Publications by authors named "Stefan Hiekel"

Genome editing strategies in barley () typically rely on -mediated genetic transformation for the delivery of required genetic reagents involving tissue culture techniques. These approaches are genotype-dependent, time-consuming, and labor-intensive, which hampers rapid genome editing in barley. More recently, plant RNA viruses have been engineered to transiently express short guide RNAs facilitating CRISPR/Cas9-based targeted genome editing in plants that constitutively express .

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Biotic stresses caused by microbial pathogens impair crop yield and quality if not restricted by expensive and often ecologically problematic pesticides. For a sustainable agriculture of tomorrow, breeding or engineering of pathogen-resistant crop varieties is therefore a major cornerstone. Maize is one of the four most important cereal crops in the world.

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Article Synopsis
  • The naked caryopsis trait in barley results from a loss-of-function mutation in the NUD gene, which is crucial for forming a cementing layer in the grain.
  • Researchers used RNA-guided Cas9 to effectively knock out the NUD gene, leading to a 57% conversion rate from hulled to naked barley in transformed plants.
  • The development of isogenic lines of hulled and naked barley offers an ideal model for studying the effects of NUD mutations on plant performance and yield, with naked barley having health benefits due to its high β-glucan content.
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Many plant genomes display high levels of repetitive sequences. The assembly of these complex genomes using short high-throughput sequence reads is still a challenging task. Underestimation or disregard of repeat complexity in these datasets can easily misguide downstream analysis.

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Background: Although customized endonucleases [transcription activator-like effector nucleases (TALENs) and RNA-guided endonucleases (RGENs)] are known to be effective agents of mutagenesis in various host plants, newly designed endonuclease constructs require some pre-validation with respect to functionality before investing in the creation of stable transgenic plants.

Results: A simple, biolistics-based leaf epidermis transient expression test has been developed, based on reconstituting the translational reading frame of a mutated, non-functional yfp reporter gene. Quantification of mutation efficacy was made possible by co-bombarding the explant with a constitutive mCherry expression cassette, thereby allowing the ratio between the number of red and yellow fluorescing cells to serve as a metric for mutation efficiency.

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Natural illumination conditions are highly variable and because of their sessile life style, plants are forced to acclimate to them at the cellular and molecular level. Changes in light intensity or quality induce changes in the reduction/oxidation (redox) state of the photosynthetic electron chain that acts as a trigger for compensatory acclimation responses comprising functional and structural adjustments of photosynthesis and metabolism. Such responses include redox-controlled changes in plant gene expression in the nucleus and organelles.

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Transcription activator-like effector nucleases (TALENs) are customizable fusion proteins able to cleave virtually any genomic DNA sequence of choice, and thereby to generate site-directed genetic modifications in a wide range of cells and organisms. In the present study, we expressed TALENs in pollen-derived, regenerable cells to establish the generation of instantly true-breeding mutant plants. A gfp-specific TALEN pair was expressed via Agrobacterium-mediated transformation in embryogenic pollen of transgenic barley harboring a functional copy of gfp.

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