Manipulation of light spectrum is an effective tool to regulate biochemical traits and gene expression in lettuce under different replacement methods of nutrient solution.

The use of light-emitting diode (LED) technology represents a promising approach to improve plant growth and metabolic activities. The aim of this study was to investigate the effect of different light spectra: red (656 nm), blue (450 nm), red/blue (3:1), and white (peak at 449 nm) on biochemical properties, photosynthesis and gene expression in two lettuce cultivars (Lollo Rossa and Lollo Bionda) grown under different methods of nutrient solution replacement in hydroponics. Complete replacement and EC-based replacement of nutrient solution increased content of proline and soluble sugars and activity of antioxidant enzymes (CAT, GPX and SOD) under the red/blue LED and red LED light treatments in both cultivars. In addition, the red/blue and the monochromatic red light increased the soluble protein content and the antioxidant activity in the Lollo Rosa cultivar under the replacement method according to the needs of the plant. An increase in flavonoid content in the EC-based method in the Lollo Rosa variety treated with a combination of red and blue light was also observed. The red/blue light had the greatest induction effect on anthocyanin content, expression of the UFGT, CHS, and Rubisco small subunit genes, and the net photosynthetic rate. Data presented here will directly contribute to the development of nutrient solution and LED spectrum management strategies to significantly improve plant growth and metabolism, while avoiding water and nutrient waste, and environmental pollution.

How photoautotrophy, photomixotrophy, and ventilation affect the stomata and fluorescence emission of pistachios rootstock?

The effects of ventilation and sucrose concentration on proliferation and organogenesis of pistachio cutting and photosynthetic performance of two in vitro cultures of pistachio rootstocks have been assessed. The apical leaf buds (Qazvini and UCB1 cultivars) were cultured in filter vessels containing Murashige and Skoog medium supplemented with 0, 10, 15, and 30 g L -1 of sucrose. The plants treated with 10, 15, and 30 g L -1 sucrose showed no significant differences regarding the measured traits; therefore, this treatment was set aside from the final statistical analyses. Use of different ventilation systems showed to be suitable for increasing the growth of pistachio. Referring to root production difficulties under in vitro cultivation of pistachio, ventilation increased the root production and length. However, the full ventilation system was more effective in improving the growth properties. Regression between fluorescence feature vs root length showed that F v/F m had a significant positive relationship with root length. Stomata of cell parameters under ventilation systems improved compared to no ventilation, which was highly similar to the trend in the greenhouse. The overall results indicated that low concentrations of sucrose (e.g., 10 g L -1) and full ventilation are recommended for producing high quality and vigorous pistachio plantlets under in vitro conditions.

Antioxidant capacity of several Iranian, wild and cultivated strains of the button mushroom.

The white button mushroom, Agaricus bisporus, is the most commonly grown mushroom in Iran; however, there is a significant shortage of research on its antioxidant activity and other medicinal properties. The aim of this study was to evaluate antioxidant capacity of the methanolic extracts from four cultivated strains and four Internal Transcribed Spacer (ITS)-identified, Iranian wild isolates of A. bisporus. Evaluations were made for total phenols, flavonoids and anthocyanins, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Overall, results showed that all the wild isolates exhibited significantly lower DPPH-derived EC50, compared to the cultivated strains (p < 0.05). A relatively high relationship was observed between total phenols and flavonoids or anthocyanins (r(2) > 0.60). However, these constituents could not statistically differentiate the group of wild samples from the cultivated ones, and there was low correlation with the DPPH-derived EC50s (r(2) < 0.40). In conclusion, comparisons showed that wild isolate 4 and cultivated strains A15 and H1 had higher antioxidant capacity than the others (p < 0.05). This result identifies these mushrooms as good candidates for further investigation.

Antioxidant capacity of several Iranian, wild and cultivated strains of the button mushroom

The white button mushroom, Agaricus bisporus, is the most commonly grown mushroom in Iran; however, there is a significant shortage of research on its antioxidant activity and other medicinal properties. The aim of this study was to evaluate antioxidant capacity of the methanolic extracts from four cultivated strains and four Internal Transcribed Spacer (ITS)-identified, Iranian wild isolates of A. bisporus. Evaluations were made for total phenols, flavonoids and anthocyanins, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Overall, results showed that all the wild isolates exhibited significantly lower DPPH-derived EC₅₀, compared to the cultivated strains (p < 0.05). A relatively high relationship was observed between total phenols and flavonoids or anthocyanins (r² > 0.60). However, these constituents could not statistically differentiate the group of wild samples from the cultivated ones, and there was low correlation with the DPPH-derived EC₅₀s (r² < 0.40). In conclusion, comparisons showed that wild isolate 4 and cultivated strains A15 and H1 had higher antioxidant capacity than the others (p < 0.05). This result identifies these mushrooms as good candidates for further investigation.