Respiratory processes in non-photosynthetic plastids

Chlororespiration is a respiratory process located in chloroplast thylakoids which consists in an electron transport chain from NAD(P)H to oxygen. This respiratory chain involves the NAD(P)H dehydrogenase complex, the plastoquinone pool and the plastid terminal oxidase (PTOX), and it probably acts as a safety valve to prevent the over-reduction of the photosynthetic machinery in stress conditions. The existence of a similar respiratory activity in non-photosynthetic plastids has been less studied. Recently, it has been reported that tomato fruit chromoplasts present an oxygen consumption activity linked to ATP synthesis. Etioplasts and amyloplasts contain several electron carriers and some subunits of the ATP synthase, so they could harbor a similar respiratory process. This review provides an update on the study about respiratory processes in chromoplasts, identifying the major gaps that need to be addressed in future research. It also reviews the proteomic data of etioplasts and amyloplasts, which suggest the presence of a respiratory electron transport chain in these plastids

Oxygen consumption and lipoxygenase activity in isolated tomato fruit chromoplasts

This Study using purified tomato fruit chromoplasts has shown significant rates of oxygen consumption even in the absence of external precursors. Oxygen consumption rates increased up to 7-fold when chromoplast samples were incubated for 24 h at room temperature. This increase in oxygen consumption is most likely due to the activation of lipoxygenase in the chromoplasts

Respiratory processes in non-photosynthetic plastids

Chlororespiration is a respiratory process located in chloroplast thylakoids which consists in an electron transport chain from NAD(P)H to oxygen. This respiratory chain involves the NAD(P)H dehydrogenase complex, the plastoquinone pool and the plastid terminal oxidase (PTOX), and it probably acts as a safety valve to prevent the over-reduction of the photosynthetic machinery in stress conditions. The existence of a similar respiratory activity in non-photosynthetic plastids has been less studied. Recently, it has been reported that tomato fruit chromoplasts present an oxygen consumption activity linked to ATP synthesis. Etioplasts and amyloplasts contain several electron carriers and some subunits of the ATP synthase, so they could harbor a similar respiratory process. This review provides an update on the study about respiratory processes in chromoplasts, identifying the major gaps that need to be addressed in future research. It also reviews the proteomic data of etioplasts and amyloplasts, which suggest the presence of a respiratory electron transport chain in these plastids

Biología I: una experiencia de aprendizaje activo para asumir competencias generales y específicas

Podeu consultar la versió catalana a recurs relacionat.[spa] En este cuaderno se describe el proceso de gestación y desarrollo de la Biología I, una asignatura de 6 ECTS que se imparte en los grados de Biología, Bioquímica, Biotecnología y Ciencias Biomédicas en la Facultad de Biología de la Universidad de Barcelona. Para impartir la Biología I se constituyó un equipo docente multidisciplinar, formado por 30 profesores de diferentes departamentos. Es importante destacar la labor de coordinación y colaboración entre todos los integrantes. Consideramos esta experiencia muy importante, ya que en ninguna asignatura había participado un número tan elevado de profesores y departamentos de la Facultad de Biología. En los distintos apartados se explican detalladamente todas las actividades que se han llevado a cabo: clases de teoría, aprendizaje basado en problemas (ABP), seminarios, prácticas de campo y visitas a diferentes centros de investigación u hospitalarios. También se presentan y se discuten los resultados obtenidos. Analizando la asignatura de Biología I, tanto desde el punto de vista de la actividad docente realizada como de los resultados obtenidos, llegamos a la conclusión de que es una experiencia de aprendizaje activo que ha permitido la adquisición con éxito tanto de competencias generales como específicas.[eng] This book describes the process of conception and development of Biology I, a course of 6 ECTS, taught in the degrees of Biology, Biochemistry, Biotechnology and Biomedical Sciences at the Faculty of Biology, University of Barcelona. To teach Biology I a multidisciplinary teaching team, comprising 30 teachers from different departments, was created. It is important to highlight the work of coordination and cooperation between all those members. We consider this experience as very important because, never before, such a large number of teachers and departments of the Faculty of Biology were involved in one single course. Through the different book sections, all the activities that took place are explained in detail: lecturers, problem based learning (PBL), seminars, field practicals and visits to research centers or hospitals. Results are also presented and discussed. Both from the standpoint of the work done and the final results, we conclude that this Biology I course proposal is an experience of active learning which allowed the successful achievement of general and specific skills by the students

Potential of local bio-geoengineering to mitigate dangerous temperature increases in a global warming scenario

Crops and forests are already responding to rising atmospheric carbon dioxide and air temperatures. Increasing atmospheric CO2 concentrations are expected to enhance plant photosynthesis. Nevertheless, after long-term exposure, plants acclimate and show a reduction in photosynthetic activity (i.e. down-regulation). If in the future the Earth"s temperature is allowed to rise further, plant ecosystems and food security will both face significant threats. The scientific community has recognized that an increase in global temperatures should remain below 2°C in order to combat climate change. All this evidence suggests that, in parallel with reductions in CO2 emissions, a more direct approach to mitigate global warming should be considered. We propose here that global warming could be partially mitigated directly through local bio-geoengineering approaches. For example, this could be done through the management of solar radiation at surface level, i.e. by increasing global albedo. Such an effect has been documented in the south-eastern part of Spain, where a significant surface air temperature trend of -0.3°C per decade has been observed due to a dramatic expansion of greenhouse horticulture

Respiratory processes in non-photosynthetic plastids

Chlororespiration is a respiratory process located in chloroplast thylakoids which consists in an electron transport chain from NAD(P)H to oxygen. This respiratory chain involves the NAD(P)H dehydrogenase complex, the plastoquinone pool and the plastid terminal oxidase (PTOX), and it probably acts as a safety valve to prevent the over-reduction of the photosynthetic machinery in stress conditions. The existence of a similar respiratory activity in non-photosynthetic plastids has been less studied. Recently, it has been reported that tomato fruit chromoplasts present an oxygen consumption activity linked to ATP synthesis. Etioplasts and amyloplasts contain several electron carriers and some subunits of the ATP synthase, so they could harbor a similar respiratory process. This review provides an update on the study about respiratory processes in chromoplasts, identifying the major gaps that need to be addressed in future research. It also reviews the proteomic data of etioplasts and amyloplasts, which suggest the presence of a respiratory electron transport chain in these plastids.Work from our group was supported by grants of the Spanish Ministerio de Ciencia e Innovación (BIO2009-09523) and Ministerio de Economía y Competitividad (AGL2013-43522-R) and the Generalitat de Catalunya (2014SGR-1434). MR received a predoctoral fellowship FPU from the Spanish Ministerio de Educación.Peer reviewedPeer Reviewe