RESUMEN

Improving plant performance in salinity-prone conditions is a significant challenge in breeding programs. Genomic selection is currently integrated into many plant breeding programs as a tool for increasing selection intensity and precision for complex traits and for reducing breeding cycle length. A rice reference panel (RP) of 241 Oryza sativa L. japonica accessions genotyped with 20,255 SNPs grown in control and mild salinity stress conditions was evaluated at the vegetative stage for eight morphological traits and ion mass fractions (Na and K). Weak to strong genotype-by-condition interactions were found for the traits considered. Cross-validation showed that the predictive ability of genomic prediction methods ranged from 0.25 to 0.64 for multi-environment models with morphological traits and from 0.05 to 0.40 for indices of stress response and ion mass fractions. The performances of a breeding population (BP) comprising 393 japonica accessions were predicted with models trained on the RP. For validation of the predictive performances of the models, a subset of 41 accessions was selected from the BP and phenotyped under the same experimental conditions as the RP. The predictive abilities estimated on this subset ranged from 0.00 to 0.66 for the multi-environment models, depending on the traits, and were strongly correlated with the predictive abilities on cross-validation in the RP in salt condition (r = 0.69). We show here that genomic selection is efficient for predicting the salt stress tolerance of breeding lines. Genomic selection could improve the efficiency of rice breeding strategies for salinity-prone environments.

Asunto(s)

Oryza , Oryza/genética , Tolerancia a la Sal/genética , Fitomejoramiento , Genómica , Genotipo

RESUMEN

Adaptation to different soil conditions is a well-regulated process vital for plant life. AtHB23 is a homeodomain-leucine zipper I transcription factor (TF) that was previously revealed as crucial for plant survival under salinity conditions. We wondered whether this TF has partners to perform this essential function. Therefore, TF cDNA library screening, yeast two-hybrid, bimolecular fluorescence complementation, and coimmunoprecipitation assays were complemented with expression analyses and phenotypic characterization of silenced, mutant, overexpression, and crossed plants in normal and salinity conditions. We revealed that AtHB23, AtPHL1, and AtMYB68 interact with each other, modulating root development and the salinity response. The encoding genes are coexpressed in specific root tissues and at specific developmental stages. In normal conditions, amiR68 silenced plants have fewer initiated roots, the opposite phenotype to that shown by amiR23 plants. AtMYB68 and AtPHL1 play opposite roles in lateral root elongation. Under salinity conditions, AtHB23 plays a crucial positive role in cooperating with AtMYB68, whereas AtPHL1 acts oppositely by obstructing the function of the former, impacting the plant's survival ability. Such interplay supports the complex interaction between these TF in primary and lateral roots. The root adaptation capability is associated with the amyloplast state. We identified new molecular players that through a complex relationship determine Arabidopsis root architecture and survival in salinity conditions.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Raíces de Plantas , Tolerancia a la Sal , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Tolerancia a la Sal/genética

RESUMEN

Teak (Tectona grandis) is one of the most important wood sources, and it is cultivated in tropical regions with a significant market around the world. Abiotic stresses are an increasingly common and worrying environmental phenomenon because it causes production losses in both agriculture and forestry. Plants adapt to these stress conditions by activation or repression of specific genes, and they synthesize numerous stress proteins to maintain their cellular function. For example, APETALA2/ethylene response factor (AP2/ERF) was found to be involved in stress signal transduction. A search in the teak transcriptome database identified an AP2/ERF gene named TgERF1 with a key AP2/ERF domain. We then verified that the TgERF1 expression is rapidly induced by Polyethylene Glycol (PEG), NaCl, and exogenous phytohormone treatments, suggesting a potential role in drought and salt stress tolerance in teak. The full-length coding sequence of TgERF1 gene was isolated from teak young stems, characterized, cloned, and constitutively overexpressed in tobacco plants. In transgenic tobacco plants, the overexpressed TgERF1 protein was localized exclusively in the cell nucleus, as expected for a transcription factor. Furthermore, functional characterization of TgERF1 provided evidence that TgERF1 is a promising candidate gene to be used as selective marker on plant breeding intending to improve plant stress tolerance.

Asunto(s)

Nicotiana , Factores de Transcripción , Factores de Transcripción/metabolismo , Nicotiana/genética , Sequías , Regulación de la Expresión Génica de las Plantas , Fitomejoramiento , Plantas Modificadas Genéticamente/genética , Estrés Fisiológico/genética , Tolerancia a la Sal/genética , Proteínas de Plantas/genética , Filogenia

RESUMEN

Plants adjust their complex molecular, biochemical, and metabolic processes to overcome salt stress. Here, we investigated the proteomic and epigenetic alterations involved in the morphophysiological responses of Pfaffia glomerata, a medicinal plant, to salt stress and the demethylating agent 5-azacytidine (5-azaC). Moreover, we investigated how these changes affected the biosynthesis of 20-hydroxyecdysone (20-E), a pharmacologically important specialized metabolite. Plants were cultivated in vitro for 40 days in Murashige and Skoog medium supplemented with NaCl (50 mM), 5-azaC (25 µM), and NaCl + 5-azaC. Compared with the control (medium only), the treatments reduced growth, photosynthetic rates, and photosynthetic pigment content, with increase in sucrose, total amino acids, and proline contents, but a reduction in starch and protein. Comparative proteomic analysis revealed 282 common differentially accumulated proteins involved in 87 metabolic pathways, most of them related to amino acid and carbohydrate metabolism, and specialized metabolism. 5-azaC and NaCl + 5-azaC lowered global DNA methylation levels and 20-E content, suggesting that 20-E biosynthesis may be regulated by epigenetic mechanisms. Moreover, downregulation of a key protein in jasmonate biosynthesis indicates the fundamental role of this hormone in the 20-E biosynthesis. Taken together, our results highlight possible regulatory proteins and epigenetic changes related to salt stress tolerance and 20-E biosynthesis in P. glomerata, paving the way for future studies of the mechanisms involved in this regulation.

Asunto(s)

Amaranthaceae , Proteómica , Azacitidina/farmacología , Cloruro de Sodio/farmacología , Tolerancia a la Sal/genética , Epigénesis Genética , Proteínas de Plantas/metabolismo , Estrés Fisiológico

RESUMEN

NAC transcription factors play critical roles in xylem secondary development and in regulation of stress response in plants. NAC proteins related to secondary cell wall development were recently identified and characterized in Tectona grandis (teak), one of the hardwood trees of highest economic importance in the world. In this work, we characterized the novel TgNAC01 gene, which is involved in signaling pathways that mediate teak response to stress. Abscisic acid (ABA) increases TgNAC01 expression in teak plants. Therefore, this gene may have a role in signaling events that mediate ABA-dependent osmotic stress responsive in this plant species. Stable expression in tobacco plants showed that the TgNAC01 protein is localized in the cell nucleus. Overexpression of TgNAC01 in two out three independent transgenic tobacco lines resulted in increased growth, leaf senescence and salt tolerance compared to wild type (WT) plants. Moreover, the stress tolerance of transgenic plants was affected by levels of TgNAC01 gene expression. Water potential, gas exchange and chlorophyll fluorescence were used to determine salt stress tolerance. The 35S:TgNAC01-6 line under 300 mM NaCl stress responded with a significant increase in photosynthesis rate, stomatal conductance, transpiration and carboxylation efficiency, but lower water potential compared to WT plants. The data indicate that the TgNAC01 transcription factor acts as a transcriptional activator of the ABA-mediated regulation and induces leaf senescence.

Asunto(s)

Nicotiana , Tolerancia a la Sal , Plantas Modificadas Genéticamente/genética , Tolerancia a la Sal/genética , Nicotiana/genética , Senescencia de la Planta , Proteínas de Plantas/genética , Estrés Salino/genética , Ácido Abscísico/farmacología , Factores de Transcripción/genética , Agua/metabolismo

RESUMEN

Soil salinity is one abiotic stress that threatens agriculture in more than 100 countries. Gliricidia [Gliricidia sepium (Jacq.) Kunth] is a multipurpose tree known for its ability to adapt to a wide range of soils; however, its tolerance limits and responses to salt stress are not yet well understood. In this study, after characterizing the morphophysiological responses of young gliricidia plants to salinity stress, leaf metabolic and transcription profiles were generated and submitted to single and integrated analyses. RNA from leaf samples were subjected to RNA sequencing using an Illumina HiSeq platform and the paired-end strategy. Polar and lipidic fractions from leaf samples were extracted and analyzed on an ultra-high-performance liquid chromatography (UHPLC) coupled with electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (MS) system. Acquired data were analyzed using the OmicsBox, XCMS Online, MetaboAnalyst, and Omics Fusion platforms. The substrate salinization protocol used allowed the identification of two distinct responses to salt stress: tolerance and adaptation. Single analysis on transcriptome and metabolome data sets led to a group of 5,672 transcripts and 107 metabolites differentially expressed in gliricidia leaves under salt stress. The phenylpropanoid biosynthesis was the most affected pathway, with 15 metabolites and three genes differentially expressed. Results showed that the differentially expressed metabolites and genes from this pathway affect mainly short-term salt stress (STS). The single analysis of the transcriptome identified 12 genes coding for proteins that might play a role in gliricidia response at both STS and long-term salt stress (LTS). Further studies are needed to reveal the mechanisms behind the adaptation response.

Asunto(s)

Fabaceae , Transcriptoma , Fabaceae/genética , Metabolómica , Salinidad , Estrés Salino/genética , Tolerancia a la Sal/genética

RESUMEN

Soil salinity is one of the most limiting stresses for crop productivity and quality worldwide. In this sense, jasmonates (JAs) have emerged as phytohormones that play essential roles in mediating plant response to abiotic stresses, including salt stress. Here, we reviewed the mechanisms underlying the activation and response of the JA-biosynthesis and JA-signaling pathways under saline conditions in Arabidopsis and several crops. In this sense, molecular components of JA-signaling such as MYC2 transcription factor and JASMONATE ZIM-DOMAIN (JAZ) repressors are key players for the JA-associated response. Moreover, we review the antagonist and synergistic effects between JA and other hormones such as abscisic acid (ABA). From an applied point of view, several reports have shown that exogenous JA applications increase the antioxidant response in plants to alleviate salt stress. Finally, we discuss the latest advances in genomic techniques for the improvement of crop tolerance to salt stress with a focus on jasmonates.

Asunto(s)

Adaptación Fisiológica/genética , Ciclopentanos/metabolismo , Genómica , Oxilipinas/metabolismo , Plantas/genética , Estrés Salino/genética , Tolerancia a la Sal/genética

RESUMEN

Hexokinases (HXKs) and fructokinases (FRKs) are the only two families of enzymes in plants that have been identified as able to phosphorylate Glucose (Glc) and Fructose (Fru). Glc can only be phosphorylated in plants by HXKs, while Fru can be phosphorylated by either HXKs or FRKs. The various subcellular localizations of HXKs in plants indicate that they are involved in diverse functions, including anther dehiscence and pollen germination, stomatal closure in response to sugar levels, stomatal aperture and reducing transpiration. Its association with modulating programmed cell death, and responses to oxidative stress and pathogen infection (abiotic and biotic stresses) also have been reported. To extend our understanding about the function of HXK-like genes in the response of Prunus rootstocks to abiotic stress, we performed a detailed bioinformatic and functional analysis of hexokinase 3-like genes (HXK3s) from two Prunus rootstock genotypes, 'M.2624' (Prunus cerasifera Ehrh × P. munsoniana W.Wight & Hedrick) and 'M.F12/1' (P. avium L.), which are tolerant and sensitive to hypoxia stress, respectively. A previous large-scale transcriptome sequencing of roots of these rootstocks, showed that this HXK3-like gene that was highly induced in the tolerant genotype under hypoxia conditions. In silico analysis of gene promoters from M.2624 and M.F12/1 genotypes revealed regulatory elements that could explain differential transcriptional profiles of HXK3 genes. Subcellular localization was determinates by both bioinformatic prediction and expression of their protein fused to the green fluorescent protein (GFP) in protoplasts and transgenic plants of Arabidopsis. Both approaches showed that they are expressed in plastids. Metabolomics analysis of Arabidopsis plants ectopically expressing Prunus HXK3 genes revealed that content of several metabolites including phosphorylated sugars (G6P), starch and some metabolites associated with the TCA cycle were affected. These transgenic Arabidopsis plants showed improved tolerance to salt and drought stress under growth chamber conditions. Our results suggest that Prunus HXK3 is a potential candidate for enhancing tolerance to salt and drought stresses in stone fruit trees and other plants.

Asunto(s)

Arabidopsis/fisiología , Hexoquinasa/genética , Prunus/genética , Tolerancia a la Sal/genética , Secuencia de Aminoácidos , Arabidopsis/genética , Hexoquinasa/química , Hipoxia/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Homología de Secuencia de Aminoácido

RESUMEN

With the notable exception of angiosperms, all phototrophs contain different sets of flavodiiron proteins that help to relieve the excess of excitation energy on the photosynthetic electron transport chain during adverse environmental conditions, presumably by reducing oxygen directly to water. Among them, the Flv2-Flv4 dimer is only found in ß-cyanobacteria and induced by high light, supporting a role in stress protection. The possibility of a similar protective function in plants was assayed by expressing Synechocystis Flv2-Flv4 in chloroplasts of tobacco and Arabidopsis. Flv-expressing plants exhibited increased tolerance toward high irradiation, salinity, oxidants, and drought. Stress tolerance was reflected by better growth, preservation of photosynthetic activity, and membrane integrity. Metabolic profiling under drought showed enhanced accumulation of soluble sugars and amino acids in transgenic Arabidopsis and a remarkable shift of sucrose into starch, in line with metabolic responses of drought-tolerant genotypes. Our results indicate that the Flv2-Flv4 complex retains its stress protection activities when expressed in chloroplasts of angiosperm species by acting as an additional electron sink. The flv2-flv4 genes constitute a novel biotechnological tool to generate plants with increased tolerance to agronomically relevant stress conditions that represent a significant productivity constraint.

Asunto(s)

Adaptación Biológica , Arabidopsis/fisiología , Cloroplastos/genética , Nicotiana/fisiología , Proteínas de Plantas/genética , Estrés Fisiológico/genética , Sequías , Regulación de la Expresión Génica de las Plantas , Estrés Oxidativo , Fenotipo , Complejo de Proteína del Fotosistema II/genética , Complejo de Proteína del Fotosistema II/metabolismo , Fenómenos Fisiológicos de las Plantas , Plantas Modificadas Genéticamente , Plastidios/genética , Tolerancia a la Sal/genética

RESUMEN

BACKGROUND: Soil salinity causes huge economic losses to agriculture productivity in arid and semiarid areas worldwide. The affected plants face disturbances in osmotic adjustment, nutrient transport, ionic toxicity and reduced photosynthesis. Conventional breeding approaches produce little success in combating various stresses in plants. However, non-conventional approaches, such as in vitro tissue culturing, produce genetic variability in the development of salt-tolerant plants, particularly in woody trees. RESULTS: Embryogenic callus cultures of the date palm cultivar Khalas were subjected to various salt levels ranging from 0 to 300 mM in eight subcultures. The regenerants obtained from the salt-treated cultures were regenerated and evaluated using the same concentration of NaCl with which the calli were treated. All the salt-adapted (SA) regenerants showed improved growth characteristics, physiological performance, ion concentrations and K+/Na+ ratios than the salt non-adapted (SNA) regenerants and the control. Regression between the leaf Na+ concentration and net photosynthesis revealed an inverse nonlinear correlation in the SNA regenerants. Leaf K+ contents and stomatal conductance showed a strong linear relationship in SA regenerants compared with the inverse linear correlation, and a very poor coefficient of determination in SNA regenerants. The genetic fidelity of the selected SA regenerants was also tested using 36 random amplified polymorphic DNA (RAPD) primers, of which 26 produced scorable bands. The primers generated 1-10 bands, with an average of 5.4 bands per RAPD primer; there was no variation between SA regenerants and the negative control. CONCLUSION: This is the first report of the variants generated from salt-stressed cultures and their potential adaptation to salinity in date palm cv. Khalas. The massive production of salt stress-adapted date palm plants may be much easier using the salt adaptation approach. Such plants can perform better during exposure to salt stress compared to the non-treated date palm plants.

Asunto(s)

Aclimatación , Phoeniceae/genética , Tolerancia a la Sal/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Salinidad

RESUMEN

MAIN CONCLUSION: Accumulation of specific metabolites, mainly γ-aminobutyric acid, polyamines, and proline, was essential to homeostasis regulation and differential salt tolerance in sorghum genotypes. Salinity is severe abiotic stress that limits plant growth and development in arid and semi-arid regions. Survival to abiotic stresses depends on metabolic and sometimes even morphological adjustments. We measured the growth parameters, water relations, the content of ions (Na+, K+, Cl-), compatible solutes [some free amino acids (FAAs) including γ-aminobutyric acid (GABA) and proline and soluble carbohydrates) and polyamines (PAs), the activity of PAs metabolism enzymes, and metabolomic profile in plants after 14 days of salt stress treatment. These analyses were to evaluate the influence of metabolomic responses of sorghum genotypes exhibiting sensitivity (CSF18) or tolerance (CSF20) to salinity on plant growth. The salinity promoted growth reductions and induced increases in Na+ and Cl- content and decreases in K+ content. The water status and osmotic potential (Ψo) were reduced by salt stress, but to minimize damage, especially in the CSF20, the osmolytes and PAs contributed to the osmotic adjustment. The results showed that salinity induced an increase in putrescine (Put) in the sensitive genotype. However, it raised spermidine (Spd), spermine (Spm), and cadaverine (Cad) in the tolerant genotype. In addition, the regulation of polyamine oxidase can be related to Spm and GABA biosynthesis. Differential metabolic changes to salt tolerance include metabolites associated with tricarboxylic acid (TCA) cycle intermediates and the metabolisms of sugars, FAAs, and PAs.

Asunto(s)

Desarrollo de la Planta/genética , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Tolerancia a la Sal/genética , Tolerancia a la Sal/fisiología , Sorghum/genética , Sorghum/metabolismo , Variación Genética , Genotipo , Desarrollo de la Planta/fisiología , Estrés Salino/genética , Estrés Salino/fisiología

RESUMEN

Soybean is an economically important plant, and its production is affected in soils with high salinity levels. It is important to understand the adaptive mechanisms through which plants overcome this kind of stress and to identify potential genes for improving abiotic stress tolerance. RNA-Seq data of two Glycine max cultivars, a drought-sensitive (C08) and a tolerant (Conquista), subjected to different periods of salt stress were analyzed. The transcript expression profile was obtained using a transcriptogram approach, comparing both cultivars and different times of treatment. After 4 h of salt stress, Conquista cultivar had 1400 differentially expressed genes, 647 induced and 753 repressed. Comparative expression revealed that 719 genes share the same pattern of induction or repression between both cultivars. Among them, 393 genes were up- and 326 down-regulated. Salt stress also modified the expression of 54 isoforms of miRNAs in Conquista, by the maturation of 39 different pre-miRNAs. The predicted targets for 12 of those mature miRNAs also have matches with 15 differentially expressed genes from our analyses. We found genes involved in important pathways related to stress adaptation. Genes from both ABA and BR signaling pathways were modulated, with possible crosstalk between them, and with a likely post-transcriptional regulation by miRNAs. Genes related to ethylene biosynthesis, DNA repair, and plastid translation process were those that could be regulated by miRNA.

Asunto(s)

Glycine max/genética , Estrés Salino/genética , Tolerancia a la Sal/genética , Adaptación Fisiológica/genética , Agricultura/métodos , Sequías , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica de las Plantas/genética , Salinidad , Transducción de Señal/genética , Estrés Fisiológico/genética , Factores de Transcripción/genética , Transcriptoma/genética

RESUMEN

BACKGROUND: Pyruvic acid (PA), a vital α-oxocarboxylic acid, plays an important role in energy and carbon metabolism. The oleaginous yeast Yarrowia lipolytica (Y. lipolytica) has considerable potential for the production of PA. An increased NaCl concentration reportedly increases the biomass and PA yield of Y. lipolytica. RESULTS: To increase the yield of PA, the NaCl-tolerant Y. lipolytica A4 mutant was produced using the atmospheric and room temperature plasma method of mutation. The A4 mutant showed growth on medium containing 160 g/L NaCl. The PA yield of the A4 mutant reached 97.2 g/L at 120 h (0.795 g/g glycerol) in a 20-L fermenter with glycerol as the sole carbon source, which was 28.9% higher than that of the parental strain. CONCLUSION: The PA yield from Y. lipolytica can be improved by increasing its NaCl tolerance.

Asunto(s)

Ácido Pirúvico/metabolismo , Yarrowia/genética , Yarrowia/metabolismo , Presión Osmótica , Levaduras , Carbono/metabolismo , Cloruro de Sodio , Reactores Biológicos , Tolerancia a la Sal/genética , Fermentación , Glicerol/metabolismo , Mutación

RESUMEN

In northern Mexico, aridity, salinity and high temperatures limit areas that can be cultivated. To investigate the nature of nitrogen-fixing symbionts of Phaseolus filiformis, an adapted wild bean species native to this region, their phylogenies were inferred by MLSA. Most rhizobia recovered belong to the proposed new species Ensifer aridi. Phylogenetic analyses of nodC and nifH show that Mexican isolates carry symbiotic genes acquired through horizontal gene transfer that are divergent from those previously characterized among bean symbionts. These strains are salt tolerant, able to grow in alkaline conditions, high temperatures, and capable of utilizing a wide range of carbohydrates and organic acids as carbon sources for growth. This study improves the knowledge on diversity, geographic distribution and evolution of bean-nodulating rhizobia in Mexico and further enlarges the spectrum of microsymbiont with which Phaseolus species can interact with, including cultivated bean varieties, notably under stressed environments. Here, the species Ensifer aridi sp. nov. is proposed as strain type of the Moroccan isolate LMR001T (= LMG 31426T; = HAMBI 3707T) recovered from desert sand dune.

Asunto(s)

Phaseolus/metabolismo , Rhizobiaceae/clasificación , Rhizobiaceae/aislamiento & purificación , Nódulos de las Raíces de las Plantas/microbiología , ADN Bacteriano/genética , Calor , México , Phaseolus/crecimiento & desarrollo , Filogenia , ARN Ribosómico 16S/genética , Rhizobiaceae/genética , Tolerancia a la Sal/genética , Arena , Análisis de Secuencia de ADN , Simbiosis

RESUMEN

BACKGROUND: Soil salinity causes huge economic losses to agriculture productivity in arid and semiarid areas world-wide. The affected plants face disturbances in osmotic adjustment, nutrient transport, ionic toxicity and reduced photosynthesis. Conventional breeding approaches produce little success in combating various stresses in plants. However, non-conventional approaches, such as in vitro tissue culturing, produce genetic variability in the development of salt-tolerant plants, particularly in woody trees. RESULTS: Embryogenic callus cultures of the date palm cultivar Khalas were subjected to various salt levels ranging from 0 to 300 mM in eight subcultures. The regenerants obtained from the salt-treated cultures were regenerated and evaluated using the same concentration of NaCl with which the calli were treated. All the salt-adapted (SA) regenerants showed improved growth characteristics, physiological performance, ion concentrations and K+/Na+ ratios than the salt non-adapted (SNA) regenerants and the control. Regression between the leaf Na+ concentration and net photosynthesis revealed an inverse nonlinear correlation in the SNA regenerants. Leaf K+ contents and stomatal conductance showed a strong linear relationship in SA regenerants compared with the inverse linear correlation, and a very poor coefficient of determination in SNA regenerants. The genetic fidelity of the selected SA regenerants was also tested using 36 random amplified polymorphic DNA (RAPD) primers, of which 26 produced scorable bands. The primers generated 1-10 bands, with an average of 5.4 bands per RAPD primer; there was no variation between SA regenerants and the negative control. CONCLUSION: This is the first report of the variants generated from salt-stressed cultures and their potential adaptation to salinity in date palm cv. Khalas. The massive production of salt stress-adapted date palm plants may be much easier using the salt adaptation approach. Such plants can perform better during exposure to salt stress compared to the non-treated date palm plants.

Asunto(s)

Tolerancia a la Sal/genética , Phoeniceae/genética , Aclimatación , Técnica del ADN Polimorfo Amplificado Aleatorio , Salinidad

RESUMEN

Intermediate-salinity environments are distributed around the world. Here, we present a snapshot characterization of two Peruvian thalassohaline environments at high altitude, Maras and Acos, which provide an excellent opportunity to increase our understanding of these ecosystems. The main goal of this study was to assess the structure and functional diversity of the communities of microorganisms in an intermediate-salinity environment, and we used a metagenomic shotgun approach for this analysis. These Andean hypersaline systems exhibited high bacterial diversity and abundance of the phyla Proteobacteria, Bacteroidetes, Balneolaeota, and Actinobacteria; in contrast, Archaea from the phyla Euryarchaeota, Thaumarchaeota, and Crenarchaeota were identified in low abundance. Acos harbored a more diverse prokaryotic community and a higher number of unique species compared with Maras. In addition, we obtained the draft genomes of two bacteria, Halomonas elongata and Idiomarina loihiensis, as well as the viral genomes of Enterobacteria lambda-like phage and Halomonas elongata-like phage and 27 partial novel viral halophilic genomes. The functional metagenome annotation showed a high abundance of sequences associated with detoxification, DNA repair, cell wall and capsule formation, and nucleotide metabolism; sequences for these functions were overexpressed mainly in bacteria and also in some archaea and viruses. Thus, their metabolic profiles afford a decrease in oxidative stress as well as the assimilation of nitrogen, a critical energy source for survival. Our work represents the first microbial characterization of a community structure in samples collected from Peruvian hypersaline systems.

Asunto(s)

Metagenómica/métodos , Microbiota/genética , Microbiota/fisiología , Tolerancia a la Sal/genética , Actinobacteria/genética , Altitud , Archaea/genética , Bacterias/genética , Bacteroidetes/genética , Biodiversidad , Euryarchaeota/genética , Perú , Filogenia , Proteobacteria/genética , ARN Ribosómico 16S/genética , Salinidad , Virus/genética

RESUMEN

High throughput phenotyping technologies are lagging behind modern marker technology impairing the use of secondary traits to increase genetic gains in plant breeding. We aimed to assess whether the combined use of hyperspectral data with modern marker technology could be used to improve across location pre-harvest yield predictions using different statistical models. A maize bi-parental doubled haploid (DH) population derived from F1, which consisted of 97 lines was evaluated in testcross combination under heat stress as well as combined heat and drought stress during the 2014 and 2016 summer season in Ciudad Obregon, Sonora, Mexico (27°20" N, 109°54" W, 38 m asl). Full hyperspectral data, indicative of crop physiological processes at the canopy level, was repeatedly measured throughout the grain filling period and related to grain yield. Partial least squares regression (PLSR), random forest (RF), ridge regression (RR) and Bayesian ridge regression (BayesB) were used to assess prediction accuracies on grain yield within (two-fold cross-validation) and across environments (leave-one-environment-out-cross-validation) using molecular markers (M), hyperspectral data (H) and the combination of both (HM). Highest prediction accuracy for grain yield averaged across within and across location predictions (rGP) were obtained for BayesB followed by RR, RF and PLSR. The combined use of hyperspectral and molecular marker data as input factor on average had higher predictions for grain yield than hyperspectral data or molecular marker data alone. The highest prediction accuracy for grain yield across environments was measured for BayesB when molecular marker data and hyperspectral data were used as input factors, while the highest within environment prediction was obtained when BayesB was used in combination with hyperspectral data. It is discussed how the combined use of hyperspectral data with molecular marker technology could be used to introduce physiological genomic estimated breeding values (PGEBV) as a pre-harvest decision support tool to select genetically superior lines.

Asunto(s)

Agricultura/métodos , Respuesta al Choque Térmico/genética , Zea mays/genética , Teorema de Bayes , Biomarcadores , Sequías , Grano Comestible/genética , Predicción/métodos , Genoma de Planta/genética , Genómica , Genotipo , Calor , México , Modelos Genéticos , Fenotipo , Fitomejoramiento/métodos , Tolerancia a la Sal/genética , Selección Genética/genética

RESUMEN

KEY MESSAGE: In this study we show that expression of the Arabidopsis ABF4 gene in potato increases tuber yield under normal and abiotic stress conditions, improves storage capability and processing quality of the tubers, and enhances salt and drought tolerance. Potato is the third most important food crop in the world. Potato plants are susceptible to salinity and drought, which negatively affect crop yield, tuber quality and market value. The development of new varieties with higher yields and increased tolerance to adverse environmental conditions is a main objective in potato breeding. In addition, tubers suffer from undesirable sprouting during storage that leads to major quality losses; therefore, the control of tuber sprouting is of considerable economic importance. ABF (ABRE-binding factor) proteins are bZIP transcription factors that regulate abscisic acid signaling during abiotic stress. ABF proteins also play an important role in the tuberization induction. We developed transgenic potato plants constitutively expressing the Arabidopsis ABF4 gene (35S::ABF4). In this study, we evaluated the performance of 35S::ABF4 plants grown in soil, determining different parameters related to tuber yield, tuber quality (carbohydrates content and sprouting behavior) and tolerance to salt and drought stress. Besides enhancing salt stress and drought tolerance, constitutive expression of ABF4 increases tuber yield under normal and stress conditions, enhances storage capability and improves the processing quality of the tubers.

Asunto(s)

Proteínas de Arabidopsis/genética , Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Sequías , Regulación de la Expresión Génica de las Plantas , Tubérculos de la Planta/genética , Tubérculos de la Planta/fisiología , Tolerancia a la Sal/genética , Solanum tuberosum/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Clorofila/metabolismo , Transporte de Electrón/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Oxidación-Reducción , Fotosíntesis/efectos de los fármacos , Estomas de Plantas/efectos de los fármacos , Estomas de Plantas/genética , Estomas de Plantas/fisiología , Transpiración de Plantas/efectos de los fármacos , Transpiración de Plantas/genética , Tubérculos de la Planta/efectos de los fármacos , Plantas Modificadas Genéticamente , Prolina/metabolismo , Tolerancia a la Sal/efectos de los fármacos , Cloruro de Sodio/farmacología , Solanum tuberosum/efectos de los fármacos , Agua

RESUMEN

Background: Soil salinity can significantly reduce crop production, but the molecular mechanism of salinity tolerance in peanut is poorly understood. A mutant (S1) with higher salinity resistance than its mutagenic parent HY22 (S3) was obtained. Transcriptome sequencing and digital gene expression (DGE) analysis were performed with leaves of S1 and S3 before and after plants were irrigated with 250 mM NaCl. Results: A total of 107,725 comprehensive transcripts were assembled into 67,738 unigenes using TIGR Gene Indices clustering tools (TGICL). All unigenes were searched against the euKaryotic Ortholog Groups (KOG), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and these unigenes were assigned to 26 functional KOG categories, 56 GO terms, 32 KEGG groups, respectively. In total 112 differentially expressed genes (DEGs) between S1 and S3 after salinity stress were screened, among them, 86 were responsive to salinity stress in S1 and/or S3. These 86 DEGs included genes that encoded the following kinds of proteins that are known to be involved in resistance to salinity stress: late embryogenesis abundant proteins (LEAs), major intrinsic proteins (MIPs) or aquaporins, metallothioneins (MTs), lipid transfer protein (LTP), calcineurin B-like protein-interacting protein kinases (CIPKs), 9-cis-epoxycarotenoid dioxygenase (NCED) and oleosins, etc. Of these 86 DEGs, 18 could not be matched with known proteins. Conclusion: The results from this study will be useful for further research on the mechanism of salinity resistance and will provide a useful gene resource for the variety breeding of salinity resistance in peanut.

Asunto(s)

Arachis/genética , Plantas Tolerantes a la Sal/genética , Tolerancia a la Sal/genética , Transcriptoma/genética , Suelo , Cloruro de Sodio , Análisis de Secuencia de ARN/métodos , Perfilación de la Expresión Génica/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa , Mutación

RESUMEN

Glycine-rich protein (GRP) is involved in the response to abiotic and biotic stresses in plants. A novel GRP gene in Lablab purpureus has been identified. The cDNA of LpGRP was obtained from an SSH library constructed with root tissues of L. purpureus MEIDOU 2012 by waterholding for 10 days. The function of LpGRP was also evaluated in Arabidopsis. The cDNA of LpGRP has 555 bp and encodes a 184-amino acid protein. LpGRP was induced by drought and improved tolerance to abiotic stress. In LpGRP overexpressing Arabidopsis, the tolerance of transgenic seedlings to drought and salt was improved, and transgenic seeds showed insensitivity to both ABA and NaCl. The insensitivity to ABA indicated that there was crosstalk between LpGRP and ABA-responsive genes. These results indicated that LpGRP is a drought-responsive gene that can increase the drought and salt tolerance of Arabidopsis seedlings overexpressing LpGRP.

Asunto(s)

Proteínas de Arabidopsis/genética , Fabaceae/genética , Plantas Modificadas Genéticamente/genética , Estrés Fisiológico/genética , Arabidopsis/genética , Sequías , Fabaceae/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Germinación/genética , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Tolerancia a la Sal/genética , Semillas/genética , Semillas/crecimiento & desarrollo