Effects of surface sterilisation with green synthesised silver nanoparticles on Lamiaceae seeds.

Nanoparticles have been used in many areas of biotechnology. In this study, an alternative surface sterilisation method was established for plant tissue cultures. Silver nanoparticles synthesised via green synthesis were used for the surface sterilisation of Lamiaceae seeds (Salvia farinecae, Ocimum basilicum - Large Leaf Italian, Thymus vulgaris, Ocimum basilicum var. purpurascens). Water extracts of dried Alkanna tinctorum rhizomes and Syzygium aromaticum flowers were utilised in the bioreduction of silver ions. The seeds were exposed to 0, 1, 7, 14 and 28 day-old colloidal solutions of silver nanoparticles and their effects on germination and surface sterilisation were determined. Fresh (0 and 1 day-old) colloidal solutions of silver nanoparticles were found very effective on surface sterilisation (100%). Moreover, they showed no negative effect on both germination and morphology of plantlets. It was shown that silver nanoparticles can be used as a surface sterilisation agent and they have no adverse effects on seed germination and in vitro plantlet growth.

Immobilization of Rubia tinctorum L. Suspension Cultures and Biomass Production.

Plants are natural sources of valuable secondary metabolites used as pharmaceuticals, agrochemicals, flavors, fragrances, colors, biopesticides, and food additives. There is an increasing demand to obtain these metabolites through more productive plant tissue applications and cell culture methods due to the importance of secondary metabolites.Immobilization of plant cells is a method used in plant cell cultures to induce secondary metabolite production. In this method, plant cells are fixed in or on a supporting material or matrix such as agar, agarose, calcium alginate, glass, or polyurethane foam. In the present study, three natural lignocellulosic materials, loofah sponge, and the long fibers of sisal and jute, were used to immobilize suspended R. tinctorum cells.

Determination of phenolic content and antioxidant activity of extracts obtained from Rosmarinus officinalis' calli.

Rosmarinus officinalis is widely found in the lands of Aegean and Mediterranean regions of Turkey. Stem explants of very young shoots were cultured in both woody plant medium (WPM) and Murashige and Skoog (MS) media supplemented with 7g/L agar, 30g/L sucrose, and 1 and 3mg/L naphthaleneacetic acid (NAA) for callus initiation. Induced calli were subcultured 4 times with intervals of 7-10 days. MS medium supplemented with 1mg/L NAA proved to be the best medium for the production of callus (65.0%) among the samples tested. The lyophilized calli were subjected to solvent extraction. Active constituents of 8 calli extracts were analyzed by HPLC, and rosmarinic acid (RA) was determined to be the primary compound. Calli cultivated in WPM supplemented with 1mg/L NAA and extracted at 50 degrees C, yielded the highest amount of RA (34.4mg/g dry weight). Moreover, antioxidant activity of calli extracts was determined using a number of in vitro assays, including total phenol assay, DPPH radical scavenging activity (RSA), and trolox equivalent antioxidant capacity (TEAC). On the basis of the current findings, we conclude that WPM supplemented with 1mg/L NAA yields higher phenolic content as well as higher antioxidant activity.