In silico interaction analysis of abscisic acid receptors in Zea mays: Insights into stress tolerance mechanisms

Harsh climates, mechanical injuries, and pathogen infection inflict significant loss to crop productivity, necessitating the development of more resilient agricultural varieties. The phytohormone Abscisic acid (ABA) plays a crucial role in mediating plant responses to diverse sources of stress, primarily through its interaction with pyrabactin resistance 1 (PYR1) and PYR1-like (PYL) receptors. Genetic modifications can enhance the ABA receptors’ signalling capabilities. The advancement of bioinformatics has made in silico prediction and analysis increasingly accurate and reliable, enabling a more rational-based selection of site-directed mutagenesis. This study aimed to model the structure of the 13 known ZmPYL receptors in maize (Zea mays) and evaluate their interactions with ABA using in silico approaches, including molecular docking and molecular dynamics (MD) simulations. Phylogenetic analysis assessed the evolutionary relationships among ZmPYLs, Arabidopsis thaliana PYLs (AtPYLs), and Oryza sativa PYLs (OsPYLs). ZmPYL3 exhibited the strongest binding affinity to ABA, as determined by mm/GBSA free binding energy calculations (−34.172 kcal/mol). This PYL receptor formed a unique clade distinct from other ZmPYLs. The contact frequency and mutational analysis identified key residues, Lys68, Tyr129, and Asn174, as critical for ABA binding, while Gly95, Leu96, and Pro97 were essential for interactions with protein phosphatase 2C (PP2C). The characterised ZmPYLs’ structures, particularly the ZmPYL3 offers valuable insights into their function, and the in silico strategy applied in this study would pave the way for future research on improving the PYL receptors.