Seminar Hideyuki Inui

Abstract

Persistent pollutants are widespread in the environment due to the continuous release of these compounds from everyday human activities. Due to their specific characteristics, such as extremely high chemical stability, these pollutants persist for more than several decades. They also have adverse effects on wildlife and human health after their bioaccumulation through the food web. As crop contamination is one of the first steps in the uptake of pollutants into the human body, it is important to understand the mechanisms involved in the uptake of persistent pollutants into crops. Major latex-like proteins (MLPs) have been identified as a transport factor for these pollutants in the Cucurbitaceae family plants, such as cucumber, pumpkin, and zucchini. It has been recognized that MLPs are determinants for contamination of persistent pollutants in crops due to their binding activity to these pollutants and their presence in the xylem sap, which is a transport pathway from roots to aboveground parts of plants. Therefore, the elucidation of the molecular mechanisms of persistent pollutant uptake under the control of MLPs suggests that the functional regulation of MLPs will provide novel techniques for both sides of the effects, i.e. accumulation of pollutants (remediation) in plants and the reduction of pollution in crops (safe crop production). Dioxins and polycyclic aromatic hydrocarbons as hydrophobic persistent pollutants and per- and polyfluoroalkyl substances (PFAS) as hydrophilic persistent pollutants are used in this study. Cucurbitaceae family plants accumulated high levels of these pollutants leading to remediation, and the reduction of pollutants was achieved by suppressing MLP gene expression.

In the future, bioaugmentation of PFAS-degrading bacteria on Cucurbitaceae family plants can be applied for efficient phytoremediation. Genome editing of MLP genes provides safe crop production because MLPs cannot transport pollutants. These techniques open up a new avenue for sustainable, clean, and safe crop production.