PhD ceremony: Mr. M. Shahbaz, 12.45 uur, Aula Academiegebouw, Broerstraat 5, Groningen
Dissertation: Copper toxicity and sulfur metabolism in Chinese cabbage
Promotor(s): prof. J.T.M. Elzenga
Faculty: Mathematics and Natural Sciences
Copper is an essential nutrient for plants, however, at enhanced concentrations in the root environment it may rapidly become phytotoxic. Muhammad Shahbaz has investigated the physiological basis of the phytotoxicity of Cu and significance of sulfur metabolism in its detoxification in Chinese cabbage. From his research it was evident that enhanced Cu2+ concentrations (> 2 μM) in the root environment are toxic for Chinese cabbage. The presence of UV radiation strongly enhanced Cu toxicity. Enhanced Cu2+ concentrations resulted in sulfate accumulation in the shoot and an enhanced synthesis of other sulfur-rich compounds (viz. phytochelatins and glutathione) in the root. Enhanced Cu2+ concentrations interfered with the regulation of the uptake and assimilation of sulfur in Chinese cabbage, but there was no direct relation between the plant sulfur status and Cu toxicity. It is generally presumed that sulfate itself or metabolic products of the sulfate assimilation, viz. thiols (glutathione), would act as signals in the regulation of the expression and activity of the sulfate transporters. This presumed signal transduction pathway in regulation of expression and activity of the sulfate transporters (sulfate and thiols) were by-passed or overruled, if Chinese cabbage was exposed to enhanced Cu2+ concentrations. It is proposed that undissociated H2S may function as an endogenous gaseous transmitter in the cross-talk between the sulfate reduction pathway in chloroplast/plastid and the transcription of sulfate transporters in the nucleus. A Cu-induced decrease in subcellular H2S concentration might be responsible for the observed upregulation of the expression and activity of the sulfate transporters.
Aan het einde van de zomer komen er naast veel Nederlandse studenten ook internationale studenten naar Groningen om voor kortere of langere tijd te studeren aan de Hanzehogeschool Groningen (HG) of de Rijksuniversiteit Groningen (RUG). Vanwege de...
NWA Idea Generator project for Kottapalli to develop low-cost sensorized shoes for patients to monitor gait and avoid fall conditions through a biofeedback voice alert.
Ymkje Stienstra (UMCG), Joram Tarusaria and Ajay Kottapalli receive an NWA Idea Generator Grant .