Scientists from the RIKEN Center for Sustainable Resource Science in Japan, working with scientists from the University of Science in Malaysia, have now decoded the genome of the rubber tree. In a paper published in Scientific Reports, the authors detail over 90% of the expressed genes, including gene regions used for rubber production.
The rubber tree, Hevea brasiliensis, is a large tree species originally found in the Amazon rainforest. The plant is very important commercially due to the latex that flows inside. Latex is used to protect the tree from insects and other predators. This natural resource can be tapped and utilized for the synthesis of natural rubber products.
The researchers analyzed clones of a strain of rubber tree commonly used for commercial purposes. Using a mixture of modern gene-sequencing techniques, the scientists were able to identify 84,440 protein-coding genes, including genes specific to latex production. Two major proteins that contribute to rubber creation were named Rubber Elongation Factor and Small Rubber Particle. These proteins were expressed by genes in a specific region that appeared to be used for latex creation. The researchers then used a method called cap analysis gene expression, first developed at the RIKEN Center, to show that the expression of these proteins was specific to certain plant tissue. Rubber Elongation Factor and Small Rubber Particle were both much more likely to be expressed in the parts of the plant responsible for latex production, as opposed to other parts of the plant such as the leaves.
Certain strains of Hevea brasiliensis have produced more rubber than others and this new research finally sheds some light on the mystery. By identifying the genes used for latex production, the researchers can show why certain plants are more productive than others. More importantly, these findings can be used to breed and develop rubber trees that produce higher quantities of rubber. The researchers also intend to use this newly found genome in additional studies. They hope to modify chemical pathways to produce higher quality rubber and are looking to discover ways to produce it synthetically through other organisms, such as algae. This has great economic significance since there is currently no viable alternative to natural rubber in many industries.
Nyok-Sean Lau et al. The rubber tree genome shows expansion of gene family associated with rubber biosynthesis. Scientific Reports (2016).