Transfer of Anthocyanin Accumulating Delila and Rosea1 Genes from the Transgenic Tomato Micro-Tom Cultivar to Moneymaker Cultivar by Conventional Breeding.

Delila and Rosea1 anthocyanin accumulation genes were subjected to bioinformatics analysis. Delila protein has 56-69% similarity with different anthocyanin-rich plants, while Rosea1 protein has 83-87% with anthocyanin-rich plant proteins. This study aimed at transferring Delila and Rosea1 genes from the transgenic Micro-tom tomato cultivar to the Moneymaker tomato cultivar using traditional breeding for enhancing their fruit anthocyanin content. Results of all produced F1 plants of manual hybridization between both cultivars were consistent with the Mendelian inheritance hypothesis. Plants of F2 populations showed a 3:1 Mendelian segregation proportion (75% of plants have anthocyanin pigmentation). Seeds of F2 were individually cultured to get four homozygous lines with anthocyanin accumulation in fruits. The total anthocyanin in the anthocyanin-enriched inbred fruit (3 g/kg DM) represented a relative increase of about 131% of the parent level. The total phenolic compounds in inbred tomato fruits were 54.9 mg/100 g DM referring to a relative increase of about 51% of the respective parent plant. The antioxidant activity of inbred fruit at maturity (m) was 83.5% compared with 91% for TBHQ. The inbred (m) tomato fruit extract reduced the growth of G- bacteria G+ bacteria by 99% and 95%, respectively.

New insights into plant salt acclimation: the roles of vesicle trafficking and reactive oxygen species signalling in mitochondria and the endomembrane system.

In this study, we investigated the cellular and molecular mechanisms that regulate salt acclimation. The main objective was to obtain new insights into the molecular mechanisms that control salt acclimation. Therefore, we carried out a multidisciplinary study using proteomic, transcriptomic, subcellular and physiological techniques. We obtained a Nicotiana tabacum BY-2 cell line acclimated to be grown at 258 mM NaCl as a model for this study. The proteomic and transcriptomic data indicate that the molecular response to stress (chaperones, defence proteins, etc.) is highly induced in these salt-acclimated cells. The subcellular results show that salt induces sodium compartmentalization in the cell vacuoles and seems to be mediated by vesicle trafficking in tobacco salt-acclimated cells. Our results demonstrate that abscisic acid (ABA) and proline metabolism are crucial in the cellular signalling of salt acclimation, probably regulating reactive oxygen species (ROS) production in the mitochondria. ROS may act as a retrograde signal, regulating the cell response. The network of endoplasmic reticulum and Golgi apparatus is highly altered in salt-acclimated cells. The molecular and subcellular analysis suggests that the unfolded protein response is induced in salt-acclimated cells. Finally, we propose that this mechanism may mediate cell death in salt-acclimated cells.

Intrinsic water use efficiency controls the adaptation to high salinity in a semi-arid adapted plant, henna (Lawsonia inermis L.).

Adaptation to salinity of a semi-arid inhabitant plant, henna, is studied. The salt tolerance mechanisms are evaluated in the belief that gas exchange (water vapor and CO2) should play a key role on its adaptation to salt stress because of the strong evaporation conditions and soil water deficit in its natural area of distribution. We grow henna plants hydroponically under controlled climate conditions and expose them to control (0mM NaCl), and two levels of salinity; medium (75mM NaCl) and high (150mM NaCl). Relative growth rate (RGR), biomass production, whole plant and leaf structure and ultrastructure adaptation, gas exchange, chlorophyll fluorescence, nutrients location in leaf tissue and its balance in the plant are studied. RGR and total biomass decreased as NaCl concentration increased in the nutrient solution. At 75mM NaCl root biomass was not affected by salinity and RGR reached similar values to control plants at the end of the experiment. At this salinity level henna plant responded to salinity decreasing shoot to root ratio, increasing leaf specific mass (LSM) and intrinsic water use efficiency (iWUE), and accumulating high concentrations of Na(+) and Cl(-) in leaves and root. At 150mM NaCl growth was severely reduced but plants reached the reproductive phase. At this salinity level, no further decrease in shoot to root ratio or increase in LSM was observed, but plants increased iWUE, maintaining water status and leaf and root Na(+) and Cl(-) concentrations were lower than expected. Moreover, plants at 150mM NaCl reallocated carbon to the root at the expense of the shoot. The effective PSII quantum yield [Y(II)] and the quantum yield of non-regulated energy dissipation [Y(NO)] were recovered over time of exposure to salinity. Overall, iWUE seems to be determinant in the adaptation of henna plant to high salinity level, when morphological adaptation fails.