Glutathione (GSH) is an antioxidant that plays a key role in plants.
It is not only involved in the removal of harmful reactive oxygen species, but also involved in the resistance of plants to stress, such as drought, low temperature, heavy metals and salt stress.
Molecular properties of glutathione
Glutathione is a tripeptide composed of glutamic acid, cysteine and glycine,
and its unique sulfhydryl group (-SH) allows it to bind to harmful substances such as free radicals and heavy metals to play a detoxification role.
In plants, GSH mainly exists in two forms: reduced form (GSH) and oxidized form (GSSG),
which together maintain the REDOX balance in the cell.
The physiological mechanism of glutathione
- Scavenging free radicals: Glutathione is an important free radical scavenger in plant cells. It works synergistically with GSH peroxidase (GSH-Px) and glutathione reductase (GR) to protect plant cells from oxidative damage through antioxidant systems such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT).
- Detoxification: GSH can combine with toxic heavy metal ions into plant cells to form non-toxic compounds and reduce the toxicity of heavy metals to cells.
- Amino acid absorption and transport: GSH participates in the gamma-glutamyl cycle to help plant cells absorb amino acids from the outside world and synthesize proteins within the cell, which is essential for maintaining protein synthesis and cell growth.
GSH fights stress
- Temperature stress: Both low and high temperatures can cause stress to plants. GSH enhances the plant’s ability to adapt to temperature changes by enhancing the antioxidant system in the plant.
- Drought stress: Drought will lead to an increase in the production of free radicals in plants, and GSH can reduce the damage of drought to plants through antioxidant effects.
- Heavy metal ion stress: Heavy metals such as cadmium and copper are harmful to plant growth. Glutathione is able to bind to these heavy metal ions, reducing their toxicity.
- Salt stress: High salt will affect plant growth. Glutathione protects plant cells through an antioxidant system and reduces salt stress.
GSH is an important protective factor for plants in the face of adversity.
Through a variety of physiological mechanisms,
it helps plants resist various environmental stresses and maintain the normal physiological functions of cells.
With the deepening of scientific research, the application prospect of glutathione in plant stress resistance will be more broad.