The rubber tree genome shows expansion of gene family associated with rubber biosynthesis

<jats:title>Abstract</jats:title><jats:p><jats:italic>Hevea brasiliensis</jats:italic> Muell. Arg, a member of the family Euphorbiaceae, is the sole natural resource exploited for commercial production of high-quality natural rubber. The properties of natural rubber latex are almost irreplaceable by synthetic counterparts for many industrial applications. A paucity of knowledge on the molecular mechanisms of rubber biosynthesis in high yield traits still persists. Here we report the comprehensive genome-wide analysis of the widely planted <jats:italic>H</jats:italic>. <jats:italic>brasiliensis</jats:italic> clone, RRIM 600. The genome was assembled based on ~155-fold combined coverage with Illumina and PacBio sequence data and has a total length of 1.55 Gb with 72.5% comprising repetitive DNA sequences. A total of 84,440 high-confidence protein-coding genes were predicted. Comparative genomic analysis revealed strong synteny between <jats:italic>H</jats:italic>. <jats:italic>brasiliensis</jats:italic> and other Euphorbiaceae genomes. Our data suggest that <jats:italic>H</jats:italic>. <jats:italic>brasiliensis</jats:italic>’s capacity to produce high levels of latex can be attributed to the expansion of rubber biosynthesis-related genes in its genome and the high expression of these genes in latex. Using cap analysis gene expression data, we illustrate the tissue-specific transcription profiles of rubber biosynthesis-related genes, revealing alternative means of transcriptional regulation. Our study adds to the understanding of <jats:italic>H</jats:italic>. <jats:italic>brasiliensis</jats:italic> biology and provides valuable genomic resources for future agronomic-related improvement of the rubber tree.</jats:p>