Salt-Tolerant Rice Research Group, Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand.
Department of Pharmacognosy and Toxicology, Faculty of Pharmaceutical Science, Khon Kaen University, Khon Kaen, Thailand.
PeerJ. 2022 Feb 7;10:e12892. doi: 10.7717/peerj.12892. eCollection 2022.
Pokeweed ( L.) is regarded as an invasive plant in many parts of the world but possesses therapeutic characteristics used for antitumor and rheumatism treatment. This study investigated the effects of auxins and four explants on pokeweed callus induction. The effects of cytokinins and combinations between cytokinins and NAA on shoot and root induction were also studied. TPC, TFC and antioxidant activity of calli were screened and compared with other pokeweed plant parts.
Four explants were used to induce callus using 2,4-D and IBA at 1, 2, 3 and 4 mg/l for each auxin. Direct shoot organogenesis from nodal explants was investigated using BAP, kinetin and TDZ (1, 2 and 4 mg/l for each cytokinin). Combined effects between cytokinins and NAA at 0.1, 0.2 and 0.3 mg/l were further simultaneously estimated with root induction. Calli derived from the leaves were compared with other plant parts for TPC, TFC and antioxidant activity using the Folin-Ciocalteu, AlCl colorimetric assay and DPPH assays, respectively.
Results showed that MS medium containing 2 mg/l 2,4-D induced callus formation on leaf explants that provided highest fresh and dry weights. Three types of synthetic cytokinins as kinetin, TDZ and BAP were used for direct shoot organogenesis from pokeweed nodes. MS medium containing 2 mg/l kinetin was effective in stimulating normal shoots, with the largest number of shoots and leaves and the longest shoots. The combination between cytokinins and NAA showed no positive effect on shoot and root induction from pokeweed nodal explants. For TPC and TFC determination, pokeweed seeds and leaves possessed the highest phenolic and flavonoid contents, respectively. Highest phenolic content of pokeweed seeds led to lowest IC by DPPH assay. Phenolic content was higher than flavonoid content.
Results suggested promising conditions for callus induction. Leaf explants cultured on MS medium with 2 mg/l 2,4-D and nodal explants cultured on MS medium with 2 mg/l kinetin provided the largest number of normal shoots and leaves. NAA did not show positive effects on shoot and root induction when combined with cytokinins. Chemical constituent screening indicated that seeds and leaves provided highest TPC and TFC, respectively, while pokeweed calli contained higher phenolic than flavonoid content. This is the first report describing chemical constituent screening and antioxidant activity of calli and other parts of the pokeweed plant. Results provided significant information to further enhance bioactive compound contents of pokeweed calli using elicitation methods.
pokeweed（L.）在世界许多地区被视为入侵植物，但具有治疗特性，可用于抗肿瘤和风湿治疗。本研究调查了生长素和四种外植体对 pokeweed 愈伤组织诱导的影响。还研究了细胞分裂素及其与 NAA 的组合对芽和根诱导的影响。筛选了愈伤组织的 TPC、TFC 和抗氧化活性，并与其他 pokeweed 植物部分进行了比较。
使用 2,4-D 和 IBA 在 1、2、3 和 4mg/L 下，用四种外植体诱导愈伤组织。用 BAP、激动素和 TDZ（每种细胞分裂素 1、2 和 4mg/L）研究来自节间外植体的直接芽器官发生。进一步同时估计细胞分裂素与 NAA 之间的组合效应，浓度为 0.1、0.2 和 0.3mg/L，同时诱导生根。与其他植物部分相比，叶片来源的愈伤组织的 TPC、TFC 和抗氧化活性分别采用 Folin-Ciocalteu、AlCl 比色法和 DPPH 法进行测定。
结果表明，含有 2mg/L 2,4-D 的 MS 培养基诱导叶片外植体形成愈伤组织，其提供的鲜重和干重最大。三种合成细胞分裂素，即激动素、TDZ 和 BAP，用于 pokeweed 节间的直接芽器官发生。含有 2mg/L 激动素的 MS 培养基可有效刺激正常芽的形成，芽和叶数量最多，芽最长。细胞分裂素与 NAA 的组合对 pokeweed 节间外植体的芽和根诱导没有积极作用。对于 TPC 和 TFC 的测定，pokeweed 种子和叶片分别具有最高的酚类和类黄酮含量。 pokeweed 种子的最高酚含量导致 DPPH 测定的最低 IC。酚含量高于类黄酮含量。
结果表明，愈伤组织诱导具有良好的条件。在含有 2mg/L 2,4-D 的 MS 培养基上培养的叶片外植体和在含有 2mg/L 激动素的 MS 培养基上培养的节间外植体提供了最多的正常芽和叶片。细胞分裂素与 NAA 组合使用时，对芽和根的诱导没有积极作用。化学成分筛选表明，种子和叶片分别提供了最高的 TPC 和 TFC，而 pokeweed 愈伤组织的酚类含量高于类黄酮含量。这是首次描述 pokeweed 愈伤组织和其他部分的化学成分筛选和抗氧化活性。结果提供了重要信息，可进一步使用诱导方法提高 pokeweed 愈伤组织中生物活性化合物的含量。
