Transgenic Soybean Research Articles

Arabidopsis non-host resistance PSS30 gene enhances broad-spectrum disease resistance in the soybean cultivar Williams 82.

Non-host resistance (NHR), which protects all members of a plant species from non-adapted or non-host plant pathogens, is the most common form of plant immunity. NHR provides the most durable and robust form of broad-spectrum immunity against non-adaptive pathogens pathogenic to other crop species. In a mutant screen for loss of Arabidopsis (Arabidopsis thaliana) NHR against the soybean (Glycine max (L.) Merr.) pathogen Phytophthora sojae, the Phytophthora sojae-susceptible 30 (pss30) mutant was identified. The pss30 mutant is also susceptible to the soybean pathogen Fusarium virguliforme. PSS30 encodes a folate transporter, AtFOLT1, which was previously localized to chloroplasts and implicated in the transport of folate from the cytosol to plastids. We show that two Arabidopsis folate biosynthesis mutants with reduced folate levels exhibit a loss of non-host immunity against P. sojae. As compared to the wild-type Col-0 ecotype, the steady-state folate levels are reduced in the pss1, atfolt1 and two folate biosynthesis mutants, suggesting that folate is required for non-host immunity. Overexpression of AtFOLT1 enhances immunity of transgenic soybean lines against two serious soybean pathogens, the fungal pathogen F. virguliforme and the soybean cyst nematode (SCN) Heterodera glycines. Transgenic lines showing enhanced SCN resistance also showed increased levels of folate accumulation. This study thus suggests that folate contributes to non-host plant immunity and that overexpression of a non-host resistance gene could be a suitable strategy for generating broad-spectrum disease resistance in crop plants.

Gm6PGDH1, a Cytosolic 6-Phosphogluconate Dehydrogenase, Enhanced Tolerance to Phosphate Starvation by Improving Root System Development and Modifying the Antioxidant System in Soybean.

Phosphorus plays an important role in plant growth and development, and is an important limiting factor for crop yield. Although previous studies have shown that 6-phosphogluconate dehydrogenase (6PGDH) plays an important role in plant resistance to adversity, its response to low phosphorus (P) stress remains unknown. In this study, we reported the cloning and characterization of a cytosolic 6PGDH gene, Gm6PGDH1, which enhanced the tolerance to phosphate (Pi) starvation by improving root system development and modifying the antioxidant system in transgenic plants. Gm6PGDH1 was highly expressed in the root at full bloom stage, and strongly induced by Pi starvation. The results from intact soybean composite plant and soybean plant, both containing a Gm6PGDH1-overexpressing construct, showed that Gm6PGDH1 was involved in root system development, and subsequently affected P uptake under Pi-deficient conditions. Meanwhile, the accumulation of reactive oxygen species (ROS) in the root tip of transgenic soybean was reduced, and the activity of ROS-scavenging enzymes was enhanced compared with those of the wild type under Pi-deficient conditions. Interestingly, we found that the overexpression of Gm6PGDH1 weakened the response of several other important Pi-answer genes to Pi starvation, such as some purple acid phosphatases (PAPs) and redox-related genes. In addition, the results from a virus-induced gene silencing (VIGS) indicated that Gm6PGDH1 might have functional redundancy in soybean, and the results from a heterogeneous transformation system showed that overexpressing Gm6PGDH1 also enhanced tolerance to Pi starvation in transgenic Arabidopsis. Together, these results suggested the great potential of Gm6PGDH1 in crop breeding for low Pi tolerance.

<p><strong><em>In vitro </em>florigenesis: an efficient regeneration system avoiding time consuming vegetative phase in popular Indian soybean variety JS-335</strong></p>

Soybean ( Glycine max L.) is a major legume crop cultivated principally as protein rich bean. Improving quality and yield received considerable attention from researchers. Here, we explored molecular approaches to improve soybean quality and yield. In spite of recalcitrance, soybean plants successfully regenerated through complex and time consuming in vitro regeneration protocols via organogenesis and/or somatic embryogenesis and being used for transgenic development. Transformation efficiency is highly dependent on the regeneration as not all the cells transformed lead to the recovery of viable plant regeneration. Consequently, efficient in vitro regeneration found to be directly associated with the recovery of transformants. In the present study, we standardized the in vitro florigenesis using cotyledonary node with axillary bud as explant of soybean variety JS-335. Flower buds were directly induced from proximal end of the explant on Murashige-Skoog (MS) medium augmented with thidiazuron (TDZ) and α naphthalene acetic acid (NAA). TDZ proved a potential growth regulator to induce in vitro florigenesis. As a result of in vitro fertilization, pods were developed from flowers and matured within 40-45 days on hormone-free medium. Pods and seed set under in vitro conditions resemble pods and seeds produced under in vivo conditions. This pathway of in vitro florigenesis showed great potential for successful induction of in vitro flowering, which in turn can be explored in producing transgenic soybean seeds in popular Indian soybean genotype without escaping transgene.

Nuclear factor Y subunit GmNFYA competes with GmHDA13 for interaction with GmFVE to positively regulate salt tolerance in soybean.

Soybean is an important crop worldwide, but its production is severely affected by salt stress. Understanding the regulatory mechanism of salt response is crucial for improving the salt tolerance of soybean. Here, we reveal a role for nuclear factor Y subunit GmNFYA in salt tolerance of soybean likely through the regulation of histone acetylation. GmNFYA is induced by salt stress. Overexpression of GmNFYA significantly enhances salt tolerance in stable transgenic soybean plants by inducing salt‐responsive genes. Analysis in soybean plants with transgenic hairy roots also supports the conclusion. GmNFYA interacts with GmFVE, which functions with putative histone deacetylase GmHDA13 in a complex for transcriptional repression possibly by reducing H3K9 acetylation at target loci. Under salt stress, GmNFYA likely accumulates and competes with GmHDA13 for interaction with GmFVE, leading to the derepression and maintenance of histone acetylation for activation of salt‐responsive genes and finally conferring salt tolerance in soybean plants. In addition, a haplotype I GmNFYA promoter is identified with the highest self‐activated promoter activity and may be selected during future breeding for salt‐tolerant cultivars. Our study uncovers the epigenetic regulatory mechanism of GmNFYA in salt‐stress response, and all the factors/elements identified may be potential targets for genetic manipulation of salt tolerance in soybean and other crops.

English

The pat gene confers tolerance to glufosinate in transgenic soybean plants; however, some aspects of the selectivity of this herbicide need to be better elucidated. This study aimed to evaluate the development of soybean plants with the pat gene under the application of different glufosinate rates. The experiment was conducted in a greenhouse and included seven different glufosinate rates of and two soybean cultivars (LL0291 and LL0767) with the pat gene, with four replications in a completely randomized design. Glufosinate was applied at the V4 stage (4 nodes on the main stem with fully developed leaves beginning with the unifoliolate nodes) of soybean, and the variables analyzed were: soybean injury, chlorophyll index, plant height, dry and fresh matter of shoots and roots, wet nodules, dry nodules, and total number of nodules. It was found that for both cultivars, the maximum recommended glufosinate rate of 700 g of active ingredient (ai) ha-1 was safe, rates above 1,250 g ai ha-1 may interfere with development, especially biomass accumulation, and, in general, cultivar LL0291 exhibited more injuries than cultivar LL0767. The glufosinate-tolerant soybean (with pat gene) is a great option for farmers, but care should be taken with respect to rates above the maximum recommended in the package insert, so that there is no damage to soybean. © 2021 Friends Science Publishers

Increased copy number of gibberellin 2-oxidase 8 genes reduced trailing growth and shoot length during soybean domestication.

Copy number variations (CNVs) play important roles in crop domestication. However, there is only very limited information on the involvement of CNVs in soybean domestication. Trailing growth and long shoots are soybean adaptations for natural habitats but cause lodging that hampers yield in cultivation. Previous studies have focused on Dt1/2 affecting the indeterminate/determinate growth habit, whereas the possible role of the gibberellin pathway remained unclear. In the present study, quantitative trait locus (QTL) mapping of a recombinant inbred population of 460 lines revealed a trailing-growth-and-shoot-length QTL. A CNV region within this QTL was identified, featuring the apical bud-expressed gibberellin 2-oxidase 8A/B, the copy numbers of which were positively correlated with expression levels and negatively with trailing growth and shoot length, and their effects were demonstrated by transgenic soybean and Arabidopsis thaliana. Based on the fixation index, this CNV region underwent intense selection during the initial domestication process.

Using 14C-glyphosate to investigate the distribution of two formulations in transgenic glyphosate-resistant soybean

Glyphosate residues in grain can be explained by the concentrations and formulations of glyphosate products. This study aimed to evaluate the residues from glyphosate formulations labeled with 14C-glyphosate applied to leaves of glyphosate-resistant soybean (GRS) in two life cycles by liquid scintillation spectrometry. Different plant tissues were analyzed after the end of the plants’ life cycles. The experimental design was four repetitions of three treatments: Roundup® Original, Roundup Ready®, and unformulated glyphosate (control). The application of the dosing solution was 120 µL on the first four trifoliate leaves (10 µL per leaflet) of each plant, deposited manually with a 1-µL dispenser. All treatment solutions were calculated at a 1.2 kg a.e ha−1 of glyphosate. Glyphosate formulations of Roundup® Original and Roundup Ready® increased 14C-glyphosate distribution in GRS compared to the unformulated herbicide, regardless of the experiment (first or second cycle). Overall, the percentages of total radioactivity applied (18.33 kBq) found in grains were less than 5%. Grains, stems, and leaves showed the highest levels of herbicide residues compared to other parts of the plant. Despite the Roundup Ready® formulation having increased residues, the highest value found in grains, 1.95 mg kg−1, was less than 10 mg kg−1, the maximum residue limit (MRL) in Brazil.

Nuclear transport factor GmNTF2B-1 enhances soybean drought tolerance by interacting with oxidoreductase GmOXR17 to reduce reactive oxygen species content.

Drought is a critical abiotic stressor that modulates soybean yield. Drought stress drastically enhances reactive oxygen species (ROS) formation, and maintaining ROS content above a cytostatic level but below a cytotoxic level is essential for normal biology processes in plants. At present, most of the known ROS-scavenging systems are in the cytoplasm, and the mechanism of ROS regulation in the nucleus remains unclear. GmNTF2B-1 is a member of the IV subgroup in the nucleus transporter family. Its expression is localized to the roots and is stimulated by drought stress. In this study, the overexpression of GmNTF2B-1 was found to improve the drought tolerance of transgenic soybean by influencing the ROS content in plants. An oxidoreductase, GmOXR17, was identified to interact with GmNTF2B-1 in the nucleus through the yeast two-hybrid, coimmunoprecipitation and bimolecular fluorescence complementation assays. The drought tolerance of GmOXR17 transgenic soybean was similar to that of GmNTF2B-1. GmNTF2B-1 was expressed in both cytoplasm and nucleus, and GmOXR17 transferred from the cytoplasm to the nucleus under drought stress. The overexpression of GmNTF2B-1 enhanced the nuclear entry of GmOXR17, and the overexpression of GmNTF2B-1 or GmOXR17 could decrease the H2 O2 content and oxidation level in the nucleus. In conclusion, the interaction between GmNTF2B-1 and GmOXR17 may enhance the nuclear entry of GmOXR17, thereby enhancing nuclear ROS scavenging to improve the drought resistance of soybean.

Screening of Vietnamese soybean genotypes for Agrobacterium-mediated transgenic transformation

Soybean [Glycine max (L) Merr.] is one of the most important crops used for human food and animal feed globally. Transgenic soybean covers more than 74% of the global soybean production area, which is an achievement of genetically modified programs. The Agrobacterium-mediated method is commonly used for soybean transformation, but the efficiency of this method is affected by various factors including genotypes. Screening of the soybean genotypes suitable for Agrobacterium-infection and plant regeneration is the most important step to establish an efficient genetic transformation system. In this study, we screened thirty Vietnamese soybean genotypes including seventeen cultivated soybean genotypes (CSG) and thirteen local soybean genotypes (LCG) for shoot regeneration ability and transient infection via Agrobacterium tumefaciens method. Two CSG cultivars, DT22 and VX93, had significantly high efficiencies for shoot regeneration and transient infection compared with the control genotypes Jack and William 82. The shoot regeneration of DT22 and VX93 was 92.32% with 5.75 shoots/explant and 93.35% with 5.92 shoots/explant, respectively, whereas the control genotypes Jack and William 82 had 91.35% with 4.6 shoots/explant and 82.64% with 5.7 shoots/explant. Similarly, the transient infection of DT22 and VX93 was 84% and 86%, respectively, which was comparable with that of Jack (86%) William (82%). The success of transgenic development was confirmed by the β-Glucuronidase staining, PCR, and Basta leaf painting. The results indicated that cultivars DT22 and VX93 could be used for stable Agrobacterium-media transformation. Keywords: Soybean, Agrobacterium, transformation, transient infection, transgenic.

Microrna Regulation of Nodule Zone-Specific Gene Expression In Soybean

Microrna Regulation of Nodule Zone-Specific Gene Expression In Soybean

A phosphate starvation responsive malate dehydrogenase, GmMDH12 mediates malate synthesis and nodule size in soybean (Glycine max)

In legume nodules, malate is generally considered to provide carbon for both nodule bacteroid respiration and skeletons for NH4+ assimilation. Although it has been suggested that phosphorus (P) deficiency inhibits legume nodule growth through adversely affecting carbon partitioning, the molecular mechanisms underlying malate synthesis and its roles in nodule growth remain largely unknown in soybean (Glycine max). In this study, we found that P deficiency led to a significant decrease of soybean nodule size (fresh weight of individual soybean nodule), accompanying with increased malate concentration. Meanwhile, 16 malate dehydrogenase (GmMDH) members were identified in the soybean genome, and their expression patterns were investigated in soybean nodules in responses to P deficiency. Among them, GmMDH12 was up-regulated by phosphate (Pi) starvation. Enzymatic analysis of GmMDH12 revealed its functions in catalyzing malate synthesis through reduction of oxaloacetate to form malate in vitro. Furthermore, overexpression of GmMDH12 resulted in a significant decrease in nodule size, but a significant increase in concentrations of malate and several carbohydrates in transgenic soybean nodules. Taken together, these results suggest that P deficiency inhibits soybean nodule size due to enhancement of malate synthesis, which is regulated by GmMDH12 transcripts.

Effects and characterization of different soybean varieties in yield and organoleptic properties of tofu

Tofu is a soft food made from soybean processing. Soybeans are made up of two types of Genetically Modified Organism (GMO) and non-Genetically Modified Organism (non-GMO). Transgenic soybeans are soybeans that undergo genetic changes for a specific purpose. Non-transgenic soybeans that do not undergo genetic changes. The purpose of this study was to analysis of the effect of raw material soybeans on yield, protein content, and water content, amino acid type, and organoleptic properties of tofu. This study uses two types of soybeans to make tofu, namely transgenic soybeans (Lotus USA) and non-GMO (Anjasmoro). Its methods include soybean soaking, soy milk peeling, filtration, heating, coagulation, and squeezing. The results showed the yield and tofu protein of non-transgenic soybeans were higher than transgenic. The non-transgenic soybean water content is lower than transgenic. The taste and aroma of non-transgenic soybeans are superior to that of transgenic soybeans because they are more savory and smell typical of soybeans, for the texture and color of tofu transgenic soybeans are superior to non-transgenic soybeans. Tofu of non-transgenic soybeans has lower levels of the essential amino acids arginine, phenylalanine, and leucine than transgenic. But tofu of non-transgenic soybeans has higher levels of the non-essential amino acid glutamic than transgenic.

Expression of a maize SOC1 gene enhances soybean yield potential through modulating plant growth and flowering

Yield enhancement is a top priority for soybean (Glycine max Merr.) breeding. SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) is a major integrator in flowering pathway, and it is anticipated to be capable of regulating soybean reproductive stages through its interactions with other MADS-box genes. Thus, we produced transgenic soybean for a constitutive expression of a maize SOC1 (ZmSOC1). T1 transgenic plants, in comparison with the nontransgenic plants, showed early flowering, reduced height of mature plants, and no significant impact on grain quality. The transgenic plants also had a 13.5–23.2% of higher grain weight per plant than the nontransgenic plants in two experiments. Transcriptome analysis in the leaves of 34-day old plants revealed 58 differentially expressed genes (DEGs) responding to the expression of the ZmSOC1, of which the upregulated FRUITFULL MADS-box gene, as well as the transcription factor VASCULAR PLANT ONE-ZINC FINGER1, contributed to the promoted flowering. The downregulated gibberellin receptor GID1B could play a major role in reducing the plant height. The remaining DEGs suggested broader effects on the other unmeasured traits (e.g., photosynthesis efficiency and abiotic tolerance), which could contribute to yield increase. Overall, modulating expression of SOC1 in soybean provides a novel and promising approach to regulate plant growth and reproductive development and thus has a potential either to enhance grain yield or to change plant adaptability.

Determination of amino acids and nutritional aspects in transgenic soybean exposed to glyphosate/ Determinação de aminoácidos e aspectos nutricionais na soja transgênica exposta ao glifosato

With the increase of glyphosate tolerant transgenic soybean cultivation areas, this substance has become the main herbicide for this crop, its use may interfere in the metabolism and nutritional aspects of transgenic plants. In this scenario, the objective of this work was to verify the oil, protein, phytate and amino acid concentrations in glyphosate tolerant soybean cultivar. Comparing the averages between oil, protein and total amino acid levels in transgenic soybean exposed and not exposed to glyphosate, it was found that there was no significant difference by Tukey test at 5% probability. In conclusion, the data indicate that although the transgenic event affects some routes, amino acid synthesis was not affected nor in nutritional terms at the glyphosate doses studied.

Analysis of expression characteristics of soybean leaf and root tissue-specific promoters in Arabidopsis and soybean

The characterization of tissue-specific promoters is critical for studying the functions of genes in a given tissue/organ. To study tissue-specific promoters in soybean, we screened tissue-specific expressed genes using published soybean RNA-Seq-based transcriptome data coupled with RT-PCR analysis. We cloned the promoters of three genes, GmADR1, GmBTP1, and GmGER1, and constructed their corresponding β-Glucuronidase (GUS) promoter-GUS reporter vectors. We generated transgenic Arabidopsis plants and examined the expression patterns of these promoters by GUS staining and RT-PCR analysis. We also transformed the promoter-GUS reporter vectors into soybean to obtain hairy roots, and examined promoter expression by GUS staining. We found a root-specific expression pattern of GmADR1 and GmBTP1 in both Arabidopsis and soybean, and the promoter of GmGER1 showed a leaf-specific pattern in transgenic Arabidopsis plants. To test the potential utility of these promoters in soybean improvement by transgenic means, we used the GmADR1 promoter to drive expression of a salt resistance gene in soybean, GmCaM4, by generating transgenic soybean plants. We found that the transgenic plants had significantly enhanced salt tolerance compared to non-transformed wild-type, suggesting that introducing endogenous promoters by transgenic means can drive the expression of functional genes in specific tissues and organs in soybean.

A Bacillus thuringiensis Cry protein controls soybean cyst nematode in transgenic soybean plants

Plant-parasitic nematodes (PPNs) are economically important pests of agricultural crops, and soybean cyst nematode (SCN) in particular is responsible for a large amount of damage to soybean. The need for new solutions for controlling SCN is becoming increasingly urgent, due to the slow decline in effectiveness of the widely used native soybean resistance derived from genetic line PI 88788. Thus, developing transgenic traits for controlling SCN is of great interest. Here, we report a Bacillus thuringiensis delta-endotoxin, Cry14Ab, that controls SCN in transgenic soybean. Experiments in C. elegans suggest the mechanism by which the protein controls nematodes involves damaging the intestine, similar to the mechanism of Cry proteins used to control insects. Plants expressing Cry14Ab show a significant reduction in cyst numbers compared to control plants 30 days after infestation. Field trials also show a reduction in SCN egg counts compared with control plants, demonstrating that this protein has excellent potential to control PPNs in soybean.

Effect of GM maize on metabolism and performance of chicken

Effect of GM maize on metabolism and performance of chicken

Natural hybridization between transgenic and wild soybean genotypes

Natural hybridization between transgenic and wild soybean genotypes

Transformation of an artificial microRNA to soybean (Glycine max (L.) Merr.) to reduce the parasitism of Meloidogyne incognita

Effectors are specific proteins secreted by nematodes into plant cells that facilitate their parasitism to host plants. Inactivation of these effectors could reduce the parasitic ability of nematodes on plants and the damage caused by nematodes. Gene Minc14137encodes an effector unknown function that is cloned from the Meloidogyne incognita. Artificial microRNAs capable of inactivating the gene Minc14137 were synthesised and inserted into an expression vector in soybean. This construct was transformed into the soybean cotyledon node mediated by Agrobacterium tumefaciens and regenerated transgenic plants. Copy number and the expression level of miRNA in T0 transgenic plants were determined by the qPCR technique. In T1 transgenic soybean plants, the pathogenic ability of root-knot nematode is reduced by 44.6-50.5% compared to the control plants. Results show that effector MINC14137 could play an important role in the parasitism of Meloidogyne incognita.

A transcriptional regulatory module controls lipid accumulation in soybean.

Soybean (Glycine max) is one of the most important oilseed crops. However, the regulatory mechanism that governs the process of oil accumulation in soybean remains poorly understood. In this study, GmZF392, a tandem CCCH zinc finger (TZF) protein which was identified in our previous RNA-seq analysis of seed-preferred transcription factors, was found to function as a positive regulator of lipid production. GmZF392 promotes seed oil accumulation in both transgenic Arabidopsis and stable transgenic soybean plants by binding to a bipartite cis-element, containing TG- and TA-rich sequences, in promoter regions, activating the expression of genes in the lipid biosynthesis pathway. GmZF392 physically interacts with GmZF351, our previously identified transcriptional regulator of lipid biosynthesis, to synergistically promote downstream gene expression. Both GmZF392 and GmZF351 are further upregulated by GmNFYA, another transcription factor involved in lipid biosynthesis, directly (in the former case) and indirectly (in the latter case). Promoter sequence diversity analysis showed that the GmZF392 promoter may have been selected at the origin of the Glycine genus and further mildly selected during domestication from wild soybeans to cultivated soybeans. Our study reveals a regulatory module containing three transcription factors in the lipid biosynthesis pathway, and manipulation of the module may improve oil production in soybean and other oilseed crops.