المؤلفون: Petros P. Sigalas, Peter Buchner, Alex Kröper, Malcolm J. Hawkesford

المصدر: International Journal of Molecular Sciences, Vol 25, Iss 1, p 509 (2023)

مصطلحات موضوعية: NRT2, NRT3, nitrate, nitrogen, wheat, gene expression, Biology (General), QH301-705.5, Chemistry, QD1-999

الوصف: High-affinity nitrate transporters (NRT) are key components for nitrogen (N) acquisition and distribution within plants. However, insights on these transporters in wheat are scarce. This study presents a comprehensive analysis of the NRT2 and NRT3 gene families, where the aim is to shed light on their functionality and to evaluate their responses to N availability. A total of 53 NRT2s and 11 NRT3s were identified in the bread wheat genome, and these were grouped into different clades and homoeologous subgroups. The transcriptional dynamics of the identified NRT2 and NRT3 genes, in response to N starvation and nitrate resupply, were examined by RT-qPCR in the roots and shoots of hydroponically grown wheat plants through a time course experiment. Additionally, the spatial expression patterns of these genes were explored within the plant. The NRT2s of clade 1, TaNRT2.1-2.6, showed a root-specific expression and significant upregulation in response to N starvation, thus emphasizing a role in N acquisition. However, most of the clade 2 NRT2s displayed reduced expression under N-starved conditions. Nitrate resupply after N starvation revealed rapid responsiveness in TaNRT2.1-2.6, while clade 2 genes exhibited gradual induction, primarily in the roots. TaNRT2.18 was highly expressed in above-ground tissues and exhibited distinct nitrate-related response patterns for roots and shoots. The TaNRT3 gene expression closely paralleled the profiles of TaNRT2.1-2.6 in response to nitrate induction. These findings enhance the understanding of NRT2 and NRT3 involvement in nitrogen uptake and utilization, and they could have practical implications for improving nitrogen use efficiency. The study also recommends a standardized nomenclature for wheat NRT2 genes, thereby addressing prior naming inconsistencies.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1422-0067/25/1/509Test; https://doaj.org/toc/1661-6596Test; https://doaj.org/toc/1422-0067Test

الوصول الحر: https://doaj.org/article/b2479099757845c0b3957aab6da7527cTest

المؤلفون: Malcolm J. Hawkesford, Renu Pandey, P. R. Soumya, Krishnapriya Vengavasi, Kadambot H. M. Siddique

المصدر: Plant Physiology Reports. 26:600-613

مصطلحات موضوعية: Phosphorus uptake, Rhizosphere, Carboxylic acids, Root exudation, Physiology, Phosphorus, Microorganism, Phosphatases, food and beverages, chemistry.chemical_element, Plant physiology, Low molecular weight compounds, Cell Biology, Plant Science, Anion transporters, Bioavailability, Plant ecology, chemistry, Agronomy, Soil water, Genetics, Eutrophication, Ecology, Evolution, Behavior and Systematics

الوصف: Phosphorus (P) is an essential element for crop growth and development. In acid soils, inorganic P (Pi) is immobilised with Fe3+ and Al3+, whereas in calcareous soils, it is fixed with Ca2+. Therefore, P nutrition is not constrained by soil P content per se but by its bioavailability to plants. The large amounts of P fertiliser applied to agricultural land to increase crop P availability can cause eutrophication of non-flowing water bodies. Being a non-renewable resource, P reserves are becoming depleted. Soil P mobilisation is governed by multiple adaptations at the physiological and molecular levels. Below-ground physiological processes including favourable root architecture and morphology, and release of carboxylates, protons and root secretory phosphohydrolases result in significant modification of the rhizosphere microenvironment thereby enhancing P acquisition. Beneficial soil microorganisms work in tandem with plants to mobilise bioavailable soil P. Phosphorus acquisition through rhizosphere modifications is an exciting area of research for plant nutritionists.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::174d9abae602271379a062267abe7d29Test
https://doi.org/10.1007/s40502-021-00627-8Test

المؤلفون: C. E. E. Stuiver, Dharmendra H. Prajapati, Erica Zuidersma, L.J. De Kok, Malcolm J. Hawkesford, Ties Ausma

المساهمون: Verhulst lab, Elzenga lab, De Kok lab

المصدر: Plant Biology (Stuttgart, Germany)
Plant Biology, 22(2), 331-336. Wiley-Blackwell

مصطلحات موضوعية: 0106 biological sciences, EXPRESSION, EXCESS MOLYBDENUM, sulphate uptake, Plant Science, Brassica, sulphate assimilation, Molybdate, Biology, Sulphate assimilation, 010603 evolutionary biology, 01 natural sciences, REDUCTASE, chemistry.chemical_compound, Nitrate, Soil Pollutants, SELENATE, Food science, TOLERANCE, EXPOSURE, ATP SULFURYLASE, heavy metals, Ecology, Evolution, Behavior and Systematics, ACCUMULATION, Molybdenum, SULFATE TRANSPORTERS, Chlorosis, General Medicine, Metabolism, Research Papers, chemistry, Heavy metals, Seedlings, Shoot, Toxicity, Composition (visual arts), Phytotoxicity, ATMOSPHERIC H2S, Sulphate uptake, Sulfur, 010606 plant biology & botany, Research Paper

الوصف: In polluted areas, plants may be exposed to supra‐optimal levels of the micronutrient molybdenum. The physiological basis of molybdenum phytotoxicity is poorly understood. Plants take up molybdenum as molybdate, which is a structural analogue of sulphate. Therefore, it is presumed that elevated molybdate concentrations may hamper the uptake and subsequent metabolism of sulphate, which may induce sulphur deficiency.In the current research, Chinese cabbage (Brassica pekinensis) seedlings were exposed to 50, 100, 150 and 200 μm Na2MoO4 for 9 days.Leaf chlorosis and a decreased plant growth occurred at concentrations ≥100 μm. Root growth was more affected than shoot growth. At ≥100 μm Na2MoO4, the sulphate uptake rate and capacity were increased, although only when expressed on a root fresh weight basis. When expressed on a whole plant fresh weight basis, which corrects for the impact of molybdate on the shoot‐to‐root ratio, the sulphate uptake rate and capacity remained unaffected. Molybdate concentrations ≥100 μm altered the mineral nutrient composition of plant tissues, although the levels of sulphur metabolites (sulphate, water‐soluble non‐protein thiols and total sulphur) were not altered. Moreover, the levels of nitrogen metabolites (nitrate, amino acids, proteins and total nitrogen), which are generally strongly affected by sulphate deprivation, were not affected. The root water‐soluble non‐protein thiol content was increased, and the tissue nitrate levels decreased, only at 200 μm Na2MoO4.Evidently, molybdenum toxicity in Chinese cabbage was not due to the direct interference of molybdate with the uptake and subsequent metabolism of sulphate.
Exposure to excessive molybdate may constrain plant growth. It is presumed that elevated molybdate concentrations may hamper the uptake and subsequent metabolism of sulfate, which may induce sulfur deficiency. However, our research showed that in Chinese cabbage molybdate toxicity was not due to the direct interference of molybdate with the uptake and subsequent metabolism of sulfate.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8939bbdd51f323bc4344b61ac72fe4f5Test
http://europepmc.org/articles/PMC7065239Test

المؤلفون: Stephen J. Powers, Karl H. Mühling, Anne Rossmann, Malcolm J. Hawkesford, Peter Buchner, George P Savill

المصدر: Journal of Agricultural and Food Chemistry. 67:12709-12719

مصطلحات موضوعية: 0106 biological sciences, 01 natural sciences, Anthesis, Gene expression, Grain protein distribution, Storage protein, chemistry.chemical_classification, biology, Chemistry, Protein, 010401 analytical chemistry, food and beverages, General Chemistry, Gluten, 0104 chemical sciences, Horticulture, Protein body, Plant protein, Wheat, biology.protein, Protein body size distribution, Composition (visual arts), General Agricultural and Biological Sciences, Gliadin, 010606 plant biology & botany

الوصف: The major components of wheat storage proteins are gliadins and glutenins, and as they contribute differently to baking quality, a balanced mixture of these components is essential. The application of foliar nitrogen (N) at anthesis is a common practice to improve protein concentration and composition. The aim of this study was to investigate the effects of a foliar N application at anthesis on storage protein gene expression during grain development and on the distribution of protein concentration and protein body size within the grain. In this experiment, an additional N application at anthesis stimulated the expression of genes of the majority of storage proteins when the N supply was low. Furthermore, it led to higher protein concentrations in the subaleurone layers, while in the center of the lobes, the protein concentrations were decreased. These changes will affect the protein recovery in white flours, as proportionally more protein might be lost during milling processes.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::aeedb600e518ad5dba123a0147bc03a6Test
https://doi.org/10.1021/acs.jafc.9b04634Test

المؤلفون: Malcolm J. Hawkesford, Y. Ge, Jessica Evans, R. W. Ashton, Sacha J. Mooney, William R. Whalley, Ciro Antonio Rosolem

المساهمون: Rothamsted Res, Universidade Estadual Paulista (Unesp), Univ Nottingham

المصدر: Soil & Tillage Research
Web of Science
Repositório Institucional da UNESP
Universidade Estadual Paulista (UNESP)
instacron:UNESP

مصطلحات موضوعية: Soil Science, Article, law.invention, chemistry.chemical_compound, Nutrient, Root impedance, Nitrate, law, Root impedence, Earth-Surface Processes, Chemistry, Abiotic stress, fungi, food and beverages, 04 agricultural and veterinary sciences, Hydroponics, Penetrometer, Nutrient stress, Water potential, Agronomy, Loam, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Leaf stunting, Elongation, Agronomy and Crop Science

الوصف: Highlights • Leaf elongation is lower when roots are impeded irrespective of nitrate supply. • Root impedance and soil drying have a similar impact on root and shoot grow. • We found genotypic effects in leaf stunting due to abiotic stress. • Root diameter decreases with decreasing nitrate availability. • Root diameter increases with root impedance and moderate soil drying.
In the field, wheat experiences a combination of physical and nutrient stresses. There has been a tendency to study root impedance and water stress in separation and less is known about how they might interact. In this study, we investigated the effect of root impedance on the growth of three wheat varieties (Cadenza, Xi19 and Battalion) at different levels of nitrate availability, from 0–20 mM nitrate, in sand culture. This model system allows soil strength to be increased while maintaining adequate water availability. In a separate pot experiment, we grew the same wheat varieties in a loamy sand where soil was allowed to dry sufficiently to both reduce water potential and increase root impedance. This pot experiment also had a range of nitrate availabilities 0–20 mM nitrate. Once the seedlings were established we limited water supply to apply a matric potential of approximately −200 kPa to the roots. Soil drying increased the penetrometer resistance from approximately 300 kPa to more than 1 MPa. There were differences between the two experimental systems; growth was smaller in the soil-based experiment compared to the sand culture. However, the effects of the experimental treatment, root impedance or water withholding, relative to the control were comparable. Our data confirmed that leaf elongation in Cadenza (carrying the tall Rht allele) was the most sensitive to root impedance. Leaf stunting occurred irrespective of nitrate availability. Leaf elongation in the Xi19 and Battalion (carrying the semi-dwarf Rht allele) was less sensitive to root impedance and drought than Candenza. We suggest that the critical stress in a pot experiment where the soil was allowed to dry to approximately −200 kPa was root impedance and not water availability.

وصف الملف: application/pdf; PDF

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3a1c589e1a63cc706752e678a7414cfdTest
https://doi.org/10.1016Test/j.still.2019.04.005

المؤلفون: Peter R. Shewry, Malcolm J. Hawkesford, Zhiqiang Shi, Kirsty L. Hassall, Yongfang Wan, Yan Wang, Dong Jiang

المصدر: Journal of Agricultural and Food Chemistry. 67:8706-8714

مصطلحات موضوعية: chemistry.chemical_classification, Free amino acids, Glutens, Gluten proteins, Flour, food and beverages, nutritional and metabolic diseases, Embryo, General Chemistry, Gluten Proteins, digestive system, Gluten, digestive system diseases, Caryopsis, Amino acid, chemistry, Longitudinal gradients, Gene expression, Composition (visual arts), Food science, Amino Acids, Wheat grain, General Agricultural and Biological Sciences, Gene, Triticum

الوصف: Gradients in the contents and compositions of gluten proteins and free amino acids and the expression levels of gluten protein genes in developing wheat caryopses were determined by dividing the caryopsis into three longitudinal sections, namely, proximal (En1), middle (En2), and distal (En3) to embryo. The total gluten protein content was lower in En1 than in En2 and En3, with decreasing proportions of HMW-GS, LMW GS, and α/β- and γ-gliadins and increasing proportions of ω-gliadins. These differences were associated with the abundances of gluten protein transcripts. Gradients in the proportions of the gluten protein polymers which affect dough processing quality also occurred, but not in total free amino acids. Microscopy showed that the lower gluten protein content in En1 may have resulted, at least in part, from the presence of modified cells in the dorsal part of En1, but the reasons for the differences in composition are not known.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::827ffa4e934ae5adedf2c85046fd1fa5Test
https://doi.org/10.1021/acs.jafc.9b02728Test

المؤلفون: Tahereh A. Aghajanzadeh, Meike Burow, Martin M. Reich, Malcolm J. Hawkesford

المساهمون: Elzenga lab

المصدر: Aghajanzadeh, T A, Reich, M, Hawkesford, M J & Burow, M 2019, ' Sulfur metabolism in Allium cepa is hardly affected by chloride and sulfate salinity ', Archives of Agronomy and Soil Science, vol. 65, no. 7, pp. 945-956 . https://doi.org/10.1080/03650340.2018.1540037Test
Archives of agronomy and soil science, 65(7), 945-956. Taylor & Francis Ltd

مصطلحات موضوعية: 0106 biological sciences, Allium cepa, Potassium, ASSIMILATION, Sulfur metabolism, Soil Science, chemistry.chemical_element, Salt (chemistry), 01 natural sciences, Chloride, chemistry.chemical_compound, NACL, medicine, alliin, PLANTS, TOLERANCE, Sulfate, ACCUMULATION, chemistry.chemical_classification, fungi, food and beverages, EXCESS SULFUR, 04 agricultural and veterinary sciences, Sulfur, TRANSPORT, Salinity, SALT STRESS, Horticulture, sulfate salinity, chemistry, Shoot, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, chloride salinity, sulfur metabolism, GROWTH, ATMOSPHERIC H2S, allilin, Agronomy and Crop Science, 010606 plant biology & botany, medicine.drug

الوصف: Salinity as a major agricultural problem can affect crop growth and quality. Onion (Allium cepa L.) plant contains a wide variety of sulfur-containing compounds which may be involved in plant protection against salt stress. In the current study, a similar reduction in growth caused by chloride and sulfate salts was observed when onion was exposed to equimolar concentrations of Na+. Also, no difference was observed for shoot/root ratio and dry matter content of roots and shoots. Plants accumulated Na+ and the respective anions (chloride and sulfate) which in turn caused changes in the content of other nutrients. The content of potassium and calcium was decreased more than the other elements by both sodium salts. Sulfate salinity resulted in substantial increase in total sulfur and sulfate content but chloride salinity affected neither the total sulfur nor sulfate content of the roots and shoots, only in onion exposed to 200 mM chloride salt, those of roots and shoots were reduced. Furthermore, the water-soluble non-protein thiol content as well as the content of alliin remained rather unaffected. In conclusion, either salts affected the uptake and distribution of sulfate in onion, but had no or only a minor effect on the plant sulfur metabolism.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c411ffad1a5dbc319c15b2ed757ed7cdTest
https://hdl.handle.net/11370/677c74cf-ce24-437a-ab56-72204dbdb0d0Test

المؤلفون: Malcolm J. Hawkesford, Luit J. De Kok, Tahereh A. Aghajanzadeh, Saroj Parmar, Martin M. Reich

المساهمون: De Kok lab, Elzenga lab

المصدر: Journal of Plant Physiology, 231, 1-8. ELSEVIER GMBH, URBAN & FISCHER VERLAG

مصطلحات موضوعية: Chlorophyll, inorganic chemicals, 0106 biological sciences, 0301 basic medicine, Physiology, chemistry.chemical_element, Plant Science, Calcium, Salt Stress, 01 natural sciences, Sulfate salinity, salinity, calcium sulfate, 03 medical and health sciences, chemistry.chemical_compound, Gene Expression Regulation, Plant, Amino Acids, Brassica rapa, calcium sulfate, salinity,sulfate transport, vacuole, Sulfate, Sulfate assimilation, Growth medium, vacuole, Sulfates, Brassica rapa, Salt Tolerance, Sulfur, Sulfate transport, Salinity, sulfate transport, 030104 developmental biology, chemistry, Biochemistry, Toxicity, Agronomy and Crop Science, 010606 plant biology & botany

الوصف: Salinity stress in Brassica, often only associated with osmotic effects and the toxicity of Na+, was more severe when applied as Na2SO4 than as NaCl, indicating that SO42- ions had toxic effects as well. Application of 10 mM calcium in the form of CaCl2 in the growth medium of plants only slightly ameliorated growth impairment by NaCl and KCl, but almost completely prevented negative effects of Na2SO4 and K2SO4 on plant biomass production. This effect was calcium specific, as MgCl2 ameliorated sulfate toxicity to a much lower extent. This sulfate toxicity coincided with a strong decrease in the plant content of calcium and manganese upon sulfate salinity. Application of CaCl2 largely alleviated this decrease, however, it did not prevent the higher tissue concentration of sulfate. CaCl2 prevented the increase in organic sulfur compounds presumably by reducing of relative gene expression of ATP-sulfurylase (ATPS) and adenosine 5'-phosphosulfate reductase (APR) indicating a possible regulation of sulfate assimilation by calcium. The upregulation of the genes encoding for Group 4 sulfate transporters (Sultr4;1 and 4;2) upon sulfate salinity, was absent in the presence of CaCl2. Therefore, additional calcium may facilitate an increased vacuolar capacity for sulfate accumulation.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7c5dacdab8a3baaff3872bd101ac2c97Test
https://doi.org/10.1016Test/j.jplph.2018.08.014

المؤلفون: Yan Wang, Stephen J. Powers, Kirsty L. Hassall, Alison K. Huttly, Peter R. Shewry, Caroline A. Sparks, Yongfang Wan, Peter Buchner, Malcolm J. Hawkesford, Doris Rentsch, Jane L. Ward, Zhiqiang Shi

المصدر: Wan, Yongfang; Wang, Yan; Shi, Zhiqiang; Rentsch, Doris; Ward, Jane L.; Hassall, Kirsty; Sparks, Caroline A.; Huttly, Alison K.; Buchner, Peter; Powers, Stephen; Shewry, Peter R.; Hawkesford, Malcolm J. (2021). Wheat amino acid transporters highly expressed in grain cells regulate amino acid accumulation in grain. PLoS ONE, 16(2), e0246763. Public Library of Science 10.1371/journal.pone.0246763 <http://dx.doi.org/10.1371/journal.pone.0246763Test>
PLoS ONE
PLoS ONE, Vol 16, Iss 2, p e0246763 (2021)

مصطلحات موضوعية: 0106 biological sciences, 0301 basic medicine, Magnetic Resonance Spectroscopy, Fruit and Seed Anatomy, Amino Acid Transport Systems, Physiology, Overexpression, Flour, Plant Science, 580 Plants (Botany), Biochemistry, 01 natural sciences, Endosperm, RNA interference, Glutenin, Gene Expression Regulation, Plant, Aleurone, Medicine and Health Sciences, RNA-Seq, Amino Acids, Promoter Regions, Genetic, Chromatography, High Pressure Liquid, Triticum, Plant Proteins, chemistry.chemical_classification, Multidisciplinary, biology, Chemistry, Amino acid transporter, Plant Anatomy, Eukaryota, food and beverages, Plants, Grain size, Up-Regulation, Amino acid, Nucleic acids, Genetic interference, Physiological Parameters, Wheat, Amino Acid Analysis, Medicine, Hyperexpression Techniques, Epigenetics, Grain metabolites, Research Article, Glutens, Amino Acid Transport Systems, Acidic, Nitrogen, Science, Phloem, Real-Time Polymerase Chain Reaction, Research and Analysis Methods, 03 medical and health sciences, Genetics, Gene Expression and Vector Techniques, Storage protein, Grasses, Molecular Biology Techniques, Wheat grain, Molecular Biology, Nutrition, Molecular Biology Assays and Analysis Techniques, Body Weight, fungi, Organisms, Fungi, Biology and Life Sciences, Grain nitrogen, Yeast, Diet, Plant Leaves, Glutamine, 030104 developmental biology, Food, RNAi, Glycine, biology.protein, RNA, Gene expression, Edible Grain, 010606 plant biology & botany

الوصف: Amino acids are delivered into developing wheat grains to support the accumulation of storage proteins in the starchy endosperm, and transporters play important roles in regulating this process. RNA-seq, RT-qPCR, and promoter-GUS assays showed that three amino acid transporters are differentially expressed in the endosperm transfer cells (TaAAP2), starchy endosperm cells (TaAAP13), and aleurone cells and embryo of the developing grain (TaAAP21), respectively. Yeast complementation revealed that all three transporters can transport a broad spectrum of amino acids. RNAi-mediated suppression of TaAAP13 expression in the starchy endosperm did not reduce the total nitrogen content of the whole grain, but significantly altered the composition and distribution of metabolites in the starchy endosperm, with increasing concentrations of some amino acids (notably glutamine and glycine) from the outer to inner starchy endosperm cells compared with wild type. Overexpression of TaAAP13 under the endosperm-specific HMW-GS (high molecular weight glutenin subunit) promoter significantly increased grain size, grain nitrogen concentration, and thousand grain weight, indicating that the sink strength for nitrogen transport was increased by manipulation of amino acid transporters. However, the total grain number was reduced, suggesting that source nitrogen remobilized from leaves is a limiting factor for productivity. Therefore, simultaneously increasing loading of amino acids into the phloem and delivery to the spike would be required to increase protein content while maintaining grain yield. © 2021 Wan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0c1f00e23bf7aecde1e9b54974eb09b9Test

المؤلفون: Rainer Hoefgen, Saroj Parmar, Alexander Erban, Sarah J. Whitcomb, Joachim Kopka, Franziska Brückner, Apidet Rakpenthai, Malcolm J. Hawkesford, Axel Fischer

المصدر: Frontiers in Plant Science
Frontiers in Plant Science, Vol 11 (2020)

مصطلحات موضوعية: 0106 biological sciences, 0301 basic medicine, Low protein, Cysteine (Cys), Oryza sativa, Nutritional quality, Plant Science, lcsh:Plant culture, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Biosynthesis, Serine acetyltransferase, Endoplasmic reticulum (ER stress), Seed Storage Protein (SSPs), Storage protein, lcsh:SB1-1110, Methionine synthase, cysteine, Original Research, methionine, chemistry.chemical_classification, Methionine, biology, Endoplasmic reticulum, nutritional quality, serine acetyltransferase, food and beverages, seed storage protein, Amino acid, Oryza sativa (rice), endoplasmic reticulum, 030104 developmental biology, Methionine (Met), chemistry, Biochemistry, biology.protein, Cystathionine gamma-synthase, cystathionine gamma-synthase, 010606 plant biology & botany, Cysteine

الوصف: Staple crops in human and livestock diets suffer from deficiencies in certain “essential” amino acids including methionine. With the goal of increasing methionine in rice seed, we generated a pair of “Push × Pull” double transgenic lines, each containing a methionine-dense seed storage protein (2S albumin from sunflower, HaSSA) and an exogenous enzyme for either methionine (feedback desensitized cystathionine gamma synthase from Arabidopsis, AtD-CGS) or cysteine (serine acetyltransferase from E. coli, EcSAT) biosynthesis. In both double transgenic lines, the total seed methionine content was approximately 50% higher than in their untransformed parental line, Oryza sativa ssp. japonica cv. Taipei 309. HaSSA-containing rice seeds were reported to display an altered seed protein profile, speculatively due to insufficient sulfur amino acid content. However, here we present data suggesting that this may result from an overloaded protein folding machinery in the endoplasmic reticulum rather than primarily from redistribution of limited methionine from endogenous seed proteins to HaSSA. We hypothesize that HaSSA-associated endoplasmic reticulum stress results in redox perturbations that negatively impact sulfate reduction to cysteine, and we speculate that this is mitigated by EcSAT-associated increased sulfur import into the seed, which facilitates additional synthesis of cysteine and glutathione. The data presented here reveal challenges associated with increasing the methionine content in rice seed, including what may be relatively low protein folding capacity in the endoplasmic reticulum and an insufficient pool of sulfate available for additional cysteine and methionine synthesis. We propose that future approaches to further improve the methionine content in rice should focus on increasing seed sulfur loading and avoiding the accumulation of unfolded proteins in the endoplasmic reticulum. Oryza sativa ssp. japonica: urn:lsid:ipni.org:names:60471378-2.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4afbc2113db5e17d4a872a6fe99f7ec4Test
https://doi.org/10.3389/fpls.2020.01118Test