Effects of Sound Stimulation on Physiological and Biochemical Responses of <i>Salvia splendens</i>

Abstract

Plants are inevitably influenced by environmental stresses due to their immobility. Sound waves are one of these environmental factors affecting plants. The present study was designed to explore the less-known relationship between sound waves and plant responses. For this purpose, <em>Salvia splendens</em>, a common plant in urban green spaces, was exposed to sound waves at a frequency of 1000 Hz and at intensities of 90, 100 or 110 dB, as well as a control, for one hour a day for one month. Seedlings were obtained from the seeds of <em>Salvia</em>, were cultivated in an MS medium under <em>in-vitro</em> conditions and were sub-cultured every 20 days. The treatments were started 15 days after planting the seeds. The results of growth and antioxidant enzyme activities showed that the increase in the intensity of the sound waves at 1000 Hz frequency increased plant growth. Maximum root and shoot length, fresh weight and dry weight were observed at 110 dB. The sound waves also increased protein content and catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) enzymes activity. Malondialdehyde content was increased with an increase in intensity. Overall, <em>Salvia splendens</em> responded to the sound wave stress by improving growth, physiological and biochemical parameters.