Characterization of Bean Seeds, Germination, and Phenolic Compounds of Seedlings by UV-C Radiation

Abstract

We quantitatively evaluate the effects of UV-C radiation on bean seeds Oti (Phaseolus vulgaris), their germination and phenolic compounds of seedlings, by means of photoacoustic spectroscopy and scanning electron microscopy. It is shown that: i) The photoacoustic signal produced by the bean seeds exposed to UV-C radiation during 15 minutes, reduces from 0.24 to 0.10 mV for the wavelengths of 295 and 340 nm, as a result of their degradation. This significant reduction of 58.3% decreases, but keeps over 50% for other spectral UV wavelengths within the interval (270-400 nm). ii) As the UV-C radiation time increases from 2 to 15 min, the morphological changes at the surface of the bean seeds exhibits micro-holes and detachment of the cotyledon sclereids. iii) There are no significant statistical differences in the variables of germination, dry weight and seedling length, for exposure times up to 15 minutes. iv). The phenolic acids and flavonoids of the bean seedlings of seeds treated by UV-C for different exposure times (0, 2, 5, 10 and 15 min) display significant statistical differences (P ≤ 0.05) in both roots and foliage. For both the roots and foliage, the highest concentration of phenolic acids is observed at 10 and 15 minutes, while for root flavonoids, it appears at 5 and 15 minutes.

Anything New under the Sun? An Update on Modulation of Bioactive Compounds by Different Wavelengths in Agricultural Plants

“…This review specifically focuses on the influence of the different light radiations, from red–far-red to UV-B, on the main classes of secondary metabolites, such as phenolic compounds, terpenoids, tocopherols, glucosinolates, and ascorbic acid in agricultural plant species, because of the recognised role that these compounds generally play as promoters of human wellness [ 43 , 44 , 45 , 46 ]. UV-C radiation was reported to modulate accumulation of health-promoting compounds in different plants and fruits of food interest, such as tomato fruit [ 47 ], bean seedlings [ 48 ] and peanut sprouts [ 49 ], this review exclusively discusses the effects of those wavelengths that reach the Earth’s surface, and to which plants have adapted fine-tuning perception mechanisms and consequent molecular and biochemical responses through evolution.…”

Involvement of Photoprotective Compounds of a Phenolic Nature in the Response of Arabidopsis Thaliana Leaf Tissues to Low‐Intensity Laser Radiation

“…In work (52), the effect of the magnetic field (75 mT) on soybean seeds was reported to increase the total PC content by around two times, the same being the case for LILR effect. The changes in the PC composition in the plant tissues can be induced both by the effect of a certain physical factor on the whole plants (50) and on the seeds during the presowing seed treatment (7,53,54). In the latter case, the changes in the PC composition in the seedlings obtained from these seeds last for a fairly long time.…”

Biophysical methods used to generate tolerance to drought stress in seeds and plants: a review

“…Sustainable methods designed to improve this tolerance have been reported by several authors. These include physical methods such as ultraviolet (UV) radiation (three types are defined below), laser, magnetic (B) and electric fields (E), X-rays, ionizing radiation, microwaves and magnetically treated water (Hernández-Aguilar et al, 2009a;2021a;Thomas and Puthur, 2017;Rifna et al, 2019;Gudkov et al, 2019;Waqas et al, 2019).…”