Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
Oxygen limitation (hypoxia), arising as a key stress factor due to flooding, negatively affects plant development. Consequently, maintaining root growth under such stress is crucial for plant survival, yet we know little about the root system\'s adaptions to low‐oxygen conditions and its regulation by phytohormones. In this study, we examine the impact of hypoxia and, herein, the regulatory role of group VII ETHYLENE‐RESPONSE FACTOR (ERFVII) transcription factors on root growth in Arabidopsis. We found lateral root (LR) elongation to be actively maintained by hypoxia via ERFVII factors, as erfVII seedlings possess hypersensitivity towards hypoxia regarding their LR growth. Pharmacological inhibition of abscisic acid (ABA) biosynthesis revealed ERFVII‐driven counteraction of hypoxia‐induced inhibition of LR formation in an ABA‐dependent manner. However, postemergence LR growth under hypoxia mediated by ERFVIIs was independent of ABA. In roots, ERFVIIs mediate, among others, the induction of ABA‐degrading ABA 8′‐hydroxylases CYP707A1 expression. RAP2.12 could activate the pCYC707A1:LUC reporter gene, indicating, combined with single mutant analyses, that this transcription factor regulates ABA levels through corresponding transcript upregulation. Collectively, hypoxia‐induced adaptation of the Arabidopsis root system is shaped by developmental reprogramming, whereby ERFVII‐dependent promotion of LR emergence, but not elongation, is partly executed through regulation of ABA degradation.
Publikation
Mpetga, J. D. S.; Nago, R. D. T.; Tamokou, J.-D.-D.; Fobofou, S. A. T.; Bitchagno, G. T. M.; Wessjohann, L. A.; Tene, M.; Ngouela, A. S.;A new ceramide from Cissus aralioides Baker (Vitaceae) and its antimicrobial activityChem. Biodivers.19e202200678(2022)DOI: 10.1002/cbdv.202200678
Purification through repeated column chromatography over silica gel and Sephadex LH-20 of the ethanol extract of the stems of Cissus aralioides (Baker) Planch. resulted in the isolation of a new ceramide, aralioidamide A (1) along with five known compounds (2-6). Their structures were determined by the extensive analysis of their spectroscopic (1D and 2D NMR) and spectrometric data, and comparison with those reported in the literature. Aralioidamide A (1) displayed weak antibacterial activity (MIC = 256 μg/mL) against Bacillus subtilis, Staphylococcus aureus and Shigella flexneri and was inactive (MIC > 256 μg/mL) against the tested fungi.
Publikation
Zeng, M.; Hause, B.; van Dam, N. M.; Uthe, H.; Hoffmann, P.; Krajinski, F.; Martínez‐Medina, A.;The mycorrhizal symbiosis alters the plant defence strategy in a model legume plantPlant Cell Environ.453412-3428(2022)DOI: 10.1111/pce.14421
Arbuscular mycorrhizal (AM) symbiosis modulates plant‐herbivore interactions. Still, how it shapes the overall plant defence strategy and the mechanisms involved remain unclear. We investigated how AM symbiosis simultaneously modulates plant resistance and tolerance to a shoot herbivore, and explored the underlying mechanisms. Bioassays with Medicago truncatula plants were used to study the effect of the AM fungus Rhizophagus irregularis on plant resistance and tolerance to Spodoptera exigua herbivory. By performing molecular and chemical analyses, we assessed the impact of AM symbiosis on herbivore‐triggered phosphate (Pi)‐ and jasmonate (JA)‐related responses. Upon herbivory, AM symbiosis led to an increased leaf Pi content by boosting the mycorrhizal Pi‐uptake pathway. This enhanced both plant tolerance and herbivore performance. AM symbiosis counteracted the herbivore‐triggered JA burst, reducing plant resistance. To disentangle the role of the mycorrhizal Pi‐uptake pathway in the plant\'s response to herbivory, we used the mutant line ha1‐2, impaired in the H+‐ATPase gene HA1, which is essential for Pi‐uptake via the mycorrhizal pathway. We found that mycorrhiza‐triggered enhancement of herbivore performance was compromised in ha1‐2 plants. AM symbiosis thus affects the defence pattern of M. truncatula by altering resistance and tolerance simultaneously. We propose that the mycorrhizal Pi‐uptake pathway is involved in the modulation of the plant defence strategy.
Publikation
Feiner, A.; Pitra, N.; Matthews, P.; Pillen, K.; Wessjohann, L. A.; Riewe, D.;Downy mildew resistance is genetically mediated by prophylactic production of phenylpropanoids in hopPlant Cell Environ.44323-338(2021)DOI: 10.1111/pce.13906
Downy mildew in hop (Humulus lupulus L.) is caused by Pseudoperonospora humuli and generates significant losses in quality and yield. To identify the biochemical processes that confer natural downy mildew resistance (DMR), a metabolome- and genomewide association study was performed. Inoculation of a high density genotyped F1 hop population (n = 192) with the obligate biotrophic oomycete P. humuli led to variation in both the levels of thousands of specialized metabolites and DMR. We observed that metabolites of almost all major phytochemical classes were induced 48 hr after inoculation. But only a small number of metabolites were found to be correlated with DMR and these were enriched with phenylpropanoids. These metabolites were also correlated with DMR when measured from the non-infected control set. A genome-wide association study revealed co-localization of the major DMR loci and the phenylpropanoid pathway markers indicating that the major contribution to resistance is mediated by these metabolites in a heritable manner. The application of three putative prophylactic phenylpropanoids led to a reduced degree of leaf infection in susceptible genotypes, confirming their protective activity either directly or as precursors of active compounds.