| More and more attentions have been taken to the effects of environmental stresses (e.g., mechanical vibration, sound wave stimulation, treatment with electromagnetic filed etc.) on the growth and development of plant cells and tissues. Making efforts on this field not only can broaden our knowledge of plant physiology and cytobiology, but also are of significance to breed quality plant varieties, to enhance plant adaptability to varied environments and to implement extensively efficient agricultural technologies.Using test-tube seedling and callus cultured from stalks of Actinidia chinensis, this study dealed with the effects of sound wave stimulation and mechanical vibration on plant cell growth, enzymatic activity, cell membrane structure and function, energy metabolize ,photosynthesis and respiration of test-tube seedlings, and on the vitality of root system. The results indicated that there occurs bidirectional effects of these physical factors on the growth of plant cells and tissues. Moderate stresses would be advantageous to the growth and development of A. chinensis. The results are shown as the followings: 1. Bidirectional effects, i.e., promotive and suppressive actions of sound wave stimulation and mechanical vibration on the growth and development of A. chinensis were observed. Among selected intensities and frequencies of external stresses, the vibration frequency of approximate 3 Hz, the sound intensity of about 100 dB and sound frequency of approximate 1000 Hz are optimal external stresses for the growth and development of A. chinensis. With the increase of intensity or frequency of the two environmental stresses, almost all physiological indexes are better than that of CK.When calluses were cultured under environmental stresses exceeded optimal frequencies to certain extent, indexes such as accumulating rate of fresh callus weight, activity of SOD, content of soluble proteins and content of ATP were elevated to different degrees as the increases of intensity and frequency of mechanical vibration and sound wave. It revealed that appropriate stresses are favorable to plant growth and development and to enhance adversity resistance. However, when vibration frequency imposed exceeds 3 Hz or the intensity and frequency of sound wave applied exceed 100 dB and 1000 Hz, indexes described above descended to different extent. Meanwhile, the changing trends of IAA oxidase activity and of calcium absorptivity of tissues were quite the contrary. It indicated that environmental stresses imposed exceeding optimal scopes were no longer in favour of, even began to inhibit regular growth of plants. Remarkablepromotive effects on plant growth were observed under these stresses, which is consistent with our previous corresponding findings obtained from herbaceous Gerbera Jamesonii acrocarpous.2. The stress effects of test-tube seedlings differed with those of callus. Moderate physical stresses can enhance the photosynthetic rate and lower respiration intensity, thereby in favour of accumulating nutrition and biomass of seedlings, but no significant promotive effect was observed statistically. Apparent promotive effects of either mechanical vibration or sound wave stresses on seedling growth were observed in respect to such indexes related to the development of root system as rooting ability, quantity of generating roots and activity of root system. The optimal promotiveness was also observed under approximate 3 Hz of mechanical vibration or about 100dB or 1000 Hz of sound wave stresses. Furthermore, similar positive effect was also observed in terms of plasma membrane permeability that represents plant ability of adversity resistance. Moderate vibration or sound wave stresses lowered the permeability of cell plasma membrane, which could improve plant ability to resist formidable habitats.The mechanisms of stress effects of mechanical vibration and sound wave stimulation on A. chinensis were comprehensively discussed in the light of plant physiology, cytobiology and molecular biology. Specific at...
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