Short-term airborne ultrasound induced cell death in tobacco cells and changed their wall components

The effects of low-intensity ultrasound on plants such as piezoelectric and ultrasonic water baths, on plants have been extensively studied. However, the specific effect of airborne ultrasound on plant cells has yet to be reported. The present study was conducted to elucidate the physiological responses of plant cells to airborne US. Homogeneous suspension-cultured tobacco cells (Nicotiana tabacum L. cv Burley 21) were subjected to airborne US at 24 kHz in two pulsatile and continuous modes for 10 and 20 s. The study's outcome revealed that airborne US triggered the production of H2O2, elevated internal calcium concentration, and reduced antioxidant capacity upon cavitation. Alteration of covalently bound peroxidase and other wall-modifying enzyme activities was accompanied by reduced cellulose, pectin, and hemicellulose B but increased lignin and hemicellulose A. The biomass and viability of tobacco cells were also significantly decreased by airborne US, which ultimately resulting in PCD and secondary necrosis. The results highlight the potential risks of even short-time exposure to the airborne US on plant physiology and cell wall chemical composition raising significant concerns about its implications.

Determination of the carrot (Daucus carota L.) yields parameters by vermicompost and earthworms (Eisenia foetida)

The impact of different types of vermicomposts as well as different species and genera of earthworms on the quantity of the cultivated crops yield has been studied for decades. There is scarce information about the effects of these factors on the quality of plant production. One of the qualitative parameters of vegetables, to which a special attention is paid, is the content of antioxidants (vitamin C, total polyphenols and other substances). The pot experiment carried out in the vegetation cage studied: A) the influence of soil itself, soil mixed with vermicompost in a ratio of 4:1; B) the influence of earthworms number (genus Eisenia foetida, 10 and 20 individuals per pot) supplied to soil mixed with vermicompost in a ratio of 4:1 on the weight of radish roots and leaves, to the total chlorophylls content in leaves, to the selected qualitative parameters of the roots and leaves (vitamin C, total polyphenols content,  total antioxidant activity). The results showed that the supplementation of vermicompost into soil increased the content of the total chlorophylls in leaves. The carrot roots and leaves yield has also been risen. In the roots the content of vitamin C and content of total polyphenols (TPC) was decreased and the total antioxidant activity (TAA) dropped, too. The increased content of vitamin C and TPC was detected in leaves. The inoculation of soil containing vermicompost by earthworms increased the root yield and TAA in roots. It increased the content of vitamin C and TPC in leaves. From the viewpoint of antioxidant content (vitamin C and total polyphenols) the leaves are more attractive than a root.