The physiological characteristics of the extremely boron (B)-tolerant plant species, Puccinellia distans, were compared with those of the moderately tolerant Gypsophila arrostil, two species collected from a B-mining area of Eskişehir, Turkey. Boron was supplied to plants hydroponically at B concentrations ranging from 0.5 to 50 mg B/L for G. arrostil, and from 0.5 to 2000 mg B/L for P. distans. The results show that P. distans has a strikingly greater tolerance to B than G. arrostil. While G. arrostil was unable to survive B supply concentrations greater than 50 mg B/L, P. distans grew at B supply concentrations exceeding 1250 mg B/L. Our research supports the conclusion that from 0.5 to 50 mg B/L, P. distans is better able to restrict the accumulation of B in the whole plant, and the transport of B from root to shoot, than G. arrostil. We propose that P. distans uses several strategies to achieve B tolerance including the ability to restrict the accumulation of B relative to its accumulation of biomass, the ability to restrict the transport of B from root to shoot, and, to a lesser extent, the ability to tolerate high concentrations of B in its shoot and root tissues.

Prolific shoot regeneration via organogenesis was induced from leaf and leaf petiole explants of the endemic Astragalus cariensis species on Murashige and Skoog (MS) medium with a-naphthaleneacetic acid (NAA) and benzyladenine (BA) within 8 week. The highest number of shoots (23/explants) was obtained from leaf explants cultured on MS with 0.5 mg/l NAA and 4 mg/l BA. Elongated shoots were successfully rooted in MS medium with 0.5 mg/l indole-3-butyric acid. Rooted plantlets were acclimatized in pots containing 1:1 mixture of peat and perlite.

The objective of this study was to obtain transgenic tobacco (Nicotiana tabacum L. cv. Samsun NN) plants resistant to tobacco mosaic virus, TMV-vulgare strain, by the expression of a single-chain variable fragment ( scFv-anti-TMV) against the TMV coat protein.The scFv-anti-TMV gene was made by combining the coding sequences of the heavy and light chain variable domains of the full antibody molecule with a sequence encoding a. flexible linker. The scFv-anti-TMV was cloned under the control of the 35S promoter in the plant expression vector pBI12I, and used for Agrobcterium-mediated transformation of tobacco. Integration of the scFv-anti-TMV gene into the genome of the transgenic plants and its expression were confirmed using PCR, immunoblot, and ELISA analysis. Transgenic plants expressing scFv-anti-TMV and untransformed control plants transformed with pBII2I only were inoculated with I f-Lg/ml TMV. Constitutive expression of this scFv-anti-TMV resulted in complete immunity against TMV infection in transgenic plants ( 100% reduction of virus infection). In contrast, control plants were heavily infected by TMV. These results confirmed the applicability of antibody expression as a means of protecting plants from virus infection.