Study of phytohormones effects on UV-B stress seeds of thyme species

Document Type : Original article


Department of Agronomy and Medicinal Plants, Faculty of Agriculture, Shahrekord Branch, Islamic Azad University, Po.Box:166. Shahrekord, Iran.



Background & Aim: Thymus vulgaris L. and Thymus daenensis Celak (Thyme), members of the family Lamiaceae, are widely used in Iranian folk medicine. The aim of this research was to study how salicylic acid (SA), gibberellin (GA), and indole acetic acid (IAA)-seed priming affect UV-B radiation in seeds of Thyme (T. vulgaris, T. daenensis Celak) under both laboratory and outdoor conditions.
Experimental: The effects of phytohormones (200, 400, 600 ppm) and irradiation performed in a 60 Co Gamma cell 220 source at a dose of 3 kGy (10, 20 and 30 min) on seeds of Thyme species were studied. Seeds were tested under in vitro and outdoor conditions in a complete randomized factorial layout with 4 and 3 replications, respectively. The characters measured under in vitro condition were seed germination percentage, mean time of germination, root and stem length. On the field, the characters evaluated were number of leaf, length of plant, root and shoot dry matter and essential oil.
Results: SA treatment was better under in vitro conditions. No significant effects were obtained from GA and IAA. The most destructive effects and the best beneficial phytohormones were UV 30 min and SA (200 and 400 ppm), respectively. The effects of foliar application of hormones were determined on growth and essential oil production in medicinal plants in two consecutive years. Shoot dry matter increased in both years with SA applications but IAA and GA had no beneficial effects on germination characters after UV radiation.
Recommended applications/industries: SA-priming of seeds protects thyme seedlings against UV-B radiation. The results of this study also showed that elevation of free SA levels in plants, either by exogenous feeding or genetically may enhance their tolerance to abiotic stress.


Article Title [فارسی]

مطالعه اثر فیتوهورمون ها بر بذور گونه های آویشن تحت استرس اشعه فرابنفش.

Author [فارسی]

  • مهراب یادگاری
گروه گیاهان داروئی، دانشکده کشاورزی، دانشگاه ازاد واحد شهرکرد، شهرکرد، ایران
Abstract [فارسی]

پیش زمینه و اهداف: Thymus vulgaris L. وT.daenensiscelakدو گونه دارویی چندساله متعلق به خانواده نعناعیان می باشند. هدف این تحقیق مطالعه اثرات پرایمینگ بذور دو گونه آویشن  Thymus vulgaris L. وT.daenensiscelakتحت تنش اشعه فرابنفش با سالیسیلیک اسید، جیبرلیک اسید و ایندول استیک اسید در شرایط آزمایشگاهی و مزرعه ای بود.
شرایط آزمایشی: بذور تحت تیمار با هورمون‌های گیاهی با دوزهای 200، 400 و 600 ppmو اشعه فرابنفش با 220 گاماسل و شدت 3 kGy در سه زمان 10، 20 و 30 دقیقه قرار گرفتند. طرح آزمایشی در آزمایشگاه به صورت کاملاً تصادفی به صورت فاکتوریل و در مزرعه به صورت کاملاً تصادفی با سه تکرار انجام شد. صفات مورد برآورد در آزمایشگاه شامل درصد جوانه­زنی، متوسط زمان جوانه­زنی، طول ریشه­چه و ساقه­چه و در شرایط مزرعه تعداد برگ، ارتفاع گیاه، وزن خشک ریشه و اندام هوایی و میزان اسانس بود.
نتایج و بحث:نتایج در تمامی گیاهان نشاندهنده آن بود که در شرایط آزمایشگاه، سالیسیلیک اسید بهتر از سایر تیمارها بود و تفاوت معنی‌داری در مورد اثرات جیبرلیک اسید و ایندول استیک اسید، دیده نشد. بیشترین اثرات مخرب و بهترین اثرات مفیدبه ترتیب بواسطه تابش اشعه فرابنفش به مدت 30 دقیقه و هورمون سالیسیلیک اسید با غلظت 200 و 400 ppm بدست آمد. اثرات کاربرد هورمون‌ها توسط رشد و عملکرد گیاهان در دو سال متمادی تعیین شد. وزن خشک اندام هوایی در هر دو سال بواسطه کاربرد سالیسیلیک اسید افزایش یافت اما ایندول استیک اسید و جیبرلیک اسید تأثیر سودمندی بر بذور تحت تنش اشعه فرابنفش نداشتند.
توصیه کاربردی/ صنعتی: پرایمینگ با سالیسیلیک اسید بر خلاف ایندول استیک اسید و جیبرلیک اسید، منجر به محافظت بذور تحت تنش اشعه فرابنفش می شود. نتایج این تحقیق نشاندهنده آنست که افزایش سالیسیلیک اسید در گیاهان، چه به صورت کاربرد خارجی چه به صورت طبیعی منجر به تحمل به تنش های غیرزنده می شود.

Keywords [فارسی]

  • هورمون های گیاهی
  • گونه های آویشن
  • تنش اشعه فرابنفش
Bandurska, H. and Cieślak, M. 2013. The interactive effect of water deficit and UV-B radiation on salicylic acid accumulation in barley roots and leaves. Environmental of experimental and Botanical, volume 94: 9-18.
Bilkay, I.S., Karakoç, S. and Aksöz, N. 2010. Indole-3-acetic acid and gibberellic acid production in Aspergillus niger. Turkish Journal of Biology, volume 34: 313-318.
Brown, B.A. and Jenkins, G.I. 2008. UV-B signaling pathways with different flounce-rate response profiles are distinguished in mature Arabidopsis leaf tissue by requirement for UVR8, HY5, and HYH. Plant Physiology, volume 146: 576- 588.
Caldwell, M.M., Bornman, J.F., Ballare, C.L. and Kulandaivelu, G. 2007. Terrestrial ecosystems, increased solar ultraviolet radiation and interactions with other climatic factors. Photochemistry Photobiology Science, volume 6: 252-266.
Chen, Y.P. 2008. Isatis indigotica seedlings derived from laser stimulated seeds showed improved resistance to elevated UV-B. Plant Growth Regulators, volume 55: 73–79.
Choudhary. K.K. and Agrawal, S.B. 2014. Ultraviolet-B induced changes in morphological, physiological and biochemical parameters of two cultivars of pea (Pisum sativum L.). Ecotoxicology Environment Safety, volume 100:178–187.
Eguchi, K. and Sato, T. 2009. Differences in the Ratios of Cyanidin-3-O-glucoside and Cyanidin-3-O-rutinocide to Total Anthocyanin under UV and Non-UV Conditions in Tartary Buckwheat (Fagopyrum tataricum Garten). Plant Production Science, volume 12 issue 2: 150―155.
Ervin, E.H., Zhang, X. andFike, J.H. 2004. Ultraviolet-B radiation damage on Kentucky bluegrass. II. Hormone supplement effects. Horticultural Science, volume 39: 1471-1474.
Fattahi, M., Nazeri, V., Sefidkon, F., Zamani, Z. and Palazon, J. 2011. The Effect of Pre-sowing Treatments and Light on Seed Germination of Dracocephalum kotschyi Boiss: An Endangered Medicinal Plant in Iran. Horticultural Environmental Biotechnology, volume 52 issue 6: 559-566.
Kostina, E., Wulff, A. andTiitto, R.J. 2001. Growth, structure, stomatal responses and secondary metabolites of birch seedlings (Betula pendula) under elevated UV-B radiation in the field. Trees, volume 15: 483–491.
Lavola, A., Nybakken, L., Rousi, M., Pusenius, J. and Petrelius, M. 2013. Combination treatment of elevated UVB radiation, CO2 and temperature has little effect on silver birch (Betula pendula) growth and phytochemistry. Physiology Plant, volume 149: 499–514.
Liu, B., Liu, X.B., Li, Y.S. and Herbert, S.J. 2013. Effects of enhanced UV-B radiation on seed growth characteristics and yield components in soybean. Field Crop Research, volume 154: 158-163.
Lee, M.J., Son, J.E. and Oh, M.M. 2013. Growth and phenolic content of Sowthistle grown in a closed-type plant production system with a UV-A or UV-B Lamp. Horticultural EnvironmentalBiotechnology, volume 54 issue 6: 492-500.
Li, X.M., Ma, L.J., Bu, N., Li, Y.Y. and Zhang, L.H.2014. Effects of salicylic acid pre-treatment on cadmium and/or UV-B stress in soybean seedlings. Biologia Plantarum, volume 58 issue 1: 195-199.
Mahdavian, K., Kalantari, K.M., Ghorbanli, M. and Torkzade, M. 2008. The effects of salicylic acid on pigment contents in ultraviolet radiation stressed pepper plants. Biology of Plant, volume 52:170-172.
Moussa, H.R. and El-Gamal, S.M. 2010. Effect of salicylic acid pretreatment on cadmium toxicity in wheat. Biology of Plant, volume 54: 315-320.
Mustafic, A., Li, Ch. and Haidekker, M. 2014. Blue and UV LED-induced fluorescence in cotton foreign matter. Journal of Biology Engineering, volume 8 issue 29: 2-11.
Rashad, R.T. andHussien, R.A. 2014. A comparison study on the effect of some growth regulators on the nutrients content of maize plant under salinity conditions. Annals of Agricultural Science, volume 59 issue 1: 89-94.
Saruhan, N., Saglam, A. and Kadioglu, A. 2012. Salicylic acid pretreatment induces drought tolerance and delays leaf rolling by inducing antioxidant systems in maize genotypes. Acta Physiology Planetarium, volume 34: 97-106.
Singh, V.P., Kumar, J., Singh, M., Singh, S., Prasad, S.M. and Dwivedi, R. 2015. Role of salicylic acid-seed priming in the regulation of chromium (VI) and UV-B toxicity in maize seedlings. Plant Growth Regulators, DOI 10.1007/s10725-015-0076-4.
Sunita, K., and Guruprasad, K.N. 2012. Solar UV-B and UV-A/B exclusion effects onintra specific variations in crop growth and yield of wheat varieties. Field Crop Research, volume 125: 8–13.
Taipina, M.S., Garbelottib, M.L., Leda, C.A. and Rodas, A.B. 2011. The effect of gamma irradiation on the nutrional properties of sunflower whole grain cookies. Procedia Food Science, volume 1:1992-1996.
Tian, X.R. and Lei, Y.B. 2007. Physiological Responses of Wheat Seedlings to Drought and UV-B Radiation. Effect of Exogenous Sodium Nitroprusside Application. Russian Journal of Plant Physiology, volume 54 issue 5: 676–682.
Xu, Z.H. and Li, J.Y. 2006. Plant hormones research in China: past, present and future. Chaining Bulletin of Botany, volume 23: 433–442.
Yadegari, M. 2015. Foliar application of micronutrients on essential oils of borago, thyme and marigold. Journal of Soil Science and Plant Nutrition, volume 15 issue 4: 949-964.
Yang, D., Luo, Y., Ni, Y., Yin, Y., Yang, W., Peng, D., Cui, Z. and Wang, Z. 2014. Effects of exogenous ABA application on post-anthesis dry matter redistribution and grain starch accumulation of winter wheat with different stay green characteristics. Crop Journal, volume 2: 144-153.