Insilico assisted identification of peppery aroma compound ‘rotundone’ backbone genes from black pepper

Rotundone, an oxygenated sesquiterpene compound, responsible for the peppery aroma. The importance of the rotundone in the flavor industry warrants search for the precursor genes in plants. We report in this study, the first on the identification of rotundone backbone genes viz., α-guaiene synthase & α-guaiene oxidase in black pepper. We identified the precursor genes of rotundone using berry transcriptome profiling. The metabolite profiling using head space mass spectrometry showed the presence of the direct precursor compounds for rotundone biosynthesis in black pepper berries. The identification of the genes & compounds of the guaiene skeleton is expected to help in bioprospecting of black pepper varieties & also in recombinant production of the aroma compound. Communicated by Ramaswamy H. Sarma Identification of rotundone backbone genes & precursor compounds from Piper nigrum

圆柚酮（Rotundone）是一种含氧倍半萜类化合物，可赋予特征性的胡椒辛辣香气。鉴于圆柚酮在香精香料工业中的重要应用价值，亟需挖掘植物体内其生物合成前体基因。本研究首次完成了黑胡椒（Piper nigrum）中圆柚酮骨架合成关键基因的鉴定，即α-愈创木烯合酶（α-guaiene synthase）与α-愈创木烯氧化酶（α-guaiene oxidase）。本研究通过对黑胡椒浆果开展转录组分析（transcriptome profiling），成功筛选得到圆柚酮的前体合成基因；借助顶空质谱法（head space mass spectrometry）进行代谢组表征后证实，黑胡椒浆果中存在圆柚酮生物合成所需的直接前体化合物。本次鉴定得到的愈创木烯骨架相关基因与化合物，将有助于黑胡椒品种的生物勘探以及该香气物质的异源重组生产。本稿件由Ramaswamy H. Sarma转交。黑胡椒中圆柚酮骨架基因与前体化合物的鉴定（Identification of rotundone backbone genes & precursor compounds from Piper nigrum）