Plants are immobile and are therefore known to produce substances such as proteins which act like "poison" to prevent being eaten by insects and other organisms. Such substances can be used as pesticides for controlling insect pests. With the appearance of insects that develop resistance to traditional pesticides, these proteins are drawing attention and could potential source of materials that may lead to the development of new formulation of pesticides.
Mulberry leaves are well known as natural silkworm diet, but most other insects besides silkworms do not make use of mulberry as food source. The Institute of Agrobiological Sciences, NARO (NIAS) has discovered that certain proteins (MLX56 family proteins) contained in mulberry latex inhibit pest growth with a completely new mechanism that has never been reported. This family of proteins were found to cause digestive disfunction by abnormally thickening the thin peritrophic membrane in the digestive tract of larvae of moths. Moreover, it inhibits the growth of larvae remarkably even if it is added to the diet at an extremely low concentration of 0.01-0.04%.
Proteins of MLX 56 family are promising candidates as materials for new technology development to protect plants from pests.
Source: NARO