High throughput sequencing of small RNAs reveals dynamic microRNAs expression of lipid metabolism during Camellia oleifera and C. meiocarpa seed natural drying

Background: Camellia species are ancient oilseed plants with a history of cultivation over two thousand years. Prior to oil extraction, natural seed drying is often practiced, a process affecting fatty acid quality and quantity. MicroRNAs (miRNA) of lipid metabolism associated with camellia seed natural drying are unexplored. To obtain insight into the function of miRNAs in lipid metabolism during natural drying, Illumina sequencing of C. oleifera and C. meiocarpa small-RNA was conducted. Results: A total of 274 candidate miRNAs were identified and 3733 target unigenes were annotated by performing a BLASTX. Through integrated GO and KEGG function annotation, 23 miRNA regulating 131 target genes were identified as lipid metabolism, regulating fatty acid biosynthesis, accumulation and catabolism. We observed one, two, and four miRNAs of lipid metabolism which were specially expressed in C. Meiocarpa, C. oleifera, and the two species collectively, respectively. At 30% moisture contents,...背景：山茶属（Camellia）物种是一类拥有两千余年栽培历史的古老油料植物。在油料提取前，通常会对种子进行自然干燥处理，该过程会显著影响脂肪酸的品质与含量。目前，与山茶种子自然干燥相关的脂质代谢微小核糖核酸（microRNAs, miRNA）的功能尚未得到系统探究。为深入解析自然干燥过程中miRNA在脂质代谢中的调控功能，本研究对油茶（C. oleifera）和小果油茶（C. meiocarpa）的小RNA开展了Illumina高通量测序（Illumina sequencing）。 结果：本研究共鉴定出274个候选miRNA，并通过BLASTX比对注释得到3733个靶单基因簇（unigene）。通过整合基因本体论（Gene Ontology，GO）与京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes，KEGG）的功能注释信息，最终筛选出23个调控131个靶基因的miRNA，这些miRNA均参与脂质代谢过程，具体调控脂肪酸的生物合成、积累与分解代谢。研究发现，分别有1个、2个和4个脂质代谢相关miRNA在小果油茶、油茶以及两个物种中共同特异性表达。当种子含水量达到30%时，……