Plant-Derived Peptides: (Neglected) Natural Products for Drug Discovery

Abstract

Peptides have emerged as key regulators in various physiological processes, including growth, development, stress, and defense responses within plants as well as ecological interactions of plants with microbes and animals. Understanding and harnessing plant peptides can lead to the development of innovative strategies for crop improvement, increasing agricultural productivity, and enhancing resilience to environmental challenges such as drought, pests, and diseases. Moreover, some plant peptides have shown promise in human health applications, with potential therapeutic benefits as ingredients in herbal medicines as well as novel drug leads. The exploration of plant peptides is essential for unraveling the mysteries of plant biology and advancing peptide drug discovery. This short personal commentary provides a very brief overview about the field of plant-derived peptides and a personal word of motivation to increase the number of scientists in pharmacognosy working with these fascinating biomolecules.

Fig. 1

Structural diversity of plant peptides. Compilation of structural cartoons of representative members of different classes of plant-derived peptides. Exemplarily shown are: cyclotide – a cyclic knottin – from Oldenlandia affinis DC. (pdb code: 1NB1), a small cyclic trypsin inhibitor from Helianthus annuus L. (1JBL), a thionin(-like) peptide from Viscum album L. (1ED0), a defensin from Nicotiana alata Link & Otto (1MR4), an α -amylase inhibitor from Amaranthus hypochondriacus L. (1QFD), a knottin-type trypsin inhibitor from Ecballium elaterium (L.) A.Rich. (2IT7), an α -hairpinin from Hordeum vulgare L. (2M6A), a lipid transfer protein from Pisum sativum L. (2N81), a hevein-like peptide from Gypsophila vaccaria (L.) Sm. (5XDI), and orbitide (cyclic) from Jatropha ribifolia (Pohl) Baill. (6DKZ). Disulfide bonds are shown in yellow.