No abstract

Radiation mutagenesis has been used in sustainable agriculture as a tool for increasing plant variability and providing new lines for selection. This necessitates a comparison, by using suitable stress markers, of the newly created lines with some well-established varieties, which are stress tolerant or susceptible. Drought is one of the most frequently encountered stresses with deleterious effects on plant performance and crop yield. Winter wheat seedlings (soil cultures at 3–4th leaf stage) from one mutant line (M181/1338K), one drought-tolerant (Guinness) and one sensitive variety (Farmer) were subjected to severe drought stress by water withholding, followed by recovery. Changes in leaf protein profiles, the amount of Rubisco large subunit (RLS), some specific chloroplast proteins such as Rubisco binding protein (RPB), Rubisco activase (RA), the chaperone subunit clpA/C of clp protease, as well as the activities of exo- and endo-proteases were analyzed. At the protein level, some differences were found in the drought response of genotypes – stability of RLS and RBP in M181/1338K and Guinness, diminution of RLS and increase in RBP in Farmer. RA presented strong up-regulation at recovery in Guinness but decreased in content under drought in M181/1338K and Farmer. Increase in ClpA/C level was found in all compared varieties under stress. Strong increase in total proteolytic activity was detected under drought only in Farmer. Inhibitory analysis revealed a predominance of cysteine and serine protease types. Aminopeptidase activities remained higher at recovery in M181/1338K and Farmer. Results are discussed in terms of genotype-linked different stress coping strategies.

Artemisia alba Turra is an essential oil-bearing shrub, with a Euro-Mediterranean distribution widespread in the south-eastern parts of Europe. Phytochemical investigations have evidenced the presence of volatile mono- and sesquiterpene derivatives, as well as non-volatile sesquiterpenoids, flavonoids and phenolic acids contributing to the anti-inflammatory, antimicrobial, antioxidant and pro-apoptotic activity of different preparations, obtained from the plant. The current research aims at elucidation of the potential for biotechnological polyphenolic compounds productivity of non-differentiated cell lines of the plant. For this purpose, non-differentiated cell aggregates were initiated from either leaf or root explants of the sterile grown plant. They were cultivated either in the dark or at 16/8 h photoperiod in liquid media, supplemented with N6-benzyladenine (BA) as auxin. The cytokinin effects of indole-3-butyric acid (IBA) and 1-naphthalene acetic acid (NAA) were compared. It was established that NAA supplementation was superior to IBA and light treatment – to dark growth conditions in terms of polyphenolics productivity. In addition, NAA supplementation led to better expressed compaction and larger size of the cell aggregates as compared with IBA. The results of the present experiment indicate that secondary metabolites productivity in vitro is a dynamic process closely related to the plant’s growth and development and is in close relation to the interactions of the plant with its environmental conditions.