clustering analysis,
gene structure determination, detection of conserved motifs, subcellular localization,
conserved motifs, cis-acting elements and promoter region analysis. Based on homology
study total of 15 Nod inducing genes were identified and characterization of the genes
reveals the structural and functional similarity with the difference in amino acids at few
positions. Invitro studies were conducted on the golden variety of peanut to identify the
effects of nitrogen fertilizer (calcium nitrate) on flavonoid exudation and biological
nitrogen fixation. The experimental design consisted of four different treatments (T1=soil
control, T2=Ca(NO3)2, T3 = biochar, T4=Biochar+ Ca(NO3)2 ). Phenotypic and chlorophyll
analysis suggested that the use of calcium nitrate fertilizer has no growth benefits to the
plant. This study not only not only provides identification and characterization of genes
underlying developmental and functional stages of nodulation and biological nitrogen
fixation but also lays the foundation for further revelation of Nod inducing gene family. In
addition, this study also helps to make a potent nitrogen fertilizer that is not only
environmentally friendly but also provides high yields of plants.
