| 21. |
- Sweetlove, Lee J., et al.
(författare)
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Engineering central metabolism – a grand challenge for plant biologists
- 2017
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Ingår i: Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 90:4, s. 749-763
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Tidskriftsartikel (refereegranskat)abstract
- The goal of increasing crop productivity and nutrient-use efficiency is being addressed by a number of ambitious research projects seeking to re-engineer photosynthetic biochemistry. Many of these projects will require the engineering of substantial changes in fluxes of central metabolism. However, as has been amply demonstrated in simpler systems such as microbes, central metabolism is extremely difficult to rationally engineer. This is because of multiple layers of regulation that operate to maintain metabolic steady state and because of the highly connected nature of central metabolism. In this review we discuss new approaches for metabolic engineering that have the potential to address these problems and dramatically improve the success with which we can rationally engineer central metabolism in plants. In particular, we advocate the adoption of an iterative ‘design-build-test-learn’ cycle using fast-to-transform model plants as test beds. This approach can be realised by coupling new molecular tools to incorporate multiple transgenes in nuclear and plastid genomes with computational modelling to design the engineering strategy and to understand the metabolic phenotype of the engineered organism. We also envisage that mutagenesis could be used to fine-tune the balance between the endogenous metabolic network and the introduced enzymes. Finally, we emphasise the importance of considering the plant as a whole system and not isolated organs: the greatest increase in crop productivity will be achieved if both source and sink metabolism are engineered.
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| 22. |
- Vågsholm, Ivar
(författare)
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Statement on a request from the European Commission for the assessment of the scientific elements supporting the prohibition for the placing on the market of GM potato EH92-527-1 for cultivation purposes in Austria
- 2012
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Austria notified to the European Commission its ordinance implementing a national safeguard measure prohibiting the placing on the market of GM potato EH92-527-1 for cultivation purposes in Austria, after which the European Commission asked the European Food Safety Authority to assess the scientific elements supporting the prohibition. Having considered the information package provided by Austria and all relevant scientific publications, the GMO and BIOHAZ Panels concluded that: i) no new data specific to the safety of the nptII gene have been provided; ii) the risk posed by the formation of mosaic structures of aminoglycoside phosphotransferase genes could not be assessed without data documenting the existence of such structures among the existing gene variants and such data were not provided; iii) the therapeutic relevance of kanamycin and neomycin was already addressed in the EFSA's opinion on ARM genes and as of yet there is no evidence to indicate that resistance to these antibiotics in clinically-relevant bacteria has developed as a result of acquisition of the nptII gene; iv) the knowledge gaps and uncertainties highlighted in the Austrian document have already been considered in the EFSA's opinion on ARM genes. Austria did not provide any new or additional information on the molecular characterisation or PMEM of potato EH92-527-1 after the date of consent for this GM event that would require the reassessment of existing information. The EFSA GMO Panel reiterates its scientific opinion on the 2010 monitoring report of GM potato EH92-527-1 in which it provides specific recommendations to improve the methodology of the PMEM of the GM potato. Further, the EFSA GMO Panel concludes that no grounds exist to date that would lead to reconsideration of its opinion on GM potato EH92-527-1.
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| 23. |
- Ivarson, Emelie, et al.
(författare)
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Effects of overexpression of WRI1 and hemoglobin genes on the seed oil content of Lepidium campestre
- 2017
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The wild species field cress (Lepidium campestre), belonging to the Brassicaceae family, has potential to be developed into a novel oilseed- and catch crop, however, the species needs to be further improved regarding some important agronomic traits. One of them is its low oil content which needs to be increased. As far as we know there is no study aiming at increasing the oil content that has been reported in this species. In order to investigate the possibility to increase the seed oil content in field cress, we have tried to introduce the Arabidopsis WRINKLED1 (AtWRI1) or hemoglobin (Hb) genes from either Arabidopsis thaliana (AtHb2) or Beta vulgaris (BvHb2) into field cress with the seed specific expression. The hypothesis was that the oil content would be increased by overexpressing these target genes. The results showed that the oil content was indeed increased by up to 29.9, 20.2, and 25.9% in the transgenic lines expressing AtWRI1, AtHb2, and BvHb2, respectively. The seed oil composition of the transgenic lines did not significantly deviate from the seed oil composition of the wild type plants. Our results indicate that genetic modification can be used in this wild species for its fast domestication into a future economically viable oilseed and catch crop.
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| 24. |
- Kianersi, Farzad, et al.
(författare)
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Biosynthesis of rutin changes in Capparis spinosa due to altered expression of its pathway genes under elicitors' supplementation
- 2020
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Ingår i: Plant Cell Tissue and Organ Culture. - : Springer Nature. - 0167-6857 .- 1573-5044. ; 141:3, s. 619-631
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Tidskriftsartikel (refereegranskat)abstract
- Caper plant is (Capparis spinosa L.) a good source of rutin which plays a key role in the human diet. In this study, the effect of different concentrations of salicylic acid (SA) and methyl jasmonate (MeJA) on the weight of anther-derived calli and their rutin contents were assessed in caper plants. Also, we investigated the rutin content and expression pattern of some rutin related genes in leaves of caper plants at vegetative and fresh fruiting growth stages under SA and MeJA treatments. In the first experiment, the highest rutin contents were observed in anther-derived calli treated with 10 mu M MeJA and 100 mg L-1 SA after 2 weeks from initial treatments, which were 2.44 and 2.22-fold higher than control. Also, the treatment of caper plants with150 mu M MeJA and 100 mg L-1 SA resulted in a higher increase in the rutin content of leaves at the fresh fruiting stage (61.46 and 9.99 mg g(-1) DW, respectively), in the second experiment. Among the studied genes, the FLS gene showed the highest expression in the leaves of the MeJA- and SA-treated plants at vegetative growth stage, while in the fresh fruiting stage the highest expression was related to the RT gene. Use of 150 mu M MeJA and 100 mg L-1 SA enhanced the expression levels of the RT gene up to 7.36 and 2.89 times of the control, respectively. These results suggest that rutin content and the expression patterns of rutin biosynthesis genes in caper can be significantly enhanced by the SA and MeJA treatments in a growth stage-dependent manner. Key message Methyl jasmonate and salicylic acid treatments enhance the rutin contents of Capparis spinosa in vitro and in vivo and up-regulate the rutin biosynthetic related genes at two different growth stages.
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| 25. |
- Niazi, Adnan, et al.
(författare)
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Genome Analysis of Bacillus amyloliquefaciens Subsp. plantarum UCMB5113: A Rhizobacterium That Improves Plant Growth and Stress Management
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The Bacillus amyloliquefaciens subsp. plantarum strain UCMB5113 is a Gram-positive rhizobacterium that can colonize plant roots and stimulate plant growth and defense based on unknown mechanisms. This reinforcement of plants may provide protection to various forms of biotic and abiotic stress. To determine the genetic traits involved in the mechanism of plantbacteria association, the genome sequence of UCMB5113 was obtained by assembling paired-end Illumina reads. The assembled chromosome of 3,889,532 bp was predicted to encode 3,656 proteins. Genes that potentially contribute to plant growth promotion such as indole-3-acetic acid (IAA) biosynthesis, acetoin synthesis and siderophore production were identified. Moreover, annotation identified putative genes responsible for non-ribosomal synthesis of secondary metabolites and genes supporting environment fitness of UCMB5113 including drug and metal resistance. A large number of genes encoding a diverse set of secretory proteins, enzymes of primary and secondary metabolism and carbohydrate active enzymes were found which reflect a high capacity to degrade various rhizosphere macromolecules. Additionally, many predicted membrane transporters provides the bacterium with efficient uptake capabilities of several nutrients. Although, UCMB5113 has the possibility to produce antibiotics and biosurfactants, the protective effect of plants to pathogens seems to be indirect and due to priming of plant induced systemic resistance. The availability of the genome enables identification of genes and their function underpinning beneficial interactions of UCMB5113 with plants.
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| 26. |
- Ramesh, Vetukuri, et al.
(författare)
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Evidence for Small RNAs Homologous to Effector-Encoding Genes and Transposable Elements in the Oomycete Phytophthora infestans
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:12, s. e51399-
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Tidskriftsartikel (refereegranskat)abstract
- Phytophthora infestans is the oomycete pathogen responsible for the devastating late blight disease on potato and tomato. There is presently an intense research focus on the role(s) of effectors in promoting late blight disease development. However, little is known about how they are regulated, or how diversity in their expression may be generated among different isolates. Here we present data from investigation of RNA silencing processes, characterized by non-coding small RNA molecules (sRNA) of 19-40 nt. From deep sequencing of sRNAs we have identified sRNAs matching numerous RxLR and Crinkler (CRN) effector protein genes in two isolates differing in pathogenicity. Effector gene-derived sRNAs were present in both isolates, but exhibited marked differences in abundance, especially for CRN effectors. Small RNAs in P. infestans grouped into three clear size classes of 21, 25/26 and 32 nt. Small RNAs from all size classes mapped to RxLR effector genes, but notably 21 nt sRNAs were the predominant size class mapping to CRN effector genes. Some effector genes, such as PiAvr3a, to which sRNAs were found, also exhibited differences in transcript accumulation between the two isolates. The P. infestans genome is rich in transposable elements, and the majority of sRNAs of all size classes mapped to these sequences, predominantly to long terminal repeat (LTR) retrotransposons. RNA silencing of Dicer and Argonaute genes provided evidence that generation of 21 nt sRNAs is Dicer-dependent, while accumulation of longer sRNAs was impacted by silencing of Argonaute genes. Additionally, we identified six microRNA (miRNA) candidates from our sequencing data, their precursor sequences from the genome sequence, and target mRNAs. These miRNA candidates have features characteristic of both plant and metazoan miRNAs.
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| 27. |
- Sandin, Per, et al.
(författare)
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Technology Neutrality in European Regulation of GMOs
- 2022
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Ingår i: Ethics, Policy & Environment. - : Informa UK Limited. - 2155-0085 .- 2155-0093. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- Objections to the current EU regulatory system on genetically modified organisms (GMOs) in terms of high cost and lack of consistency, speed and scientific underpinning have prompted proposals for a more technology-neutral system. We sketch the conceptual background of the notion of ‘technology neutrality’ and propose a refined definition of the term. The proposed definition implies that technology neutrality of a regulatory system is a gradual and multidimensional feature. We use the definition to analyze two regulatory reform proposals: One proposal from the Netherlands for improving the exemption mechanism for GMOs under Directive 2001/18/EC, and one from the Norwegian Biotechnology Advisory Board, outlining a new stratified risk assessment procedure. While both proposals offer some degree of improved technology neutrality in some dimensions compared to current EU regulation, in some extents and dimensions, they do not. We conclude that proposals for more technology-neutral regulation of GMOs need, first, to make explicit to what extent and in what dimensions the proposal improves neutrality and, second, to present arguments supporting that these specific improvements constitute desirable policy change against the background of objections to current policy.
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| 28. |
- Abreha, Kibrom Berhe, et al.
(författare)
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Understanding the Sorghum–Colletotrichum sublineola interactions for enhanced host resistance
- 2021
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 12
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Forskningsöversikt (refereegranskat)abstract
- Improving sorghum resistance is a sustainable method to reduce yield losses due to anthracnose, a devastating disease caused by Colletotrichum sublineola. Elucidating the molecular mechanisms of sorghum–C. sublineola interactions would help identify biomarkers for rapid and efficient identification of novel sources for host-plant resistance improvement, understanding the pathogen virulence, and facilitating resistance breeding. Despite concerted efforts to identify resistance sources, the knowledge about sorghum–anthracnose interactions remains scanty. Hence, in this review, we presented an overview of the current knowledge on the mechanisms of sorghum-C. sublineola molecular interactions, sources of resistance for sorghum breeding, quantitative trait loci (QTL), and major (R-) resistance gene sequences as well as defense-related genes associated with anthracnose resistance. We summarized current knowledge about C. sublineola populations and its virulence. Illustration of the sorghum-C. sublineola interaction model based on the current understanding is also provided. We highlighted the importance of genomic resources of both organisms for integrated omics research to unravel the key molecular components underpinning compatible and incompatible sorghum–anthracnose interactions. Furthermore, sorghum-breeding strategy employing rapid sorghum germplasm screening, systems biology, and molecular tools is presented.
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| 29. |
- Brhanie Mesfin, Haftom, et al.
(författare)
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Novel GBS-Based SNP Markers for Finger Millet and Their Use in Genetic Diversity Analyses
- 2022
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Ingår i: Frontiers in Genetics. - : Frontiers Media SA. - 1664-8021. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Eleusine coracana (L.) Gaertn., commonly known as finger millet, is a multipurpose crop used for food and feed. Genomic tools are required for the characterization of crop gene pools and their genomics-led breeding. High-throughput sequencing-based characterization of finger millet germplasm representing diverse agro-ecologies was considered an effective method for determining its genetic diversity, thereby suggesting potential candidates for breeding. In this study, the genotyping-by-sequencing (GBS) method was used to simultaneously identify novel single nucleotide polymorphism (SNP) markers and genotype 288 finger millet accessions collected from Ethiopia and Zimbabwe. The accessions were characterized at individual and group levels using 5,226 bi-allelic SNPs, with a minimum allele frequency (MAF) of above 0.05, distributed across 2,500 scaffolds of the finger millet reference genome. The polymorphism information content (PIC) of the SNPs was 0.23 on average, and a quarter of them have PIC values over 0.32, making them highly informative. The grouping of the 288 accessions into seven populations based on geographic proximity and the potential for germplasm exchange revealed a narrow range of observed heterozygosity (Ho; 0.09-0.11) and expected heterozygosity (He) that ranged over twofold, from 0.11 to 0.26. Alleles unique to the different groups were also identified, which merit further investigation for their potential association with desirable traits. The analysis of molecular variance (AMOVA) revealed a highly significant genetic differentiation among groups of accessions classified based on the geographic region, country of origin, days to flowering, panicle type, and Al tolerance (p < 0.01). The high genetic differentiation between Ethiopian and Zimbabwean accessions was evident in the AMOVA, cluster, principal coordinate, and population structure analyses. The level of genetic diversity of finger millet accessions varies moderately among locations within Ethiopia, with accessions from the northern region having the lowest level. In the neighbor-joining cluster analysis, most of the improved cultivars included in this study were closely clustered, probably because they were developed using genetically less diverse germplasm and/or selected for similar traits, such as grain yield. The recombination of alleles via crossbreeding genetically distinct accessions from different regions of the two countries can potentially lead to the development of superior cultivars.
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| 30. |
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