Khalifa Asmaa M, Abd-ElShafy Eman, Abu-Khudir Rasha, Gaafar Reda M
Botany and Microbiology Department, Faculty of Science, Al Azhar University (Girls Branch), Cairo, Egypt.
Chemistry Department, College of Science, King Faisal University, Al-Hofuf, Al-Ahsa, 31982, Saudi Arabia.
J Genet Eng Biotechnol. 2022 Dec 15;20(1):166. doi: 10.1186/s43141-022-00424-2.
A useful technique for growing large amounts of plant material is in vitro propagation of important medicinal plants. The present investigation deals with the enhancement of secondary metabolite production via elicitation using gamma (γ)-radiation and phenylalanine (Phe) precursor feeding in callus cultures of Silybum marianum L.
Seeds were exposed to two doses of γ-radiation (25 and 50 Gy) and the calli derived from stem explants obtained from seedlings of these radiated seeds were treated with different concentrations of Phe. The biosynthesis of phenols and flavonoids was evaluated. It was found that callus cultures derived from explants of the seeds exposed to 25 Gy γ-radiation and treated with 4 mg/l Phe accumulated the maximum phenolic content (34.27±0.02 mg/g d.wt.), while the highest flavonoid content (9.56±0.12 mg/g d.wt.) was found in callus cultures derived from explants of seeds radiated with 25 Gy γ-radiation and subjected to 1 mg/l Phe. Similarly, HPLC quantification revealed that the production of flavonoids was highly accumulated (1343.06 μg/mg d.wt.) in callus cultures from explants of seeds exposed to 25 Gy γ-radiation and grown at 1 mg/l Phe compared to the other treatments. In addition, a total of 11 important flavonoids have been determined in all callus cultures, except for acacetin-7-O-rutinoside, which was not found in the callus culture of the control.
These findings suggest that γ-radiation combined with Phe can improve the metabolism of S. marianum L. and could be used to produce such valuable metabolites on a commercial scale.
大量培育植物材料的一种有用技术是重要药用植物的离体繁殖。本研究涉及通过在水飞蓟愈伤组织培养中使用γ射线辐射和苯丙氨酸（Phe）前体饲喂来提高次生代谢产物的产量。
种子接受两种剂量的γ射线辐射（25和50 Gy），从这些辐射种子的幼苗获得的茎外植体衍生的愈伤组织用不同浓度的Phe处理。评估了酚类和黄酮类化合物的生物合成。发现来自接受25 Gy γ射线辐射并经4 mg/l Phe处理的种子外植体的愈伤组织培养物积累了最高的酚含量（34.27±0.02 mg/g干重），而在来自接受25 Gy γ射线辐射并经1 mg/l Phe处理的种子外植体的愈伤组织培养物中发现了最高的黄酮含量（9.56±0.12 mg/g干重）。同样，高效液相色谱定量分析表明，与其他处理相比，来自接受25 Gy γ射线辐射并在1 mg/l Phe浓度下生长的种子外植体的愈伤组织培养物中黄酮类化合物的产量高度积累（1343.06 μg/mg干重）。此外，在所有愈伤组织培养物中总共测定了11种重要的黄酮类化合物，但对照愈伤组织培养物中未发现刺槐素-7-O-芸香糖苷。
这些发现表明，γ射线辐射与Phe结合可以改善水飞蓟的代谢，并可用于商业规模生产此类有价值的代谢产物。
