Hazelnut is one of the most important nut plants recently suggested as a sustainable source for paclitaxel. In the present study, the effect of the concentration and combination of PGRs, different basal medium and ultrasonic waves on callus induction and growth, physiological characteristics, and taxol and baccatin III production in hazelnut callus cultures were investigated. The results indicated that combining 2,4-D (2 mg/L) and Kin (0.2 mg/L) with the sonication of explants for 1 min provides an optimized condition for callus induction and growth. Hazelnut explants exhibited different callus production and biochemical and metabolic characteristics depending on the basal medium type, ultrasound treatment, and inclusion of ascorbic acid in the medium. So that, the highest percentage of callogenesis (100%) observed in ½ MS + 1 min US, ½ MS + 150 mg/L AA, B5 + 1 min US and B5 + 150 mg/L AA, and also ½ MS salt + Nitsch vitamins + 150 mg/L AA. Furthermore, the highest callus growth (7.86 g FW) was obtained from ½ MS + 1 min US. The highest amount of baccatin III production (147.98 and 147.85 mg/L) was obtained from the WPM and MS basal media; the highest taxol production (44.89 mg/L) was observed in the WPM basal medium. The cultures in the MS, WPM, and MS salts + Nitsch vitamins media, had the highest H₂O₂ and MDA content, antioxidant enzymes activity, and phenolic compounds. In conclusion, culture media nutrient composition and concentration not only affect the cell growth and physiological status of the cultures but also improve secondary metabolites production and accumulation.

Galega officinalis L. is an herbaceous legume used to treat symptoms associated with hyperglycemia or diabetes mellitus because of its dominant alkaloid, galegine. In this study, we induced hairy roots in this plant using Rhizobium rhizogenes strain A4, and investigated the effect of type, concentration, and duration of elicitor application on galegine content and some phytochemical characteristics in the hairy roots. Hence, the best growing hairy root line in terms of growth rate was selected and subcultured for treatment with elicitors. Then, at the end of the log phase of growth, chitosan (100, 200, and 400 mg/L), salicylic acid (100, 200, and 300 mM), and ultrasound (1, 2, and 4 min) were applied to hairy roots culture medium. High-performance liquid chromatography (HPLC) showed that the content of galegine was significantly increased after elicitation compared with the control. Thus, the highest content of galegine (14.55 mg/g FW) was obtained 2 days after elicitation when ultrasonic waves were applied to the hairy root culture medium for 4 min. Also, elicitation resulted in a significant increase in the content of total phenol, flavonoid, H₂O₂ and MDA compared with the control. So that the highest total flavonoid content was obtained in hairy roots that were treated with ultrasonic waves for 4 min and harvested 2 days after elicitation; while, application of 400 mg/L chitosan for 4 days resulted in the highest total phenol (16.84 mg/g FW). Graphical Abstract

Over the last 10 years, fluorescent semiconductor QD (quantum dot)-aptamer conjugates have emerged as an efficient platform for cancer imaging and therapy in animal models and in vitro. In addition, these conjugates show potential in a wide range of applications in environmental monitoring, disease diagnosis, and bio-sensing. The present review represents the recent developments in QDaptamer bio-conjugates for applications in cancer studies. It starts with a brief introduction to Semiconductor Quantum dots (QDs), bio-conjugation of QDs and aptamer molecules, and advantages-disadvantages of using these novel tools for biochemical applications.

In this study, a dual biosensor system for detecting chromium (VI) and zinc (II) in contaminated soil including toxic metals has been successfully designed using two strains of immobilised bioluminescent (BL) Escherichia coli Gap and Gfp. Saponinbiosurfactant was used to extract the chromium (Cr6+) and zinc (Zn2+) from soil to the aqueous phase. From obtained results when extracted metals ions were injected into the dual biosensor system, the luminescence level of biosensor decreased dramatically for both zinc and chromium. The concentrations of extracted chromium and zinc are well correlated with metals ions toxicity data achieved by biosensor system. The optimum aeration rate of biosensor system was obtained 30 ml/min. Dual biosensor system may be applied as an in-situ biosensor to detect the toxicity of chromium and zinc in contaminated soil including toxic metals. Therefore, this system can be proposed as a potential alternative to detection of toxic metals in soils.