Publications by authors named "Tinne Boeckx"
Oxygen is a key signalling component of plant biology, and whilst an oxygen-sensing mechanism was previously described in Arabidopsis thaliana, key features of the associated PLANT CYSTEINE OXIDASE (PCO) N-degron pathway and Group VII ETHYLENE RESPONSE FACTOR (ERFVII) transcription factor substrates remain untested or unknown. We demonstrate that ERFVIIs show non-autonomous activation of root hypoxia tolerance and are essential for root development and survival under oxygen limiting conditions in soil. We determine the combined effects of ERFVIIs in controlling gene expression and define genetic and environmental components required for proteasome-dependent oxygen-regulated stability of ERFVIIs through the PCO N-degron pathway.
View Article and Find Full Text PDFThe N-degron pathway is a branch of the ubiquitin-proteasome system where amino-terminal residues serve as degradation signals. In a synthetic biology approach, we expressed ubiquitin ligase PRT6 and ubiquitin conjugating enzyme 2 (AtUBC2) from in a strain with mutation in its endogenous N-degron pathway. The two enzymes re-constitute part of the plant N-degron pathway and were probed by monitoring the stability of co-expressed GFP-linked plant proteins starting with Arginine N-degrons.
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- The study explores how the polycomb repressive complex 2 (PRC2) regulates gene repression in flowering plants and identifies a new mechanism for its control related to oxygen levels.
- Researchers discovered that the plant PRC2 subunit VRN2 has an N-terminal degron that triggers its degradation, shaped by early angiosperm evolution through gene duplication.
- The findings suggest that environmental factors like hypoxia and cold exposure increase VRN2 levels by interfering with its degradation, potentially linking environmental signals to the epigenetic regulation of plant growth and development.
Polyphenol oxidases (PPOs) have a recognized role during pathogen and arthropod attack. As an immediate consequence of such wounding, cellular compartmentation is destroyed allowing the chloroplastic PPO enzyme to interact with vacuolar substrates catalyzing the oxidation of monophenols and/or -diphenols to -diquinones. This ultimately results in a reduction in the nutritional value of wounded tissue through the formation of non-digestible secondary melanin pigments.
View Article and Find Full Text PDFBackground And Aims: Polyphenol oxidases (PPOs) catalyse the oxidation of monophenols and/or o-diphenols to highly reactive o-quinones, which in turn interact with oxygen and proteins to form reactive oxygen species (ROS) and typical brown-pigmented complexes. Hence PPOs can affect local levels of oxygen and ROS. Although the currently known substrates are located in the vacuole, the enzyme is targeted to the thylakoid lumen, suggesting a role for PPOs in photosynthesis.
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- Polyphenol oxidase (PPO) plays a key role in plants by catalyzing the oxidation of certain phenols, leading to the formation of brown pigments and potential defense mechanisms against herbivores and pathogens.
- PPO is primarily located in chloroplasts, raising questions about its role beyond defense, including possible interactions with photosynthesis and responses to environmental stressors.
- This review explores the functions of PPO in plants, including its potential to enhance stress tolerance in food crops, signaling a need for further research and practical applications.