Agrobacterium rhizogenes rolB gene affects photosynthesis and chlorophyll content in transgenic tomato (Solanum lycopersicum L.) plants.

Insertion of Agrobacterium rhizogenes rolB gene into plant genome affects plant development, hormone balance and defence. However, beside the current research, the overall transcriptional response and gene expression of rolB as a modulator in plant is unknown. Transformed rolB tomato plant (Solanum lycopersicum L.) cultivar Tondino has been used to investigate the differential expression profile. Tomato is a well-known model organism both at the genetic and molecular level, and one of the most important commercial food crops in the world. Through the construction and characterization of a cDNA subtracted library, we have investigated the differential gene expression between transgenic clones of rolB and control tomato and have evaluated genes specifically transcribed in transgenic rolB plants. Among the selected genes, five genes encoding for chlorophyll a/b binding protein, carbonic anhydrase, cytochrome b6/f complex Fe-S subunit, potassium efflux antiporter 3, and chloroplast small heat-shock protein, all involved in chloroplast function, were identified. Measurement of photosynthesis efficiency by the level of three different photosynthetic parameters (Fv/Fm, rETR, NPQ) showed rolB significant increase in non-photochemical quenching and a, b chlorophyll content. Our results point to highlight the role of rolB on plant fitness by improving photosynthesis.

Chill sensitivity and cryopreservation of eggs of the greater wax moth Galleria mellonella (Lepidoptera: Pyralidae).

There is an increasing need for methods of cryopreservation of arthropods. In particular, Lepidoptera are extremely important in entomological applications for the protection of agricultural crops and forest ecosystems and also in many aspects of biodiversity conservation. Yet, few studies have dealt with cryopreservation techniques in species of this insect order. The aim of this study was to examine the chill sensitivity of eggs of the greater wax moth Galleria mellonella (L.) and the possibility to cryopreserve the eggs by vitrification methods. One day-old eggs were dechlorinated with water solutions of 1.25% sodium hypochlorite and 0.04% Tween 80, treated with cryoprotective agents in two steps, subjected to rapid cooling by immersion in LN and stored in a mechanical freezer for 48 h at -140 degrees C. They exhibited survival rates of 1.6+/-0.5% after being cooled in LN and 0.6+/-0.2% after being stored in the mechanical freezer. 92.9% of the larvae that hatched from cryopreserved eggs completed development regularly, producing adults that bred and laid fertile eggs. The hatching rate of eggs in the F1 and F2 generations was higher than 90%. Adult emergences of the progeny of eggs stored at ultra-low temperatures allowed us to establish a laboratory colony.

Phenols and antioxidative status of Raphanus sativus grown in copper excess.

Raphanus sativus L. cv. Rimbo was grown for 10 days after emergence in hydroponic culture containing 0.12 (control), 5, 10 and 15 micro M copper. The seeds were germinated in the presence of the copper solution. The Cu contents increased with the treatment in both shoots and roots, maintaining in the roots a value eight- to ten-fold higher than in the shoots. With the treatment both shoots and roots underwent growth inhibition and an increase in the percentage of dry weight. Membrane damage and lipid peroxidation increased and glutathione was oxidized as the copper concentration increased, indicating an acceleration of oxidative processes. Control shoots had high contents of reduced glutathione and low contents of phytochelatin-SH whereas roots showed an opposite pattern, suggesting an utilization of reduced glutathione for phytochelatin synthesis. In both parts phytochelatin-SH content reached the maximum at 5 micro M copper and then decreased, reaching at 15 micro M copper the control value in the roots and a value five-fold higher than the control value in the shoots. The main phenolic acids represented in R. sativus were chlorogenic, vanillic, caffeic, siringic, p-coumaric and ferulic acids whereas the least represented were gallic, protocatechuic and p-hydroxybenzoic acids. The phenolic acids as well as the total and reduced ascorbate contents increased with the intensification of copper treatment. Notwithstanding these changes, total ascorbate remained 35% higher in the shoots than in the roots. The reduced ascorbate was thus able to replenish reducing equivalents to phenoxyl radicals thus explaining the increase in the phenolic compounds.