Explore the vast range of titles available.

Although the information on the Normalized Difference Vegetation Index (NDVI) in plants under water deficit is often obtained from sensors attached to satellites, the increasing data acquisition with portable sensors has wide applicability in agricultural production because it is a fast, nondestructive method, and is less prone to interference problems. Thus, we carried out a set of experiments to investigate the influence of time, spatial plant arrangements, sampling size, height of the sensor and water regimes on NDVI readings in different soybean cultivars in greenhouse and field trials during the crop seasons 2011/12, 2012/13 and 2013/14. In experiments where plants were always evaluated under well-watered conditions, we observed that 9 a.m. was the most suitable time for NDVI readings regardless of the soybean cultivar, spatial arrangement or environment. Furthermore, there was no difference among NDVI readings in relation to the sampling size, regardless of the date or cultivar. We also observed that NDVI tended to decrease according to the higher height of the sensor in relation to the canopy top, with higher values tending to be at 0.8 m, but with no significant difference relative to 1.0 m—the height we adopted in our experiments. When different water regimes were induced under field conditions, NDVI readings measured at 9 a.m. by using a portable sensor were successful to differentiate soybean cultivars with contrasting responses to drought.

This study aimed at evaluating the relationship among lignin content in the seed coat of soybean seeds with tolerance to weathering damage and oxidative stress. Four soybean cultivars (CD 208, CD 215, CD 202 and BRS 184), with lignin contents in the seed coat of 4.2, 2.6, 2.0 and 1.7%, respectively, were used. Seeds were subjected to deterioration by moisture, through artificially simulated rains. Pods of all cultivars were subjected to irrigation by constant sprinkling during 4 hours, and then dried in oven, set at 35 °C, for 37 hours; repeating twice such procedure. After these treatments seeds were subjected to tests and then compared to the control. Tests performed were: germination, accelerated aging and tetrazolium test; thereby quantifying the occurrence of damages by weathering damage. The activity of enzymes superoxide dismutase and guaiacol peroxidase was measured; and the lipid peroxidation was assessed. Soybean cultivars CD 208 and CD 215, with higher lignin content in the seed coat, were less susceptible to weathering damage. Seeds of cultivar CD 208 have also presented lower oxidative stress, when subjected to weathering damage stress.

Rainfall is among the climatic factors that most affect production, as in the Brazilian Cerrado. Non-destructive and automated phenotyping methods are fast and efficient for genotype selection. The objective of this work was to evaluate, under field conditions, the morphophysiological changes, yield, and grain quality of soybean (Glycine max L. Merrill) under water stress in the Brazilian Cerrado. The plots comprised six soybean cultivars and the subplots of four water regimes, corresponding to 31, 44, 64 and 100% of crop evapotranspiration replacement. The experiments were conducted from May to September 2018 and 2019. An irrigation system with a bar of sprinklers with different flow rates was used. Gas exchange, vegetation indices (measured using a hyperspectral sensor embedded in a drone), yield and grain quality were evaluated. Water stress had different effects on gas exchange, vegetation indices, grain yield and chemical composition among the cultivars. Embrapa cultivar BRS 7280 Roundup ready (RR) and Nidera cultivar NA 5909 RG (glyphosate resistant) are yield stable and have a greater tolerance to drought. BRS 7280RR showed a higher tolerance to drought and higher water use efficiency (WUE) than all other tested cultivars. Vegetation indices, such as the NDVI (Normalized Difference Vegetation Index), correlated with the morphophysiological traits, such as plant height, were the most responsive variables to water stress. The NDVI can be used to predict soybean yield as a tool in a selection program under drought.

Background Bradyrhizobium japonicum strain SEMIA 5079 (= CPAC 15) is a nitrogen-fixing symbiont of soybean broadly used in commercial inoculants in Brazil. Its genome has about 50% of hypothetical (HP) protein-coding genes, many in the symbiosis island, raising questions about their putative role on the biological nitrogen fixation (BNF) process. This study aimed to infer functional roles to 15 HP genes localized in the symbiosis island of SEMIA 5079, and to analyze their expression in the presence of a nod -gene inducer. Results A workflow of bioinformatics tools/databases was established and allowed the functional annotation of the HP genes. Most were enzymes, including transferases in the biosynthetic pathways of cobalamin, amino acids and secondary metabolites that may help in saprophytic ability and stress tolerance, and hydrolases, that may be important for competitiveness, plant infection, and stress tolerance. Putative roles for other enzymes and transporters identified are discussed. Some HP proteins were specific to the genus Bradyrhizobium , others to specific host legumes, and the analysis of orthologues helped to predict roles in BNF. Conclusions All 15 HP genes were induced by genistein and high induction was confirmed in five of them, suggesting major roles in the BNF process.

ABSTRACT Soybean, the main agricultural commodity of Brazil, is sensitive to deterioration during storage due to its high fatty acid content and fragile seed coat, especially under tropical conditions where high temperature and humidity accelerate this process. The objective of this study is to investigate the mechanisms that are altered during the storage of soybean seeds under uncontrolled environmental conditions. For this purpose, RNA-seq libraries were generated from freshly harvested soybean seeds (FHS) and seeds stored under uncontrolled conditions (UES). The total RNA from seeds of the cultivar BRS 413 was extracted and sequenced for gene expression analysis. Relative expression indicated 325 genes repressed in UES and 150 induced when comparing the genes in stored seeds to freshly harvested ones. Genes related to protein folding, carbohydrate metabolism, lipids, phytohormones, and transcription factors showed a significant reduction in their expression during the storage. Among the genes uniquely expressed in UES, alanine-glyoxylate transaminase (GGAT), cysteine synthase (CSase), aldehyde dehydrogenase (ALDH), thioredoxin peroxidase (Peroxiredoxin), cytochrome P450 and protein phosphatase 2C (PP2C) stood out for making part of protective mechanisms against oxidative stress in plants. RESUMO A soja, principal commodity agrícola do Brasil, é sensível à deterioração durante o armazenamento devido ao seu alto teor de ácidos graxos e tegumento frágil, especialmente sob condições tropicais onde altas temperaturas e umidade aceleram esse processo. O objetivo deste estudo é investigar os mecanismos que são alterados durante o armazenamento de sementes de soja sob condições ambientais não controladas. Para isso, foram geradas bibliotecas de RNA-seq a partir de sementes de soja recém-colhidas (FHS) e sementes armazenadas em condições não controladas (UES). O RNA total das sementes da cultivar BRS 413 foi extraído e sequenciado para análise de expressão gênica. A expressão relativa indicou 325 genes reprimidos em UES e 150 induzidos ao comparar os genes nas sementes armazenadas com as recém-colhidas. Genes relacionados ao dobramento de proteínas, metabolismo de carboidratos, lipídios, fitohormônios e fatores de transcrição mostraram uma redução significativa em sua expressão durante o armazenamento. Entre os genes exclusivamente expressos em UES, alanina-glioxilato transaminase (GGAT), cisteína sintase (CSase), aldeído desidrogenase (ALDH), peroxidase tioredoxina (Peroxiredoxina), citocromo P450 e proteína fosfatase 2C (PP2C) se destacaram por fazerem parte de mecanismos de proteção contra o estresse oxidativo em plantas.

In soybean, studies on drought-responses are conducted during vegetative season. Information related to genes triggered in response to water-deficit (WD) in flower and pod is lacking. We performed an RNASeq and an agro-physiological characterization at stages R2 and R4 of soybean cultivar BR16, under WD. Physiological results showed a decrease in gas exchange parameters. Agronomical results showed WD impaired yield. Global Gene Ontology analyses indicated that most of the Differential Expressed Genes (DEGs) were down-regulated in flowers but up-regulated in pods. qRT-PCR revealed that WD triggered hormone biosynthesis changes. Mechanisms such as a decrease in glyceollin levels and cell wall instability were observed. This data showed tissue-specific mechanisms correlated with phenotypic responses such as drought escape, early flowering hormone-induced, and loss in grain weight. We presented here a comprehensive expression profile of flowers and pods soybean genes, which could guide researchers in the development of plants more tolerant to drought.

BackgroundThe drought condition is responsible for considerable losses in soybean production, which in turn may result in billionaire losses. After drought perception, plants activate a cascade of protecting genes against water deficit (WD), many of which are responsive to abscisic acid, the most important phytohormone to plants’ adaptation. This work aimed to recover abscisic acid (ABA)-responsive differentially expressed genes (DEG) from an RNA-Seq, carried out from leaves and roots of drought-sensitive (BR16) and tolerant (Embrapa 48) soybean cultivars under mild (MiWD), moderate (MoWD), and severe (SWD) water-deficit treatments. Enriched ABA-responsive pathways important to drought tolerance in soybean were also identified.ResultsIn drought-sensitive and tolerant soybean cultivars, approximately 75% of genes were identified as ABA-responsive by containing more than two ABRE (ABA-responsive elements) in the promoter region. Most of these genes were positively regulated. Roots were the tissue with more ABA-responsive genes and pathways triggered in response to WD in both cultivars, although, on the tolerant cultivar, these pathways were higher expressed. The most important enriched ABA pathways observed in the roots of both cultivars were involved in sugar and sulfur amino acid biosynthesis, osmoregulation, and crosstalk among ABA and ethylene, jasmonate, auxin, and cytokinin. Other pathways enriched were involved in phytoalexin production, ROS homeostasis, and membrane stability by glycerolipid and glycerophospholipid production. ABA-responsive genes were also ordered based on their expression profile in tissue and cultivar, and nine confidence groups could be observed. More than 80% of these clustered genes showed the same regulation profile under MiWd, MoWD, and SWD treatments. Activation of ABA biosynthesis under water deficit was validated by RT-qPCR by increasing the expression level of NCED3, an important enzyme in this pathway, and GOLS, a known ABA-responsive gene.ConclusionsA robust catalog of ABA-responsive genes was made available in this work. Considering ABA’s role in drought-response mechanisms, the genes in the groups pointed out in this study would be reliable candidates to be used in strategies to develop soybean lines more tolerant to drought. This paper, presented for the first time, ABA-responsive genes and ABA-enriched pathways in contrasting soybean cultivars for drought tolerance.

Soybean agglutinin (SBA) is a major antinutritional factor in soybean seeds, reducing digestibility in monogastric animals. The Le1 gene encodes the primary lectin accumulated in seeds. Genome editing offers a direct strategy to eliminate this factor in elite cultivars. Two gRNAs targeting Le1 were inserted into a CRISPR/Cas9 binary vector and used for Agrobacterium tumefaciens-mediated transformation of the soybean cultivar BRS 537. Edited plants were screened by PCR, Sanger sequencing, protein electrophoresis (SDS-PAGE), hemagglutination assays, and segregating generations were tested to identify transgene-free progeny. Agronomic traits were evaluated under field conditions. Twenty transformation events were generated, with an editing efficiency of 10%. Event AF12-13-1 carried a 4-bp deletion producing a truncated, unstable lectin protein. SDS-PAGE confirmed the absence of the ~30 kDa SBA band, and hemagglutination assays showed complete loss of lectin activity. Transgene-free T2 plants lacking Bar, Cas9, and AtU6 sequences were identified. Agronomic traits-including yield and thousand-seed weight-were comparable to the wild-type cultivar. CRISPR/Cas9 editing of Le1 effectively eliminated SBA accumulation without compromising key agronomic traits. The resulting low-lectin soybean lines represent a promising approach to improve digestibility and feed efficiency for monogastric animals.

Monitoring of soybean genotypes is important because of intellectual property over seed technology, better management over seed genetics, and more efficient strategies for its agricultural production process. This paper aims at spectrally classifying soybean genotypes submitted to diverse water availability levels at different phenological stages using leaf-based hyperspectral reflectance. Leaf reflectance spectra were collected using a hyperspectral proximal sensor. Two experiments were conducted as field trials: one experiment was at Embrapa Soja in the 2016/2017, 2017/2018, and 2018/2019 cropping seasons, where ten soybean genotypes were grown under four water conditions; and another experiment was in the experimental farm of Unoeste University in the 2018/2019 cropping season, where nine soybean genotypes were evaluated. The spectral data collected was divided into nine spectral datasets, comprising single and multiple cropping seasons (from 2016 to 2019), and two contrasting crop-growing environments. Principal component analysis, applied as an indicator of the explained variance of the reflectance spectra among genotypes within each spectral dataset, explained over 94% of the spectral variance in the first three principal components. Linear discriminant analysis, used to obtain a model of classification of each reflectance spectra of soybean leaves into each soybean genotype, achieved accuracy between 61% and 100% in the calibration procedure and between 50% and 100% in the validation procedure. Misclassification was observed only between genotypes from the same genetic background. The results demonstrated the great potential of the spectral classification of soybean genotypes at leaf-scale, regardless of the phenological stages or water status to which plants were submitted.

Soybean is one of the main sources of vegetable protein used in animal feed, but its nutritional value is limited by the presence of antinutritional factors, such as protease inhibitors (Kunitz and Bowman–Birk), lectins, phytic acid, raffinose family oligosaccharides (RFOs), and saponins, which reduce the digestibility and absorption of nutrients. In recent decades, advances in metabolic engineering and functional genomics have allowed the targeting of biochemical pathways to increase the content and quality of proteins while simultaneously reducing these undesirable compounds. This work reviews the main progress achieved through transgenesis, induced mutagenesis, and precision gene editing, highlighting the role of tools such as RNAi, CRISPR/Cas9, and AlphaFold2-guided gene editing in modifying genes involved in carbon and nitrogen metabolism and storage proteins. Recent studies demonstrate that the silencing of negative regulatory genes, such as CIF1 and AIP2 , can elevate the protein content of seeds, while the editing of sugar transporters SWEET10a and SWEET10b allows the modulation of the oil-protein balance. Simultaneously, the inactivation of genes related to antinutritional factors has significantly reduced the expression of compounds such as phytate and protease inhibitors. The integration of new approaches, such as promoter engineering and Prime Editing, promises to further enhance the precision of genetic modifications, minimizing pleiotropic effects. Taken together, these strategies consolidate metabolic engineering as a promising tool for the development of soybean cultivars with higher protein content and quality, and with lower content of antinutritional factors, optimizing their use in animal feed