Differential transcript accumulation in chickpea during early phases of compatible interaction with a necrotrophic fungus Ascochyta rabiei

The initial phases of the disease establishment are very crucial for the compatible interactions. Pathogens must overcome the responses generated by the host for the onset of disease invasion. The compatible interaction is inadequately represented in plant-pathogen interaction studies. To gain broader insight into the early responses elicited by chickpea blight fungus Ascochyta rabiei during compatible interaction; we isolated early responsive genes of chickpea using PCR based suppression subtractive hybridization (SSH) strategy. We obtained similar to 250 unique genes after homology search and redundancy elimination. Based on their potential cellular functions, these genes were broadly classified into eleven different categories viz. stress, signaling, gene regulation, cellular metabolism and genes of unknown functions. Present study revealed few unexpected genes which have a possible role in induced immunity and disease progression. We employed macroarray, northern blot, real-time PCR and cluster analysis to develop transcript profiles. Most of the genes analyzed were early induced and were transcriptionally upregulated upon 24 h post inoculation. Our approach has rendered the isolation of early responsive genes involved in signaling and regulation of metabolic changes upon fungal infection. The information obtained will help to dissect the molecular mechanisms during compatible chickpea-Ascochyta interactions.