Plant acoustics: in the search of a sound mechanism for sound signaling in plants

Abstract

Being sessile, plants continuously deal with their dynamic and complex surroundings, identifying important cues and reacting with appropriate responses. Consequently, the sensitivity of plants has evolved to perceive a myriad of external stimuli, which ultimately ensures their successful survival. Research over past centuries has established that plants respond to environmental factors such as light, temperature, moisture, and mechanical perturbations (e.g. wind, rain, touch, etc.) by suitably modulating their growth and development. However, sound vibrations (SVs) as a stimulus have only started receiving attention relatively recently. SVs have been shown to increase the yields of several crops and strengthen plant immunity against pathogens. These vibrations can also prime the plants so as to make them more tolerant to impending drought. Plants can recognize the chewing sounds of insect larvae and the buzz of a pollinating bee, and respond accordingly. It is thus plausible that SVs may serve as a long-range stimulus that evokes ecologically relevant signaling mechanisms in plants. Studies have suggested that SVs increase the transcription of certain genes, soluble protein content, and support enhanced growth and development in plants. At the cellular level, SVs can change the secondary structure of plasma membrane proteins, affect microfilament rearrangements, produce Ca(2+) signatures, cause increases in protein kinases, protective enzymes, peroxidases, antioxidant enzymes, amylase, H(+)-ATPase / K(+) channel activities, and enhance levels of polyamines, soluble sugars and auxin. In this paper, we propose a signaling model to account for the molecular episodes that SVs induce within the cell, and in so doing we uncover a number of interesting questions that need to be addressed by future research in plant acoustics.

The effect of frequency-specific sound signals on the germination of maize seeds

“…Several possible effects have been proposed to sounds in plants and more specifically in seeds [15, 16]. One of the possible effects is to affect the physical integrity of the pericarp which could facilitate the entry of water and oxygen, increasing germination.…”

Proteomic Changes in the Sound Vibration-Treated Arabidopsis thaliana Facilitates Defense Response during Botrytis cinerea Infection

“…The roles of membrane-bound mechanosensors ( i.e ., mechanosensitive ion channels and wall-associated kinase) in plant mechanosensation have been hypothesized previously (Monshausen and Haswell, 2013). These mechanosensors may play important roles in SV perception as well (Mishra et al, 2016). Previously it was observed that SV treatment alters the expression of mechanosensitive ion channels in Arabidopsis (Ghosh et al, 2017).…”

“…Being a mechanical pressure wave, SV can induce various physiological changes in plants. In earlier studies, a number of SV-induced cellular responses were noticed, which includes calcium spiking, reactive oxygen species (ROS) generation, enhanced antioxidant enzyme activities, changed physical state of membrane lipids and proteins, increased transcription, translation, and effects on cell cycle (Mishra et al, 2016). Moreover, a recent finding establishes the priming potential of SV; pre-exposure to caterpillar-chewing vibration can induce a chemical defense response in Arabidopsis by virtue of accumulating glucosinolates and anthocyanin (Appel and Cocroft, 2014).…”

Effects of sound elements on growth, viability and protein production yield in Escherichia coli

“…This system was assembled using an incubator clamp on a 1585 orbital shaking incubator (VWR, PA, USA). [2] beaker, [3] plastic supporter, [4] speaker, [5] sound generator, [6] flexible tubing, [7] sample receiver, [8] flask swab, [9] lid with two outlets, [10] syringe, [11] 0.45 mm filter, [12] tweezers, [13] cotton. bottle cap [9]; on the second outlet, a syringe [10] with a 0.45 mm filter [11] was attached to generate a pressure difference so that the sample could move from the flask to the beaker.…”

“…This knowledge may eventually lead to the development of technology in fields such as applied microbiology, bioengineering, agroindustry and medicine. Although there have been scientific reports describing the effects of sound on living organisms, especially plants, [1][2][3][4] there are few studies addressing how sound affects unicellular organisms.…”