Dep. of Biology, Faculty of Basic Sciences, Shahed University, 3319118651, Tehran, Iran.
Medicinal Plant Research Center, Shahed University, 3319118651, Tehran, Iran.
Plant Physiol Biochem. 2018 Nov;132:623-632. doi: 10.1016/j.plaphy.2018.10.015. Epub 2018 Oct 11.
Antihypertensive compound ajmalicine and antileukemic vincristine and vinblastine are three important terpenoid indole alkaloids produced by Catharanthus roseus (Apocynaceae). This study has been done to investigate the effects of methyl jasmonate (100 μM) and silver nitrate (50 and 100 μM) individually and simultaneously on the production of mentioned important medicinal alkaloids (vincristine, vinblastine, ajmalicine, vindoline and catharanthine) and the expression profile of related regulatory and biosynthetic genes in micropropagated shoots of C. roseus. The effects of these treatments are also investigated on non-enzymatic defensive metabolites (total phenolics, flavonoids and carotenoids) and antioxidant enzymes activities (peroxidase, EC 1.11.1.7, catalase, EC 1.11.1.6 and superoxide dismutase, EC 1.15.1.1). Changes of dry weight, quantity of lipid peroxidation, and photosynthetic pigments contents have been measured as well. The results showed increased contents of alkaloids and expression levels of investigated regulatory (Mitogen-activated protein kinase3 and Octadecanoid-responsive Catharanthus AP2-domain3) and biosynthetic (strictosidine synthase, geissoschizine synthase, deacetylvindoline acetyltransferase and peroxidase1) genes under the employed treatments. The maximum yields of these alkaloids and the highest levels of the mentioned genes expression were observed under 100 μM methyl jasmonate in combination with 100 μM of AgNO after seven days. The employed treatments induced increased lipid peroxidation, higher levels of enzymatic antioxidants activities and more production of non-enzymatic defensive metabolites which shows activity of plant defensive system. The results suggest that silver nitrate and methyl jasmonate signalling pathways may have cross talks and their simultaneous application make an effective combination for elicitation of medicinal alkaloids biosynthesis in C. roseus micropropagated shoots.
降压化合物阿马林碱和抗白血病长春新碱和长春碱是夹竹桃科长春花（Catharanthus roseus）产生的三种重要的萜类吲哚生物碱。本研究旨在研究茉莉酸甲酯（100μM）和硝酸银（50 和 100μM）单独和同时对重要药用生物碱（长春新碱、长春碱、阿马林碱、长春质碱和长春碱）的产生以及相关调节和生物合成基因在长春花微繁殖芽中的表达谱的影响。还研究了这些处理对非酶防御代谢物（总酚类、类黄酮和类胡萝卜素）和抗氧化酶活性（过氧化物酶、EC 1.11.1.7、过氧化氢酶、EC 1.11.1.6 和超氧化物歧化酶、EC 1.15.1.1）的影响。还测量了干重、脂质过氧化含量和光合色素含量的变化。结果表明，在所采用的处理下，生物碱含量增加，同时还观察到了所研究的调节基因（丝裂原激活蛋白激酶 3 和十八碳烯响应的长春花 AP2 结构域 3）和生物合成基因（斯特罗迪辛合酶、吉西舒碱合酶、去乙酰长春碱乙酰转移酶和过氧化物酶 1）的表达水平升高。在 7 天后，100μM 茉莉酸甲酯与 100μM 硝酸银联合使用时，这些生物碱的最大产量和上述基因表达的最高水平。所采用的处理诱导了脂质过氧化的增加、更高水平的酶抗氧化剂活性和更多的非酶防御代谢物的产生，这表明植物防御系统的活性。结果表明，硝酸银和茉莉酸甲酯信号通路可能存在交叉对话，同时应用它们可以有效地组合，以诱导长春花微繁殖芽中药用生物碱的生物合成。
