en Nitric Oxide Increased the Rosmarinic Acid and Essential Oil Production in <i>In vitro</i>-cultured <i>Melissa officinalis</i> بيوتكنولوژی Biotechnology پژوهشی Research <div dir="ltr" style="text-align: justify;"><strong>Background:</strong> Nitric oxide is a free radical that recently has emerged as a key signaling molecule in regulating important physiological processes in plants.<br> <strong>Objective:</strong> In this work, sodium nitroprusside (SNP) was utilized as the donor of nitric oxide to investigate the effects of exogenous nitric oxide on essential oil, rosmarinic acid and antioxidant activity of <em>in vitro-</em>cultured <em>Melissa officinalis </em>plants<em>.</em><br> <strong>Methods: </strong>The Plantlets were treated with different concentrations of SNP (0, 5, 10 and 20 mM) at eight leaf stages.<br> <strong>Results: </strong>The results showed that SNP decreased trans-caryophyllene and other selected essential oils in <em>M. officinalis</em> plants, while increased most of major components of essential oils. The highest content for linalool, neral and thymol was achieved at 5, 5 and 20 mM of SNP respectively. The highest monoterpene (56.17 % v/w) and sesquiterpene content (76.01 % v/w) were achieved by 5 and 20 mM SNP, respectively. In addition, the class of essential oil compounds varied depending on the SNP concentration. Application of SNP on culture media increased rosmarinic acid production and phenolic levels, which in turn improved the antioxidant properties of the extracts.<br> <strong>Conclusion:</strong> It seems that nitric oxide elicited <em>M</em><em>. officinalis </em>culture and increased the secondary metabolite production. This current finding open new opportunities for obtaining valuable natural antioxidants for commercial exploitation by using tissue culture systems.</div> <div dir="ltr" style="text-align: justify;"><strong>Background:</strong> Nitric oxide is a free radical that recently has emerged as a key signaling molecule in regulating important physiological processes in plants.<br> <strong>Objective:</strong> In this work, sodium nitroprusside (SNP) was utilized as the donor of nitric oxide to investigate the effects of exogenous nitric oxide on essential oil, rosmarinic acid and antioxidant activity of <em>in vitro-</em>cultured <em>Melissa officinalis </em>plants<em>.</em><br> <strong>Methods: </strong>The Plantlets were treated with different concentrations of SNP (0, 5, 10 and 20 mM) at eight leaf stages.<br> <strong>Results: </strong>The results showed that SNP decreased trans-caryophyllene and other selected essential oils in <em>M. officinalis</em> plants, while increased most of major components of essential oils. The highest content for linalool, neral and thymol was achieved at 5, 5 and 20 mM of SNP respectively. The highest monoterpene (56.17 % v/w) and sesquiterpene content (76.01 % v/w) were achieved by 5 and 20 mM SNP, respectively. In addition, the class of essential oil compounds varied depending on the SNP concentration. Application of SNP on culture media increased rosmarinic acid production and phenolic levels, which in turn improved the antioxidant properties of the extracts.<br> <strong>Conclusion:</strong> It seems that nitric oxide elicited <em>M</em><em>. officinalis </em>culture and increased the secondary metabolite production. This current finding open new opportunities for obtaining valuable natural antioxidants for commercial exploitation by using tissue culture systems.</div> ,Melissa officinalis, Antioxidant activity, Essential oils, Nitric oxide, Rosmarinic acid, Shoot cultures Melissa officinalis, Antioxidant activity, Essential oils, Nitric oxide, Rosmarinic acid, Shoot cultures 61 72 http://jmp.ir/browse.php?a_code=A-10-68-3&slc_lang=en&sid=1 S Esmaeilzadeh bahabadi S Esmaeilzadeh bahabadi shirin_esm@yahoo.com 100319475328460041234 100319475328460041234 Yes Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran A Rezaei A Rezaei ayarezaei@gmail.com 100319475328460041235 100319475328460041235 No Department of Biotechnology, Faculty of Agriculture, Shahed University, Tehran, Iran Department of Biotechnology, Faculty of Agriculture, Shahed University, Tehran, Iran