Characterization and evolution of gene clusters for terpenoid phytoalexin biosynthesis in tobacco

• Published in: Planta 2019-11, Vol.250 (5), p.1687-1702
• Main Authors: Chen, Xi, Liu, Fangjie, Liu, Lu, Qiu, Jie, Fang, Dunhuang, Wang, Weidi, Zhang, Xingcheng, Ye, Chuyu, Timko, Michael Paul, Zhu, Qian-Hao, Fan, Longjiang, Xiao, Bingguang
• Format: Article
• Language: English
• Subjects: Agriculture; Alkyl and Aryl Transferases - genetics; Alkyl and Aryl Transferases - metabolism; Annotations; Biomedical and Life Sciences; Biosynthesis; Cellular stress response; Cluster analysis; Cytochrome P450; Cytochromes P450; Ecology; Evolution; Forestry; Gene clusters; Gene expression; Gene Expression Regulation, Plant; Genomes; Heredity; Life Sciences; Metabolic pathways; Metabolism; Metabolites; Multigene Family; Nicotiana - genetics; Nicotiana - metabolism; ORIGINAL ARTICLE; Phytoalexins; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Sciences; Sesquiterpenes - metabolism; Terpene synthase; Terpenes - metabolism; Tobacco; Transcriptome
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-019-03255-7

Terpenoid phytoalexins play an important role in plant self-defense against pest and pathogen attack. Terpenoid biosynthesis involves terpene synthase and cytochrome P450, which always locate and function as cluster(s). In this study, we performed genome-wide investigation of metabolic gene clusters involved in terpenoid production in tobacco (Nicotiana tabacum). Due to the complexity of the tobacco genome, we modified a published prediction pipeline to reduce the influence of the large number of repeats and to improve the annotation of tobacco genes with respect to their metabolic functions. We identified 1181 metabolic gene clusters with 34 of them potentially being involved in terpenoid biosynthesis. Through integration with transcriptome and metabolic pathway annotation analyses, 3 of the 34 terpenoid biosynthesis-related gene clusters were determined to be high-confidence ones, with 2 involved in biosynthesis of capsidiol, a terpenoid recognized as 1 of the effective resistance compounds in the Nicotiana species. The capsidiol-related gene cluster was conserved in N. sylvestris, N. tomentosiformis and N. attenuate. Our findings demonstrate that phytoalexins in tobacco can arise from operon-like gene clusters, a genomic pattern characterized as being beneficial for rapid stress response, gene co-regulation, co-function and co-heredity.