Bidirectional Uptake, Transfer, and Transport of Dextran‐Based Nanoparticles in Plants for Multidimensional Enhancement of Pesticide Utilization

Abstract The development of effective multifunctional nano‐delivery approaches for pesticide absorption remains a challenge. Here, a dextran‐based pesticide delivery system (MBD) is constructed to deliver tebuconazole for multidimensionally enhancing its effective utilization on tomato plants. Spherical MBD nanoparticles are obtained through two‐step esterification of dextran, followed by tebuconazole loading using the Michael addition reaction. Confocal laser scanning microscopy shows that fluorescein isothiocyanate‐labeled MBD nanoparticles can be bidirectionally transported in tomato plants and a modified quick, easy, cheap, effective, rugged, and safe‐HPLC approach demonstrates the capacity to carry tebuconazole to plant tissues after 24 h of root uptake and foliar spray, respectively. Additionally, MBD nanoparticles could increase the retention of tebuconazole on tomato leaves by up to nearly 2.1 times compared with the tebuconazole technical material by measuring the tebuconazole content retained on the leaves. In vitro antifungal and pot experiments show that MBD nanoparticles improve the inhibitory effect of tebuconazole against botrytis cinerea by 58.4% and the protection against tomato gray molds by 74.9% compared with commercial suspensions. Furthermore, the MBD nanoparticles do not affect the healthy growth of tomato plants. These results underline the potential for the delivery system to provide a strategy for multidimensional enhancement of pesticide efficacy.