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MSc Exit Seminar – Malaika Gomes (Nambara Lab)

December 9, 2020 @ 2:00 pm - 2:30 pm

Studies on the relationship between after-ripening regulated gene expression and reactive oxygen species in Arabidopsis thaliana seed germination

After-ripening (AR) is a process promoting seed germination, which occurs in the dry seed when storage time is extended. AR increases the seed’s response to environmental signals such as nitrate, which then regulates expression of AR-regulated genes upon imbibition. However, this mechanism is unknown. In this study, the role of reactive oxygen species (ROS) in expression of AR-regulated genes was investigated. Using the promoter:β-glucuronidase reporter system, AR was shown to alter spatial expression patterns of CHOTTO1 (CHO1), an AR repressor, enhancing its expression in the vasculature. Interestingly, AR seeds of the cho1 mutant enhanced superoxide accumulation in the vasculature. Pharmacological experiments suggest H2O2 decreases expression of CHO1, while increases expression of CYP707A2, another AR-regulated gene. Furthermore, H2O2 application increases nitric oxide release, but nitrate inhibits it, through NIN-Like Protein8, involved in nitrate signalling. These findings suggest ROS form a regulatory loop to regulate expression of AR-regulated genes, CHO1 and CYP707A2.


Join Zoom Meeting

Wednesday, December 9th, 2020 at 2:00pm

Meeting ID: 868 3794 8471
Host: Eiji Nambara (eiji.nambara@utoronto.ca)


December 9, 2020
2:00 pm - 2:30 pm