Characterization of Peroxidase and Laccase Gene Families and In Silico Identification of Potential Genes Involved in Upstream Steps of Lignan Formation in Sesame

Abstract

Peroxidases and laccases are oxidative enzymes involved in physiological processes in plants, covering responses to biotic and abiotic stress as well as biosynthesis of health-promoting specialized metabolites. Although they are thought to be involved in the biosynthesis of (+)-pinoresinol, a comprehensive investigation of this class of enzymes has not yet been conducted in the emerging oil crop sesame and no information is available regarding the potential (+)-pinoresinol synthase genes in this crop. In the present study, we conducted a pan-genome-wide identification of peroxidase and laccase genes coupled with transcriptome profiling of diverse sesame varieties. A total of 83 and 48 genes have been identified as coding for sesame peroxidase and laccase genes, respectively. Based on their protein domain and Arabidopsis thaliana genes used as baits, the genes were classified into nine and seven groups of peroxidase and laccase genes, respectively. The expression of the genes was evaluated using dynamic transcriptome sequencing data from six sesame varieties, including one elite cultivar, white vs black seed varieties, and high vs low oil content varieties. Two peroxidase genes (SiPOD52 and SiPOD63) and two laccase genes (SiLAC1 and SiLAC39), well conserved within the sesame pan-genome and exhibiting consistent expression patterns within sesame varieties matching the kinetic of (+)-pinoresinol accumulation in seeds, were identified as potential (+)-pinoresinol synthase genes. Cis-acting elements of the candidate genes revealed their potential involvement in development, hormonal signaling, and response to light and other abiotic triggers. Transcription factor enrichment analysis of promoter regions showed the predominance of MYB binding sequences. The findings from this study pave the way for lignans-oriented engineering of sesame with wide potential applications in food, health and medicinal domains.

Integrative analysis of the metabolome and transcriptome provides insights into the mechanisms of lignan biosynthesis in Herpetospermum pedunculosum (Cucurbitaceae)

“…Moreover, activation of the phenylpropanoid pathway is also linked to the upregulation of DIR and POD , which controls the initiation of species-specific lignan biosynthesis [ 16 , 42 , 43 ]. Heterologous expression of PlDIR from Phryma leptostachya stereoselectively couples coniferyl alcohol to form pinoresinol [ 23 ].…”

Specialized metabolite modifications in Brassicaceae seeds and plants: diversity, functions and related enzymes

“…4). [36][37][38][39][40] Spontaneous chemical reactions, notably due to the presence of oxidants, can also lead to the modication of SM structures although data about those events are rather scarce. 4 Besides their contribution to the large SMs chemical diversity, metabolite modications can affect their chemical properties, transport and storage, thus determining their biological activities.…”

“…4). 36–40 Spontaneous chemical reactions, notably due to the presence of oxidants, can also lead to the modification of SM structures although data about those events are rather scarce. 4…”

Resequencing of 410 Sesame Accessions Identifies SINST1 as the Major Underlying Gene for Lignans Variation

“…In sesame, the biosynthetic genes of the major lignans, sesamin and sesamolin have been identified, and their mechanisms of action elucidated [ 30 , 31 ]. Recently, two laccase ( SiLAC1 and SiLAC39 ) and two peroxidase ( SiPOD52 and SiPOD63 ) family genes were identified as the potential pinoresinol synthase genes [ 32 ]. However, the regulatory mechanisms of lignan biosynthesis in sesame are largely unknown.…”