Plant peptides are small signaling molecules that help plants defend themselves against diseases and pests. These peptides can work by directly killing pathogens or by activating the plant’s immune system. Researchers have identified over 1000 different plant peptides, and this review explains how they work and how they could be used to create disease-resistant crops and natural biopesticides.
Scientists studied how different varieties of a common plant (Arabidopsis) naturally resist a destructive fungal disease caused by Sclerotinia sclerotiorum. By examining genetic differences among plant varieties and testing a fungus from different sources, they found that a gene called MED20a plays an important role in disease resistance. Plants with specific genetic variations in the MED20a gene’s control region were more resistant to infection.
Plants communicate with their shoots through chemical signals produced in their roots when soil microorganisms are present. Researchers discovered that a molecule called N-hydroxypipecolic acid acts like an on-off switch controlled by two proteins, FMO1 and UGT76B1. Beneficial fungi suppress the ‘off’ switch, allowing this signal to travel to leaves where it boosts immunity against disease. Different amounts of this signal have different effects: small amounts help the plant grow, while large amounts strengthen defenses but slow growth.