Description

Paraquat herbicide, commonly known as Gramoxone or Weedol, is a non-selective herbicide widely used to control a broad spectrum of weeds in agricultural and non-agricultural settings. Its mechanism of action involves disrupting photosynthesis in target plants, ultimately leading to their death.

When applied to plants, paraquat enters the leaf cells and accumulates in the chloroplasts, where photosynthesis takes place. Once inside the chloroplasts, paraquat acts as a photosystem I electron acceptor, interfering with the electron transport chain. This disruption prevents the production of ATP and NADPH, which are essential for powering biochemical reactions in photosynthesis.

Without ATP and NADPH, the affected plants are unable to convert light energy into chemical energy, leading to the buildup of toxic reactive oxygen species (ROS) within the chloroplasts. The accumulation of ROS damages cell membranes, proteins, and other cellular components, ultimately causing cell death and tissue necrosis.