The impact of grafting in commercial rubber tree production

Hevea brasiliensis, known as the rubber tree, is the major source of natural rubber (NR), an irreplaceable material in numerous industrial applications. Artificial selection has produced a number of high-yielding clones, though early selection of these clones was performed without an understanding of the biological mechanisms contributing to the production of NR. Bud-grafting is a common practice on Hevea plantations, and is used to introduce beneficial phenotypic variation against factors such as pathogen attacks and adverse weather conditions. The elite-clones, which constitute the scion, should provide a degree of homogeneity, yet the rootstock-scion interactions are extremely variable, often having a detrimental effect on latex-yield. Therefore, the primary aim of the project is to uncover the events surrounding bud-grafting, primarily through next-generation sequencing of transcriptomes and epigenomes. There is a broader objective of the project, which is to further elucidate the factors and mechanisms of NR biosynthesis. As such, the first stage of the project is to perform a bioinformatics meta-analysis of all available transcriptomic data online. The sequence data has been generated from a comprehensive set of multiple tissues, cultivars and conditions, and should therefore provide a thorough characterisation the expression of biosynthetic genes. It is expected that results of this analysis will greatly influence the experimental work later in this project.