Akio Sakanishi

Influence of ultrasonic stimulation on the growth and proliferation of Oryza sativa Nipponbare callus cells

Ultrasound acts as an alternative stress on cells or tissues. In this study it is aimed to investigate the effect of ultrasonic stimulation on the growth and proliferation of Oryza sativa Nipponbare cells (rice callus) in suspension culture. After the samples were stimulated by ultrasound at 28 kHz, we measured their growth and proliferation by using a colorimetric MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay as well as fresh weights of the cells. Growth curves were obtained by fresh weights in the suspension culture after ultrasonic agitation for different time from 2 to 120 s. In MTT method, the optical density was determined at 570 nm in the cell suspension on 10 days after the ultrasonic agitation. Up to 5 s agitation OD570 increased; it decreased for more prolonged stimulation. We found that ultrasonic stimulation could promote the growth and proliferation of O. sativa Nipponbare cells in suspension culture with the optimal stimulation of 5 s, while with longer agitation, its growth and proliferation was inhibited. The mechanism may be that the ultrasound activated or destroyed the cellular structure, such as cell membrane, cytoskeleton and mitochondria in which many enzymes and ion channels are affected. In addition, the enhancement of cell wall and cell membrane fluidity might be one of the factors to promote the cell growth in 5-s ultrasonic stimulation.

Effects of ultrasound on the growth and vacuolar H+-ATPase activity of aloe arborescens callus cells

Abstract Effects of ultrasound on the growth and vacuolar H+-ATPase (V-ATPase) activity of aloe arborescens callus cells were investigated. The callus cells cultured in suspension were agitated by an ultrasonic bath at 28 kHz from the exposure time ts=2–60 s, and the cell growth was the highest at ts=5 s as measured by the fresh weight of the callus. The callus cells cultured in solid were exposed by a digital sonifier at 20 kHz in 2 s

Low ultrasonic stimulates fermentation of riboflavin producing strain Ecemothecium ashbyii

The effect of low ultrasonic stimulation on fermentation of riboflavin producing strain Ecemothecium ashbyii was investigated. In this paper, several key biochemical parameters related to cell growth were measured. The results of the present study show that all of the given different frequency of low ultrasonic treatment could promote mycelium growth, at the same time also improve output of riboflavin, and the optimum frequency was about 24 kHz. After 24 kHz ultrasonic incontinuous treatments, the fermentation time was shortened by 36 h and productivity rate of riboflavin was increased by about 5 times compared with the control groups.

Effects of sound field on the growth of Chrysanthemum callus

The effects of sound field on Chrysanthemum callus were studied. The field of alternative stress was generated through a strong sound field system set up in our lab, and the activity of SOD, the content of soluble proteins, the activity of IAA oxidase and the absorption rate of calcium were measured. We found that the sound field stimulation has dual effects, which can enhance or inhibit the growth of Chrysanthemum callus, the growth effects of sound field on Chrysanthemum callus depended greatly on the intensity and frequency of sound field. The activity of SOD, the content of soluble proteins and the absorption rate of calcium in callus increased with the intensity and frequency increasing. However, those indexes began to decrease when the intensity and frequency went beyond the limit of 100 dB and 800 Hz, respectively. However, the changing tendency of IAA oxidase activity was reversed to the above three indexes. We draw a conclusion that the optimal stimulation conditions are 100 dB and 800 Hz. Under the conditions, the sound field can distinctly enhance the growth of Chrysanthemum callus. We think that moderate stress stimulation can enhance the assimilation of tissues or cells, improve their physiological activity and accelerate the growth of plants, this moderate stress stimulation is helpful to the growth of plant tissues.

CARROT CELL GROWTH RESPONSE IN A STIMULATED ULTRASONIC ENVIRONMENT

Abstract Carrot cells were exposed in suspension to 28 kHz continuous wave ultrasound. Exposure durations were from 2 to 40 s at the beginning of the cell suspension culture, so as to encompass the first decade of decreased or increased survival at each action time. In our experiment, we used a spectrophotometer to assay cell growth by means of measurement directly the absorbance (ABS) change in suspension culture. The experimental results indicated whether it would have been a positive or negative influence on plant cell growth in suspension culture with ultrasound exposed time varying; Meanwhile, we got two shake modes, a reciprocal shaker and a rotary shaker, that had almost same influences on plant cell growth under assigned conditions.

The effects of alternative stress on the cell membrane deformability of chrysanthemum callus cells.

The effects of alternative stress, which was generated through a strong sound field apparatus set up in our lab, on cultured chrysanthemum callus cells were studied. Meanwhile we measured the deformability of chrysanthemum cell membranes and studied the influence of the cytoskeleton after the treatment of colchicine using micropipette aspiration technique. Based on our experimental results, we found that the deformability of cell membrane decreased in stress condition. However, the effect disappeared after the treatment of cytochalasin. Therefore, we thought that the reason on the deformability of cells decreasing was the microfilament rearranging and consequently the cells becoming more rigid under the alternative stress.

Effect of sound wave on the metabolism of chrysanthemum roots

Environmental factors can greatly influence the growth of plants. In this paper, the effect of sound stimulation on the metabolism of chrysanthemum roots was studied and it was found that the growth of roots was not inhibited but accelerated under suitable sound stimulation. And the content of soluble sugar and protein and the activity of amylase all increased significantly, which indicated that sound stimulation could enhance the metabolism of roots and the growth of chrysanthemum.

The research into the influence of low-intensity ultrasonic on the growth of S.cerevisiaes

In this paper, an orthogonal experiment was designed which was involved in four levels and five factors including the ultrasonic frequency and power efficiency, the interval between two stimulations, the each stimulation time, and the total ultrasonic stimulation duration. The influences of ultrasonic on the growth of Saccharomyces cerevisiaes were studied when S. cerevisiaes were in lag phase, exponential phase, and stationary phase, respectively. Meanwhile, the optimum parameters of ultrasonic stimulation had been obtained. Based on the experimental data, it was found that the low-intensity ultrasonic could accelerate the growth of S. cerevisiaes in the lag phase and the exponential phase under some appropriate conditions, but almost had no influence on the growth of S. cerevisiaes in the stationary phase. And the optimum parameters of ultrasonic stimulating S. cerevisiaes in lag phase were different from that in exponential phase. Furthermore, even if both S. cerevisiaes in the lag phase and in the exponential phase were under the conditions of their own optimum parameters, the rate of S. cerevisiaes growth was different, too. The stimulation of low-intensity ultrasonic had little influences on the temperature of the medium in a way, but it could somewhat raise the mediums pH and bring about foam when S. cerevisiaes were in the exponential phase.

Effects of sound stimulation on protective enzyme activities and peroxidase isoenzymes of chrysanthemum

Abstract One of the important fields in cell biology is physical stimulus on the growth of plant cells and organs. The effects of strong sound wave on thermodynamic properties, cell cycles and calcium ion signaling transduction of plants have been studied. In this work, chrysanthemum seedlings are treated by sound wave with a certain intensity (100 db) and frequency (1000 Hz) for 3, 6, 9, 12 and 15 days, respectively, and each day for 60 min. The research results show that the activities of protective enzymes and the peroxidase isoenzymes increase at varying degrees. Compared with the control group, there is no new enzyme band in POD electrophoretogram for experimental groups. Our experimental data imply that better promotion for chrysanthemum is obtained under sound wave for 9 days.

Effect of sound wave on the synthesis of nucleic acid and protein in chrysanthemum

Abstract Environmental factors can greatly influence the growth and development of plants, even the genetic character. It had been found that sound stimulation had an obvious effect on the growth and development of plants. But the mechanism of how sound affected the growth of plants is not clear so far. In this paper, we studied the effect of sound on the nucleic acid and soluble protein to explore the mechanism of the biological effect of sound. It was found that sound wave had no obvious influence on the content of DNA but accelerated the synthesis of RNA and soluble protein. By means of the assay of relation, the content of soluble protein had a very close relationship with that of RNA. This result indicated that some stress-induced genes might be switched on under sound stimulation and the level of transcription increased.