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Down scaling of climate change scenarii to river basin level : A transdisciplinary methodology applied to Evrotas river basin, Greece
Ker Rault, Philippe A. ; Koundouri, Phoebe ; Akinsete, Ebun ; Ludwig, Ralf ; Huber-Garcia, Verena ; Tsani, Stella ; Acuna, Vicenc ; Kalogianni, Eleni ; Luttik, Joke ; Kok, Kasper ; Skoulikidis, Nikolaos ; Froebrick, Jochen - \ 2019
Science of the Total Environment 660 (2019). - ISSN 0048-9697 - p. 1623 - 1632.
Climate-change - Ecosystem-services - Land-use - Transdisciplinary - Water management
The Mediterranean region is anticipated to be (or, already is) one of the hot spots for climate change, where freshwater ecosystems are under threat from the effects of multiple stressors. Climate change is impacting natural resources and on the functioning of Ecosystem Services. The challenges about modelling climate change impact on water cycle in general and specifically on socio-economic dynamics of the society leads to an exponential amount of results that restrain interpretation and added value of forecasting at local level. One of the main challenges when dealing with climate change projections is the quantification of uncertainties. Modellers might have limited information or understanding from local river catchment management practices and from other disciplines with relevant insights on socio-economic and environmental complex relationship between biosphere and human based activities. Current General Circulation Models cannot fulfil the requirements of high spatial detail required for water management policy. This article reports an innovative transdisciplinary methodology to down scale Climate Change scenarii to river basin level with a special focus on the development of climate change narrative under SSP5-RCP8.5 combination called Myopic scenario and SSP1-RCP4.5 combination called Sustainable scenario. Local Stakeholder participative workshop in the Evrotas river basin provide perception of expected changes on water demand under to two developed scenario narratives.
An ecosystem services approach to pesticide risk assessment and risk management of non-target terrestrial plants: recommendations from a 1st SETAC Europe workshop
Arts, G.H.P. ; Dollinger, M. ; Kohlschmid, Eva ; Maltby, Lorraine ; Ochoa-Acuna, H. ; Poulsen, V. - \ 2017
Brussels : SETAC - 55 p.
Ecosystem services approach to pesticide risk assessment and management of nontarget terrestrial plants: updated summary and recommendations from SETAC Europe workshop
Arts, G.H.P. ; Maltby, L. ; Dollinger, M. ; Kohlschmid, E. ; Mayer, C. ; Meregalli, G. ; Ochoa-Acuna, H. ; Poulsen, V. ; Streissl, F. - \ 2017
The Histone Deacetylase Inhibitor Trichostatin A Promotes Totipotency in Cultured Pollen
Li, H. ; Soriano, M. ; Cordewener, J.H.G. ; Muino Acuna, J.M. ; Fukuoka, H. ; Angenent, G.C. ; Boutilier, K.A. - \ 2016
Brassica rapa - Brassica napus - GSE49070 - PRJNA212907
The haploid multicellular male gametophyte of plants, the pollen grain, is a terminally differentiated structure whose function ends at fertilization. Unlike pollen grains, the immature gametophyte retains its capacity for totipotent growth when cultured in vitro. Haploid embryo production from cultured immature male gametophytes is a widely used plant breeding and propagation technique that was described nearly 50 years ago, but one that is poorly understood at the mechanistic level. Using a chemical approach, we show that the switch to haploid embryogenesis is controlled by the activity of histone deacetylases (HDACs). Blocking HDAC activity with trichostatin A (TSA) in cultured immature male gametophytes of Brassica napus leads to a large increase in the proportion of cells that switch from pollen to embryogenic growth. Embryogenic growth is enhanced by, but not dependent on, the high temperature stress that is normally used to induce haploid embryogenesis in B. napus. The immature male gametophyte of Arabidopsis thaliana, which is recalcitrant for haploid embryo development in culture, also forms embryogenic cell clusters after TSA treatment. TSA treatment of immature male gametophytes for as little as eight hours was accompanied by hyperacetylation of histones H3 and H4, and by the upregulation of genes involved in cell-cycle progression, the auxin pathway and cell wall catabolism pathways. We propose that the totipotency of the immature male gametophyte in planta is kept in check by an HDAC-dependent mechanism, and that high temperature or other stresses used to induce haploid embryo development in culture impinge on this HDAC-dependent pathway.
How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products
Hommen, U. ; Schmitt, W. ; Heine, S. ; Brock, T.C.M. ; Duquesne, S. ; Manson, P. ; Meregali, G. ; Ochoa-Acuna, H. ; Vliet, P. van; Arts, G.H.P. - \ 2016
Integrated Environmental Assessment and Management 12 (2016)1. - ISSN 1551-3793 - p. 82 - 95.
This case study of the SETAC workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard EU risk assessment for an example herbicide based on macrophyte laboratory tests indicated risks for several exposure scenarios. Three of these scenarios are further analysed using effect models for two aquatic macrophytes, the free-floating standard test species Lemna sp. and the sediment-rooted submerged additional standard test species Myriophyllum spicatum. Both models include a toxicokinetic (TK) part, describing uptake and elimination of the toxicant, a toxicodynamic (TD) part, describing the internal concentration-response function for growth inhibition, and a description of biomass growth as a function of environmental factors to allow simulating seasonal dynamics. The TK-TD models are calibrated and tested using laboratory tests whereas the growth models were assumed to be fit for purpose based on comparisons of predictions with typical growth patterns observed in the field. For the risk assessment, biomass dynamics are predicted for the control situation and for several exposure levels. Based on specific protection goals for macrophytes, preliminary example decision criteria are suggested for evaluating the model outputs. The models refined the risk indicated by lower tier testing for two exposure scenarios, whilst confirmed the risk associated for the third. Uncertainties related to the experimental and the modelling approaches and their application in the risk assessment are discussed. Based on this case study and the assumption that the models prove suitable for risk assessment once fully evaluated, we recommend that i) ecological scenarios be developed that are also linked to the exposure scenarios and ii) quantitative protection goals be set to facilitate the interpretation of model results for risk assessment.
|An ecosystem services approach to pesticide risk assessment and risk management of non-target terrestrial plants: recommendations from a SETAC Europe workshop
Maltby, L. ; Arts, G.H.P. ; Dollinger, M. ; Kohlschmid, Eva ; Ochoa-Acuna, H. ; Poulsen, V. - \ 2015
In: SETAC Europe 25th Annual Meeting Abstract Book. - SETAC - p. 478 - 479.
The registration of Plant Protection Products (PPPs) in the EU is under Regulation 1107/2009, which recommends a tiered approach to assessing the risk to non-target terrestrial plants (NTTPs). However, little information is provided on how to perform and implement higher tier studies or how to use them to refine the risk assessments. Therefore a stakeholder workshop was organized to consolidate current knowledge and expertise to aid the further development of testing and assessment procedures for NTTPs. The agreed recommendations of the workshop relate to the three main themes, i.e. specific protection goals, risk assessment and mitigation. The participants of the workshop adopted the European Food Safety Authority (EFSA) approach of using an ecosystem services framework for identifying specific protection goals. First, delivery and protection of ecosystem services were discussed for in-crop, in-field ànd off-crop, and off-field areas. Second, lower and higher tier risk assessment methods, including modelling approaches, were evaluated. Third, options for risk mitigation of spray drift and run-off were discussed and evaluated. NTTPs provide a wide range of provisioning, regulating, cultural and supporting ecosystem services and may occur in-crop, off-crop/in-field and off-field. The workshop participants agreed that the type and relative importance of ecosystem services provided by NTTPs differ between different areas both in field and off field. A number of higher-tier options were identified and the benefits from these options addressed. A number of concerns were raised around these options and actions taken in order to reduce uncertainty. For the initial tiers, concern was especially raised around uncertainty related to test species (are standard test species protective for wild species?) and endpoints (are current regulatory endpoints protective of reproductive endpoints ?). At the level of field- or other multispecies-studies, participants concluded that these studies pose a challenge due to limited experience with this type of study and the absence of guidelines (what to measure and how ?). Related to exposure, the main question was what is the relative importance of different exposure pathways to non-target terrestrial plants ? These questions were translated into specific actions including collating and reviewing data and literature. The workshop report is foreseen for the first months of 2015 and will include the outcome of the specific actions.
An ecosystem services approach to pesticide risk assessment and risk management of non-target terrestrial plants: recommendations from a SETAC Europe workshop
Maltby, L. ; Arts, G.H.P. ; Dollinger, M. ; Kohlschmid, Eva ; Ochoa-Acuna, H. ; Poulsen, V. - \ 2015
Chemical and microbiological interactions between soils and roots in commercial banana plantations (Musa AAA, cv. Cavendish)
Segura Mena, R. ; Serrano, E. ; Pocasangre, L. ; Acuna, O. ; Bertsch, F. ; Stoorvogel, J.J. ; Sandoval, J.A. - \ 2015
Scientia Horticulturae 197 (2015). - ISSN 0304-4238 - p. 66 - 71.
A study was performed to determine the relationships between soil chemical and microbiological con-ditions and how they impact soil production. The study was carried out on six Costa Rican commercialbanana farms with high, medium and low productivity. In each of the farms sector with relatively goodand poor crop development were identified. In these sectors, microbiological and chemical properties ofthe soil and banana roots were characterized in the fertilization band, the interrow, and the rhizosphere. Inaddition, crop performance was evaluated in terms of plant height, the vigour of the pseudostem, and thenumber of hands per bunch. Higher biometric values were found in the sectors with good development,regardless of the farm, than in those with poor plant development. The pH was significantly lower in thesectors with poor crop performance in both the fertilization band and the rhizosphere. The soil chemicaland microbiological properties differed significantly between the good and poor performing areas, butalso between the fertilization band, interrow, and rhizosphere. Bacteria, fungi and actinomycetes wereless in roots from plants in the sectors with poor performance. Chemical and microbiological conditionsin the soil influenced the roots conditions according with the banana plant development and production.This study shows the complex interactions between soil chemical and microbiological conditions andhow they affect banana production.
AIL and HDG proteins act antagonistically to control cell proliferation
Horstman, A. ; Fukuoka, H. ; Muino Acuna, J.M. ; Nitsch, L.M.C. ; Guo, Changhao ; Passarinho, P.A. ; Sanchez Perez, G.F. ; Immink, R.G.H. ; Angenent, G.C. ; Boutilier, K.A. - \ 2015
Development 142 (2015). - ISSN 0950-1991 - p. 454 - 464.
arabidopsis-thaliana - transcription factors - plant transformation - ectopic expression - quantitative pcr - chip-seq - differentiation - genes - plethora - growth
AINTEGUMENTA-LIKE (AIL) transcription factors are key regulators of cell proliferation and meristem identity. Although AIL functions have been well described, the direct signalling components of this pathway are largely unknown.We show that BABY BOOM(BBM) and other AIL proteins physically interact with multiple members of the L1-expressed HOMEODOMAIN GLABROUS (HDG) transcription factor family, including HDG1, HDG11 and HDG12. Overexpression of HDG1, HDG11 and HDG12 restricts growth due to root and shoot meristem arrest, which is associated with reduced expression of genes involved in meristem development and cell proliferation pathways, whereas downregulation of multiple HDG genes promotes cell overproliferation. These results suggest a role for HDG proteins in promoting cell differentiation. We also reveal a transcriptional network in which BBM andHDG1regulate several common target genes, and whereBBM/AIL and HDG regulate the expression of each other. Taken together, these results suggest opposite roles for AIL and HDG proteins, with AILs promoting cell proliferation and HDGs stimulating cell differentiation, and that these functions are mediated at both the protein-protein interaction and transcriptional level.
An ecosystem services approach to pesticide risk assessment and risk management of non-target terrestrial plant: recommendations from a SETAC Europe workshop
Arts, G.H.P. ; Dollinger, M. ; Kohlschmid, E. ; Maltby, L. ; Ochoa-Acuna, H. ; Poulsen, V. - \ 2015
Environmental Science and Pollution Research 22 (2015)3. - ISSN 0944-1344 - p. 2350 - 2355.
The registration of plant protection products (PPPs) in the EU is under Regulation 1107/2009, which recommends a tiered approach to assessing the risk to non-target terrestrial plants (NTTPs). However, little information is provided on how to perform and implement higher tier studies or how to use them to refine the risk assessments. Therefore, a stakeholder workshop was organized to consolidate current knowledge and expertise to aid the further development of testing and assessment procedures for NTTPs. This brief communication highlights the agreed recommendations of the workshop, which relate to the three main themes, i.e. specific protection goals, risk assessment and mitigation. The participants of the workshop adopted the European Food Safety Authority (EFSA) approach of using an ecosystem services framework for identifying specific protection goals. First, delivery and protection of ecosystem services were discussed for in-crop, in-field and off-crop, and off-field areas. Second, lower and higher tier risk assessment methods, including modelling approaches, were evaluated. Third, options for risk mitigation of spray drift and run-off were discussed and evaluated. Several important knowledge gaps were identified, and specific data collation and literature-based tasks were actioned to begin to address them. A full workshop report is planned for the fall of 2014.
Managing the effects of multiple stressors on aquatic ecosystems under water scarcity
Navarro-Ortega, A. ; Acuña, V. ; Bellin, A. ; Burek, P. ; Cassiani, G. ; Choukr-Allah, R. ; Dolédec, S. ; Elosegi, A. ; Ferrari, F. ; Ginebreda, A. ; Grathwohl, P. ; Jones, C. ; Ker Rault, P.A. ; Kok, K. ; Koundouri, P. ; Ludwig, R.P. ; Merz, R. ; Milacic, R. - \ 2015
Science of the Total Environment 503-504 (2015). - ISSN 0048-9697 - p. 3 - 9.
climate-change - fresh-water - mediterranean rivers - southern europe - management - scenarios - quality - systems
Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA.
ChIP-Seq of Arabidopsis wildtype inflorescences using an antibody raised against a C-terminal peptide of SEP3
Muino Acuna, J.M. - \ 2014
GSE30616 - Arabidopsis thaliana - PRJNA144527 - E-MTAB-587
WARNING: This library was yield low amount of material and it was over-amplified by PCR. This libraries are used study the robustness of several statitical methods against PCR artifacts. ChIP experiments were performed on Arabidopsis wildtype inflorescences using an antibody raised against a C-terminal peptide of SEP3.
BABY BOOM (BBM) ChIP-seq in Arabidopsis somatic embryo tissue
Horstman, A. ; Muino Acuna, J.M. ; Boutilier, K.A. - \ 2014
Arabidopsis thaliana - GSE52400 - PRJNA227780
After fertilization, a plant's life relies on progression through embryogenesis and maintenance of the stem cell niches from which all post-embryonic organs arise. BABY BOOM (BBM) and other members of the AINTEGUMENTA-LIKE (AIL)/PLETHORA (PLT) clade of the AP2-type transcription factor family play important roles controlling these processes in Arabidopsis thaliana (Arabidopsis). Development of the plt2/bbm double mutant is blocked at during early embryogenesis (Galinha et al., 2007), and combinations of bbm with plt1 and plt3 lead to short roots as a result of meristem differentiation. In contrast, overexpression of BBM in Arabidopsis seedlings induces the formation of somatic embryos on cotyledons and leaves (Boutilier, 2002), showing that BBM is a key regulator of cell identity and proliferation. Although the functions of BBM and other AIL genes have been well described, the molecular mode of action of these transcription factors has not been well examined (reviewed in Horstman et al., 2013). Our previous study provided the first insight into BBM molecular function by identifying BBM targets through a microarray-based approach (Passarinho, 2008), but only a few BBM targets have been functionally characterized. To obtain a better understanding of BBM function, we identified direct BBM targets using a chromatin immunoprecipitation (ChIP) combined with massively-parallel DNA sequencing (ChIP-seq) approach.
The Histone Deacetylase Inhibitor Trichostatin A Promotes Totipotency in the Male Gametophyte
Li, H. ; Soriano, M. ; Cordewener, J.H.G. ; Muino Acuna, J.M. ; Riksen-Bruinsma, T. ; Fukuoka, H. ; Angenent, G.C. ; Boutilier, K.A. - \ 2014
The Plant Cell 26 (2014)1. - ISSN 1040-4651 - p. 195 - 209.
brassica-napus l - polycomb-group proteins - plant-cell cycle - somatic embryogenesis - arabidopsis-thaliana - embryo development - retinoblastoma protein - in-vitro - microspore embryogenesis - pollen embryogenesis
The haploid male gametophyte, the pollen grain, is a terminally differentiated structure whose function ends at fertilization. Plant breeding and propagation widely use haploid embryo production from in vitro–cultured male gametophytes, but this technique remains poorly understood at the mechanistic level. Here, we show that histone deacetylases (HDACs) regulate the switch to haploid embryogenesis. Blocking HDAC activity with trichostatin A (TSA) in cultured male gametophytes of Brassica napus leads to a large increase in the proportion of cells that switch from pollen to embryogenic growth. Embryogenic growth is enhanced by, but not dependent on, the high-temperature stress that is normally used to induce haploid embryogenesis in B. napus. The male gametophyte of Arabidopsis thaliana, which is recalcitrant to haploid embryo development in culture, also forms embryogenic cell clusters after TSA treatment. Genetic analysis suggests that the HDAC protein HDA17 plays a role in this process. TSA treatment of male gametophytes is associated with the hyperacetylation of histones H3 and H4. We propose that the totipotency of the male gametophyte is kept in check by an HDAC-dependent mechanism and that the stress treatments used to induce haploid embryo development in culture impinge on this HDAC-dependent pathway.
Structural determinants of DNA recognition by plant MADS-domain transcription factors
Muino Acuna, J.M. ; Smaczniak, C. ; Angenent, G.C. ; Kaufmann, K. ; Dijk, A.D.J. van - \ 2014
Nucleic acids research 42 (2014)4. - ISSN 0305-1048 - p. 2138 - 2146.
in-vitro - binding properties - flower development - antirrhinum-majus - homeotic proteins - crystal-structure - ternary complex - floral organs - box proteins - chip-chip
Plant MADS-domain transcription factors act as key regulators of many developmental processes. Despite the wealth of information that exists about these factors, the mechanisms by which they recognize their cognate DNA-binding site, called CArG-box (consensus CCW6GG), and how different MADS-domain proteins achieve DNA-binding specificity, are still largely unknown. We used information from in vivo ChIP-seq experiments, in vitro DNA-binding data and evolutionary conservation to address these important questions. We found that structural characteristics of the DNA play an important role in the DNA binding of plant MADS-domain proteins. The central region of the CArG-box largely resembles a structural motif called ‘A-tract’, which is characterized by a narrow minor groove and may assist bending of the DNA by MADS-domain proteins. Periodically spaced A-tracts outside the CArG-box suggest additional roles for this structure in the process of DNA binding of these transcription factors. Structural characteristics of the CArG-box not only play an important role in DNA-binding site recognition of MADS-domain proteins, but also partly explain differences in DNA-binding specificity of different members of this transcription factor family and their heteromeric complexes.
Balancing of Histone H3K4 Methylation States by the Kdm5c/SMCX Histone Demethylase Modulates Promoter and Enhancer Function
Outchkourov, N.S. ; Muino Acuna, J.M. ; Kaufmann, K. ; IJken, W.F.J. ; Groot Koerkamp, M.J. ; Leenen, D. van; Graaf, P. de; Holstege, F.C.P. ; Grosveld, F. ; Timmers, H.T.M. - \ 2013
Cell Reports 3 (2013)4. - ISSN 2211-1247 - p. 1071 - 1079.
little-imaginal-discs - embryonic stem-cells - binding-protein 2 - gene-expression - distinct functions - self-renewal - human genome - transcription - differentiation - reveals
The functional organization of eukaryotic genomes correlates with specific patterns of histone methylations. Regulatory regions in genomes such as enhancers and promoters differ in their extent of methylation of histone H3 at lysine-4 (H3K4), but it is largely unknown how the different methylation states are specified and controlled. Here, we show that the Kdm5c/Jarid1c/SMCX member of the Kdm5 family of H3K4 demethylases can be recruited to both enhancer and promoter elements in mouse embryonic stem cells and in neuronal progenitor cells. Knockdown of Kdm5c deregulates transcription via local increases in H3K4me3. Our data indicate that by restricting H3K4me3 modification at core promoters, Kdm5c dampens transcription, but at enhancers Kdm5c stimulates their activity. Remarkably, an impaired enhancer function activates the intrinsic promoter activity of Kdm5c-bound distal elements. Our results demonstrate that the Kdm5c demethylase plays a crucial and dynamic role in the functional discrimination between enhancers and core promoters
Good practice guidelines for biomass production studies, COST Action FP-0902, WG 2 Operations research and measurement methodologies
Magagnotti, N. ; Spinelli, R. ; Acuna, M. ; Bigot, M. ; Guerra, S. ; Hartsough, B. ; Kanzian, C. ; Kärhä, K. ; Lindroos, O. ; Roux, S. ; Talbot, B. ; Tolosana, E. ; Zormaier, F. - \ 2012
Fiorentino (FI), ITALY : CNR IVALSA - ISBN 9788890166044 - 52 p.
Arabidopsis Class I and Class II TCP Transcription Factors Regulate Jasmonic Acid Metabolism and Leaf Development Antagonistically.
Danisman, Selahattin ; Wal, F. van der; Dhondt, S. ; Waites, R. ; Folter, S. de; Bimbo, A. ; Dijk, A.D.J. van; Muino Acuna, Jose ; Cutri, L. ; Dornelas, M.C. ; Angenent, G.C. ; Immink, R.G.H. - \ 2012
Plant Physiology 159 (2012)4. - ISSN 0032-0889 - p. 1511 - 1523.
genome-wide identification - methyl jasmonate - gene-expression - target genes - chromatin immunoprecipitation - cell-division - plant-growth - dna-binding - thaliana - protein
TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR1 (TCP) transcription factors control developmental processes in plants. The 24 TCP transcription factors encoded in the Arabidopsis (Arabidopsis thaliana) genome are divided into two classes, class I and class II TCPs, which are proposed to act antagonistically. We performed a detailed phenotypic analysis of the class I tcp20 mutant, showing an increase in leaf pavement cell sizes in 10-d-old seedlings. Subsequently, a glucocorticoid receptor induction assay was performed, aiming to identify potential target genes of the TCP20 protein during leaf development. The LIPOXYGENASE2 (LOX2) and class I TCP9 genes were identified as TCP20 targets, and binding of TCP20 to their regulatory sequences could be confirmed by chromatin immunoprecipitation analyses. LOX2 encodes for a jasmonate biosynthesis gene, which is also targeted by class II TCP proteins that are under the control of the microRNA JAGGED AND WAVY (JAW), although in an antagonistic manner. Mutation of TCP9, the second identified TCP20 target, resulted in increased pavement cell sizes during early leaf developmental stages. Analysis of senescence in the single tcp9 and tcp20 mutants and the tcp9tcp20 double mutants showed an earlier onset of this process in comparison with wild-type control plants in the double mutant only. Both the cell size and senescence phenotypes are opposite to the known class II TCP mutant phenotype in JAW plants. Altogether, these results point to an antagonistic function of class I and class II TCP proteins in the control of leaf development via the jasmonate signaling pathway.
Direct target gene analyses for TCP20 using a glucocorticoid inducible TCP20 (TCP20-GR)
Danisman, S.D. ; Wal, F. van der; Folter, S. de; Naouar, N. ; Muino Acuna, J.M. ; Angenent, G.C. ; Immink, G.H. - \ 2011
Arabidopsis thaliana - GSE29012 - PRJNA140465
TCP (TEOSINTE BRANCHED1/CYCLOIDEA/PCF1) transcription factors control developmental processes in plants. We identified direct target genes of the Arabidopsis class I TCP20 protein in leaf development based on a glucocorticoid receptor induction assay and genome-wide expression studies. For this, we tagged TCP20 with a glucucorticoid receptor (GR) domain and transformed the resulting TCP20-GR construct into tcp20 knockout plants. Induction of these and wild type controls was done with Dexamethasone and Cycloheximide. Plants were harvested 8 h after induction, uninduced plants were taken as control.
Orchestration of Floral Initiation by APETALA1
Kaufmann, K. ; Muino Acuna, J.M. - \ 2010
Arabidopsis thaliana - GSE20176 - PRJNA125645
The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding studies. Many of its targets encode transcriptional regulators, including known floral repressors. The latter genes are down-regulated by AP1, suggesting that it initiates floral development by abrogating the inhibitory effects of these genes. While AP1 acts predominantly as a transcriptional repressor during the earliest stages of flower development, regulatory genes known to be required for floral organ formation were found to be activated by AP1 at more advanced stages, indicating a dynamic mode of action. Our results further imply that AP1 orchestrates floral initiation by integrating growth, patterning and hormonal pathways.