Non-transgenic Rice Research Articles

Multiplexed CRISPR-Cas9 mutagenesis of rice PSBS1 noncoding sequences for transgene-free overexpression.

Understanding CRISPR-Cas9's capacity to produce native overexpression (OX) alleles would accelerate agronomic gains achievable by gene editing. To generate OX alleles with increased RNA and protein abundance, we leveraged multiplexed CRISPR-Cas9 mutagenesis of noncoding sequences upstream of the rice PSBS1 gene. We isolated 120 gene-edited alleles with varying non-photochemical quenching (NPQ) capacity in vivo-from knockout to overexpression-using a high-throughput screening pipeline. Overexpression increased OsPsbS1 protein abundance two- to threefold, matching fold changes obtained by transgenesis. Increased PsbS protein abundance enhanced NPQ capacity and water-use efficiency. Across our resolved genetic variation, we identify the role of 5'UTR indels and inversions in driving knockout/knockdown and overexpression phenotypes, respectively. Complex structural variants, such as the 252-kb duplication/inversion generated here, evidence the potential of CRISPR-Cas9 to facilitate significant genomic changes with negligible off-target transcriptomic perturbations. Our results may inform future gene-editing strategies for hypermorphic alleles and have advanced the pursuit of gene-edited, non-transgenic rice plants with accelerated relaxation of photoprotection.

Genetic Bioaugmentation of Oryza sativa to Facilitate Self-Detoxification of Arsenic In-Situ

Arsenic accumulation in rice, the world's popular grain crop, is becoming increasingly problematic because of the repeated use of arsenic-laden groundwater for cultivation. The World Health Organization reports that arsenic contamination of soil is a global issue, threatening the health of over 150 million people worldwide. Therefore, it is vital to prevent arsenic accumulation in the rice grain while simultaneously remediating arsenic from the soil. We hypothesized that if we genetically modified the rice plants using arsenic-resistant genes, then these rice plants would not only uptake arsenic from soil, but also be able to self-detoxify arsenic and thus be safe to consume. In order to test the hypothesis, we transformed rice cotyledons with acr3 and arsC arsenic resistance genes using Agrobacterium tumefaciens. Transgenic rice plants were then grown in soil contaminated with 25 ppm arsenic. After four weeks, we observed a decline in soil arsenic from 25 ppm to 10 ppm. We also observed that the arsenic in the stem of transgenic rice plants to be less than one ppm compared to 6 ppm in non-transgenic rice plants, and arsenic was undetectable in the leaves of transgenic rice plants compared to 4 ppm in non-transgenic plants. We used the ANOVA test to assess the statistical significance. Therefore, phytoremediation, a technique using plants to clean environmental pollutants and utilizing rice plants transformed with arsenic-resistant genes, is a promising method for decontaminating polluted soil. It can significantly lower arsenic accumulation in the world's popular grain crop, thus potentially reducing serious health risks.

Genetic engineering low-arsenic and low-cadmium rice grain.

Rice is prone to take up the toxic elements arsenic (As) and cadmium (Cd) from paddy soil through the transporters for other essential elements. Disruption of these essential transporters usually adversely affects the normal growth of rice and the homeostasis of essential elements. Here we report on developing low-As and low-Cd rice grain through the co-overexpression of OsPCS1, OsABCC1, and OsHMA3 genes under the control of the rice OsActin1 promoter. Co-overexpression of OsPCS1 and OsABCC1 synergistically decreased As concentration in the grain. Overexpression of OsPCS1 also decreased Cd concentration in the grain by restricting the xylem-to-phloem Cd transport in node I, but paradoxically caused Cd hypersensitivity as the overproduced phytochelatins in OsPCS1-overexpressing plants suppressed OsHMA3-dependent Cd sequestration in vacuoles and promoted Cd transport from root to shoot. Co-overexpression of OsHAM3 and OsPCS1 overcame this suppression and complemented the Cd hypersensitivity. Compared with non-transgenic rice control, co-overexpression of OsABCC1, OsPCS1, and OsHMA3 in rice decreased As and Cd concentrations in grain by 92.1% and 98%, respectively, without causing any defect in plant growth and reproduction or of mineral nutrients in grain. Our research provides an effective approach and useful genetic materials for developing low-As and low-Cd rice grain.

Analysis of the Unintended Effects of the Bacillus thuringiensis Insecticidal Protein in Genetically Modified Rice Using Untargeted Transcriptomics

The safety and unintended effects of genetically modified (GM) crops have been the focus of public attention. Transcriptome analysis is a powerful tool to assess the potential impact of genetic modification on plant genomes. In this study, three transgenic (KMD, KF6, and TT51-1) and three non-transgenic (XS11, MH86, and MH63) rice varieties were assessed at the genomic and protein levels. The results of polymerase chain reaction (PCR) and Cry1Ab/1Ac speed test strips showed that the Bt gene was successfully expressed in transgenic rice. The results of RNA-seq analysis to analyze the unintended effects of transgenic Bt rice showed fewer differentially expressed genes (DEGs) between the transgenic and non-transgenic rice varieties than among the different varieties. Meanwhile, the results of principal component analysis and cluster analysis found no significant genetic variation between the transgenic and non-transgenic rice varieties, except for the presence of Bt in transgenic rice. There were only two co-upregulated DEGs and no co-downregulated DEGs among three comparison groups. Although there were various DEGs among the groups, the two co-upregulated DEGs were not related to any significantly enriched gene ontology (GO) term or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, indicating that the differences among the subgroups were more likely caused by complex environmental or genetic factors, rather than unintended effects due to Bt expression. This study provides useful information to further explore the unexpected effects and safety of GM rice.

Application and Development of Bt Insect Resistance Genes in Rice Breeding

As pests are an important factor in reducing crop yields, pest control is an important measure in preventing reductions in crop yields. With the aim of ending the use of chemical pesticides, biological control and genetically modified methods are now considered more reasonable pest control strategies. The bacterium Bacillus thuringiensis (Bt) can produce crystal proteins that have specific toxicity to lepidopteran insects, and so it has been applied as a microbial insecticide in the control of crop pests for several decades. With the development of plant genetic engineering, Bt genes encoding insecticidal crystal protein have been introduced into many crop species for pest control. This article indicates that, after years of experiments and research, Bt transgenic rice is close to becoming a commercial insect-resistant rice, and many studies have shown that transgenic rice has pronounced abilities in the control of pests such as yellow stem borers (Scirpophaga incertulas, YSB), striped stem borers (Chilo suppressalis, SSB), and rice leaf rollers (Cnaphalocrocis medinalis, RLR); moreover, it does not obviously differ from non-transgenic rice in terms of safety. This paper suggests that transgenic Bt rice has application potential and commercial value.

Human Naa50 Shows Serotonin N-Acetyltransferase Activity, and Its Overexpression Enhances Melatonin Biosynthesis, Resulting in Osmotic Stress Tolerance in Rice.

A new clade of serotonin N-acetyltransferase (SNAT), the penultimate enzyme in the melatonin biosynthetic pathway, has been reported in the archaeon Thermoplasma volcanium. The closest homolog of archaea SNAT in human was an N-alpha-acetyltransferase50 (Naa50). To determine whether human Naa50 (hNaa50) shows SNAT enzyme activity, we chemically synthesized and expressed the hNaa50 gene in Escherichia coli, followed by Ni2+ affinity purification. Purified recombinant hNaa50 showed SNAT activity (Km and Vmax values of 986 μM and 1800 pmol/min/mg protein, respectively). To assess its in vivo function, hNaa50 was overexpressed in rice (hNaa50-OE). The transgenic rice plants produced more melatonin than nontransgenic wild-type rice, indicating that hNaa50 is functionally coupled with melatonin biosynthesis. Due to its overproduction of melatonin, hNaa50-OE had a higher tolerance against osmotic stress than the wild type. Enhanced expression of the chaperone genes BIP1 and CNX in hNaa50-OE plants was responsible for the increased tolerance. It is concluded that hNaa50 harbors serotonin N-acetyltransferase enzyme activity in addition to its initial N-alpha-acetyltransferase, suggesting the bifunctionality of the hNaa50 enzyme toward serotonin and protein substrates. Consequently, ectopic overexpression of hNaa50 in rice enhanced melatonin synthesis, indicating that hNaa50 is in fact involved in melatonin biosynthesis.

Increasing the Activity of Sugarcane Sucrose Phosphate Synthase Enhanced Growth and Grain Yields in Transgenic Indica Rice

Sucrose is the primary form of mobile photoassimilates, and its level is regulated by sucrose-phosphate synthase (SPS) in plants. Increasing in the SPS activity was accompanied by an increase in sucrose accumulation. This study was designed to examine the effect of the overexpression sugarcane SoSPS1 gene on sucrose metabolizing enzymes, growth, and grain yield of indica rice. The SoSPS1 gene was constructed in a binary vector under the control of a rice ubiquitin promoter and transformed into indica rice using an Agrobacterium vector. Five lines of transgenic rice were selected to develop homozygous transgenic lines and used for analysis. The overexpression of the SoSPS1 gene significantly increased the transcript and protein levels, followed by increasing in SPS activity and sucrose content in the leaves of the transgenic rice lines. Moreover, the activity of soluble acid invertase (SAI) was elevated rather than sucrose synthase (SuSy) in the transgenic lines. The increase in the sucrose-degrading enzymes leads to an increase in plant growth and development. The plant height and number of tillers were significantly higher in the transgenic line compared to non-transgenic (NT) rice. In addition, the amylose content, the number of seeds per panicle, and the weight of 1000 grains of seed, including dry biomass weight, were increased in the transgenic lines. The results indicated that enhancement of SPS activity, as well as sucrose content, provides a higher carbon partitioning for higher growth and productivity of the transgenic rice lines.

Optimized prime editing efficiently generates glyphosate-resistant rice plants carrying homozygous TAP-IVS mutation in EPSPS

Optimized prime editing efficiently generates glyphosate-resistant rice plants carrying homozygous TAP-IVS mutation in EPSPS

Changes in physiological responses of OsCaM1-1 overexpression in the transgenic rice under dehydration stress.

Calmodulin, a primary calcium sensor in eukaryotes, binds calcium and regulates the activity of effector proteins in response to calcium signals that evoked in response to abiotic and biotic stress. To identify physiological responses associated with improved tolerance under dehydration stress that may be regulated by calmodulin in rice, the transgenic rice overexpressing OsCaM1-1, the control, and the wild-type KDML105 differing in their dehydration tolerance were compared 24 h after exposure to dehydration stress. The results demonstrated a greater increase in relative water content, relative growth rate, abscisic acid, photosynthetic pigment and proline contents, and antioxidant activities in the transgenic rice plants, whereas Na/K and Na/Ca ratio, lipid peroxidation, and electrolytic leakage decreased. The OsCaM1-1 gene overexpression in the transgenic rice showed greater tolerance to dehydration stress than non-transgenic rice, suggesting that OsCaM1-1 might play an important role in mitigating dehydration stress.

​​Weedy Rice (Oryza sativa f. spontanea) Complexes on Direct Seeded Rice (DSR) and its Management Strategy: A Review

Weedy rice (Oryza sativa f. spontanea) is one of the most notorious weeds occurring in rice growing areas especially in direct-seeded rice (DSR) system, worldwide and the problem is pervasive. It is a complex of Oryza morphotypes widely distributed in the commercial rice fields in more than 50 countries of Asia, Africa, Latin America and Southeast Asia. Weedy rice is progenies of crosses between wild rice and cultivated. The major characteristic of weedy rice is easy shattering. Other characteristics observed are taller plants, fewer tillers, grains having awns and high percentage of red rice in milled rice. It is difficult to manage the infestation of weedy rice because of its morphological similarities with cultivated rice. Recently, biotechnology approach using genetically modified herbicide tolerant rice varieties may be an efficient strategy. A non-transgenic rice variety ‘Clearfield’ is tolerant to Imidazolinone herbicides. It aims at determining whether the integration of Imidazolinone herbicides and tolerant trait in the genotypes can be used for controlling weedy rice in rice field. Satisfactory control of weedy rice requires an integrated approach based on the combination of preventive, cultural, mechanical, chemical and biotechnological means rather than using only a single method for its control.

Prophylactic and Therapeutic Effects of Oral Immunotherapy on Birch Pollen-Induced Allergic Conjunctivitis in Mice with a Rice-Based Edible Vaccine Expressing a Hypoallergenic Birch Pollen Allergen.

We investigated the prophylactic and therapeutic effects of the oral administration of transgenic rice seeds expressing a hypoallergenic Bet v 1 derivative of allergic birch pollen conjunctivitis in mice. Transgenic rice seed depositing a chimeric molecule called TPC7 (tree pollen chimera 7) created by DNA shuffling of Bet v 1 family sequences from birch, alder and hazel in protein bodies of endosperm was generated. BALB/c mice were sensitized to birch pollen in alum and challenged with pollen in eyedrops. They were fed TPC7 transgenic or non-transgenic (control) rice seeds for 14 d before sensitization (prophylactic protocol) or 17 d after sensitization (therapeutic protocol). The clinical score and number of conjunctival eosinophils were significantly lower in TPC7-fed mice than in the control mice based on both the prophylactic and therapeutic protocols. Serum concentration of allergen-specific IgE did not differ between TPC7-fed and control groups in either protocol. Prophylactic administration of TPC7 downregulated the production of IL-4 and IFN-γ, whereas therapeutic administration of TPC7 upregulated the production of IFN-γ by allergen-stimulated splenocytes. Prophylactic or therapeutic oral administration of transgenic rice expressing TPC7 suppressed birch pollen-induced allergic conjunctivitis in mice. Feeding transgenic rice is a potentially effective approach as an allergen-specific immunotherapy for allergic conjunctivitis.

Safety evaluation of BPL9K-4 rice in a subchronic rodent feeding study

In the present study, a new genetically modified rice producing phytase-lactoferricin fusion protein, BPL9K-4, was evaluated for safety in a 90-day rat feeding study. Rats were fed rodent diets formulated with BPL9K-4 rice, and were compared with rats fed diets formulated with its corresponding non-transgenic parental rice 9 K, commercially available non-transgenic rice Weiyou64, and a basal diet. BPL9K-4 and 9 K rice were formulated into diets at concentrations of 15%, 30% and 60%, and Weiyou64 common rice was added to diets at concentration of 60%. AIN93G diet was set as a basal-diet control. Diets of all groups were fed to rats (10/sex/group) for 90 days. Compared with rats in the 9 K, Weiyou64 and the basal-diet group, rats fed the BPL9K-4 diet did not show any treatment-related adverse effects on mortality, body weights, feed consumption, clinical chemistry, hematology, organ weights and gross and microscopic pathology. Under the conditions of this study, the genetically modified BPL9K-4 diets did not cause any toxicologically significant effects in rats following 90 days of dietary administration as compared with rats fed diets with the corresponding non-transgenic control diet and the basal-diet group. The results indicated that BPL9K-4 rice is as safe as its conventional comparators.

Generation and Starch Characterization of Non-Transgenic BEI and BEIIb Double Mutant Rice (Oryza sativa) with Ultra-High Level of Resistant Starch

BackgroundCereals high in resistant starch (RS) are gaining popularity, as their intake is thought to help manage diabetes and prediabetes. Number of patients suffering from diabetes is also increasing in Asian countries where people consume rice as a staple food, hence generation of practically growable high RS rice line has been anticipated. It is known that suppression of starch branching enzyme (BE) IIb increases RS content in cereals. To further increase RS content and for more practical use, we generated a non-transgenic be1 be2b double mutant rice (Oryza sativa) line, which completely lacked both proteins, by crossing a be1 mutant with a be2b mutant.ResultsThe be1 be2b mutant showed a decrease in intermediate amylopectin chains and an increase in long amylopectin chains compared with be2b. The amylose content of be1 be2b mutant (51.7%) was the highest among all pre-existing non-transgenic rice lines. To understand the effects of chewing cooked rice and cooking rice flour on RS content, RS content of mashed and un-mashed cooked rice as well as raw and gelatinized rice flour were measured using be1 be2b and its parent mutant lines. The RS contents of mashed cooked rice and raw rice flour of be1 be2b mutant (28.4% and 35.1%, respectively) were 3-fold higher than those of be2b mutant. Gel-filtration analyses of starch treated with digestive enzymes showed that the RS in be1 be2b mutant was composed of the degradation products of amylose and long amylopectin chains. Seed weight of be1 be2b mutant was approximately 60% of the wild type and rather heavier than that of be2b mutant.ConclusionsThe endosperm starch in be1 be2b double mutant rice were enriched with long amylopectin chains. This led to a great increase in RS content in cooked rice grains and rice flour in be1 be2b compared with be2b single mutant. be1 be2b generated in this study must serve as a good material for an ultra-high RS rice cultivar.

Detection of major rice allergenic proteins in phytase-transgenic and non-transgenic rice

The 14-16 kDa rice allergenic proteins have been reported to be the products of a multigene family, and react most frequently with IgE in serum of rice allergic patients. The aim of this study was to assay the content of endogenous 14-16 kDa rice major allergenic proteins in both phytase-transgenic (GR) and non-transgenic rice (NR) (wild-type, Oryza sative L. cv. Tainung 67). We want to investigate whether the foreign gene will change the allergenicity of rice or not, should be evaluated in order to clarify its pre-market safety. First, the RA17 gene encoding 16 kDa rice allergenic protein was amplified by reverse transcription-polymerase chain reaction (RT-PCR), and cloned into the expression vector pET-29a(+). The constructed expression vector, pET-29a(+)-RA17, was transformed into Escherichia coli BL21 (DE3). The host strain was induced to express recombinant RA17, which was purified by Ni 2+-NTA resin column and used as the antigen for the production of a polyclonal antibody via rabbits. We used the antibody as a detective tool of western blotting and enzyme-linked immunosorbent assay (ELISA) methods. The western blotting analysis showed that the content of major allergenic proteins in phytase-transgenic rice was 96.3% of that in wild-type rice. The content of 14-16 kDa allergens estimated by ELISA were 1.73 ± 0.09 (NR) and 1.66 ± 0.08 mg/g (GR). The results indicated that the level of 14-16 kDa allergens was not significantly different (p > 0.05) between wild-type rice and phytase-transgenic rice, and the transformation of phytase gene into rice plant did not enhance the content of rice major allergenic proteins in transgenic rice.

Identification and integrated analysis of glyphosate stress-responsive microRNAs, lncRNAs, and mRNAs in rice using genome-wide high-throughput sequencing

BackgroundGlyphosate has become the most widely used herbicide in the world. Therefore, the development of new varieties of glyphosate-tolerant crops is a research focus of seed companies and researchers. The glyphosate stress-responsive genes were used for the development of genetically modified crops, while only the EPSPS gene has been used currently in the study on glyphosate-tolerance in rice. Therefore, it is essential and crucial to intensify the exploration of glyphosate stress-responsive genes, to not only acquire other glyphosate stress-responsive genes with clean intellectual property rights but also obtain non-transgenic glyphosate-tolerant rice varieties. This study is expected to elucidate the responses of miRNAs, lncRNAs, and mRNAs to glyphosate applications and the potential regulatory mechanisms in response to glyphosate stress in rice.ResultsLeaves of the non-transgenic glyphosate-tolerant germplasm CA21 sprayed with 2 mg·ml− 1 glyphosate (GLY) and CA21 plants with no spray (CK) were collected for high-throughput sequencing analysis. A total of 1197 DEGs, 131 DELs, and 52 DEMs were identified in the GLY samples in relation to CK samples. Genes were significantly enriched for various biological processes involved in detoxification of plant response to stress. A total of 385 known miRNAs from 59 miRNA families and 94 novel miRNAs were identified. Degradome analysis led to the identification of 32 target genes, of which, the squamosa promoter-binding-like protein 12 (SPL12) was identified as a target of osa-miR156a_L + 1. The lncRNA-miRNA-mRNA regulatory network consisted of osa-miR156a_L + 1, two transcripts of SPL12 (LOC_Os06g49010.3 and LOC_Os06g49010.5), and 13 lncRNAs (e.g., MSTRG.244.1 and MSTRG.16577.1).ConclusionLarge-scale expression changes in coding and noncoding RNA were observed in rice mainly due to its response to glyphosate. SPL12, osa-miR156, and lncRNAs (e.g., MSTRG.244.1 and MSTRG.16577.1) could be a novel ceRNA mechanism in response to glyphosate in rice by regulating transcription and metal ions binding. These findings provide a theoretical basis for breeding glyphosate-tolerant rice varieties and for further research on the biogenesis of glyphosate- tolerance in rice.

Evaluation of MYB93 and MAD8 Genes in Transgenic and Non-Transgenic Rice

Increasing drought tolerance, especially in rice, which is one of the most important crops in Asia, is necessary. Transcription factors are specific sequence DNA-binding proteins that are capable of activating or suppressing transcription. These proteins regulate gene expression levels by binding to cis regulatory elements in the promoter of target genes to control various biological processes such as growth, cell division and response to environmental stresses. In this study, MAD8 and MYB93 genes that were involved in drought stress in rice were considered in two leaf and anther tissues at 0, 24, 48, 72 h and one week after stopping irrigation. The results of q-PCR analysis showed significant expression changes of these transcription factor genes under drought stress conditions. In this study, a significant increase in the expression of these genes at 24 h after drought stress in transgenic plants (Promoter region with accession: NC_029264.1 and GUS gene have transformed) compared to non-transgenic plants showed a relationship between these transcription factors and higher expression of transported promoter in transgenic plants.

Identification of Rice Varieties and Transgenic Characteristics Based on Near-Infrared Diffuse Reflectance Spectroscopy and Chemometrics.

Background: In recent years, genetically modified technology has developed rapidly, and the potential impact of genetically modified foods on human health and the ecological environment has received increasing attention. The currently used methods for testing genetically modified foods are cumbersome, time-consuming, and expensive. This paper proposed a more efficient and convenient detection method. Methods: Near-infrared diffuse reflectance spectroscopy (NIRDRS) combined with multivariate calibration methods, including principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and support vector machines (SVM), were used for identification of different rice varieties and transgenic (Bt63)/non-transgenic rice. Spectral pretreatment methods, including Norris–Williams smooth (NWS), standard normal variate (SNV), multiplicative scatter correction (MSC), and Savitzky–Golay 1st derivative (SG 1st-Der), were used for spectral noise reduction and effective information enhancement. Accuracy was used to evaluate the qualitative discriminant models. Results: The results showed that the SG 1st-Der pretreatment method, combined with the SVM, provided the optimal model to distinguish different rice varieties. The accuracy of the optimal model was 98.33%. For the discrimination model of transgenic/non-transgenic rice, the SNV-SVM model, MSC-SVM model, and SG 1st-Der-PLS-DA model all achieved good analysis results with the accuracy of 100%. Conclusion: The results showed that portable NIR spectroscopy combined with chemometrics methods could be used to identify rice varieties and transgenic characteristics (Bt63) due to its fast, non-destructive, and accurate advantages.

Enhancement of Iron Acquisition in Rice by the Mugineic Acid Synthase Gene With Ferric Iron Reductase Gene and OsIRO2 Confers Tolerance in Submerged and Nonsubmerged Calcareous Soils.

Iron (Fe) is an essential micronutrient for plants. Plants encounter Fe deficiency when grown in calcareous soil with low Fe availability, leading to reduced crop yield and agricultural problem. Rice acquires Fe from the soil via Strategy I–related system (ferrous ion uptake by OsIRT1) and Strategy II system (ferric ion uptake by chelation). However, rice plants have a weak ability in Fe(III) reduction and phytosiderophore secretion. We previously produced an Fe deficiency–tolerant rice harboring OsIRT1 promoter-refre1/372 (for higher Fe(III) reductase ability) and a 35S promoter-OsIRO2 (for higher phytosiderophore secretion). In this study, we produced a new Fe deficiency–tolerant rice by the additional introduction of a barley IDS3 genome fragment with refre1/372 and OsIRO2 (named as IRI lines) for further enhancement in Strategy II phytosiderophore productivity and better growth performance in various environments. Our results show that an enhanced tolerance was observed in OsIRO2 introduced line at the early growth stage, refre1/372 introduced line in the late stage, and RI line in all stages among five types of cultivation method. Moreover, we demonstrated that new IRI rice lines exhibited enhanced tolerance to Fe deficiency compared to nontransgenic (NT) rice and rice lines harboring the overexpressing OsIRO2 or the IDS3 fragment under submerged calcareous soil. The yields of IRI lines were ninefold higher than the NT line. Furthermore, under Fe-limited nonsubmerged calcareous soil condition (a new cultivation condition), IRI lines also conferred enhanced tolerance than NT, lines introducing only the OsIRT1 promoter-refre1/372 or overexpressing OsIRO2, and lines harboring both. Our results demonstrate that further enhancement of the Strategy II Fe uptake system by the mugineic acid synthase gene in addition to Fe uptake by enhanced ferric Fe reduction and phytosiderophore production in rice contributes Fe deficiency tolerance and broaden its utility in calcareous soil cultivation under paddy or nonpaddy field conditions.

Transgenic rice seeds expressing altered peptide ligands against the M3 muscarinic acetylcholine receptor suppress experimental sialadenitis-like Sjögren’s syndrome

Objective: We previously reported that Rag1−/− mice inoculated with splenocytes from M3 muscarinic acetylcholine receptor (M3R) knockout mice immunized with an M3R peptide mixture developed sialadenitis-like Sjögren’s syndrome (M3R-induced sialadenitis [MIS]). We also found that intravenous administration of altered peptide ligand (APL) of N-terminal 1 (N1), which is one of the T-cell epitopes of M3R, suppressed MIS. In this study, we aimed to evaluate the suppressive ability and its mechanisms of rice seeds expressing N1-APL7 against MIS.Methods: Rice seeds expressing N1 and N1-APL7 were orally administered to MIS mice for 2 weeks. The changes in saliva flow and sialadenitis (salivary gland inflammation) were analyzed. The M3R-specific T-cell response in the spleen and the expression of regulatory molecules in the cervical lymph nodes and mesenteric lymph nodes were also analyzed.Results: Oral administration of N1-APL7-expressing rice seeds significantly recovered reduction in saliva flow and suppressed sialadenitis when compared with treatment with nontransgenic rice seeds and N1 rice seeds. IFNγ production from M3R-reactive T cells tended to decline in the N1-APL7 rice-treated group as compared with those in the other groups. In the N1-APL7 rice-treated group, the mRNA expression levels of Foxp3 in the cervical-lymph-node CD4+ T cells were higher than those in the other groups.Conclusion: Oral administration of N1-APL7-expressing rice suppressed MIS via suppression of M3R-specific IFNγ and IL-17 production and via enhancement of regulatory molecule expression.Key messagesWe generated N1-peptide- or N1-APL7-expressing rice seeds. Oral administration of N1-APL7-expressing rice seeds significantly recovered the reduction of saliva flow and suppressed sialadenitis via the suppression of M3R specific IFNγ and IL-17 production and via enhancement of regulatory T (Treg) cells.

Environmental impacts of transgenic Bt rice and non-Bt rice cultivars in northern Iran

Abstract In the future, rice production is likely to be impacted by climate change and associated risks including pest complexes and consumption of chemical inputs, thereby decreasing production at a regional scale and one of the major global concerns. In fact, among the biotic stresses, damage caused by insect pests, which can be categorized as either minor or major pests, can severely constrain the potential yield of rice. Hence, planting transgenic rice is considered a solution for reducing environmental and human health impacts. Therefore, in this research, life cycle assessment for environmental and human health impacts of transgenic and non-transgenic rice cultivars was considered. Hence, four transgenic lines (driven from back cross of Khazar cultivar with transgenic line of Tarom Molaii) along with conventional cultivars (non-transgenic parents) were cultivated under the standard of biosafety protocol in three isolated sites in north of Iran in 2016. In order to conducted life cycle assessment, first, the results of each site were analyzed separately, and since there were not differences among the impact categories and indices in different sites, the average for the results of the three sites are being presented. Results show that decreased insecticides application in transgenic cultivars lowers the need for labor, machineries, and fuel, thereby contributing to reduction in use of energy and greenhouse gases emission from construction, transportation and application of inputs during cultivation. Furthermore, most investigated impact categories were obtained high for Tarom Molaii and Khazar and less for three transgenic lines. In addition, the most important categories were non-renewable energy, global warming, aquatic eutrophication, aquatic acidification, terrestrial acid/nutri, land occupation, terrestrial ecotoxicity, ozone layer depletion, ionizing radiation, respiratory inorganics, respiratory organics, cumulative energy demand, ecological footprint, greenhouse gas protocol, water footprint, carcinogens and non-carcinogens. Therefore, according to the findings of this research, it was observed that the emission amount of environmental pollutants has a positive correlation with the consumption of inputs and field management practices.