Differential transcriptome analysis of fused top leaflet mutant in peanut

A typical leaf of peanut (Arachis hypogaea L.) is a pinnately compound leaf with four leaflets. A new fused top leaflets mutant was isolated in the M2 by treating genotype TG 66 with gamma rays and sodium azide (NaN3). The mutant showed its distinctness from the parent based on presence of typical fused top-leaflets instead of free leaflets and absence of rachis between the proximal and distal pair of leaflets. Genetic analysis revealed a single dominant gene governs this novel fused top-leaflets trait. Based on anatomical study, it was observed that neo-vascularization in interfascicular parenchymal cells, placed between the two vascular bundles in the mid-vein of normal leaflets. This anatomical alternation governs the shape of fused top-leaflets phenotype in the mutant. Differential transcriptome analysis revealed upregulation of transcripts majorly involved in cell wall biogenesis or degradation, syncytium formation, signalling and extracellular pathways in the mutant.