27 research outputs found
Gene regulation in climacteric fruit ripening
No full textSeed dispersion and consequent plant propagation depend on the success of fruit ripening. Thus, ripening is a highly regulated developmental process aiming to maximize fruit organoleptic traits to attract herbivores. During ripening, the developing fruit experiences dramatic modifications, including color change, flavor improvement, and loss of firmness that are remarkably coordinated. Dynamic interactions between multiple hormones, transcription factors, and epigenetic modifications establish the complex regulatory network that controls the expression levels of ripening-related genes. Tomato, as a climacteric fruit, displays a burst of respiration once the seeds mature, followed by an increase in ethylene that regulates ripening. The accepted paradigm of the ripening transcriptional regulation has been recently challenged by the generation of true-null mutants of the previously considered master regulators of ripening. In addition to hormonal and transcriptional control, epigenetic shifts regulate the ripening process. Future research will contribute to better understanding the factors regulating fruit ripening
Identification of MeC3HDZ1/MeCNA as a potential regulator of cassava storage root development
No full text[EN] The storage root (SR) of cassava is the main staple food in sub-Saharan Africa, where it feeds over 500 million people. However, little is known about the genetic and molecular regulation underlying its development. Unraveling such regulation would pave the way for biotechnology approaches aimed at enhancing cassava productivity. Anatomical studies indicate that SR development relies on the massive accumulation of xylem parenchyma, a cell-type derived from the vascular cambium. The C3HDZ family of transcription factors regulate cambial cells proliferation and xylem differentiation in Arabidopsis and other species. We thus aimed at identifying C3HDZ proteins in cassava and determining whether any of them shows preferential activity in the SR cambium and/or xylem. Using phylogeny and synteny studies, we identified eight C3HDZ proteins in cassava, namely MeCH3DZ1-8. We observed that MeC3HDZ1 is the MeC3HDZ gene displaying the highest expression in SR and that, within that organ, the gene also shows high expression in cambium and xylem. In-silico analyses revealed the existence of a number of potential C3HDZ targets displaying significant preferential expression in the SR. Subsequent Y1H analyses proved that MeC3HDZ1 can bind canonical C3HDZ binding sites, present in the promoters of these targets. Transactivation assays demonstrated that MeC3HDZ1 can regulate the expression of genes downstream of promoters harboring such binding sites, thereby demonstrating that MeC3HDZ1 has C3HDZ transcription factor activity. We conclude that MeC3HDZ1 may be a key factor for the regulation of storage root development in cassava, holding thus great promise for future biotechnology applications.This work was funded by grants from the Spanish Ministry of Science (PID2019-108084RB-I00 and PID2021-125829OB-I00 to JA and PID2021-1274610B-I00 to JB) . JB is sponsored by a Ramon y Cajal contract (RYC2019-026537-I) .Solé-Gil, A.; López, A.; Ombrosi, D.; Urbez Lagunas, C.; Brumos, J.; Agustí, J. (2024). Identification of MeC3HDZ1/MeCNA as a potential regulator of cassava storage root development. Plant Science. 339. https://doi.org/10.1016/j.plantsci.2023.111938S33
A Systematic Design Procedure of Classical Dual-Mode Circular Waveguide Filters Using an Equivalent Distributed Model
No full textIn this paper, we propose a systematic procedure for the accurate design of classical dual-mode filters in circular waveguide technology. The design procedure is based on the previous synthesis of an intermediate distributed model, which links the standard lumped (or coupling matrix) elements circuit with the practical waveguide realization. We then show how the equivalent distributed model can be directly used to obtain the physical dimensions of these filter components (typically rectangular and cross-shaped irises, as well as tuning and coupling screws). The value of this paper lies in the fact that the proposed design strategy provides the final dimensions of these complex structures with unprecedented levels of accuracy and numerical efficiency, as it is shown through two dual-mode filter designs for narrowband applications, and measurements of a manufactured prototype. © 2012 IEEE.This work was supported by the Ministerio de Educacion y Ciencia, Spanish Government, under Research Project TEC2010-21520-C04-01.Cogollos Borras, S.; Brumos Vicente, M.; Boria Esbert, VE.; Vicente Quiles, CP.; Gil Raga, J.; Gimeno Martinez, B.; Guglielmi, M. (2012). A Systematic Design Procedure of Classical Dual-Mode Circular Waveguide Filters Using an Equivalent Distributed Model. IEEE Transactions on Microwave Theory and Techniques. 60(4):1006-1017. https://doi.org/10.1109/TMTT.2012.2183381S1006101760
Correction of manufacturing deviations in waveguide filters and manifold multiplexers using metal insertions
No full textMicrowave filters and multiplexers commonly employ tuning screws to compensate for small errors occurring during the fabrication process. Nevertheless, the use of tuning screws has some disadvantages, because the small gaps between the screws and the holes are prone to create unwanted effects when dealing with high-power signals, especially for space applications, and are also the source of potential radiation losses. In this paper, an alternative technique to correct manufacturing deviations is presented, in which tuning screws are replaced by fixed metal insertions. In this case, the correction is made by means of designing new insertion pieces that will be able to correct those small deviations. In order to find the dimensions of the new pieces, a space-mapping technique is applied. For verification purposes, the method has been applied over a circular-waveguide dual-mode filter and later over a manifold multiplexer containing the same type of filters. However, the technique can be directly extended to other types of waveguide filters and multiplexers where tuning screws are also employed.Cogollos Borras, S.; Carceller Candau, C.; Taroncher Calduch, M.; Boria Esbert, VE.; Guglielmi, M.; Vicente Quiles, CP.; Brumos Vicente, M. (2015). Correction of manufacturing deviations in waveguide filters and manifold multiplexers using metal insertions. International Journal of Microwave and Wireless Technologies. 7(3):219-227. doi:10.1017/S1759078715000513S21922773Guglielmi, M., Molina, R. C., & Melcon, A. A. (1992). Dual-mode circular waveguide filters without tuning screws. IEEE Microwave and Guided Wave Letters, 2(11), 457-458. doi:10.1109/75.165643Steer, M. B., Bandler, J. W., & Snowden, C. M. (2002). Computer-aided design of RF and microwave circuits and systems. IEEE Transactions on Microwave Theory and Techniques, 50(3), 996-1005. doi:10.1109/22.989983Kudsia, C., Cameron, R., & Tang, W.-C. (1992). Innovations in microwave filters and multiplexing networks for communications satellite systems. IEEE Transactions on Microwave Theory and Techniques, 40(6), 1133-1149. doi:10.1109/22.141345Bandler, J. W., Biernacki, R. M., Shao Hua Chen, Hemmers, R. H., & Madsen, K. (1995). Electromagnetic optimization exploiting aggressive space mapping. IEEE Transactions on Microwave Theory and Techniques, 43(12), 2874-2882. doi:10.1109/22.475649Cogollos S. ; Boria V.E. ; Soto P. ; Gimeno B. ; Guglielmi M. : Efficient CAD tool for inductively coupled rectangular waveguide filters with rounded corners, in 31st European Microwave Conf., 24–26 September 2001, 1–4Ke-Li Wu. (1999). An optimal circular-waveguide dual-mode filter without tuning screws. IEEE Transactions on Microwave Theory and Techniques, 47(3), 271-276. doi:10.1109/22.750222Bandler, J. W., Cheng, Q. S., Dakroury, S. A., Mohamed, A. S., Bakr, M. H., Madsen, K., & Sondergaard, J. (2004). Space Mapping: The State of the Art. IEEE Transactions on Microwave Theory and Techniques, 52(1), 337-361. doi:10.1109/tmtt.2003.820904Williams, A. E. (1970). A Four-Cavity Elliptic Waveguide Filter. IEEE Transactions on Microwave Theory and Techniques, 18(12), 1109-1114. doi:10.1109/tmtt.1970.1127419Amari, S., LeDrew, C., & Menzel, W. (2006). Space-mapping optimization of planar coupled-resonator microwave filters. IEEE Transactions on Microwave Theory and Techniques, 54(5), 2153-2159. doi:10.1109/tmtt.2006.872811Brumos M. ; Boria V.E. ; Guglielmi M. ; Cogollos S. : Correction of manufacturing deviations in circular-waveguide dual-mode filters using aggressive space mapping, in European Microwave Conf., Rome, 2014, 624–627.Accatino, L., Bertin, G., & Mongiardo, M. (1996). A four-pole dual mode elliptic filter realized in circular cavity without screws. IEEE Transactions on Microwave Theory and Techniques, 44(12), 2680-2687. doi:10.1109/22.554629Cogollos, S., Brumos, M., Boria, V. E., Vicente, C., Gil, J., Gimeno, B., & Guglielmi, M. (2012). A Systematic Design Procedure of Classical Dual-Mode Circular Waveguide Filters Using an Equivalent Distributed Model. IEEE Transactions on Microwave Theory and Techniques, 60(4), 1006-1017. doi:10.1109/tmtt.2012.2183381Atia, A. E., & Williams, A. E. (1972). Narrow-Bandpass Waveguide Filters. IEEE Transactions on Microwave Theory and Techniques, 20(4), 258-265. doi:10.1109/tmtt.1972.1127732Wu, K.-L., Zhao, Y.-J., Wang, J., & Cheng, M. K. K. (2004). An Effective Dynamic Coarse Model for Optimization Design of LTCC RF Circuits With Aggressive Space Mapping. IEEE Transactions on Microwave Theory and Techniques, 52(1), 393-402. doi:10.1109/tmtt.2003.820901FEST3D 6.8.4 Aurora Software and Testing, S.L. (on behalf of ESA/ESTEC), Valencia, Spain, 2013. Available: http://www.fest3d.com.Bandler, J. W., Biernacki, R. M., Shao Hua Chen, Grobelny, P. A., & Hemmers, R. H. (1994). Space mapping technique for electromagnetic optimization. IEEE Transactions on Microwave Theory and Techniques, 42(12), 2536-2544. doi:10.1109/22.33979
Editorial: Integration of hormonal signals in shaping root growth, development, and architecture
No full textCharacterization of AtSLAH4, a root anion cannel involved in net chloride uptake
No full textPóster nº 27 presentado en la S-VII de la XIV Reunión de Biología Molecular de Plantas 4-6 de Julio 2018 Salamanca (España)Although generally considered a toxic anion, we have shown that besides of an essential micronutrient, Chloride (Cl-) is a beneficial macronutrient (Franco-Navarro et al. 2016). Optimal growth of plants requires the synchronic supply of both Cl- and nitrate (NO3-) molecules, but salt stress causes excessive accumulation of Cl- in leaves, which can produce ion toxicity in Cl-sensitive crops such as citrus and grapevine.
Apart from the control of stomatal closure, members of the SLAC/SLAH family of slow-type anion channels are involved in the regulation of NO3- and Cl- homeostasis in the root, including root-to-shoot transport and NO3- vs. Cl- discrimination according to environmental cues (Cubero-Font et al. 2016). AtSLAH3 mediates the loading of anions into xylem vessels, with a high discrimination of NO3- over Cl-. Under optimal growing conditions, high expression of AtSLAH1 and SLAH1/SLAH3 heteromerization increase by seven times the Cl- conductance of SLAH3. Salinity and water deficit abolish AtSLAH1 expression in an ABA-dependent manner, strongly reducing root-to-shoot translocation of Cl- under abiotic stress (Cubero-Font et al. 2016).Cubero-Font, P (2017) PhD Thesis, Universidad de Sevilla, Seville, Spain
Cubero-Font P, Maierhofer T, Jaslan J, Rosales Miguel A, Espartero J, Díaz-Rueda P, Müller Heike M, Hürter A-L, Al-Rasheid Khaled AS, Marten I, Hedrich R, Colmenero-Flores José M, Geiger D (2016). Current Biology 26 (16):2213-2220. doi:10.1016/j.cub.2016.06.045
Franco-Navarro JD, Brumos J, Rosales MA, Cubero-Font P, Talon M, Colmenero-Flores JM (2016). Journal of Experimental Botany 67(3): 873-891. doi:10.1093/jxb/erv502This work has been supported by the MINECO-FEDER grants AGL2009-08339/AGR, AGL2015-71386-R and the National Network BIO2014-56153-REDT. PC-F has been supported by the CSIC JAE-Predoc and the German Academic Exchange Service DAAD
fellowshipsN
Transcriptional profile analysis of young and mature leaves of citrus trees acclimated to salinity
No full text11 páginas.-- 3 figuras.-- 2 tablas.-- 32 referencias.-- Artículo publicado en XII International Citrus Congress - International Society of CitricultureWhile the molecular response of model plants to salt stress in the short-medium term (hours-days) has been broadly studied, the knowledge about the nature of genes involved in maintaining homeostatic conditions in the long term (months-years) in woody perennial trees has not been addressed yet. We have analyzed physiological parameters and the transcriptome profiles of photosynthetically active leaves from citrus trees acclimatized to moderate salinity (NaCl 30 mM) after 2 years treatment. Through functional genomics, global gene expression in response to NaCl treatment in mature (8 months-old) and young (2 months-old) leaves has been analyzed and compared. Although young leaves (YL) accumulated low levels of chloride (0.51%±0.06), they exhibited a much stronger response to salinity in term of the number of differentially expressed genes (1,211 genes) compared with mature leaves (ML), which accumulated higher chloride levels (1.05%±0.01), and exhibited a much lower number of differentially-responsive genes (100 genes). In this work, a number of responses have been observed that differ from those described in previous studies of citrus plants non-acclimatized to salt stress (Brumos et al., 2009), whose principal manifestation was the lack of repression of primary metabolism in leaves at the molecular and physiological levels. Results describing enriched functional categories of differentially expressed genes are presented and discussed highlighting how the long-term acclimation to NaCl stress involves drastically different molecular strategies depending on the developmental stage of plant leaves.This work was partially supported by the Spanish Ministry of Science and Innovation projects AGL2007-6537-C04-04 and PS-060000-2009-7, and the European Social and FEDER Funds for financial support. Juan G. Pérez-Pérez acknowledges the ‘Instituto Nacional de Investigaciones Agrarias’ for a PhD fellowship to support his research.Peer reviewe
Identification of ovule and seed genes from Citrus clementina
No full text[EN] Seedlessness is a highly desirable trait in fresh fruit. Citrus varieties, such as Clementine mandarin and other related species, show parthenocarpic fruit development without seeds due to self-incompatibility. In spite of that, these fruits frequently contain seeds as a result of cross-pollination by insects with compatible pollen from other citrus cultivars grown nearby. To solve this problem using a biotechnological approach we aim at the destruction of ovules and/or seeds by directing the expression of a toxic gene using the promoter of an ovule and/or seed specific gene. With the purpose of isolating this kind of genes we constructed two cDNA libraries from ovules and seeds at different developmental stages of the Clementine mandarin (Citrus clementina cv. Clemenules). A total of 1,014 ESTs from the ovule library and 1,042 ESTs from the seed library were generated, with a novelty percentage of 27% and 36% among the Spanish Citrus Functional Genomic Project (CFGP) ESTs database, respectively. Quantitative PCR analysis confirmed nearly specific expression in ovule and/or seed of two genes, TRANSPARENT TESTA16 (CcTT16) and TRANSPARENT TESTA7 (CcTT7). Expression of these two genes is restricted to early seed development, and is localized in the embryo sac and endothelium. The promoters of those genes may be useful to genetically engineer citrus species to avoid seed formation in fruits of commercial varieties.The authors thank Dr. L. Navarro and J. Juarez, from the Instituto Valenciano de Investigaciones Agrarias (Generalitat Valenciana), for the use of the Clementine orchard and Fortune pollen; Dr. J Forment and the Genomics Facility at the IBMCP for sequence analysis and maintenance of to the CFGP database; and Drs. F Tadeo and J Carbonell for critical reading of the manuscript. This work was supported by grants from the Conselleria de Agricultura, Pesca y Alimentacion (Generalitat Valenciana) and Spanish Ministerio de Ciencia y Tecnologia (research grant GEN2001-4885-C05). A.G-L. received a PhD fellowship from the Conselleria de Agricultura, Pesca y Alimentacion.García Lor, A.; Garcia Martinez, JL.; Perez Amador, MA. (2012). Identification of ovule and seed genes from Citrus clementina. Tree Genetics and Genomes. 8(2):227-235. https://doi.org/10.1007/s11295-011-0435-xS22723582Al-Shahrour F, Diaz-Uriarte R, Dopazo J (2005) Discovering molecular functions significantly related to phenotypes by combining gene expression data and biological information. Bioinformatics 21:2988–2993Al-Shahrour F, Minguez P, Tarraga J, Montaner D, Alloza E, Vaquerizas JMM, Conde L, Blaschke C, Vera J, Dopazo J (2006) BABELOMICS: a systems biology perspective in the functional annotation of genome-scale experiments. 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Plant Cell 15:2514–2531Dorcey E, Urbez C, Blazquez MA, Carbonell J, Perez-Amador MA (2009) Fertilization-dependent auxin response in ovules triggers fruit development through the modulation of gibberellin metabolism in Arabidopsis. Plant J 58:318–332Debeaujon I, Peeters AJ, Léon-Kloosterziel KM, Koornneef M (2001) The TRANSPARENT TESTA12 gene of Arabidopsis encodes a multidrug secondary transporter-like protein required for flavonoid sequestration in vacuoles of the seed coat endothelium. Plant Cell 13:853–571Forment J, Gadea J, Huerta L, Abizanda L, Agusti J, Alamar S, Alos E, Andres F, Arribas R, Beltran JP, Berbel A, Blazquez MA, Brumos J, Canas LA, Cercos M, Colmenero-Flores JM, Conesa A, Estables B, Gandia M, Garcia-Martinez JL, Gimeno J, Gisbert A, Gomez G, Gonzalez-Candelas L, Granell A, Guerra J, Lafuente MT, Madueno F, Marcos JF, Marques MC, Martinez F, Martinez-Godoy MA, Miralles S, Moreno P, Navarro L, Pallas V, Perez-Amador MA, Perez-Valle J, Pons C, Rodrigo I, Rodriguez PL, Royo C, Serrano R, Soler G, Tadeo F, Talon M, Terol J, Trenor M, Vaello L, Vicente O, Vidal C, Zacarias L, Conejero V (2005) Development of a citrus genome-wide EST collection and cDNA microarray as resources for genomic studies. Plant Mol Biol 57:375–391Forment J, Gilabert F, Robles A, Conejero V, Nuez F, Blanca JM (2008) EST2uni: an open, parallel tool for automated EST analysis and database creation, with a data mining web interface and microarray expression data integration. 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Cl- homeostasis in includer and excluder citrus rootstocks: Transport mechanisms and identification of candidate genes
No full text16 pages, 9 figures, 79 references. Help and expertise of A. Almenar,A. Boix,A. López, E. Blázquez, I. López, I. Sanchís and M. Sancho are gratefully acknowledged.Artícle Free Access publisher'versionTo reveal specific Cl(-) transport activities in the symplastic pathway, uptake, long-distance transport and distribution of Cl(-) have been investigated in the citrus rootstocks Carrizo citrange (CC, Cl(-) includer) and Cleopatra mandarin (CM, Cl(-) excluder). Using an external concentration of 4.5 mm Cl(-) , both species actively transported Cl(-) to levels that exceeded the critical requirement concentration by one and two orders of magnitude in the excluder and the includer rootstocks, respectively. Both CC and CM modulated Cl(-) influx according to the availability of the nutrient as uptake capacity was induced by Cl(-) starvation, but inhibited after Cl(-) resupply. Net Cl(-) uptake was higher in the includer CC, an observation that correlated with a lower root-to-shoot transport capacity in the excluder CM. The patterns of tissue Cl(-) accumulation indicated that chloride exclusion in the salt-tolerant rootstock CM was caused by a reduced net Cl(-) loading into the root xylem. Genes CcCCC1, CcSLAH1 and CcICln1 putatively involved in the regulation of chloride transport were isolated and their expression analysed in response to both changes in the nutritional status of Cl(-) and salt stress. The previously uncharacterized ICln gene exhibited a strong repression to Cl(-) application in the excluder rootstock, suggesting a role in regulating Cl(-) homeostasis in plants.Centro de Genómica (IVIA) and IRNAS (CSIC) work were supported, respectively, by the Spanish Ministerio de Ciencia e Innovación-FEDER grants AGL2007-65437- C04-01/AGR and AGL2009-08339/AGR.Peer reviewe
Transcriptomic signature of the SHATTERPROOF2 expression domain reveals the meristematic nature of arabidopsis gynoecial medial domain
No full textPlant meristems, like animal stem cell niches, maintain a pool of multipotent, undifferentiated cells that divide and differentiate to give rise to organs. In Arabidopsis (Arabidopsis thaliana), the carpel margin meristem is a vital meristematic structure that generates ovules from the medial domain of the gynoecium, the female floral reproductive structure. The molecular mechanisms that specify this meristematic region and regulate its organogenic potential are poorly understood. Here, we present a novel approach to analyze the transcriptional signature of the medial domain of the Arabidopsis gynoecium, highlighting the developmental stages that immediately proceed ovule initiation, the earliest stages of seed development. Using a floral synchronization system and a SHATTERPROOF2 (SHP2) domain-specific reporter, paired with FACS and RNA sequencing, we assayed the transcriptome of the gynoecial medial domain with temporal and spatial precision. This analysis reveals a set of genes that are differentially expressed within the SHP2 expression domain, including genes that have been shown previously to function during the development of medial domain-derived structures, including the ovules, thus validating our approach. Global analyses of the transcriptomic data set indicate a similarity of the pSHP2-expressing cell population to previously characterized meristematic domains, further supporting the meristematic nature of this gynoecial tissue. Our method identifies additional genes including novel isoforms, cis-natural antisense transcripts, and a previously unrecognized member of the REPRODUCTIVE MERISTEM family of transcriptional regulators that are potential novel regulators of medial domain development. This data set provides genome-wide transcriptional insight into the development of the carpel margin meristem in Arabidopsis
