Wilhelm Gruissem

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Gruissem

First Name

Wilhelm

ORCID

0000-0002-1872-2998

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Publications 1 - 10 of 92

RNA-mediated resistance to cassava geminiviruses in transgenic cassava
Vanderschuren, Hervé; Akbergenov, Rashid; Pooggin, Mikhail M.; et al. (2007)
Biotechnology and Sustainable Agriculture 2006 and Beyond. Proceedings of the 11th IAPTC&B Congress, August 31-18, 2006 Beijing, China
Linking CRISPR-Cas9 interference in cassava to the evolution of editing-resistant geminiviruses
Mehta, Devang; Stürchler, Alessandra; Anjanappa, Ravi B.; et al. (2019)
Genome Biology
Background Geminiviruses cause damaging diseases in several important crop species. However, limited progress has been made in developing crop varieties resistant to these highly diverse DNA viruses. Recently, the bacterial CRISPR/Cas9 system has been transferred to plants to target and confer immunity to geminiviruses. In this study, we use CRISPR-Cas9 interference in the staple food crop cassava with the aim of engineering resistance to African cassava mosaic virus, a member of a widespread and important family (Geminiviridae) of plant-pathogenic DNA viruses. Results Our results show that the CRISPR system fails to confer effective resistance to the virus during glasshouse inoculations. Further, we find that between 33 and 48% of edited virus genomes evolve a conserved single-nucleotide mutation that confers resistance to CRISPR-Cas9 cleavage. We also find that in the model plant Nicotiana benthamiana the replication of the novel, mutant virus is dependent on the presence of the wild-type virus. Conclusions Our study highlights the risks associated with CRISPR-Cas9 virus immunity in eukaryotes given that the mutagenic nature of the system generates viral escapes in a short time period. Our in-depth analysis of virus populations also represents a template for future studies analyzing virus escape from anti-viral CRISPR transgenics. This is especially important for informing regulation of such actively mutagenic applications of CRISPR-Cas9 technology in agriculture.
Targeting intracellular transport combined with efficient uptake and storage significantly increases grain iron and zinc levels in rice
Wu, Ting-Ying; Gruissem, Wilhelm; Bhullar, Navreet K. (2019)
Plant Biotechnology Journal
Engineering vascular potassium transport increases yield and drought resilience of cassava
Zierer, Wolfgang; Fritzler, Michelle; Chiu, T.J.; et al. (2025)
Nature Plants
Cassava (Manihot esculenta) is an important crop for food security in the tropics, particularly for smallholder farmers in sub-Saharan Africa, where yields are often severely limited by pathogen pressure, nutrient deficiency and water scarcity. We expressed a non-rectifying Arabidopsis thaliana potassium (K⁺) channel gene version, AKT2_var, in the vascular tissue of cassava plants. The transgenic cassava plants had higher electron transport and CO₂ assimilation rates, a higher bulk flow velocity and increased source–sink carbohydrate transport, as demonstrated by comparative ¹¹C-positron emission tomography and tissue-specific metabolite profiling. Cassava storage root yield was significantly increased in greenhouse experiments and in a multi-year field trial conducted under subtropical conditions. AKT2_var plants were also more tolerant of drought stress and had higher storage root yield. Targeted alteration of K⁺ transport is therefore a promising strategy to improve cassava productivity without additional fertilizer input and in climate-adverse growing conditions.
Efficient replication of cloned African cassava mosaic virus in cassava leaf disks
Zhang, Peng; Gruissem, Wilhelm (2003)
Virus Research
Proteome dynamics during plastid differentiation in rice
Kleffmann, Torsten; Von Zychlinski, Anne; Russenberger, Doris; et al. (2007)
Plant Physiology
We have analyzed proteome dynamics during light-induced development of rice (Oryza sativa) chloroplasts from etioplasts using quantitative two-dimensional gel electrophoresis and tandem mass spectrometry protein identification. In the dark, the etioplast allocates the main proportion of total protein mass to carbohydrate and amino acid metabolism and a surprisingly high number of proteins to the regulation and expression of plastid genes. Chaperones, proteins for photosynthetic energy metabolism, and enzymes of the tetrapyrrole pathway were identified among the most abundant etioplast proteins. The detection of 13 N-terminal acetylated peptides allowed us to map the exact localization of the transit peptide cleavage site, demonstrating good agreement with the prediction for most proteins. Based on the quantitative etioplast proteome map, we examined early light-induced changes during chloroplast development. The transition from heterotrophic metabolism to photosynthesis-supported autotrophic metabolism was already detectable 2 h after illumination and affected most essential metabolic modules. Enzymes in carbohydrate metabolism, photosynthesis, and gene expression were up-regulated, whereas enzymes in amino acid and fatty acid metabolism were significantly decreased in relative abundance. Enzymes involved in nucleotide metabolism, tetrapyrrole biosynthesis, and redox regulation remained unchanged. Phosphoprotein-specific staining at different time points during chloroplast development revealed light-induced phosphorylation of a nuclear-encoded plastid RNA-binding protein, consistent with changes in plastid RNA metabolism. Quantitative information about all identified proteins and their regulation by light is available in plprot, the plastid proteome database (http://www.plprot.ethz.ch).
Comparison of Biclustering Methods: A Systematic Comparison and Evaluation of Biclustering Methods for Gene Expression Data
Prelić, Amela; Bleuler, Stefan; Zimmermann, Philip; et al. (2005)
TIK Report
In recent years, there have been various efforts to over-come the limitations of standard clustering approaches for the analysis of gene expression data by grouping genes and samples simultaneously.The underlying concept, which is often referred to as biclustering, allows to identify sets of genes sharing compatible expression patterns across subsets of samples, and its usefulness has been demonstrated for different organisms and data sets. Several biclustering methods have been proposed in the literature; however, it is not clear how the different techniques compare to each other with respect to the biological relevance of the clusters as well as to other characteristics such as robustness and sensitivity to noise. Accordingly, no guidelines concerning the choice of the biclustering method are currently available.
Arabidopsis replacement histone variant H3.3 occupies promoters of regulated genes
Shu, Huan; Nakamura, Miyuki; Siretskiy, Alexey; et al. (2014)
Genome Biology
Background Histone variants establish structural and functional diversity of chromatin by affecting nucleosome stability and histone-protein interactions. H3.3 is an H3 histone variant that is incorporated into chromatin outside of S-phase in various eukaryotes. In animals, H3.3 is associated with active transcription and possibly maintenance of transcriptional memory. Plant H3 variants, which evolved independently of their animal counterparts, are much less well understood. Results We profile the H3.3 distribution in Arabidopsis at mono-nucleosomal resolution using native chromatin immunoprecipitation. This results in the precise mapping of H3.3-containing nucleosomes, which are not only enriched in gene bodies as previously reported, but also at a subset of promoter regions and downstream of the 3′ ends of active genes. While H3.3 presence within transcribed regions is strongly associated with transcriptional activity, H3.3 at promoters is often independent of transcription. In particular, promoters with GA motifs carry H3.3 regardless of the gene expression levels. H3.3 on promoters of inactive genes is associated with H3K27me3 at gene bodies. In addition, H3.3-enriched plant promoters often contain RNA Pol II considerably upstream of the transcriptional start site. H3.3 and RNA Pol II are found on active as well as on inactive promoters and are enriched at strongly regulated genes. Conclusions In animals and plants, H3.3 organizes chromatin in transcribed regions and in promoters. The results suggest a function of H3.3 in transcriptional regulation and support a model that a single ancestral H3 evolved into H3 variants with similar sub-functionalization patterns in plants and animals.
Diurnal changes in the histone H3 signature H3K9ac|H3K27ac|H3S28p are associated with diurnal gene expression in Arabidopsis
Baerenfaller, Katja; Shu, Huan; Hirsch-Hoffmann, Matthias; et al. (2016)
Plant, Cell & Environment
Post-translational chromatin modifications are an important regulatory mechanism in light signalling and circadian clock function. The regulation of diurnal transcript level changes requires fine-tuning of the expression of generally active genes depending on the prevailing environmental conditions. We investigated the association of histone modifications H3K4me3, H3K9ac, H3K9me2, H3S10p, H3K27ac, H3K27me3 and H3S28p with diurnal changes in transcript expression using chromatin immunoprecipitations followed by sequencing (ChIP-Seq) in fully expanded leaves 6 of Arabidopsis thaliana grown in short-day optimal and water-deficit conditions. We identified a differential H3K9ac, H3K27ac and H3S28p signature between end-of-day and end-of-night that is correlated with changes in diurnal transcript levels. Genes with this signature have particular over-represented promoter elements and encode proteins that are significantly enriched for transcription factors, circadian clock and starch catabolic process. Additional activating modifications were prevalent in optimally watered (H3S10p) and in water-deficit (H3K4me3) plants. The data suggest a mechanism for diurnal transcript level regulation in which reduced binding of repressive transcription factors facilitates activating H3K9ac, H3K27ac and H3S28p chromatin modifications. The presence of activating chromatin modification patterns on genes only at times of the day when their expression is required can explain why some genes are differentially inducible during the diurnal cycle.
A tribute to Lars Hennig (1970-2018) Obituary
Mozgova, Iva; Alexandre, Cristina; Steinbach, Yvonne; et al. (2018)
Journal of Experimental Botany

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Wilhelm Gruissem

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