Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2021
Forfattere
Giorgia Carnovale Filipa Rosa Volha Shapaval Simona Dzurendova Achim Kohler Trude Wicklund Svein Jarle Horn Maria Barbosa Kari SkjånesSammendrag
ABSTRACT The use of microalgal starch has been studied in biorefinery frameworks to produce bioethanol or bioplastics, however, these products are currently not economically viable. Using starch−rich biomass as an ingredient in food applications is a novel way to create more value while expanding the product portfolio of the microalgal industry. Optimization of starch production in the food−approved species Chlorella vulgaris was the main objective of this study. High−throughput screening of biomass composition in response to multiple stressors was performed with FTIR spectroscopy and nitrogen starvation was identified as an important factor for starch accumulation. Further studies were subsequently performed to assess the role of light distribution, investigating photon supply rates in flat panel photobioreactors. Biomass specific photon supply rate proved to have a strong effect on the accumulation of storage compounds and starch−rich biomass with up to 30% starch was achieved in cultures with low inoculation density (0.1 g L−1) and high irradiation (1800 μmol m−2 s−1). A final large scale experiment was performed in 25 L tubular reactors, achieving a maximum of 44% starch in the biomass after 12 hours in nitrogen starved conditions. Keywords: Chlorella vulgaris, starch, FTIR, photon supply rate, microalgae
Forfattere
Isam Fattash Zachary Deitch Relindis Ghai Njah Nelson Uchechukwu Osuagwu Vera Mageney Robert Charles Wilson Jahn Davik Muath K Alsheikh Stephen RandallSammendrag
Identifying and characterizing cold responsive genes in Fragaria vesca associated with or responsible for low temperature tolerance is a vital part of strawberry cultivar development. In this study we have investigated the transcript levels of eight genes, two dehydrin genes, three putative ABA-regulated genes, two cold–inducible CBF genes and the alcohol dehydrogenase gene, extracted from leaf and crown tissues of three F. vesca genotypes that vary in cold tolerance. Transcript levels of the CBF/DREB1 transcription factor FvCBF1E exhibited stronger cold up-regulation in comparison to FvCBF1B.1 in all genotypes. Transcripts of FvADH were highly up-regulated in both crown and leaf tissues from all three genotypes. In the ‘ALTA’ genotype, FvADH transcripts were significantly higher in leaf than crown tissues and more than 10 to 20-fold greater than in the less cold-tolerant ‘NCGR1363’ and ‘FDP817’ genotypes. FvGEM, containing the conserved ABRE promoter element, transcript was found to be cold-regulated in crowns. Direct comparison of the kinetics of transcript and protein accumulation of dehydrins was scrutinized. In all genotypes and organs, the changes of XERO2 transcript levels generally preceded protein changes, while levels of COR47 protein accumulation preceded the increases in COR47 RNA in ‘ALTA’ crowns.
Forfattere
T. Haikonen Jahn Davik M. Rantanen P. Parikka J. Näkkilä S. Karhu Muath K Alsheikh S. H. HjeltnesSammendrag
Climate change may result in increased root system stresses in strawberry cultivation, requiring cultivars with root and crown-related resistance and resiliency traits. Approaches to widen the genetic basis and improve tools for the incorporation of novel variation are relevant to plant breeding for changing climate. The pre-breeding project NORDFRUIT is a Nordic public-private-partnership project that aims to introduce novel genetic variation from new sources, support the use of existing genetic resources adapted to Nordic and Baltic cultivation conditions, and develop efficient tools to speed up germplasm evaluation in breeding programs for climate adaptation. Pre-evaluated genotypes of Fragaria chiloensis or Fragaria virginiana were used as parents in interspecific (species hybridization) crosses, re-creating the garden strawberry hybrid species, F. ×ananassa. The created F1 hybrid seedlings were propagated by runners for replicated phenotyping trials. A greenhouse assay to test root-shoot biomass partition, growth vigour and Phytophthora cactorum resistance in these small plants was scaled up from an earlier assay based on nutrient film technology (NFT). The observed variation in disease symptom appearance, root-shoot ratio, and root proliferation indicated promising traits in the strawberry hybrid material, to be exploited further in genomic studies and to develop genome-assisted resistance breeding. The on-going work also includes field testing of the same hybrid material to evaluate winter hardiness, powdery mildew incidence, and fruit traits.
Forfattere
Jahn Davik Robert Charles Wilson Relindis Ghai Njah Paul Eivind Grini Stephen K. Randall Muath K Alsheikh Daniel James SargentSammendrag
Extreme cold and frost cause significant stress to plants which can potentially be lethal. Low temperature freezing stress can cause significant and irreversible damage to plant cells and can induce physiological and metabolic changes that impact on growth and development. Low temperatures cause physiological responses including winter dormancy and autumn cold hardening in strawberry (Fragaria) species, and some diploid F. vesca accessions have been shown to have adapted to low-temperature stresses. To study the genetics of freezing tolerance, a F. vesca mapping population of 143 seedlings segregating for differential responses to freezing stress was raised. The progeny was mapped using ‘Genotyping-by-Sequencing’ and a linkage map of 2,918 markers at 851 loci was resolved. The mapping population was phenotyped for freezing tolerance response under controlled and replicated laboratory conditions and subsequent quantitative trait loci analysis using interval mapping revealed a single significant quantitative trait locus on Fvb2 in the physical interval 10.6 Mb and 15.73 Mb on the F. vesca v4.0 genome sequence. This physical interval contained 896 predicted genes, several of which had putative roles associated with tolerance to abiotic stresses including freezing. Differential expression analysis of the 896 QTL-associated gene predictions in the leaves and crowns from ‘Alta’ and ‘NCGR1363’ parental genotypes revealed genotype-specific changes in transcript accumulation in response to low temperature treatment as well as expression differences between genotypes prior to treatment for many of the genes. The putative roles, and significant interparental differential expression levels of several of the genes reported here identified them as good candidates for the control of the effects of freezing tolerance at the QTL identified in this investigation and the possible role of these candidate genes in response to freezing stress is discussed.
Forfattere
Ziyan Xu Yongjie Kuang Bin Ren Daqi Yan Fang Yan Carl Jonas Jorge Spetz Wenxian Sun Guirong Wang Xueping Zhou Huanbin ZhouSammendrag
Background Plant genome engineering mediated by various CRISPR-based tools requires specific protospacer adjacent motifs (PAMs), such as the well-performed NGG, NG, and NNG, to initiate target recognition, which notably restricts the editable range of the plant genome. Results In this study, we thoroughly investigate the nuclease activity and the PAM preference of two structurally engineered SpCas9 variants, SpG and SpRY, in transgenic rice. Our study shows that SpG nuclease favors NGD PAMs, albeit less efficiently than the previously described SpCas9-NG, and that SpRY nuclease achieves efficient editing across a wide range of genomic loci, exhibiting a preference of NGD as well as NAN PAMs. Furthermore, SpRY-fused cytidine deaminase hAID*Δ and adenosine deaminase TadA8e are generated, respectively. These constructs efficiently induce C-to-T and A-to-G conversions in the target genes toward various non-canonical PAMs, including non-G PAMs. Remarkably, high-frequency self-editing events (indels and DNA fragments deletion) in the integrated T-DNA fragments as a result of the nuclease activity of SpRY are observed, whereas the self-editing of SpRY nickase-mediated base editor is quite low in transgenic rice lines. Conclusions The broad PAM compatibility of SpRY greatly expands the targeting scope of CRISPR-based tools in plant genome engineering.
Forfattere
Gunda ThömingSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunda ThömingSammendrag
Allelochemicals, chemical cues that, among other things, mediate insect–plant interactions, such as host plant recognition, have attracted notable interest as tools for ecological control of pest insects. Advances have recently been made in methods for sampling and analyzing volatile compounds and technology for tracking insects in their natural habitat. However, progress in odor-mediated behavioral bioassays of insects has been relatively slow. This perspective highlights this odor-mediated insect behavior, particularly in a natural setting and considering the whole behavioral sequence involved in the host location, which is the key to understanding the mechanisms underlying host plant recognition. There is thus a need to focus on elaborate behavioral bioassays in future studies, particularly if the goal is to use allelochemicals in pest control. Future directions for research are discussed.
Forfattere
Gunda ThömingSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunda ThömingSammendrag
Det er ikke registrert sammendrag
Forfattere
Gunda ThömingSammendrag
Det er ikke registrert sammendrag