Plant Regulation Functions of Novel Phthalimide Compounds Based on AtPYL2

Novel agents contain the structure of phthalimide, whichhas antibacterial,insecticidal, and herbicidal activities. Recently, studies reportedthat these compounds can bind to plant hormone receptors and playimportant regulatory roles. In this study, the functions of agentswere studied with in vitro and in vivo assays. The abscisic acid (ABA) receptor pyrabactin resistant-like2 (PYL2) protein in Arabidopsis thaliana was expressed, purified, and crystallized; the analysis resultsof the crystal structure showed three AtPYL2 subunits in each asymmetricunit. The affinity of compounds Z1-Z11 to the AtPYL2 protein was tested by microscale thermophoresis (MST)and then verified by isothermal titration calorimetry (ITC). Furthermore,the binding pockets were found using molecular docking to verify thetarget relationships. Relevant in vivo assays forseed germination and a root growth assay were conducted, with theplant samples being treated with target compounds. The results showthat the compounds Z3, Z5, and Z10 target AtPYL2 and that the dissociation constants for binding byMST were 3.59, 3.54, and 3.97 & mu;mol/L, respectively, among them,and the molecular docking results showed that compounds Z3, Z5, and Z10 formed hydrophobic interactionswith amino acid residues through hydrogen or halogen bonding. Thishighlights their potential as an ABA receptor protein agonist. Onthe other hand, in vivo, compounds Z3, Z5, and Z10 had different inhibitoryeffects on seed germination, with compound Z5 inhibitingthe root growth of A. thaliana andcompound Z10 affecting root growth. In conclusion, thesecompounds could regulate plant growth and could be further developedas new plant-regulating agents.

Automated summary

This study shows that novel compounds containing the structure of phthalimide have antibacterial, insecticidal, and herbicidal activities, and can bind to plant hormone receptors, playing important regulatory roles.