Gabr Ahmed M M, Ghareeb Hassan, El Shabrawi Haatem M, Smetanska Iryna, Bekheet S A
Plant Biotechnology Dept., National Research Centre, Bohouth Str., Dokki, Cairo, Egypt.
Department of Plant Food Processing, Agricultural Faculty, University of Applied Science Weihenstephan-Triesdorf, Markgrafenstr 16, 91746 Weidenbach, Germany.
J Genet Eng Biotechnol. 2016 Dec;14(2):327-333. doi: 10.1016/j.jgeb.2016.10.003. Epub 2016 Nov 4.
In the present study, the effects of the metabolite elicitors chitosan, methyl jasmonate (MeJA) and salicylic acid (SA) as well as the hairy root transformation were tested for silymarin and phenolic compound accumulation in cultures of Milk thistle. For callus induction, leaf explants were cultured on MS medium supplemented with 5 mg/l NAA + 2 mg/l Kin + 0.1 mg/l GA3. Chitosan, SA and MeJA were added separately in three concentrations 200, 400 and 800 mg/l; 10, 20 and 40 mg/l; 20, 40 and 80 mg/l, respectively, to hormone free B5 medium. Alternatively, cotyledons of 12 day old seedlings were transformed with A4 strain. Overall, increasing the concentrations of the three elicitors dramatically increased the total silymarin content. Remarkably, the elicitors mainly enhanced the accumulation of silybine A&B that were not detected in un-treated callus culture (control). In addition, the hairy root culture triggered the accumulation of silybine A&B, and silydianin, which was not detected in the non-transgenic roots. The hairy root culture was superior in production of the phenolic compounds in comparison to the control and elicitor treatments. The hairy root cultures showed also higher antioxidant capacities than non-transformed cultures and/or chemically elicited-callus cultures. Thus hairy root provide instrumental in enhancing the production of economically valuable metabolite.
在本研究中，测试了代谢物诱导剂壳聚糖、茉莉酸甲酯（MeJA）和水杨酸（SA）以及发根转化对水飞蓟培养物中水飞蓟素和酚类化合物积累的影响。为了诱导愈伤组织，将叶片外植体培养在添加了5 mg/l萘乙酸 + 2 mg/l激动素 + 0.1 mg/l赤霉素的MS培养基上。壳聚糖、SA和MeJA分别以200、400和800 mg/l；10、20和40 mg/l；20、40和80 mg/l这三种浓度分别添加到无激素的B5培养基中。另外，用A4菌株转化12日龄幼苗的子叶。总体而言，增加这三种诱导剂的浓度显著提高了水飞蓟素的总含量。值得注意的是，这些诱导剂主要增强了水飞蓟宾A和B的积累，而在未处理的愈伤组织培养物（对照）中未检测到水飞蓟宾A和B。此外，发根培养引发了水飞蓟宾A和B以及水飞蓟宁的积累，而在非转基因根中未检测到水飞蓟宁。与对照和诱导剂处理相比，发根培养在酚类化合物的产生方面更具优势。发根培养物还显示出比未转化培养物和/或化学诱导的愈伤组织培养物更高的抗氧化能力。因此，发根有助于提高具有经济价值的代谢物的产量。
