Molecular docking insights into nuclear factor Y (NF-Y) transcription factor and pyrabactin resistance 1 (PYL) receptor proteins reveal abiotic stress regulation in finger millet

Finger Millet (Eleusine coracana - (L.) Gaertn), is an important nutraceutical crop with the potential for imparting food and nutritional security. These plants have a comparatively higher tolerance for several abiotic stresses like drought, salinity, and heat. Several players including Transcription Factor (TF) like Nuclear Factor Y (NF-Y) might be associated with this enhanced level of tolerance. Further, it is unclear how phytohormones like Abscisic acid (ABA) regulate the expression of NF-Y, whether in ABA-dependent or ABA-Independent pathway. The interaction of PYL (Pyrabactin resistance1-like) receptor proteins with Nuclear Factor Y (NF-Y) Transcription Factor in the presence of phytohormones like abscisic acid (ABA) provides one insight related to the enhanced tolerance towards abiotic stresses under ABA-dependent signaling in finger millet crop. A total of three PYL receptors of finger millet designated as EcPYL1, EcPYL5, and EcPYL9 were retrieved in the finger millet genome. These receptors were modeled through the SWISS-MODEL using templates 5gwo and 3wg8 and docked with ABA. The best-docked protein-ligand complex PYL5-ABA (binding energy ΔG ​= ​-8.8 kcal mol^-1) was found to be most stable at the 50ns MD simulation study. Further protein-protein interaction between PYL5 and NF-YA2/B3/C1 sub-family members showed a good interaction. This clearly indicates the possibility of the NF-Y-PYL module in the ABA transduction pathway, which performs a crucial role in the expression of stress-responsive genes. These studies reveal the intricate relationship between the ABA, PYL receptors of finger millet, and NF-Y transcription factor in regulating the stress-responsive genes and provide an insight into the abiotic stress tolerance mechanisms, which can be targeted for crop improvement.