Saffron is a valuable plant and one of the most expensive spices worldwide. Nowadays, there is a tendency to produce this crop in indoor plant production systems. However, the production of saffron is restricted by the need for the reproduction of high-quality corms. In this study, we investigated the effect of different ratios of red (R) and blue (B) light spectra (including 100% B (monochromatic B), 75%, 50%, 40%, 25% B, and 0% B (monochromatic R) on the photosynthetic performance and biomass partitioning as well as morphological and biochemical characteristics of saffron. The growth of flower, root, and corm was improved by increasing the proportion of B to R light. B-grown plants were characterized by the highest photosynthetic functionality with efficient electron transport and lower energy dissipation when compared to R-grown plants. B light directed biomass toward the corms and floral organs, while R light directed it toward the leaves. In saffron, the weight of a daughter corm is of great importance since it determines the yield of the next year. As the ratio of B to R light increased, the daughter corms also became heavier, at the cost of reducing their number, though increasing the proportion of B-enhanced antioxidant capacity as well as the activity of ascorbate peroxidase and catalase while superoxide dismutase activity was enhanced in R-grown plants. In conclusion, B light increased the production of high-quality daughter corms and altered biomass partitioning towards harvestable organs (corms and flowers) in saffron plants.

It is already known that the process of photosynthesis depends on the quality and intensity of light. However, the influence of the new light sources recently used in horticulture, known as Light Emitting Diodes (LEDs), on this process is not yet fully understood. Chlorophyll a fluorescence measurement has been widely used as a rapid, reliable, and noninvasive tool to study the efficiency of the photosystem II (PSII) and to evaluate plant responses to various environmental factors, including light intensity and quality. In this work, we tested the responses of the tomato photosynthetic apparatus to different light spectral qualities. Our results showed that the best performance of the photosynthetic apparatus was observed under a mixture of red and blue light (R7:B3) or a mixture of red, green and blue light (R3:G2:B5). This was demonstrated by the increase in the effective photochemical quantum yield of PSII (Y[II]), photochemical quenching (qP) and electron transport rate (ETR). On the other hand, the mixture of red and blue light with a high proportion of blue light led to an increase in non-photochemical quenching (NPQ). Our results can be used to improve the production of tomato plants under artificial light conditions. However, since we found that the responses of the photosynthetic apparatus of tomato plants to a particular light regime were cultivar-dependent and there was a weak correlation between the growth and photosynthetic parameters tested in this work, special attention should be paid in future research.

Alzheimer’s disease, a neurodegenerative disease, is one of the most common causes of dementia if elderly people worldwide. Alzheimer’s disease leads to the alienation of individuals and their exclusion from social and professional life. It is characterized mainly by the degradation of memory and disorientation, which occurs as a result of the loss of neuronal structure and function in different brain areas. In recent years, more and more attention has been paid to use in the treatment of natural bioactive compounds that will be effective in neurodegenerative diseases, including Alzheimer’s disease. G. biloba L. and its most frequently used standardized extract (EGb 761), have been used for many years in supportive therapy and in the prevention of cognitive disorders. The paper presents an overview of reports on the pathogenesis of Alzheimer’s disease, as well as a summary of the properties of G. biloba extract and its effects on the possible pathogenesis of the disease. By exploring more about the pathogenesis of the disease and the benefits of G. biloba extract for patients with Alzheimer’s disease, it will be possible to create an individualized therapeutic protocol to optimize the treatment.

Strawberry is one of the plants sensitive to salt and alkalinity stress. Light quality affects plant growth and metabolic activities. However, there is no clear answer in the literature on how light can improve the performance of the photosynthetic apparatus of this species under salt and alkalinity stress. The aim of this work was to investigate the effects of different spectra of supplemental light on strawberry (cv. Camarosa) under salt and alkalinity stress conditions. Light spectra of blue (with peak 460 nm), red (with peak 660 nm), blue/red (1:3), white/yellow (1:1) (400–700 nm) and ambient light were used as control. There were three stress treatments: control (no stress), alkalinity (40 mM NaHCO3), and salinity (80 mM NaCl). Under stress conditions, red and red/blue light had a positive effect on CO2 assimilation. In addition, blue/red light increased intrinsic water use efficiency (WUEi) under both stress conditions. Salinity and alkalinity stress decreased OJIP curves compared to the control treatment. Blue light caused an increase in its in plants under salinity stress, and red and blue/red light caused an increase in its in plants under alkalinity. Both salt and alkalinity stress caused a significant reduction in photosystem II (PSII) performance indices and quantum yield parameters. Adjustment of light spectra, especially red light, increased these parameters. It can be concluded that the adverse effects of salt and alkalinity stress on photosynthesis can be partially alleviated by changing the light spectra.

Phytohormones mediate physiological, morphological, and enzymatic responses and are important regulators of plant growth and development at different stages. Even though temperature is one of the most important abiotic stressors for plant development and production, a spike in the temperature may have disastrous repercussions for crop performance. Physiology and growth of two tomato genotypes ('Ahmar' and 'Roma') were studied in two growth chambers (25 and 45 °C) when gibberellic acid (GA3) was applied exogenously. After the 45 days of planting, tomato plants were sprayed with GA3 at concentrations of 25, 50, 75, and 100 mg L−1, whereas untreated plants were kept as control. Under both temperature conditions, shoot and root biomass was greatest in 'Roma' plants receiving 75 mg L−1 GA3, followed by 50 mg L−1 GA3. Maximum CO2 index, photosynthetic rate, transpiration rate, and greenness index were recorded in 'Roma' plants cultivated at 25 °C, demonstrating good effects of GA3 on tomato physiology. Likewise, GA3 enhanced the proline, nitrogen, phosphorus, and potassium levels in the leaves of both genotypes at both temperatures. Foliar-sprayed GA3 up to 100 mg L−1 alleviated the oxidative stress, as inferred from the lower concentrations of MDA and H2O2, and boosted the activities of superoxide dismutase, peroxidase, catalase. The difference between control and GA3-treated heat-stressed plants suggests that GA3 may have a function in mitigating heat stress. Overall, our findings indicate that 75 mg L−1 of GA3 is the optimal dosage to reduce heat stress in tomatoes and improve their morphological, physiological, and biochemical characteristics.

Phragmites australis (common reed) is one of the most extensively distributed species of emergent plant worldwide. The adaptive features of this plant show its competitive character. Owing to high intraspecific diversity of common reed, as well as its phenotypic plasticity, the plant shows a broad ecological amplitude. Moreover, the plant exhibits a high capacity for acclimatization to environmental conditions which are considered adverse. This plant has been used for many years in phytoremediation to purify various types of wastewater. Phragmites australis has a high ability to accumulate various nutrients, heavy metals, and micropollutants, and in this respect, it is superior to other aquatic plants. This review examines the existing literature on the biological and ecological properties of common reed, the use of common reed in wastewater treatment for removing pollutants and tolerance for metals, and in hydrophyte treatment systems. It seems vital to conduct further research on the physiology and biochemistry of the common reed, with the aim of increasing the plant’s efficiency for pollutants removal.

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In agriculture, the search for higher net profit is the main challenge in the economy of the producers and nano biochar attracts increasing interest in recent years due to its unique environmental behavior and increasing the productivity of plants by inducing resistance against phytopathogens. The effect of rice straw biochar and fly ash nanoparticles (RSBNPs and FNPs, respectively) in combination with compost soil on bacterial leaf spot of pepper caused by Xanthomonascampestris pv. vesicatoria was investigated both in vitro and in vivo. The application of nanoparticles as soil amendment significantly improved the chili pepper plant growth. However, RSBNPs were more effective in enhancing the above and belowground plant biomass production. Moreover, both RSBNPs and FNPs, significantly reduced (30.5 and 22.5%, respectively), while RSBNPs had shown in vitro growth inhibition of X.campestris pv. vesicatoria by more than 50%. The X-ray diffractometry of RSBNPs and FNPs highlighted the unique composition of nano forms which possibly contributed in enhancing the plant defence against invading X.campestris pv. vesicatoria. Based on our findings, it is suggested that biochar and fly ash nanoparticles can be used for reclaiming the problem soil and enhance crop productivity depending upon the nature of the soil and the pathosystem under investigation.