First Draft Genome of a Brazilian Atlantic Rainforest Burseraceae reveals commercially-promising genes involved in terpenic oleoresins synthesis

Abstract

BackgroundProtium species produce abundant aromatic oleoresins composed mainly of different types of terpenes, which are highly sought after by the flavor and fragrance industry.ResultsHere we present (i) the first draft genome of an endemic tree of the Brazil’s Atlantic Rainforest (Mata Atlântica), Protium kleinii Cuatrec., (ii) a first characterization of its genes involved in the terpene pathways, and (iii) the composition of the resin’s volatile fraction. The de novo draft genome was assembled using Illumina paired-end-only data, totalizing 407 Mb in size present in 229,912 scaffolds. The N50 is 2.60 Kb and the longest scaffold is 52.26 Kb. Despite its fragmentation, we were able to infer 53,538 gene models of which 5,434 were complete. The draft genome of P. kleinii presents 76.67 % (62.01 % complete and 14.66 % partial) of plant-core BUSCO genes. InterProScan was able to assign at least one Gene Ontology annotation and one Pfam domain for 13,629 and 26,469 sequences, respectively. We were able to identify 116 enzymes involved in terpene biosynthesis, such as monoterpenes α-terpineol, 1,8-cineole, geraniol, (+)-neomenthol and (+)-(R)-limonene. Through the phylogenetic analysis of the Terpene Synthases gene family, three candidates of limonene synthase were identified. Chemical analysis of the resin’s volatile fraction identified four monoterpenes: terpinolene, limonene, α-pinene and α-phellandrene.ConclusionThese results provide resources for further studies to identify the molecular bases of the main aroma compounds and new biotechnological approaches to their production.