Gang Roggers, Yang Sungyu, Happy Kenneth, Mudondo Joyce, Haniffadli Ariranur, Okello Denis, Ban Yeongjun, Kang Youngmin
Korean Convergence Medical Science Major, University of Science and Technology (UST), Daejeon, 34113, South Korea.
Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine (KIOM), 111 Geonjae-Ro, Naju-Si, South Korea.
Sci Rep. 2025 Jul 30;15(1):27791. doi: 10.1038/s41598-025-13476-4.
Aspilia africana (Pers.) C. D. Adams is a valuable medicinal plant, and the expanding therapeutic use of the plant due to explosion of human population is causing depletion of its wild population, thus requiring propagation. This study established an effective method for direct somatic embryogenesis in A. africana using leaf explants. We evaluated the effects of exogenous plant growth regulators (PGRs) and some molecules on induction, development, and maturation of somatic embryos. Murashige and Skoog (MS) medium supplemented with 1.0 mg/L benzylaminopurine (BAP) and 3.472 × 10 mg/L adenosine 5-monophosphate (AMP) optimally induced direct somatic embryogenesis in A. africana leaf explants (100% response and 9.50 ± 0.29 somatic embryos per explant). Differentiation and maturation of somatic embryos was enhanced under osmotic stress induced by using 9 g/L gelrite in MS medium augmented with 0.5 mg/L abscisic acid (ABA) and 6.634 × 10 mg/L nicotinamide adenine dinucleotide (NAD) (6.27 ± 0.36 globular, 3.40 ± 0.35 heart, 2.60 ± 0.51 torpedo, and 4.73 ± 0.41 cotyledonary). Half strength MS medium containing 0.5 mg/L gibberellin (GA) and 0.1 mg/L naphthaleneacetic acid (NAA) optimally supported germination (31 ± 1.73%) of cotyledonary somatic embryos. Pre-germination treatment of cold (stratification at 4 C) further stimulated somatic embryo germination (60.00%) and their conversion into plantlets (26.67%). After five weeks of acclimatization, the survival rate of somatic embryo derived A. africana plants was 75.00%. Histological observations and flow cytometric analysis confirmed different somatic embryo stages and stability in genome size of regenerated plants, respectively. Moreover, chlorophyll contents and photosynthetic rates were similar between zygotic and somatic embryo derived plants. This method could be employed in mass clonal regeneration, conservation, synthetic seed production, cryopreservation, and genetic improvement of A. africana. Additionally, the system would provide suitable model for investigating molecular, biochemical, and physiological events, which occur at the induction and development of embryogenesis in A. africana.
非洲兔儿风（Aspilia africana (Pers.) C. D. Adams）是一种珍贵的药用植物，由于人口增长导致该植物的治疗用途不断扩大，其野生种群正在枯竭，因此需要进行繁殖。本研究利用叶片外植体建立了一种有效的非洲兔儿风直接体细胞胚胎发生方法。我们评估了外源植物生长调节剂（PGR）和一些分子对体细胞胚胎诱导、发育和成熟的影响。添加1.0 mg/L苄氨基嘌呤（BAP）和3.472×10 mg/L腺苷5-单磷酸（AMP）的Murashige和Skoog（MS）培养基能最佳地诱导非洲兔儿风叶片外植体直接体细胞胚胎发生（响应率100%，每个外植体有9.50±0.29个体细胞胚胎）。在添加0.5 mg/L脱落酸（ABA）和6.634×10 mg/L烟酰胺腺嘌呤二核苷酸（NAD）的MS培养基中，使用9 g/L吉丽兰诱导渗透胁迫，可增强体细胞胚胎的分化和成熟（球形胚6.27±0.36个、心形胚3.40±0.35个、鱼雷形胚2.60±0.51个、子叶形胚4.73±0.41个）。含有0.5 mg/L赤霉素（GA）和0.1 mg/L萘乙酸（NAA）的1/2强度MS培养基能最佳地支持子叶形体细胞胚胎的萌发（31±1.73%）。预萌发的冷处理（4℃分层）进一步刺激了体细胞胚胎的萌发（60.00%）及其转化为植株（26.67%）。驯化五周后，体细胞胚胎来源的非洲兔儿风植株的成活率为75.00%。组织学观察和流式细胞术分析分别证实了不同的体细胞胚胎阶段和再生植株基因组大小的稳定性。此外，合子胚和体细胞胚来源的植株之间的叶绿素含量和光合速率相似。该方法可用于非洲兔儿风的大规模克隆繁殖、保存、合成种子生产、超低温保存和遗传改良。此外，该体系将为研究非洲兔儿风胚胎发生诱导和发育过程中发生的分子、生化和生理事件提供合适的模型。
