Stimulating effect of biogenic nanoparticles on the germination of basil (Ocimum basilicum L.) seeds.

Metal nanoparticles synthesized using various biosources are the subject of focus in many research areas thanks to their improved biological effects and increased bioavailability. Silver (Ag), zinc oxide (ZnO) and magnetite (Fe3O4) nanoparticles (NPs) were obtained by using low-cost, low-energy, environmentally friendly, non-toxic chemicals and easily accessible thyme leaves and lavender flowers. The effects of various concentrations of biosynthesized NPs on the germination and germination index of basil seeds were defined comparatively. Phytochemicals in lavender flower extract acted as reducing and capping agents in the biosynthesis of Ag-NPs, and phytochemicals in thyme leaves extract acted for the biosynthesis of ZnO-NPs ve Fe3O4-NPs. Relative root length was detected at 25 mg/L ZnO-NP, stem length at 50 mg/L ZnO-NP, and relative seed germination 100 mg/L Fe3O4-NP with the maximum value. However, germination percentage, germination index, germination vigor index and root length were found to be maximum compared to other NP applications at Ag-NPs at 200 mg/L. This research showed that the germination promoting effects of NPs, which may be essential microelements, are related to their size, surface area, morphology and concentration. Thus, it promoted early and rapid germination by breaking the NP's seed dormancy.

Interactions of melatonin with the micro-morphological structures and physiological characteristics of lemon balm.

Melatonin (MEL) is defined as a plant master regulator. It regulates plant growth and development in various stress environments by increasing in amount. Effects of external MEL application on the content of the secretion products in micro-morphological structures of leaf trichomes of Melissa officinalis L. (lemon balm) without the presence of external stress factors were characterized. The relationships between different MEL concentrations and changes in type, density and size of trichomes, total chlorophyll and proline amounts, and secretion products were defined. Furthermore, monoterpenoids, which are the main products of trichomes that determine the quality of essential oils in lemon balm, varied under the effects of MEL. Especially 100 mM MEL concentration had the most dramatic impact. The highest number of glandular trichomes (GT) were observed at this concentration. 150 mM concentration of MEL had the opposite effect. At this concentration, significant decreases in secondary metabolite content and glandular structures were observed. Thus, it was concluded that MEL had a positive effect on these parameters up to a certain concentration. Changes in the size and number of GT due to MEL application is greatly reflected by the quality and content of secondary metabolites. Total chlorophyll, proline and monoterpene numbers were highest at 100 mM MEL concentration. The effects of MEL application without the presence of any stress conditions were supported by total chlorophyll and proline content. Important information was obtained about the relationship of these effects with the density of peltate trichomes and the chemical compounds and quality of essential oils.

Response of maize (Zea mays L. saccharata Sturt) to different concentration treatments of deltamethrin.

The aim of this study was to investigate the effect of the deltamethrin pesticide on the biological properties of maize (Zea mays L. saccharata Sturt). Maize seeds were exposed to environmentally relevant dosages (0.01, 0.05, 0.1 and 0.5 ppm) of deltamethrin. On the 7th day of germination, morphological, anatomical and physiological responses were determined. All seedling growth characters were decreased with increasing deltamethrin levels. The most negative effect on the radicle length of maize was observed by the highest deltamethrin concentration with a 61% decrease (P <0.05). Both stomatal density and stomatal dimension reduction were caused by increasing concentrations of deltamethrin. Moreover, the pigments like chlorophyll a, chlorophyll b, total chlorophyll and caretonoids decreased with the increase in deltamethrin concentration. Conversely, anthocyanin and proline content increased in parallel with deltamethrin concentration. As a result, all morphological traits and pigments except for proline and anthocyanin were significantly reduced with an increase in pesticide concentration, compared to control (P <0.05).