Deciphering MAP kinase pathway in Cicer arietinum upon Helicoverpa armigera -infestation

Abstract

The activation of Mitogen-Activated Protein Kinase (MAPK) pathway is recognized as a key regulator of the plant defense mechanisms in response to insect attacks. The MAPK pathway comprises three main components: MAP Kinase Kinase Kinase (MAPKKK), MAP Kinase Kinase (MAPKK) and MAP Kinase (MAPK). The MAPKKK is the first kinase in the MAPK cascade, which typically responds to external stimuli and activates downstream component, MAPKK, which, in turn, activates the final component, MAPK, which further plays a key role in regulating gene expression of defense-associated transcription factors. Elucidation of complete MAPK pathway and its components has been investigated in the model plants in the past, however, it has not been attempted in leguminous plant, chickpea, which is attacked vigorously by Helicoverpa armigera, causing huge loss in crop production. Therefore, the study aims to decipher and elucidate MAP kinase pathway activated during chickpea-H. armigera interaction. MAPKKK, MAPKK, MAPK are a family of genes and specific genes from each components, were identified and selected for further analysis based on their expression patterns in response to H. armigera-infestation. Further, three dimensional structure prediction, validation, docking and simulation of the selected proteins from each component of the pathway, were executed and specific components from chickpea were predicted. The probable pathway forecasted is MEKK4/Raf22 (MAPKKK)-MAPKK(4)10-MAPK12/6). This article provides an overview of the molecular mechanisms involved in plant's response to pest attacks, unravelling the components of MAPK pathway in chickpea induced during herbivory. Further validation of this pathway by in vitro/in vivo approaches is highly recommended.