Bekele Bantayehu, Andargie Mebeaselassie, Gallach Miguel, Beyene Dereje, Tesfaye Kassahun
Department of Microbial, Cellular, and molecular biology, Addis Ababa University, Addis Ababa, Ethiopia.; Biology Department, Oda bultum University, Chiro, Ethiopia.
Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
Genomics. 2025 Mar;117(2):110997. doi: 10.1016/j.ygeno.2025.110997. Epub 2025 Jan 12.
Sesame (Sesamum indicum L., 2n = 2× = 26) from the Pedaliaceae family is primarily grown for its high oil content, rich in unsaturated fatty acids like linoleic acid (LA) and alpha-linolenic acid (ALA). However, the molecular mechanisms of sesame oil accumulation remain poorly understood. This study analyzed transcriptomes at two seed development stages: Young Stage (YS, pods 1.5-2.5 cm) and Mature Stage (MS, brown pods >2.5 cm), to explore regulatory mechanisms and identify key genes involved in lipid biosynthesis. From 25,173 genes, 18,820 with expression values >10 CPM in at least 70 % of replicates were included in differential expression (DE) analysis. Active expression (LFC > 0) was observed in 9372 and 9448 genes at YS and MS, respectively. DEGs were annotated, revealing roles in various biological processes, (e.g., mRNA metabolic process, reproduction-related developmental processes, seed development), molecular functions (e.g., aminoacyltransferase activity, ubiquitin-like protein and ubiquitin-protein transferase activities), and cellular components (e.g., peroxisome, microbody, lipid droplet). KEGG analysis highlighted genes involved in fatty acid synthesis (e.g., fabG, fabZ), TAG biosynthesis (DGAT1, GPAT), and alpha-linolenic acid metabolism (AOS, LCAT3). Key genes upregulated at MS included SIN_1025205 (protein transport), SIN_1006853 (acetylajmalan esterase), and SIN_1003267 (gamma-cadinene synthase). The study generated a valuable transcriptome dataset and gene list for seed development and lipid biosynthesis, which will be validated through functional studies. An interactive webpage is provided for data exploration.
芝麻（Sesamum indicum L.，2n = 2× = 26）属于胡麻科，主要因其含油量高而被种植，富含亚油酸（LA）和α-亚麻酸（ALA）等不饱和脂肪酸。然而，芝麻油积累的分子机制仍知之甚少。本研究分析了种子发育两个阶段的转录组：幼龄期（YS，豆荚1.5 - 2.5厘米）和成熟期（MS，棕色豆荚>2.5厘米），以探索调控机制并鉴定参与脂质生物合成的关键基因。在25173个基因中，至少70%的重复样本中表达值>10 CPM的18820个基因被纳入差异表达（DE）分析。在YS和MS阶段，分别在9372个和9448个基因中观察到活跃表达（LFC > 0）。对差异表达基因进行了注释，揭示了它们在各种生物学过程（如mRNA代谢过程、与生殖相关的发育过程、种子发育）、分子功能（如氨酰基转移酶活性、泛素样蛋白和泛素-蛋白质转移酶活性）以及细胞成分（如过氧化物酶体、微体、脂滴）中的作用。KEGG分析突出了参与脂肪酸合成（如fabG、fabZ）、三酰甘油生物合成（DGAT1、GPAT）和α-亚麻酸代谢（AOS、LCAT3）的基因。在MS阶段上调的关键基因包括SIN_1025205（蛋白质转运）SIN_1006853（乙酰阿吗啉酯酶）和SIN_1003267（γ-杜松烯合酶）。该研究生成了一个关于种子发育和脂质生物合成的有价值的转录组数据集和基因列表，将通过功能研究进行验证。提供了一个交互式网页用于数据探索。
