Idrees Muhammad, Sania Bibi, Hafsa Bibi, Kumari Sana, Khan Haji, Fazal Hina, Ahmad Ishfaq, Akbar Fazal, Ahmad Naveed, Ali Sadeeq, Ahmad Nisar
Centre for Biotechnology and Microbiology, University of Swat, 19200 Swat, Pakistan.
Pakistan Council of Scientific and Industrial Research (PCSIR) Laboratories Complex, 25120 Peshawar, Pakistan.
C R Biol. 2018 Jul-Aug;341(6):334-342. doi: 10.1016/j.crvi.2018.05.003. Epub 2018 May 30.
Stevia rebaudiana (S. rebaudiana) is the most important therapeutic plant species and has been accepted as such worldwide. It has a tendency to accumulate steviol glycosides, which are 300 times sweeter than marketable sugar. Recently, diabetic patients commonly use this plant as a sugar substitute for sweet taste. In the present study, the effects of different spectral lights were investigated on biomass accumulation and production of secondary metabolites in adventitious root cultures of S. rebaudiana. For callus development, leaf explants were excised from seed-derived plantlets and inoculated on a Murashige and Skoog (MS) medium containing the combination of 2,4-dichlorophenoxy acetic acid (2, 4-D, 2.0mg/l) and 6-benzyladenine (BA, 2.0mg/l), while 0.5mg/l naphthalene acetic acid (NAA) was used for adventitious root culture. Adventitious root cultures were exposed to different spectral lights (blue, green, violet, red and yellow) for a 30-day period. White light was used as control. The growth kinetics was studied for 30days with 3-day intervals. In this study, the violet light showed the maximum accumulation of fresh biomass (2.495g/flask) as compared to control (1.63g/flask), while red light showed growth inhibition (1.025g/flask) as compared to control. The blue light enhanced the highest accumulation of phenolic content (TPC; 6.56mg GAE/g DW), total phenolic production (TPP; 101mg/flask) as compared to control (5.44mg GAE/g DW; 82.2mg GAE/g DW), and exhibited a strong correlation with dry biomass. Blue light also improved the accumulation of total flavonoid content (TFC; 4.33mg RE/g DW) and total flavonoid production (TFP; 65mg/flask) as compared to control. The violet light showed the highest DPPH inhibition (79.72%), while the lowest antioxidant activity was observed for control roots (73.81%). Hence, we concluded that the application of spectral lights is an auspicious strategy for the enhancement of the required antioxidant secondary metabolites in adventitious root cultures of S. rebaudiana and of other medicinal plants.
甜叶菊是最重要的药用植物物种，已在全球范围内得到认可。它倾向于积累甜菊糖苷，其甜度是市售糖的300倍。最近，糖尿病患者普遍使用这种植物作为甜味的糖替代品。在本研究中，研究了不同光谱光对甜叶菊不定根培养物中生物量积累和次生代谢产物产生的影响。为了诱导愈伤组织，从种子苗上切下叶片外植体，并接种在含有2,4-二氯苯氧乙酸（2,4-D，2.0mg/l）和6-苄基腺嘌呤（BA，2.0mg/l）组合的Murashige和Skoog（MS）培养基上，而0.5mg/l萘乙酸（NAA）用于不定根培养。不定根培养物在30天内暴露于不同光谱光（蓝色、绿色、紫色、红色和黄色）下。白光用作对照。以3天为间隔研究了30天的生长动力学。在本研究中，与对照（1.63g/瓶）相比，紫光显示出最大的新鲜生物量积累（2.495g/瓶），而与对照相比，红光显示出生长抑制（1.025g/瓶）。与对照（5.44mg GAE/g DW；82.2mg GAE/g DW）相比，蓝光促进了酚类含量（TPC；6.56mg GAE/g DW）、总酚产量（TPP；101mg/瓶）的最高积累，并且与干生物量表现出强相关性。与对照相比，蓝光还提高了总黄酮含量（TFC；4.33mg RE/g DW）和总黄酮产量（TFP；65mg/瓶）的积累。紫光显示出最高的DPPH抑制率（79.72%），而对照根的抗氧化活性最低（73.81%）。因此，我们得出结论，光谱光的应用是一种促进甜叶菊和其他药用植物不定根培养物中所需抗氧化次生代谢产物积累的吉祥策略。
