Preliminary study of the production of metabolites from in vitro cultures of C. ensiformis

Assessing pollution degree and human health risks from hazardous element distribution in soils near gold mines in a Colombian Andean region: Correlation with phytotoxicity biomarkers

The assessment of human health risk due to the presence of hazardous elements in the environment is now necessary for environmental management and legislative initiatives. This study aims to determine the contamination by As, Cd, Pb, and Cr in soils near gold mines in three municipalities located in the Andean region of Colombia. One of the main objectives of the study is to explore possible correlations between the Lifetime Cancer Risk (LCR) and phytotoxicity biomarkers using a simple and rapid-response plant model, radish (Raphanus sativus L.). In the municipality of Yalí, Puerto Berrío, and Buriticá, the hazardous elements concentrations ranged from 8.1 to 35.5, 1.7 to 892, and 5.8 to 49.8 for As, 0.1 to 4.6, 0.1 to 65.2, and 0.5 to 18.2 for Cd, 18.5 to 201.3, 13.0 to 1908, and 189 to 2345 for Pb, and 5.4 to 118.4, 65.4 to 301, and 5.4 to 102.3 for Cr, respectively. The results showed that the biomarkers intracellular H2O2 concentration, antioxidant activity, and radicle elongation exhibited significant (P < 0.05) variations associated with the concentration of hazardous elements in the soils. Significant correlations (P < 0.05, r > 0.58) were found between the biomarkers and the LCR for Cd, Pb, and Cr, but not for As. The results using biomarkers reveal that soil pH and organic matter content are important variables that control the bioavailability of these elements in the soil. The use of indicators like LCR alone has limitations and should be accompanied by the use of biomarkers that allow for a better understanding of the biological system's response to exposure to potentially toxic elements. The results obtained show the urgent need to implement public policies to minimize exposure to hazardous substances in areas near gold mining projects.

Light Quality-Mediated Influence of Morphogenesis in Micropropagated Horticultural Crops: A Comprehensive Overview

In plants, light quality plays significant roles in photomorphogenesis and photosynthesis. Efficient in vitro plant propagation techniques involve tailoring of various environmental cues and culture media according to the plant species. Plant tissue culture consists of several applications in scientific research, agriculture, biotechnology, and commercial industrial purposes. Utilization of light to enhance the quality of the in vitro raised plants have been evidenced by numerous researchers in plant tissue culture. The advent of light-emitting diode- (LED-) based artificial lighting systems in plant tissue culture for micropropagation has enhanced callus induction, shoot and root organogenesis, and acclimatization of in vitro propagated plants. Plants tend to perceive the light spectra present in the photosynthetically active region (PAR) ranging from 400 to 700 nm; this includes blue and red light wavelengths. Although the influence of spectral quality is being investigated in diverse plant species, particularly, its importance in in vitro propagated horticultural crops is gaining notable interest among researchers. In recent days, the application of LEDs provides better amenability according to the plant species of interest for efficient plant regeneration. Considering the growing necessity and emerging applications of LED supplemental lights for propagation of plants in in vitro, the present review summarizes the outcomes of various research studies dealing with LEDs in plant tissue culture. Moreover, the present endeavor has provided a comprehensive overview on the effects of LEDs in the morphogenesis of plants cultured in vitro.

Application of Light-Emitting Diodes for Improving the Nutritional Quality and Bioactive Compound Levels of Some Crops and Medicinal Plants

Light is a key factor that affects phytochemical synthesis and accumulation in plants. Due to limitations of the environment or cultivated land, there is an urgent need to develop indoor cultivation systems to obtain higher yields with increased phytochemical concentrations using convenient light sources. Light-emitting diodes (LEDs) have several advantages, including consumption of lesser power, longer half-life, higher efficacy, and wider variation in the spectral wavelength than traditional light sources; therefore, these devices are preferred for in vitro culture and indoor plant growth. Moreover, LED irradiation of seedlings enhances plant biomass, nutrient and secondary metabolite levels, and antioxidant properties. Specifically, red and blue LED irradiation exerts strong effects on photosynthesis, stomatal functioning, phototropism, photomorphogenesis, and photosynthetic pigment levels. Additionally, ex vitro plantlet development and acclimatization can be enhanced by regulating the spectral properties of LEDs. Applying an appropriate LED spectral wavelength significantly increases antioxidant enzyme activity in plants, thereby enhancing the cell defense system and providing protection from oxidative damage. Since different plant species respond differently to lighting in the cultivation environment, it is necessary to evaluate specific wavebands before large-scale LED application for controlled in vitro plant growth. This review focuses on the most recent advances and applications of LEDs for in vitro culture organogenesis. The mechanisms underlying the production of different phytochemicals, including phenolics, flavonoids, carotenoids, anthocyanins, and antioxidant enzymes, have also been discussed.