Pesticides Can Protect Cops From Hydrophobic Pollutants

Researchers have revealed that commercial pesticides can be applied to crops in the Cucurbitaceae family to decrease their accumulation of hydrophobic pollutants, thereby improving crop safety. The research group consisted of Fujita Kentaro (1st year Ph.D. student) of Kobe University's Graduate School of Agricultural Science, Academic Researcher Yoshihara Ryouhei (now an assistant professor at Saitama University) and Associate Professor Inui Hideyuki of Kobe University's Biosignal Research Center, Senior Research Scientist Kondoh Yasumitsu, Technical Staff Honda Kaori and Group Director Osada Hiroyuki of RIKEN, and Lead Researcher Haga Yuki and Senior Scientist Matsumura Chisato of Hyogo Prefectural Institute of Environmental Sciences.

The team developed two approaches to control the functions of plant proteins related to the transport of hydrophobic pollutants. These findings will lead to these new functions of pesticides being utilized in agriculture, enabling safer crops to be produced. These results were published online in the international scientific journal Science of the Total Environment on June 23 and in Environmental Pollution on July 18.

Main Points

• Crops in the Cucurbitaceae family can accumulate hydrophobic pollutants (such as dioxins) in their fruits from contaminated soil. Major latex-like proteins (MLPs) play a key role in transporting hydrophobic pollutants to their fruits.
• Approach 1: Treatment with a pesticide that suppresses the expression of MLP gene decreases the concentrations of hydrophobic pollutants in the xylem sap.
• Approach 2: Treatment with a pesticide that binds to MLPs inhibits the binding of the proteins to hydrophobic pollutants. Thus, the concentrations of hydrophobic pollutants in the xylem sap that were transported via MLPs were reduced.
• It was shown that pesticides could provide a simple and low-cost solution to the production of safer crops.
• This study revealed, for the first time in the world, a new way that pesticides can be used in agriculture, which is different from current methods.

Hydrophobic pollutants include dioxins, the insecticide dieldrin, and endocrine disruptors. These pollutants are highly toxic, and their manufacture and use are now prohibited. However, these substances were used in large quantities up until they were banned, causing widespread environmental pollution that also affects agricultural land.

The Cucurbitaceae family includes crops such as cucumbers and squashes. Members of this family are different from other plant species in that they accumulate high concentrations of hydrophobic pollutants in their fruits. Associate Professor Inui et al. previously discovered that major latex-like proteins (MLPs) in the Cucurbitaceae family play a key role in this accumulation. MLPs bind to hydrophobic pollutants taken up from the soil by the roots of the plant. The Cucurbitaceae family then accumulate hydrophobic pollutants in the leaves and fruits via the sap in the stems (Figure 1). Consequently, MLPs are a major factor that causes crop contamination in the Cucurbitaceae family.