Effects of Nitrate and L-Arginine on Content of Nitric Oxide and Activities of Antioxidant Enzymes in Roots of Wheat Seedlings and Their Heat Resistance
Separate and combined effects of nitrate (NaNO3) and L-arginine as potential sources of nitric oxide (NO) on the content of endogenous NO in roots of wheat (Triticum aestivum L.) seedlings and on their heat resistance were studied. Both agents increased the seedling resistance to the damaging heating; the effect was maximal at 20 mM NaNO3 or 5 mM L-arginine. The treatment with L-arginine elevated the NO content in the roots within the first 2 h of the treatment. Nitrate caused a stronger and longer rise in nitric oxide. Activity of nitrate reductase considerably (2–3 times) increased in the roots exposed to nitrate. The augmentation in the nitric oxide level caused by nitrate or L-arginine was prevented by the root pretreatment with an inhibitor of nitrate reductase (sodium tungstate) or an inhibitor of animal NO-synthase—NG-nitro-L-arginine methyl ester (L-NAME). Upon the combined treatment with NaNO3 and L-arginine, the nitrateinduced stimulation of the nitrate reductase activity, NO level in the roots, and seedling heat resistance were less pronounced than after separate application. In the presence of L-NAME, the negative influence of L-arginine on nitrate effects was markedly attenuated. The plant exposure to nitrate or L-arginine increased the activities of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase). A mixture of NaNO3, and L-arginine caused weaker effects. It was suggested that nitrate-dependent and arginine-dependent pathways of NO formation are antagonistic to each other in wheat roots.
KeywordsTriticum aestivum antioxidant system L-arginine heat resistance nitrate nitric oxide
NG-nitro-L-arginine methyl ester (inhibitor of NO-synthase)
2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (scavenger of NO)
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- 4.Glyan'ko, A.K. and Vasil’eva, G.G., Reactive oxygen and nitrogen species in legume–rhizobial symbiosis: a review, Appl. Biochem. Microbiol., 2010, vol. 46, pp. 21–28.Google Scholar
- 8.Oz, M.T., Eyidogan, F., Yucel, M., and Oktem, H.A., Functional role of nitric oxide under abiotic stress conditions, in Nitric Oxide Action in Abiotic Stress Responses in Plants, Khan, M.N., Mobin, M., Mohammad, F., and Corpas, F.J., Eds., Heidelberg: Springer, 2015, pp. 21–42.Google Scholar
- 9.Mur, L.A.J., Mandon, J., Persijn, S., Cristescu, S.M., Moshkov, I.E., Novikova, G.V., Hall, M.A., Harren, F.J.M., Hebelstrup, K.H., and Gupta, K.J., Nitric oxide in plants: an assessment of the current state of knowledge, AoB Plants, 2013, vol. 5: pls052. doi 10.1093/aobpla/pls052CrossRefPubMedGoogle Scholar
- 17.Kolupaev, Yu.E., Plant cell antioxidants and their role in ROS signaling and plant resistance, Usp. Sovrem. Biol., 2016, vol. 136, pp. 181–198.Google Scholar