Investigation of carbon sequestration processes of reconstructed grasslands and wetlands to aid ecosystem service-based decision making

In this paper, we analysed the effect of habitat reconstructions on some parameters characterizing the carbon exchange processes of ecosystems. Besides extending our knowledge on the ecophysiological functioning of different plant communities, our work was motivated by international policy goals as well: a considerable amount of degraded ecosystems and their services was declared in the European Union to be reconstructed in the next few years. These kinds of projects need detailed impact analyses and a methodological grounding. We would like to contribute to these goals with the results of field measurements carried out in an extensive habitat reconstruction area in the Egyek-Pusztakócs habitat complex (Hortobágy National Park, Eastern Hungary). In this paper, we analysed the results of carbon and nitrogen contents of soils and biomass samples and the average net ecosystem exchange values of the investigated ecosystem types. Our results show that natural or near-natural, well-structured grasslands have an outstanding carbon sequestration and storing potential in the studied landscape type, the restored grasslands lag behind in every parameters. In the process of secondary succession, the carbon exchange characteristics of the restored grasslands seem to follow mainly the species composition, and the effects of land management can modify the effects of regeneration from the point of view of ecophysiological functioning

ABA-overproduction response under salinity

[SPA] Con el fin de comprender la influencia de la fitohormona ácido abscísico (ABA) en la adaptación al riego salino, dos líneas transgénicas independientes de tomate (Solanum lycopersicum L.), sp12 y sp5, que sobreexpresan constitutivamente el gen NCED1 (codifica para la enzima que cataliza un paso limitante en la biosíntesis de ABA) y la variedad silvestre Ailsa Craig, se han estudiado en experimentos o bien i) como planta entera o ii) como portainjerto bajo condiciones control y de estrés salino. Aunque la expresión constitutiva de NCED disminuye el crecimiento bajo condiciones control, minimiza los efectos producidos por la sal (planta completa) y mejora significativamente el crecimiento cuando se usa como portainjerto. El análisis de la savia xilemática de raíz mostró que los fenotipos resultantes bajo las diferentes condiciones de cultivo eran difíciles de explicar en términos de sobreproducción de ABA. Para intentar explicar estos resultados se llevó a cabo un análisis de expresión de un conjunto de genes relacionados con hormonas y estrés mediante PCR cuantitativa, así como un estudio transcriptómico mediante microarrays en la raíz. Los resultados sugieren que la sobreexpresión de NCED parece alterar diversas rutas de señalización, derivando en una respuesta adaptativa al estrés que podría ayudar a explicar los fenotipos observados. [ENG] With the aim of better understanding the influence of the plan hormone abscisic acid (ABA) in adaptation to saline irrigation, two independent transgenic tomato (Solanum lycopersicum L.) lines, sp12 and sp5, overexpressing constitutively NCED1 (the enzyme that catalyzes a key rate-limiting step in ABA biosynthesis) and the wild type Ailsa Craig, have been studied in experiments either i) as whole plants or ii) as rootstocks under control and salinity conditions. While NCED overexpression penalizes growth under control conditions, it minimized the effect of salinity (whole plants) or significantly improved plant growth and yield when used as rootstocks. The analysis of the root xylem sap revealed that the phenotypes resulting under the different conditions were difficult to explain in terms of ABA overproduction. With the aim of explaining these results, the expression of a set of hormone and stress associated genes (analysed by real time PCR) as well as a transcriptomic analysis (by using one-color microarray) were performed in roots. The results suggest that NCED overexpression seems to alter several signalling pathways leading to stress adaptive responses that could help to explain the observed phenotypes.The authors thank Andrew J. Thompson from Cranfield University, the NCED seeds set. This work was supported by CICYT-FEDER (project AGL2011-27996) and European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289365(ROOTOPOWER project)

Root ABA signalling in salinized tomato

[SPA] Con el fin de comprender la influencia de la fitohormona ácido abscísico (ABA) en la adaptación al riego salino, dos líneas transgénicas independientes de tomate (Solanum lycopersicum L.), sp12 y sp5, que sobreexpresan constitutivamente el gen NCED1 (codifica para la enzima que cataliza un paso limitante en la biosíntesis de ABA) y la variedad silvestre Ailsa Craig, se han estudiado en experimentos o bien i) como planta entera o ii) como portainjerto bajo condiciones control y de estrés salino. Aunque la expresión constitutiva de NCED disminuye el crecimiento bajo condiciones control, minimiza los efectos producidos por la sal (planta completa) y mejora significativamente el crecimiento cuando se usa como portainjerto. El análisis de la savia xilemática de raíz mostró que los fenotipos resultantes bajo las diferentes condiciones de cultivo eran difíciles de explicar en términos de sobreproducción de ABA. Para intentar explicar estos resultados se llevó a cabo un análisis de expresión de un conjunto de genes relacionados con hormonas y estrés mediante PCR cuantitativa, así como un estudio transcriptómico mediante microarrays en la raíz. Los resultados sugieren que la sobreexpresión de NCED parece alterar diversas rutas de señalización, derivando en una respuesta adaptativa al estrés que podría ayudar a explicar los fenotipos observados. [ENG] With the aim of better understanding the influence of the plan hormone abscisic acid (ABA) in adaptation to saline irrigation, two independent transgenic tomato (Solanum lycopersicum L.) lines, sp12 and sp5, overexpressing constitutively NCED1 (the enzyme that catalyzes a key rate-limiting step in ABA biosynthesis) and the wild type Ailsa Craig, have been studied in experiments either i) as whole plants or ii) as rootstocks under control and salinity conditions. While NCED overexpression penalizes growth under control conditions, it minimized the effect of salinity (whole plants) or significantly improved plant growth and yield when used as rootstocks. The analysis of the root xylem sap revealed that the phenotypes resulting under the different conditions were difficult to explain in terms of ABA overproduction. With the aim of explaining these results, the expression of a set of hormone and stress associated genes (analysed by real time PCR) as well as a transcriptomic analysis (by using one-color microarray) were performed in roots. The results suggest that NCED overexpression seems to alter several signalling pathways leading to stress adaptive responses that could help to explain the observed phenotypes.The authors thank Andrew J. Thompson from Cranfield University, the NCED seeds set. This work was supported by CICYT-FEDER (project AGL2011-27996) and European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289365(ROOTOPOWER project).. -2010-5 European Union)

Resequencing

[ES] La revolución que supone la secuenciación de próxima generación está permitiendo la resecuenciación del genoma completo (WGRS) de cientos o incluso miles de ejemplares de cultivos básicos y especies modelo. Con el lanzamiento de su genoma de referencia, progresivamente se están emprendiendo proyectos WGRS también para otras especies de plantas en una amplia variedad de estudios. En berenjena común (Solanum melongena L.), aunque se ha publicado un primer borrador de la secuencia del genoma de referencia, hasta el momento no se han realizado estudios de resecuenciación. En este capítulo presentamos los primeros resultados de la resecuenciación de ocho accesiones, siete de berenjena común y una del pariente silvestre S. incanum L., que corresponden a los progenitores de un cruce multiparental de generación avanzada (MAGIC) población que se encuentra actualmente en desarrollo utilizando la secuencia del genoma de la berenjena recién desarrollada que se presenta en el Cap. 7 de este libro. Se identificaron más de diez millones de polimorfismos entre las accesiones, el 90% de ellos en el S. incanum silvestre relacionado, lo que confirma la erosión genética de la berenjena común cultivada. Entre los progenitores de la población MAGIC, el patrón de distribución de polimorfismos comunes a lo largo de los cromosomas ha revelado posibles huellas de introgresión ancestral de cruces interespecíficos. El conjunto de polimorfismos se ha anotado extensamente y actualmente se está utilizando para análisis adicionales con el fin de genotipar eficientemente la población MAGIC en curso y diseccionar rasgos agronómicos y morfológicos importantes. La información proporcionada en este primer estudio de resecuenciación en berenjena será extremadamente útil para ayudar al fitomejoramiento a desarrollar nuevas variedades mejoradas y resistentes para enfrentar futuras amenazas y desafíos.[EN] The next-generation sequencing revolution is allowing the whole-genome resequencing (WGRS) of hundreds or even thousands of accessions for staple crops and model species. With the release of their reference genome, progressively also other plants, species are undertaking WGRS projects for a broad variety of studies. In common eggplant (Solanum melongena L.), although a first draft of the reference genome sequence has been published, no resequencing studies have been performed so far. In this chapter, we present the first results of the resequencing of eight accessions, seven of common eggplant and one of the wild relative S. incanum L., that correspond to the parents of a multi-parent advanced generation inter-cross (MAGIC) population that is currently under develop- ment using the newly developed eggplant genome sequence presented in Chap. 7 of this book. Over ten million polymorphisms were identified among the accessions, 90% of them in the wild related S. incanum, confirming the genetic erosion of the cultivated common eggplant. Among the MAGIC population parents, the common polymorphism distribu- tion pattern along the chromosomes has revealed possible footprints of ancestral intro- gression from interspecific crosses. The set of polymorphisms has been extensively anno- tated and currently is being used for further analyses in order to efficiently genotype the ongoing MAGIC population and to dissect important agronomic and morphological traits. The information provided in this first resequencing study in eggplant will be extremely helpful to assist plant breeding to develop new improved and resilient varieties to face future threats and challenges.This work has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 677379 (G2P-SOL project: Linking genetic resources, genomes and phenotypes of Solanaceous crops) and from Spanish Ministerio de Economía, Industria y Competitividad and Fondo Europeo de Desarrollo Regional (grant AGL2015-64755-R from MINECO/FEDER).Prohens Tomás, J.; Vilanova Navarro, S.; Gramazio, P. (2019). Resequencing. En The Eggplant Genome. Springer. 81-89. http://hdl.handle.net/10251/181875S818

APC/C-Mediated Degradation of dsRNA-Binding Protein 4 (DRB4) Involved in RNA Silencing

Background: Selective protein degradation via the ubiquitin-26S proteasome is a major mechanism underlying DNA replication and cell division in all Eukaryotes. In particular, the APC/C (Anaphase Promoting Complex or Cyclosome) is a master ubiquitin protein ligase (E3) that targets regulatory proteins for degradation allowing sister chromatid separation and exit from mitosis. Interestingly, recent work also indicates that the APC/C remains active in differentiated animal and plant cells. However, its role in post-mitotic cells remains elusive and only a few substrates have been characterized. Methodology/Principal Findings: In order to identify novel APC/C substrates, we performed a yeast two-hybrid screen using as the bait Arabidopsis APC10/DOC1, one core subunit of the APC/C, which is required for substrate recruitment. This screen identified DRB4, a double-stranded RNA binding protein involved in the biogenesis of different classes of small RNA (sRNA). This protein interaction was further confirmed in vitro and in plant cells. Moreover, APC10 interacts with DRB4 through the second dsRNA binding motif (dsRBD2) of DRB4, which is also required for its homodimerization and binding to its Dicer partner DCL4. We further showed that DRB4 protein accumulates when the proteasome is inactivated and, most importantly, we found that DRB4 stability depends on APC/C activity. Hence, depletion of Arabidopsis APC/C activity by RNAi leads to a strong accumulation of endogenous DRB4, far beyond its normal level of accumulation. However, we could not detect any defects in sRNA production in lines where DRB4 was overexpressed

Conserved CDC20 Cell Cycle Functions Are Carried out by Two of the Five Isoforms in Arabidopsis thaliana

The CDC20 and Cdh1/CCS52 proteins are substrate determinants and activators of the Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligase and as such they control the mitotic cell cycle by targeting the degradation of various cell cycle regulators. In yeasts and animals the main CDC20 function is the destruction of securin and mitotic cyclins. Plants have multiple CDC20 gene copies whose functions have not been explored yet. In Arabidopsis thaliana there are five CDC20 isoforms and here we aimed at defining their contribution to cell cycle regulation, substrate selectivity and plant development.Studying the gene structure and phylogeny of plant CDC20s, the expression of the five AtCDC20 gene copies and their interactions with the APC/C subunit APC10, the CCS52 proteins, components of the mitotic checkpoint complex (MCC) and mitotic cyclin substrates, conserved CDC20 functions could be assigned for AtCDC20.1 and AtCDC20.2. The other three intron-less genes were silent and specific for Arabidopsis. We show that AtCDC20.1 and AtCDC20.2 are components of the MCC and interact with mitotic cyclins with unexpected specificity. AtCDC20.1 and AtCDC20.2 are expressed in meristems, organ primordia and AtCDC20.1 also in pollen grains and developing seeds. Knocking down both genes simultaneously by RNAi resulted in severe delay in plant development and male sterility. In these lines, the meristem size was reduced while the cell size and ploidy levels were unaffected indicating that the lower cell number and likely slowdown of the cell cycle are the cause of reduced plant growth.The intron-containing CDC20 gene copies provide conserved and redundant functions for cell cycle progression in plants and are required for meristem maintenance, plant growth and male gametophyte formation. The Arabidopsis-specific intron-less genes are possibly "retrogenes" and have hitherto undefined functions or are pseudogenes

A Putative Homologue of CDC20/CDH1 in the Malaria Parasite Is Essential for Male Gamete Development

Cell-cycle progression is governed by a series of essential regulatory proteins. Two major regulators are cell-division cycle protein 20 (CDC20) and its homologue, CDC20 homologue 1 (CDH1), which activate the anaphase-promoting complex/cyclosome (APC/C) in mitosis, and facilitate degradation of mitotic APC/C substrates. The malaria parasite, Plasmodium, is a haploid organism which, during its life-cycle undergoes two stages of mitosis; one associated with asexual multiplication and the other with male gametogenesis. Cell-cycle regulation and DNA replication in Plasmodium was recently shown to be dependent on the activity of a number of protein kinases. However, the function of cell division cycle proteins that are also involved in this process, such as CDC20 and CDH1 is totally unknown. Here we examine the role of a putative CDC20/CDH1 in the rodent malaria Plasmodium berghei (Pb) using reverse genetics. Phylogenetic analysis identified a single putative Plasmodium CDC20/CDH1 homologue (termed CDC20 for simplicity) suggesting that Plasmodium APC/C has only one regulator. In our genetic approach to delete the endogenous cdc20 gene of P. berghei, we demonstrate that PbCDC20 plays a vital role in male gametogenesis, but is not essential for mitosis in the asexual blood stage. Furthermore, qRT-PCR analysis in parasite lines with deletions of two kinase genes involved in male sexual development (map2 and cdpk4), showed a significant increase in cdc20 transcription in activated gametocytes. DNA replication and ultra structural analyses of cdc20 and map2 mutants showed similar blockage of nuclear division at the nuclear spindle/kinetochore stage. CDC20 was phosphorylated in asexual and sexual stages, but the level of modification was higher in activated gametocytes and ookinetes. Changes in global protein phosphorylation patterns in the Δcdc20 mutant parasites were largely different from those observed in the Δmap2 mutant. This suggests that CDC20 and MAP2 are both likely to play independent but vital roles in male gametogenesis

Ecological conditions, flora and vegetation of a large doline in the Mecsek Mountains (South Hungary)

Vegetation-environment relationships were investigated in a large doline of the Mecsek Mts (South Hungary). To reveal the vegetation pattern, we collected vegetation data and environmental variables along a 243 m long transect. Atotal of 144 vascular plant species and 4 vegetation types were identified in the doline.We found that both the species composition and the vegetation pattern are significantly influenced by air temperature, air humidity, soil moisture and altitude. Our results confirm the putative temperature and vegetation inversion in the doline