The Great Latex Defense
Latex from plants is a naturally occurring white opaque sap that emanates from a plant's point of damage. About 10% of plants use Latex as a method of defense. Latex is also an essential ingredient in natural rubber. But different plants use latex in different ways. Researchers at the University of Oxford wanted to understand the mechanical properties of natural latex in relation to their respective defense application. As a result, researchers tested two latex producing plant species that use it differently: the Euphorbia and the Ficus.
Dr. Chris Holland, currently at the University of Sheffield, led the research team. According to Holland, "When injured, the latex of Euphorbia plants takes a long time to harden. This gives the plant time to deliver a cocktail of poisonous compounds to stop biting insects. Ficus latex on the other hand hardens rapidly, sealing the wound to prevent infection and fluid loss."
The study focused on the rheological (flow) properties of latex from each plant to determine its role in the biological function of the plant. The team studied the latex coagulation properties from each plant. They noted that the latex from the Euphorbia used a slow evaporative process as compared to the latex from the Ficus, which used additional biochemical components to speed up the rate of coagulation. The result of the study highlights the two primary yet distinct defensive roles that latex production plays in each plant: the facilitation of the delivery of anti-herbivory compounds (Euphorbia) and rapid wound healing (Ficus).
The research team used naturally grown plant specimens whose species related to those used for industrial latex production from the university’s Botanic Garden and a local commercial nursery. This was to ensure that their results would be relevant to the industry, yet based upon a selection that was natural and not artificial.
The purpose of the study was to gain insight into the various properties of natural latex for subsequent industrial application. The researchers hope these studies, which cross the interface between physical and life sciences, will provide better understanding of the ways materials are used in nature.
To learn more about this study read more at the University of Oxford.