Plant biomineralization: Plant defense strategies

Abstract

  With some exceptions, most land plants are static. Being static always involves the risk of being preyed. To counter that, plants have evolved various defence mechanisms against herbivores. These defence mechanisms can be divided into two main strategies. The first is called chemical defence, which involves synthesizing and storing organic compounds such as alkaloids, terpenes, polyphenols, and proteolytic enzymes. These organic compounds act as chemical weapons that are toxic to herbivores, or causes digestion and nutrient blockages. The second mechanism is physical defence, where the cellulose in the cell walls is often reinforced with deposits of inorganic minerals, forming an organic-inorganic hybrid armour. In this paper, we review several reports on plant biomineralization, which is an example of physical defence in plants, and discuss the molecular mechanism and significance of the mineral formation process from a biological point of view.