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.

Outsourcing and strategy in Spanish town halls: a field study

Purpose – This study seeks to analyse the links between strategies, structures and processes in the case of the largest Spanish town halls, using the Miles and Snow's models about organisational strategies, and asking the following questions: “What is the situation of municipal services' outsourcing in the largest Spanish town halls?”; “Do Spanish town halls follow the strategies suggested in Miles and Snow's model?”; and “Is there a relationship between the strategic position adopted by town halls and their stance on outsourcing?”. Design/methodology/approach – In order to achieve these aims a questionnaire was administered to the human resource managers in the town halls of the largest Spanish cities. Findings – The paper finds that outsourcing is a complement, which seeks to improve the services delivered, and local institutions do not resort to it due to a lack of internal resources but as a way to complement their own capabilities. Originality/value – The paper has identified three distinct strategic profiles in the town halls interviewed which coincide with the profiles that Miles and Snow call prospective, defensive and reactive strategies. It reveals that town halls which outsource to a greater extent are the ones which identify more with the prospective or reactive strategy, whereas those which outsource less are closer to the defensive strategy.