Medium salt strength induced changes in growth, physiology and secondary metabolite content in adventitious roots of Morinda citrifolia: the role of antioxidant enzymes and phenylalanine ammonia lyase
Medium salt strength induced changes in growth, physiology and secondary metabolite content in adventitious roots of Morinda citrifolia: the role of antioxidant enzymes and phenylalanine ammonia lyase
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DOI：
10.1007/s00299-010-0854-4
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发表时间：
2010-07-01
影响因子：
6.2
通讯作者：
Paek, Kee-Yoeup
中科院分区：
文献类型：
--
作者：
Baque, Md. Abdullahil;Lee, Eun-Jung;Paek, Kee-Yoeup
以不同强度的海巴戟天不定根为材料，研究了不同强度对海巴戟不定根生长和次生代谢产物产生的影响，并探讨了其生理和抗氧化酶活性变化的可能机制（0.25、0.50、0.75、1.0、1.5和2.0）的Murashige和Skoog（MS）培养基，其补充有5 mg/l（-1）吲哚丁酸和30 g/l（-1）蔗糖。四分之一强度MS培养基被证明适合于生产的根生物量和次生代谢产物[蒽醌（AQ），酚类化合物和黄酮类化合物]。随着盐浓度的增加，根系生长量和AQ积累量显著下降。较高的盐强度（1.5和2 MS）引起的渗透胁迫导致超过两倍的游离脯氨酸积累比低盐强度处理的根，诱导自由基清除活性。苯丙氨酸解氨酶活性与盐强度呈正相关，盐强度导致苯酚生物合成增加，而AQ形成减少。2.0 MS处理后，根中过氧化氢酶（CAT）、愈创木酚过氧化物酶（G-POD）和超氧化物歧化酶（SOD）活性升高，抗坏血酸过氧化物酶（APX）活性降低，而0.25 MS处理后，APX活性沿着被激活，CAT活性显著升高。而CAT、G-POD和APX的共同作用，在0.25MS处理下，能有效地消除H_2O_2的潜在危害，表现为H_2O_2的积累和膜脂过氧化程度较低。
In an attempt to improve growth and secondary metabolite production, and to understand the possible mechanism involved in relation to the changes in physiology and activities of antioxidant enzymes, we cultured Morinda citrifolia adventitious roots in different strength (0.25, 0.50, 0.75, 1.0, 1.5 and 2.0) of Murashige and Skoog (MS) medium supplemented with 5 mg l(-1) indole butyric acid and 30 g l(-1) sucrose. Quarter-strength MS medium was proven suitable for the production of both root biomass and secondary metabolites [anthraquinone (AQ), phenolics and flavonoids]. With the increasing salt strength, root growth and AQ accumulation decreased significantly. Higher (1.5 and 2 MS) salt strength provoked osmotic stress resulted in more than twofold free proline accumulation than lower salt strength treated roots and induced free radical scavenging activity. Phenylalanine ammonia lyase activity showed a positive correlation in relation to salt strength that leads to an increase in phenol biosynthesis in expense of AQ formation. The elevated catalase (CAT), guaiacol peroxidase (G-POD) and superoxide dismutase activities and decreased ascorbate peroxidase (APX) activities were observed in roots treated with 2.0 MS. On the other hand, APX activity was strongly activated along with considerable increase in CAT activity at 0.25 MS treated culture. However, the joint functions of CAT, G-POD and APX at 0.25 MS treated cultures were efficient to eliminate the potential danger of hydrogen peroxide (H2O2) as evidenced from low H2O2 accumulation and low level of lipid peroxidation.