AtLHT1 Transporter Can Facilitate the Uptake and Translocation of a Glycinergic-Chlorantraniliprole Conjugate in Arabidopsis thaliana.

Understanding of the transporters involved in the uptake and translocation of agrochemicals in plants could provide an opportunity to guide pesticide to the site of insect feeding. The product of Arabidopsis thaliana gene AtLHT1 makes a major contribution to the uptake into the roots of free amino acids and some of their derivatives. Here, a chlorantraniliprole-glycine conjugate (CAP-Gly-1) was tested for its affinity to AtLHT1 both in planta and in vitro. Seedlings deficient in AtLHT1 exhibited a reduction with respect to both the uptake and root-to-shoot transfer of CAP-Gly-1; plants in which AtLHT1 was constitutively expressed were more effective than wild type in term of their root uptake of CAP-Gly-1. Protoplast patch clamping showed that the presence in the external medium of CAP-Gly-1 was able to induce AtLHT1 genotype-dependent inward currents. An electrophysiology-based experiment carried out in Xenopus laevis oocytes expressing AtLHT1 showed that AtLHT1 had a high in vitro affinity for CAP-Gly-1. The observations supported the possibility of exploiting AtLHT1 as a critical component of a novel delivery system for amino acid-based pesticide conjugates.