Xavier Serrat - Academia.edu (original) (raw)
Papers by Xavier Serrat
Weed research, Apr 5, 2024
RePEc: Research Papers in Economics, 2021
Agriculture
The selection of non-food crops for bioenergy production in limiting environments is a priority f... more The selection of non-food crops for bioenergy production in limiting environments is a priority for energy security and climate change mitigation. Therefore, more studies are needed on the interactions between species and environmental factors in specific sites which allows their selection for biomass production. The objective of this work is to study the impact of drought on the morpho-physiological parameters of perennial rhizomatous grasses Panicum virgatum L., Miscanthus × giganteus, and Arundo donax L. in the Mediterranean environment. Plants were grown on field and trials were carried out under support-irrigation and rainfed conditions during two consecutive years. Morpho-physiological parameters were measured in May, June and August, and dry biomass at the end of the experiment. Under rainfed conditions, A. donax presented the highest photosynthesis rate (25, 15 and 10 CO2 m−2 s−1), relative water content (85–90%), and dry biomass (~4500 g plant−1) compared with P. virgatum (...
Rice
Background Rice is one of the most salt sensitive crops at seedling, early vegetative and reprodu... more Background Rice is one of the most salt sensitive crops at seedling, early vegetative and reproductive stages. Varieties with salinity tolerance at seedling stage promote an efficient growth at early stages in salt affected soils, leading to healthy vegetative growth that protects crop yield. Saltol major QTL confers capacity to young rice plants growing under salt condition by maintaining a low Na+/K+ molar ratio in the shoots. Results Marker-assisted backcross (MABC) procedure was adopted to transfer Saltol locus conferring salt tolerance at seedling stage from donor indica IR64-Saltol to two temperate japonica varieties, Vialone Nano and Onice. Forward and background selections were accomplished using polymorphic KASP markers and a final evaluation of genetic background recovery of the selected lines was conducted using 15,580 SNP markers obtained from Genotyping by Sequencing. Three MABC generations followed by two selfing, allowed the identification of introgression lines achie...
Agronomy
Rice holds an important sociocultural meaning in Europe, and especially in the gastronomy of its ... more Rice holds an important sociocultural meaning in Europe, and especially in the gastronomy of its Mediterranean regions, as it is used for world-famous recipes such as Risotto in Italy and Paella in Spain. Paella is prepared with highly appreciated pearled (white-core) rice cultivars such as Bomba or Montsianell, while Risotto is prepared with white-belly Carnaroli cultivar among others. Pearled rice grains have a limited and enclosed translucent zone which is physicochemically different from stress-induced chalky grains present in any rice cultivar at a low rate, and whose opaque area covers at least three quarters of the grain surface. We have studied for the first time the physicochemical aspects of grains from pearled white-belly, white-core and crystalline rice grains of Mediterranean japonica rice cultivars in comparison with their defective stress-induced chalky grains in order to shed some light on their differences. Spanish Bomba and Montsianell white-core (pearled) cultivar...
Frontiers in Plant Science
Rice is the most salt sensitive cereal crop and its cultivation is particularly threatened by sal... more Rice is the most salt sensitive cereal crop and its cultivation is particularly threatened by salt stress, which is currently worsened due to climate change. This study reports the development of salt tolerant introgression lines (ILs) derived from crosses between the salt tolerant indica rice variety FL478, which harbors the Saltol quantitative trait loci (QTL), and the salt-sensitive japonica elite cultivar OLESA. Genotyping-by-sequencing (GBS) and Kompetitive allele specific PCR (KASPar) genotyping, in combination with step-wise phenotypic selection in hydroponic culture, were used for the identification of salt-tolerant ILs. Transcriptome-based genotyping allowed the fine mapping of indica genetic introgressions in the best performing IL (IL22). A total of 1,595 genes were identified in indica regions of IL22, which mainly located in large introgressions at Chromosomes 1 and 3. In addition to OsHKT1;5, an important number of genes were identified in the introgressed indica segme...
This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (... more This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (Arundo donax L. and Panicum virgatum L.) grown under water stress in greenhouse conditions. Plants were exposed to three water stress levels: control (C, 100% Pot Capacity), mild stress (MS, 50% PC) and severe stress (SS, 25% PC). Photosynthesis, fluorescence parameters and relative water content were measured at the beginning (Ti) and the end of the experiment (Tf). Biomass parameters were measured at Tf. Short-term double labelling with 13C and 15N stable isotopes was performed in both species. Isotopic analyses of total organic matter, total soluble sugars and the CO2 respired were undertaken at T0 (prelabelling), T1 (24h after labelling) and T2 (7 days after labelling). Immediately after the 13C and 15N labelling, stems and rhizomes seemed to be the main sinks for labelled carbon and nitrogen in both species. Moreover, not all of the labelled carbon and nitrogen substrate was used by...
EMS mutagenesis in mature seed-derived rice calli as a new method for rapidly obtaining TILLING m... more EMS mutagenesis in mature seed-derived rice calli as a new method for rapidly obtaining TILLING mutant populations Serrat et al.
Agronomy, 2021
The present study assessed the behavior of four clones of Arundo donax L. (giant reed) as a peren... more The present study assessed the behavior of four clones of Arundo donax L. (giant reed) as a perennial rhizomatous grass of increasing interest due to its high biomass production and great adaptability to stress conditions. In this study, a molecular, physiological, and biomass characterization was performed in greenhouse conditions on four Mediterranean clones. The majority of physiological and biomass parameters were not significantly different between clones. However, it was possible to observe large differences in the chromosome count for the four clones. In this way, we detected different numbers of chromosomes for each clone (98 to 122), but surprisingly, no correlation was observed between their chromosome numbers and their physiological and biomass responses.
Journal of Plant Sciences, 2018
This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (... more This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (Arundo donax L. and Panicum virgatum L.) grown under water stress in greenhouse conditions. Plants were exposed to three water stress levels: control (C, 100% Pot Capacity), mild stress (MS, 50% PC) and severe stress (SS, 25% PC). Photosynthesis, fluorescence parameters and relative water content were measured at the beginning (Ti) and the end of the experiment (Tf). Biomass parameters were measured at Tf. Short-term double labelling with 13C and 15N stable isotopes was performed in both species. Isotopic analyses of total organic matter, total soluble sugars and the CO2 respired were undertaken at T0 (pre-labelling), T1 (24h after labelling) and T2 (7 days after labelling). Immediately after the 13C and 15N labelling, stems and rhizomes seemed to be the main sinks for labelled carbon and nitrogen in both species. Moreover, not all of the labelled carbon and nitrogen substrate was used b...
Agronomy, 2021
Arundo donax L. (giant reed) is a perennial rhizomatous grass and has been identified as an impor... more Arundo donax L. (giant reed) is a perennial rhizomatous grass and has been identified as an important non-food biomass crop with capacity for cultivation in marginal and degraded lands where water scarcity conditions frequently occur due to climate change. This review analyzes the effect of water stress on photosynthetic capacity and biomass production in multiple giant reed ecotypes grown in different regions around the world. Furthermore, this review will attempt to explain the reason for the high photosynthetic capacity of giant reed even under changing environmental conditions as well as indicate other morphological reasons that could contribute to maintaining this high photosynthetic rate. Finally, future research in favor of selecting ecotypes with drought tolerance is proposed.
The Crop Journal, 2020
Rice, a major staple, is the most salt-sensitive cereal. High salinity triggers several adaptive ... more Rice, a major staple, is the most salt-sensitive cereal. High salinity triggers several adaptive responses in rice to cope with osmotic and ionic stress at the physiological, cellular, and molecular levels. A major QTL for salinity tolerance, named Saltol, is present on chromosome 1 of Indian landraces such as Pokkali and Nona Bokra. The early proteomic and physiological responses to salinity in roots and shoots of FL478, an inbred rice line harboring the Saltol QTL, were characterized. Plantlets were cultured in hydroponic cultures with 100 mmol L À1 NaCl and evaluated at 6, 24, and 48 h. At the physiological level, root length significantly increased at 48 h, whereas shoot length was reduced. The Na + /K + ratio was maintained at lower levels in shoots than in roots, suggesting that roots play a protective role. More than 2000 proteins were detected in both tissues. Roots showed a faster and more coordinated proteomic response than shoots, evident after only 6 h of treatment. These responses showed clear correspondence with those of proteins involved in transcription and translation. Maintenance of mitochondrial activity and amino acid metabolism in roots, and activation of stress-responsive proteins such as dehydrins and PLAT in shoots, may play a key role during the response of the plant to salinity stress. Proteomic and physiological responses showed that roots respond in a more highly adaptive manner than shoots to salinity stress, suggesting that this tissue is critical to the tolerance observed in cultivars harboring Saltol.
Plant Biotechnology, 2019
Anther culture is a fast tool to obtain double haploid plant lines for breeding purposes. In rice... more Anther culture is a fast tool to obtain double haploid plant lines for breeding purposes. In rice, this procedure is commonly performed in two steps: i) induction of calli from anthers and ii) regeneration of plantlets from calli. It has been stated that genotype highly influences the anther culture efficiency, so the media used in each step should be optimized for each variety. In this study, we tested different media modifications of an efficient protocol optimized for a medium sized grain temperate japonica NRVC980385, used as a control, in a long grain temperate japonica rice variety (NRVC20120346), and two long grain tropical japonica varieties (303012 and 303013). We found that the addition of 150 mg l −1 colchicine to the induction medium worked best for all genotypes except for NRVC20120346, whose best induction was obtained with the colchicine-free medium. Referring to regeneration, increased gelling agent in the medium provided the best rates in NRVC980385, improving our former NRVC980385-optimized anther culture protocol. Sorbitol fortified regeneration medium worked the best in the case of the long grain varieties. The presence of colchicine in the induction medium was also related to a higher obtention of double haploid plantlets. This study highlights that genotype is a key factor in the performance of rice anther culture. It has set a first anther culture study on long grain japonica varieties and optimizes the anther culture protocol for temperate japonica medium grain NRVC980385 with the use of colchicine and other additives that increase osmotic stress.
Plant Biotechnology, 2018
Rice is one of the greatest calorie supply for the world population, especially since its product... more Rice is one of the greatest calorie supply for the world population, especially since its production is almost entirely destined to direct human consumption and its demand will increase along with the world population. There are efforts worldwide to increase rice yields by obtaining new improved and stabilized rice lines. The rice anther culture, a fast and cheap technique, allows to obtain double haploid lines in less than one year. We report its application with an improved protocol in four Mediterranean japonica rice genotypes at F 2 generation. We performed a screening test for cold-pretreatment at 5.0±0.1°C and concluded that the optimum duration was 9 days as it produced the higher rate of anther-derived callus induction. This revised protocol was successfully applied to the four genotypes, obtaining good results in all the procedure's steps. At the end, more than 100 of double haploid green plants were generated. Moreover, 9 lines obtained from the anther culture procedure showed good qualities for the Spanish market at the growing, farming and grain production level during the field assays. Therefore, we report an improved anther culture procedure for obtaining double haploid lines from temperate japonica rice genotypes showing high commercialization expectance.
BioEnergy Research, 2018
Switchgrass (Panicum virgatum L.) is a warm perennial grass with valuable characteristics as a bi... more Switchgrass (Panicum virgatum L.) is a warm perennial grass with valuable characteristics as a biofuel crop. To avoid competition with food crops, biofuel crops will be likely relegated to less productive soils such as marginal lands. Consequently, the salinity and water scarcity problems that commonly affect marginal lands, compromise biofuel crops germination, emergence and seedling establishment. The aims of this study were to study the germination and seedling growth of switchgrass under salinity and water stress, and to describe the morpho-anatomical responses of the roots and leaves in the seedlings to these stresses. The effect of salt and water stress was assessed using sodium chloride (NaCl) and polyethylene glycol 8000 (PEG) at the same water potentials of-0.8,-1.0 and-1.2 MPa. Seeds were moist prechilled for 7 days at 5 ºC and germinated at 30ºC/15 ºC (8 h light/16 h dark). NaCl treatments (-0.8 and-1.0 MPa) delayed germination rates but did not reduce the final germination percentage, whereas at a lower potential (-1.2 MPa) the final germination percentage was diminished. The effects of PEG (-1.0 and-1.2 MPa) on the germination rate and final percentage, were more detrimental than those induced by iso-osmotic concentrations of NaCl. PEG and NaCl reduced significantly the vigor index of-0.8 to-1.2 MPa. The morpho-anatomical changes such as the reduction in the root cross-section area and the thickening of the endodermis walls for both stress conditions and aerenchyma formation in the cortex under salinity, could significantly contribute in the survival and tolerance during the early seedling stages.
Journal of Plant Studies, 2019
Flow cytometry trituration methods and the efficiency of isolation buffer solutions are compared ... more Flow cytometry trituration methods and the efficiency of isolation buffer solutions are compared in this study for extraction of nuclei from fresh leaves of rice. The razor blade sample trituration procedure has been widely used to release nuclei from tissues in many plant species, and combined with different isolation buffers for low throughput analysis. In contrast, the bead beating trituration method has rarely been used for DNA ploidy determination, despite it being proposed as a less tedious alternative procedure to prepare nuclear suspensions. In this study, bead beating was assessed and compared with the traditional chopping procedure. Each trituration method was combined with one of three nuclear isolation buffers (i.e. Hanson’s, Otto’s and LB01 buffer). Bead beating was applied for the first time using all three of the buffers, resulting in a rapid and effective procedure for ploidy determination in fresh rice leaves. In addition, bead beating saved, while reducing the expo...
Frontiers in Plant Science, 2019
Gibberellins (GAs) are a very important group of phytohormones involved in seed germination, vege... more Gibberellins (GAs) are a very important group of phytohormones involved in seed germination, vegetative growth, flowering, and fruit development, being only 4 of the 136 known bioactives: GA 1 , GA 3 , GA 4 , and GA 7. It has been evidenced that mutations in the OsGA20ox-2 gene produce rice (Oryza sativa) dwarf varieties, which were one of the main pillars of the green revolution. In this work two main objectives were proposed: (i) develop a rapid and broad phytohormone profiling method and (ii) to study the effects on the GA content of the GA20ox-2 mutation in several rice developmental stages using three varieties (tall variety, elite variety, mutated variety). A phytohormone extraction using an SPE step and HPLC-MS/MS detection using a QqQ instrument was determined which resulted in limits of detection (LOD) and limits of quantification (LOQ) for GAs that varied between 0.1-0.7 and 0.3-2.3 pg • g −1 (f.w.) of rice sample, respectively, allowing highly sensitive phytohormones detection in samples. Moreover, a good reproducibility was obtained for the GAs as relative standard deviations (RSD) for a 40 ng • mL −1 pattern varied between 0.3 and 0.9%. Notoriously, GA 1 was absent in the coleoptile and GA 4 was the GA with higher content in the majority of developmental stages. We also observed a large content increase of the four bioactive GAs in the internode of the flag leaf of the mutated variety allowing to reach same height as the elite variety. Therefore, we provide a rapid and broad phytohormonal profiling method and evidence that the GA20ox-2 mutation is not the only factor generating dwarf varieties. To our knowledge, this is the first study that it has been reported such a high number of simultaneously analyzed gibberellins in rice samples (Oryza sativa ssp. japonica) in different tissues of different growth stages.
Plant Cell, Tissue and Organ Culture (PCTOC), 2018
Rice double haploid (DH) plants are produced mainly through anther culture. In order to improve t... more Rice double haploid (DH) plants are produced mainly through anther culture. In order to improve the anther culture protocol, microspores of two japonica rice genotypes (NRVC980385 and H28) were subjected to three growth regulator combinations and four colchicine treatments on induction medium. In addition, a post anther culture procedure using colchicine or oryzalin was tested to induce double haploid plantlets from haploid plantlets. A cold pre-treatment of microspores for 9 days at 10 °C increased callus induction 50-fold in the NRCV980385 genotype. For both genotypes, 2 mg L −1 2,4-D and 1 mg L −1 kinetin on colchicine-free induction medium gave the best culture responses. The culturability of both genotypes changed on colchicine-supplemented induction media. A high genotype dependency was recorded for callus induction, callus regenerating green plantlets and regeneration of green double haploid plantlets. Colchicine at 300 mg L −1 for 48 h enhanced callus induction 100-fold in H28. Colchicine-supplemented media clearly improved green double haploid plantlet regeneration. We showed that the post-anther culture treatment of haploid plantlets at 500 mg L −1 of colchicine permitted fertile double haploid plantlets to be generated. Finally, an enhanced medium-throughput flow cytometry protocol for rice was tested to analyse all the plantlets from anther and post anther culture.
Weed research, Apr 5, 2024
RePEc: Research Papers in Economics, 2021
Agriculture
The selection of non-food crops for bioenergy production in limiting environments is a priority f... more The selection of non-food crops for bioenergy production in limiting environments is a priority for energy security and climate change mitigation. Therefore, more studies are needed on the interactions between species and environmental factors in specific sites which allows their selection for biomass production. The objective of this work is to study the impact of drought on the morpho-physiological parameters of perennial rhizomatous grasses Panicum virgatum L., Miscanthus × giganteus, and Arundo donax L. in the Mediterranean environment. Plants were grown on field and trials were carried out under support-irrigation and rainfed conditions during two consecutive years. Morpho-physiological parameters were measured in May, June and August, and dry biomass at the end of the experiment. Under rainfed conditions, A. donax presented the highest photosynthesis rate (25, 15 and 10 CO2 m−2 s−1), relative water content (85–90%), and dry biomass (~4500 g plant−1) compared with P. virgatum (...
Rice
Background Rice is one of the most salt sensitive crops at seedling, early vegetative and reprodu... more Background Rice is one of the most salt sensitive crops at seedling, early vegetative and reproductive stages. Varieties with salinity tolerance at seedling stage promote an efficient growth at early stages in salt affected soils, leading to healthy vegetative growth that protects crop yield. Saltol major QTL confers capacity to young rice plants growing under salt condition by maintaining a low Na+/K+ molar ratio in the shoots. Results Marker-assisted backcross (MABC) procedure was adopted to transfer Saltol locus conferring salt tolerance at seedling stage from donor indica IR64-Saltol to two temperate japonica varieties, Vialone Nano and Onice. Forward and background selections were accomplished using polymorphic KASP markers and a final evaluation of genetic background recovery of the selected lines was conducted using 15,580 SNP markers obtained from Genotyping by Sequencing. Three MABC generations followed by two selfing, allowed the identification of introgression lines achie...
Agronomy
Rice holds an important sociocultural meaning in Europe, and especially in the gastronomy of its ... more Rice holds an important sociocultural meaning in Europe, and especially in the gastronomy of its Mediterranean regions, as it is used for world-famous recipes such as Risotto in Italy and Paella in Spain. Paella is prepared with highly appreciated pearled (white-core) rice cultivars such as Bomba or Montsianell, while Risotto is prepared with white-belly Carnaroli cultivar among others. Pearled rice grains have a limited and enclosed translucent zone which is physicochemically different from stress-induced chalky grains present in any rice cultivar at a low rate, and whose opaque area covers at least three quarters of the grain surface. We have studied for the first time the physicochemical aspects of grains from pearled white-belly, white-core and crystalline rice grains of Mediterranean japonica rice cultivars in comparison with their defective stress-induced chalky grains in order to shed some light on their differences. Spanish Bomba and Montsianell white-core (pearled) cultivar...
Frontiers in Plant Science
Rice is the most salt sensitive cereal crop and its cultivation is particularly threatened by sal... more Rice is the most salt sensitive cereal crop and its cultivation is particularly threatened by salt stress, which is currently worsened due to climate change. This study reports the development of salt tolerant introgression lines (ILs) derived from crosses between the salt tolerant indica rice variety FL478, which harbors the Saltol quantitative trait loci (QTL), and the salt-sensitive japonica elite cultivar OLESA. Genotyping-by-sequencing (GBS) and Kompetitive allele specific PCR (KASPar) genotyping, in combination with step-wise phenotypic selection in hydroponic culture, were used for the identification of salt-tolerant ILs. Transcriptome-based genotyping allowed the fine mapping of indica genetic introgressions in the best performing IL (IL22). A total of 1,595 genes were identified in indica regions of IL22, which mainly located in large introgressions at Chromosomes 1 and 3. In addition to OsHKT1;5, an important number of genes were identified in the introgressed indica segme...
This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (... more This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (Arundo donax L. and Panicum virgatum L.) grown under water stress in greenhouse conditions. Plants were exposed to three water stress levels: control (C, 100% Pot Capacity), mild stress (MS, 50% PC) and severe stress (SS, 25% PC). Photosynthesis, fluorescence parameters and relative water content were measured at the beginning (Ti) and the end of the experiment (Tf). Biomass parameters were measured at Tf. Short-term double labelling with 13C and 15N stable isotopes was performed in both species. Isotopic analyses of total organic matter, total soluble sugars and the CO2 respired were undertaken at T0 (prelabelling), T1 (24h after labelling) and T2 (7 days after labelling). Immediately after the 13C and 15N labelling, stems and rhizomes seemed to be the main sinks for labelled carbon and nitrogen in both species. Moreover, not all of the labelled carbon and nitrogen substrate was used by...
EMS mutagenesis in mature seed-derived rice calli as a new method for rapidly obtaining TILLING m... more EMS mutagenesis in mature seed-derived rice calli as a new method for rapidly obtaining TILLING mutant populations Serrat et al.
Agronomy, 2021
The present study assessed the behavior of four clones of Arundo donax L. (giant reed) as a peren... more The present study assessed the behavior of four clones of Arundo donax L. (giant reed) as a perennial rhizomatous grass of increasing interest due to its high biomass production and great adaptability to stress conditions. In this study, a molecular, physiological, and biomass characterization was performed in greenhouse conditions on four Mediterranean clones. The majority of physiological and biomass parameters were not significantly different between clones. However, it was possible to observe large differences in the chromosome count for the four clones. In this way, we detected different numbers of chromosomes for each clone (98 to 122), but surprisingly, no correlation was observed between their chromosome numbers and their physiological and biomass responses.
Journal of Plant Sciences, 2018
This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (... more This study compares photosynthesis, growth, 13C and 15N labelling patterns of two biomass crops (Arundo donax L. and Panicum virgatum L.) grown under water stress in greenhouse conditions. Plants were exposed to three water stress levels: control (C, 100% Pot Capacity), mild stress (MS, 50% PC) and severe stress (SS, 25% PC). Photosynthesis, fluorescence parameters and relative water content were measured at the beginning (Ti) and the end of the experiment (Tf). Biomass parameters were measured at Tf. Short-term double labelling with 13C and 15N stable isotopes was performed in both species. Isotopic analyses of total organic matter, total soluble sugars and the CO2 respired were undertaken at T0 (pre-labelling), T1 (24h after labelling) and T2 (7 days after labelling). Immediately after the 13C and 15N labelling, stems and rhizomes seemed to be the main sinks for labelled carbon and nitrogen in both species. Moreover, not all of the labelled carbon and nitrogen substrate was used b...
Agronomy, 2021
Arundo donax L. (giant reed) is a perennial rhizomatous grass and has been identified as an impor... more Arundo donax L. (giant reed) is a perennial rhizomatous grass and has been identified as an important non-food biomass crop with capacity for cultivation in marginal and degraded lands where water scarcity conditions frequently occur due to climate change. This review analyzes the effect of water stress on photosynthetic capacity and biomass production in multiple giant reed ecotypes grown in different regions around the world. Furthermore, this review will attempt to explain the reason for the high photosynthetic capacity of giant reed even under changing environmental conditions as well as indicate other morphological reasons that could contribute to maintaining this high photosynthetic rate. Finally, future research in favor of selecting ecotypes with drought tolerance is proposed.
The Crop Journal, 2020
Rice, a major staple, is the most salt-sensitive cereal. High salinity triggers several adaptive ... more Rice, a major staple, is the most salt-sensitive cereal. High salinity triggers several adaptive responses in rice to cope with osmotic and ionic stress at the physiological, cellular, and molecular levels. A major QTL for salinity tolerance, named Saltol, is present on chromosome 1 of Indian landraces such as Pokkali and Nona Bokra. The early proteomic and physiological responses to salinity in roots and shoots of FL478, an inbred rice line harboring the Saltol QTL, were characterized. Plantlets were cultured in hydroponic cultures with 100 mmol L À1 NaCl and evaluated at 6, 24, and 48 h. At the physiological level, root length significantly increased at 48 h, whereas shoot length was reduced. The Na + /K + ratio was maintained at lower levels in shoots than in roots, suggesting that roots play a protective role. More than 2000 proteins were detected in both tissues. Roots showed a faster and more coordinated proteomic response than shoots, evident after only 6 h of treatment. These responses showed clear correspondence with those of proteins involved in transcription and translation. Maintenance of mitochondrial activity and amino acid metabolism in roots, and activation of stress-responsive proteins such as dehydrins and PLAT in shoots, may play a key role during the response of the plant to salinity stress. Proteomic and physiological responses showed that roots respond in a more highly adaptive manner than shoots to salinity stress, suggesting that this tissue is critical to the tolerance observed in cultivars harboring Saltol.
Plant Biotechnology, 2019
Anther culture is a fast tool to obtain double haploid plant lines for breeding purposes. In rice... more Anther culture is a fast tool to obtain double haploid plant lines for breeding purposes. In rice, this procedure is commonly performed in two steps: i) induction of calli from anthers and ii) regeneration of plantlets from calli. It has been stated that genotype highly influences the anther culture efficiency, so the media used in each step should be optimized for each variety. In this study, we tested different media modifications of an efficient protocol optimized for a medium sized grain temperate japonica NRVC980385, used as a control, in a long grain temperate japonica rice variety (NRVC20120346), and two long grain tropical japonica varieties (303012 and 303013). We found that the addition of 150 mg l −1 colchicine to the induction medium worked best for all genotypes except for NRVC20120346, whose best induction was obtained with the colchicine-free medium. Referring to regeneration, increased gelling agent in the medium provided the best rates in NRVC980385, improving our former NRVC980385-optimized anther culture protocol. Sorbitol fortified regeneration medium worked the best in the case of the long grain varieties. The presence of colchicine in the induction medium was also related to a higher obtention of double haploid plantlets. This study highlights that genotype is a key factor in the performance of rice anther culture. It has set a first anther culture study on long grain japonica varieties and optimizes the anther culture protocol for temperate japonica medium grain NRVC980385 with the use of colchicine and other additives that increase osmotic stress.
Plant Biotechnology, 2018
Rice is one of the greatest calorie supply for the world population, especially since its product... more Rice is one of the greatest calorie supply for the world population, especially since its production is almost entirely destined to direct human consumption and its demand will increase along with the world population. There are efforts worldwide to increase rice yields by obtaining new improved and stabilized rice lines. The rice anther culture, a fast and cheap technique, allows to obtain double haploid lines in less than one year. We report its application with an improved protocol in four Mediterranean japonica rice genotypes at F 2 generation. We performed a screening test for cold-pretreatment at 5.0±0.1°C and concluded that the optimum duration was 9 days as it produced the higher rate of anther-derived callus induction. This revised protocol was successfully applied to the four genotypes, obtaining good results in all the procedure's steps. At the end, more than 100 of double haploid green plants were generated. Moreover, 9 lines obtained from the anther culture procedure showed good qualities for the Spanish market at the growing, farming and grain production level during the field assays. Therefore, we report an improved anther culture procedure for obtaining double haploid lines from temperate japonica rice genotypes showing high commercialization expectance.
BioEnergy Research, 2018
Switchgrass (Panicum virgatum L.) is a warm perennial grass with valuable characteristics as a bi... more Switchgrass (Panicum virgatum L.) is a warm perennial grass with valuable characteristics as a biofuel crop. To avoid competition with food crops, biofuel crops will be likely relegated to less productive soils such as marginal lands. Consequently, the salinity and water scarcity problems that commonly affect marginal lands, compromise biofuel crops germination, emergence and seedling establishment. The aims of this study were to study the germination and seedling growth of switchgrass under salinity and water stress, and to describe the morpho-anatomical responses of the roots and leaves in the seedlings to these stresses. The effect of salt and water stress was assessed using sodium chloride (NaCl) and polyethylene glycol 8000 (PEG) at the same water potentials of-0.8,-1.0 and-1.2 MPa. Seeds were moist prechilled for 7 days at 5 ºC and germinated at 30ºC/15 ºC (8 h light/16 h dark). NaCl treatments (-0.8 and-1.0 MPa) delayed germination rates but did not reduce the final germination percentage, whereas at a lower potential (-1.2 MPa) the final germination percentage was diminished. The effects of PEG (-1.0 and-1.2 MPa) on the germination rate and final percentage, were more detrimental than those induced by iso-osmotic concentrations of NaCl. PEG and NaCl reduced significantly the vigor index of-0.8 to-1.2 MPa. The morpho-anatomical changes such as the reduction in the root cross-section area and the thickening of the endodermis walls for both stress conditions and aerenchyma formation in the cortex under salinity, could significantly contribute in the survival and tolerance during the early seedling stages.
Journal of Plant Studies, 2019
Flow cytometry trituration methods and the efficiency of isolation buffer solutions are compared ... more Flow cytometry trituration methods and the efficiency of isolation buffer solutions are compared in this study for extraction of nuclei from fresh leaves of rice. The razor blade sample trituration procedure has been widely used to release nuclei from tissues in many plant species, and combined with different isolation buffers for low throughput analysis. In contrast, the bead beating trituration method has rarely been used for DNA ploidy determination, despite it being proposed as a less tedious alternative procedure to prepare nuclear suspensions. In this study, bead beating was assessed and compared with the traditional chopping procedure. Each trituration method was combined with one of three nuclear isolation buffers (i.e. Hanson’s, Otto’s and LB01 buffer). Bead beating was applied for the first time using all three of the buffers, resulting in a rapid and effective procedure for ploidy determination in fresh rice leaves. In addition, bead beating saved, while reducing the expo...
Frontiers in Plant Science, 2019
Gibberellins (GAs) are a very important group of phytohormones involved in seed germination, vege... more Gibberellins (GAs) are a very important group of phytohormones involved in seed germination, vegetative growth, flowering, and fruit development, being only 4 of the 136 known bioactives: GA 1 , GA 3 , GA 4 , and GA 7. It has been evidenced that mutations in the OsGA20ox-2 gene produce rice (Oryza sativa) dwarf varieties, which were one of the main pillars of the green revolution. In this work two main objectives were proposed: (i) develop a rapid and broad phytohormone profiling method and (ii) to study the effects on the GA content of the GA20ox-2 mutation in several rice developmental stages using three varieties (tall variety, elite variety, mutated variety). A phytohormone extraction using an SPE step and HPLC-MS/MS detection using a QqQ instrument was determined which resulted in limits of detection (LOD) and limits of quantification (LOQ) for GAs that varied between 0.1-0.7 and 0.3-2.3 pg • g −1 (f.w.) of rice sample, respectively, allowing highly sensitive phytohormones detection in samples. Moreover, a good reproducibility was obtained for the GAs as relative standard deviations (RSD) for a 40 ng • mL −1 pattern varied between 0.3 and 0.9%. Notoriously, GA 1 was absent in the coleoptile and GA 4 was the GA with higher content in the majority of developmental stages. We also observed a large content increase of the four bioactive GAs in the internode of the flag leaf of the mutated variety allowing to reach same height as the elite variety. Therefore, we provide a rapid and broad phytohormonal profiling method and evidence that the GA20ox-2 mutation is not the only factor generating dwarf varieties. To our knowledge, this is the first study that it has been reported such a high number of simultaneously analyzed gibberellins in rice samples (Oryza sativa ssp. japonica) in different tissues of different growth stages.
Plant Cell, Tissue and Organ Culture (PCTOC), 2018
Rice double haploid (DH) plants are produced mainly through anther culture. In order to improve t... more Rice double haploid (DH) plants are produced mainly through anther culture. In order to improve the anther culture protocol, microspores of two japonica rice genotypes (NRVC980385 and H28) were subjected to three growth regulator combinations and four colchicine treatments on induction medium. In addition, a post anther culture procedure using colchicine or oryzalin was tested to induce double haploid plantlets from haploid plantlets. A cold pre-treatment of microspores for 9 days at 10 °C increased callus induction 50-fold in the NRCV980385 genotype. For both genotypes, 2 mg L −1 2,4-D and 1 mg L −1 kinetin on colchicine-free induction medium gave the best culture responses. The culturability of both genotypes changed on colchicine-supplemented induction media. A high genotype dependency was recorded for callus induction, callus regenerating green plantlets and regeneration of green double haploid plantlets. Colchicine at 300 mg L −1 for 48 h enhanced callus induction 100-fold in H28. Colchicine-supplemented media clearly improved green double haploid plantlet regeneration. We showed that the post-anther culture treatment of haploid plantlets at 500 mg L −1 of colchicine permitted fertile double haploid plantlets to be generated. Finally, an enhanced medium-throughput flow cytometry protocol for rice was tested to analyse all the plantlets from anther and post anther culture.