Person: Benito Jiménez, César
Universidad Complutense de Madrid
Faculty / Institute
Genética, Fisiología y Microbiología
Now showing 1 - 10 of 14
PublicationSulfate nutrition improves short-term Al3+-stress tolerance in roots of Lolium perenne L(Elsevier, 2020-06-10) Vera-Villalobos, Hernán; Lunario-Delgado, Lizzeth; Pérez-Retamal, Diana; Román, Domingo; Leiva, Juan Carlos; Zamorano, Pedro; Mercado-Seguel, Ana; Gálvez, Anita S; Benito Jiménez, César; Wulff-Zottele, CristiánTrivalent aluminum ions (Al3+) in acidic soils are a major constraint for crop productivity inhibiting root elongation and promoting cell death. Al3+-toxicity has adverse biochemical and physiological effects on plant root growth. Sulfur is an essential macronutrient assimilated from the soil in the form of sulfate. However, the implication of sulfate nutritional status in the modulation of short-term Al3+-tolerance mechanisms in plant roots has not been previously reported. Here, we evaluated the effects of increased sulfate supply on short-term Al3+-toxicity in roots of Lolium perenne, measuring Al, Ca, Mg and S uptake, lipid peroxidation, total SOD activity, and transcriptional levels of Cu/Zn and Fe-SOD genes. First, the nitrogen sulfur ratio (N/S) in the TF nutrient solutions used in this study were computed to confirm that L. perenne plants were grown in sulfate deficiency (120 μM), optimal supply (240 μM), or overdoses conditions (360 μM), without affecting dry root biomass. Sulfate supplementation (>240 μM, and N/S ratio < 16) played a significant protection to Al3+-stress that prevents morphological changes in root tips, inhibits lipid peroxidation and differentially up-regulates total SOD activity, due changes in SOD gene expression. The results support the importance of sulfate nutritional status, on plant tissue homeostasis, enhancing the physiological tolerance mechanisms modulating lipid peroxidation damage induced by short-term Al3+-toxicity. PublicationRepression of Mitochondrial Citrate Synthase Genes by Aluminum Stress in Roots of Secale cereale and Brachypodium distachyon(Frontiers Media, 2022-04-07) Abd El-Moneim, Diaa Ahmed Mohamed; Contreras, Roberto; Silva Navas, Javier; Gallego Rodríguez, Francisco Javier; Figueiras Merino, Ana Margarita; Benito Jiménez, CésarAluminum (Al) toxicity in acid soils influences plant development and yield. Almost 50% of arable land is acidic. Plants have evolved a variety of tolerance mechanisms for Al. In response to the presence of Al, various species exudate citrate from their roots. Rye (Secale cereale L.) secretes both citrate and malate, making it one of the most Al-tolerant cereal crops. However, no research has been done on the role of the mitochondrial citrate synthase (mCS) gene in Al-induced stress in the rye. We have isolated an mCS gene, encoding a mitochondrial CS isozyme, in two S. cereale cultivars (Al-tolerant cv. Ailés and Al-sensitive inbred rye line Riodeva; ScCS4 gene) and in two Brachypodium distachyon lines (Al-tolerant ABR8 line and Al-sensitive ABR1 line; BdCS4 gene). Both mCS4 genes have 19 exons and 18 introns. The ScCS4 gene was located on the 6RL rye chromosome arm. Phylogenetic studies using cDNA and protein sequences have shown that the ScCS4 gene and their ScCS protein are orthologous to mCS genes and CS proteins of different Poaceae plants. Expression studies of the ScCS4 and BdSC4 genes show that the amount of their corresponding mRNAs in the roots is higher than that in the leaves and that the amounts of mRNAs in plants treated and not treated with Al were higher in the Al-tolerant lines than that in the Al-sensitive lines of both species. In addition, the levels of ScCS4 and BdCS4 mRNAs were reduced in response to Al (repressive behavior) in the roots of the tolerant and sensitive lines of S. cereale and B. distachyon. PublicationBiochemical, physiological and genetic analysis of aluminum tolerance of different rye species(Elsevier, 2019-02-07) Santos, E.; Pinto-Carnide, O.; Figueiras Merino, Ana Margarita; Benito Jiménez, César; Matos, M.Aluminum (Al) toxicity is the major limitation for crop productivity in acid soils which are widespread all overthe world. Plant species differ in their responses to this abiotic stress having developed resistance mechanisms todetoxify and tolerate Al both internally and externally. Rye (Secale cerealeL.) is one of the most Al-tolerant cerealwith a valuable genetic background for breeding purposes. Wild relatives (Secalespp.) have great importanceonce they can provide new sources of genes related to this trait. Different cellular disorders possibly related to Altolerance/toxicity were observed through histochemical root staining methods in cultivated and wild ryes and acorrelation was found. Moreover, expression studies of seven candidate Al-tolerance genes (ScALMT1,ScMATE2,ScSTOP1,ScMDH1,ScMDH2,ScCu/ZnSODandScMnSOD) were performed in roots and shoots offive wild ryes.All genes seems to have an active contribution on Al resistance mechanisms of these ryes, however,ScALMT1andScMATE2genes clearly have a key role in the Al-tolerance increment. Al tolerance inSecalegenus seems tobe a genetically complex trait where different resistance mechanisms coexist, due to several genes whose cu-mulative effects improves the ability to withstand Al phytotoxicity PublicationMolecular diversity and genetic relationships in Secale(Indian Academy of Sciences, 2016-06) Santos, E.; Matos, M.; Silva, P.; Figueiras Merino, Ana Margarita; Benito Jiménez, César; Pinto-Carnide, O.The objective of this study was to quantify the molecular diversity and to determine the genetic relationships among Secale spp. and among cultivars of Secale cereale using RAPDs, ISSRs and sequence analysis of six exons of ScMATE1 gene. Thirteen ryes (cultivated and wild) were genotyped using 21 RAPD and 16 ISSR primers. A total of 435 markers (242 RAPDs and 193 ISSRs) were obtained, with 293 being polymorphic (146 RAPDs and 147 ISSRs). Two RAPD and nine ISSR primers generated more than 80% of polymorphism. The ISSR markers were more polymorphic and informative than RAPDs. Further, 69% of the ISSR primers selected achieved at least 70% of DNA polymorphism. The study of six exons of the ScMATE1 gene also demonstrated a high genetic variability that subsists in Secale genus. One difference observed in exon 1 sequences from S. vavilovii seems to be correlated with Al sensitivity in this species. The genetic relationships obtained using RAPDs, ISSRs and exons of ScMATE1 gene were similar. S. ancestrale, S. kuprijanovii and S. cereale were grouped in the same cluster and S. segetale was in another cluster. S. vavilovii showed evidences of not being clearly an isolate species and having great intraspecific differences. PublicationOn the consequences of aluminium stress in rye: repressionof two mitoch ondrial malate dehydrogenase mRNAs(Wiley, 2015-01) El-Moneim D., Abd; Contreras, R.; Silva Navas, J.; Gallego Rodríguez, Francisco Javier; Figueiras Merino, Ana Margarita; Benito Jiménez, CésarPlants have developed several external and internal aluminium (Al) tolerance mecha-nisms. The external mechanism best characterised is the exudation of organic acidsinduced by Al. Rye (Secale cereale L.), one of the most Al-tolerant cereal crops, secretesboth citrate and malate from its roots in response to Al. However, the role of malatedehydrogenase (MDH) genes in Al-induced stress has not been studied in rye. Wehave isolated the ScMDH1 and ScMDH2 genes, encoding two different mitochondrialMDH isozymes, in three Al-tolerant rye cultivars (Ailes, Imperial and Petkus) and onesensitive inbred rye line (Riodeva). These genes, which have seven exons and sixintrons, were located on the 1R (ScMDH1) and 3RL(ScMDH2) chromosomes. Exon 1of ScMDH1 and exon 7 of ScMDH2 were the most variable among the different ryes.The hypothetical proteins encoded by these genes were classified as putative mito-chondrial MDH isoforms. The phylogenetic relationships obtained using both cDNAand protein sequences indicated that the ScMDH1 and ScMDH2 proteins are ortholo-gous to mitochondrial MDH1 and MDH2 proteins of different Poaceae species. Theexpression studies of the ScMDH1 and ScMDH2 genes indicate that it is more intensein roots than in leaves. Moreover, the amount of their corresponding mRNAs in rootsfrom plants treated and not treated with Al was higher in the tolerant cultivar Petkusthan in the sensitive inbred line Riodeva. In addition, ScMDH1 and ScMDH2 mRNAlevels decreased in response to Al stress (repressive behaviour) in the roots of both thetolerant Petkus and the sensitive line Riodeva. PublicationThe role of two superoxide dismutase mRNAs in rye aluminium tolerance(Wiley, 2015) Sánchez Parra, B.; Figueiras Merino, Ana Margarita; El Moneim, D. Abd; Contreras, R.; Rouco, R.; Gallego Rodríguez, Francisco Javier; Benito Jiménez, CésarAluminium (Al) is the main factor that limits crop production in acidic soils. There is evidence that antioxidant enzymes such as superoxide dismutase (SOD) play a key role against Al-induced oxidative stress in several plant species. Rye is one of the most Al-tolerant cereals and exudes both citrate and malate from the roots in response to Al. The role of SOD against Al-induced oxidative stress has not been studied in rye. Al accumulation, lipid peroxidation, H2O2 production and cell death were significantly higher in sensitive than in tolerant rye cultivars. Also, we characterised two genes for rye SOD: ScCu/ZnSOD and ScMnSOD. These genes were located on the chromosome arms of 2RS and 3RL, respectively, and their corresponding hypothetical proteins were putatively classified as cytosolic and mitochondrial, respectively. The phylogenetic relationships indicate that the two rye genes are orthologous to the corresponding genes of other Poaceae species. In addition, we studied Al-induced changes in the expression profiles of mRNAs from ScCu/ZnSOD and ScMnSOD in the roots and leaves of tolerant Petkus and sensitive Riodeva rye. These genes are mainly expressed in roots in both ryes, their repression being induced by Al. The tolerant cultivar has more of both mRNAs than the sensitive line, indicating that they are probably involved in Al tolerance. PublicationDefense proteins from sugarcane studied by convenaional biochemical techniques, genomics and proteomics: and overview(Science Publishing Group, 2020-07-13) Sánchez Elordi, Elena; Contreras, Roberto; Armas, Roberto de; Benito Jiménez, César; Santiago, Rocío; Vicente Córdoba, Carlos; Legaz González, María EstrellaSugarcane is a C4 plant from the NADP-ME family, which performs a double photosynthetic carboxylation. It is a plant specialized in accumulating and storing large amounts of sucrose in the parenchymatous cells of its stalks. Perhaps because of these characteristics, this species shows to be extremely sensitive to a large number of diseases caused by viruses, bacteria, phytoplasmas, fungi, insects and nematodes, as well as to various abiotic stresses. A large number of varieties and cultivars resistant to many of these diseases have been achieved through conventional plant breeding techniques and also through biotechnological applications. In addition to this, the ability of the plant itself to produce pathogen resistance factors has been a field of research that has provided excellent weapons to combat crop-destroying pests This review describes those proteins that are synthesized by the plant as resistance factors against different diseases from the point of view of conventional biochemistry and also with the tools that modern genomics and proteomics provide. Special emphasis has been placed on the study of those proteins aimed at increasing the physical resistance of the plant that hinders the entry of the pathogen as well as those proteins related to the synthesis of bioactive phenols, polysaccharide hydrolysis enzymes, bacteriocins, oxygenases, oxidases and oxido-reductases. PublicationDifferential physiological responses of portuguese bread wheat (Triticum aestivum L.) genotypes under aluminium Stress(MDPI, 2016-12-07) García-Oliveira, Ana Luisa; Martíns-Lópes, Paula; Tolrà, Roser; Poschenrieder, Charlotte; Guedes-Pinto, Henrique; Benito Jiménez, CésarThe major limitation of cereal production in acidic soils is aluminium (Al) phytotoxicity which inhibits root growth. Recent evidence indicates that different genotypes within the same species have evolved different mechanisms to cope with this stress. With these facts in mind, root responses of two highly Al tolerant Portuguese bread wheat genotypes—Barbela 7/72/92 and Viloso mole—were investigated along with check genotype Anahuac (Al sensitive), using different physiological and histochemical assays. All the assays confirmed that Barbela 7/72/92 is much more tolerant to Al phytotoxicity than Viloso Mole. Our results demonstrate that the greater tolerance to Al phytotoxicity in Barbela 7/72/92 than in Viloso Mole relies on numerous factors, including higher levels of organic acid (OAs) efflux, particularly citrate efflux. This might be associated with the lower accumulation of Al in the root tips, restricting the Al-induced lipid peroxidation and the consequent plasma membrane integrity loss, thus allowing better root regrowth under Al stress conditions. Furthermore, the presence of root hairs in Barbela 7/72/92 might also help to circumvent Al toxicity by facilitating a more efficient uptake of water and nutrients, particularly under Al stress on acid soils. In conclusion, our findings confirmed that Portuguese bread wheat genotype Barbela 7/72/92 represents an alternative source of Al tolerance in bread wheat and could potentially be used to improve the wheat productivity in acidic soils. PublicationIsolation and characterization of a new MATE gene located in the same chromosome arm of the aluminium tolerance (Alt1) rye locus(Wiley, 2020-03-05) Santos, E.; Matos, M.; Benito Jiménez, César•Aluminium (Al) toxicity is the major constraint for crop productivity in acid soils. Wild rye species (Secale spp.) exhibit high Al tolerance, being a good source of genes related to this trait. The Alt1 locus located on the 6RS chromosome arm is one of the four main loci controlling Al tolerance in rye and is known to harbour major genes but, so far, none have been found. •Through synteny among the short arm of the rye chromosome 6R and the main grass species, we found a candidate MATE gene for the Atl1 locus, later named ScMATE3, which was isolated and characterized in different Secale species. • The sequence comparisons revealed both intraspecific and interspecific variability, with high sequence conservation in the Secale genus. SNP with replacement substitution that changed the structure of the protein and can be involved in the Al tolerance trait were found in ScMATE3 gene. The predicted subcellular localization of ScMATE3 is the vacuolar membrane which, together with the phylogenetic relationships performed with other MATE genes of the Poaceae related to Al detoxification, suggest involvement of ScMATE3 in an internal tolerance mechanism. Moreover, expression studies of this gene in rye corroborate its contribution in some Al resistance mechanisms. • The ScMATE3 gene is located on the 6RS chromosome arm between the same markers in which the Alt1 locus is involved in Al resistance mechanisms in rye, thus being a good candidate gene for this function. PublicationNeutral molecular markers support common origin of aluminium tolerance in three congeneric grass species growing in acidic soils(Annals of Botany Company, 2017) Contreras, Roberto; Figueiras, Ana M.; Gallego Rodríguez, Francisco Javier; Benavente, Elena; Manzaneda, Antonio J.; Benito Jiménez, CésarAluminium (Al) toxicity is the main abiotic stress limiting plant productivity in acidic soils that are widely distributed among arable lands. Plant species differ in the level of Al resistance showing intraspecific and interspecific variation in many crop species. However, the origin of Al-tolerance is not well known. Three annual species, difficult to distinguish phenotypically and that were until recently misinterpreted as a single complex species under Brachypodium distachyon, have been recently separated into three distinct species: the diploids B. distachyon (2n = 10) and B. stacei (2n = 20), and B. hybridum (2n = 30), the allotetraploid derived from the two diploid species. The aims of this work were to know the origin of Al-tolerance in acidic soil conditions within these three Brachypodium species and to develop new DNA markers for species discrimination. Two multiplex SSR-PCRs allowed to genotype a group of 94 accessions for 17 pentanucleotide microsatellite (SSRs) loci. The variability for 139 inter-microsatellite (ISSRs) markers was also examined. The genetic relationships obtained using those neutral molecular markers (SSRs and ISSRs) support that all Al-tolerant allotetraploid accessions of B. hybridum have a common origin that is related with both geographic location and acidic soils. The possibility that the adaptation to acidic soils caused the isolation of the tolerant B. hybridum populations from the others is discussed. We finally describe a new, easy, DNA barcoding method based in the upstream-intron 1 region of the ALMT1 gene, a tool that is 100 % effective to distinguish among these three Brachypodium species.