Elucidating TOR Function in Plant Development

UoM administered thesis: Phd

  • Authors:
  • Victoria Spencer

Abstract

Plants must coordinate development in response to nutrient availability, to maximise survival and reproduction in a changing environment. Eukaryotes share a central nutrition sensing pathway, characterised by the master regulator, TARGET OF RAPAMYCIN (TOR). This kinase mediates growth and development in response to nutrient and energy levels. The central signalling components (TOR, LST8, RAPTOR, and S6K) have been characterised in plants, however, their upstream and downstream targets remain elusive. By analysing TOR function in Arabidopsis thaliana and Kalanchoe daigremontiana, this project aims to uncover potential links between TOR signalling and plant development to investigate whether, over evolutionary time, TOR has been recruited into shoot-specific processes. To address this, both chemical and genetic perturbations were used, and the expression of downstream targets was elucidated by RNA Sequencing, qRT-PCR, and MUG Assays of GUS reporter lines. It was found that the meristem repressor, CLAVATA3, is induced upon TOR repression in the growing seedling, whilst it is repressed in the flower bud. Other key developmental genes also changed, including the floral induction gene, LEAFY. Furthermore, TOR activity may feedback to control TOR complex component expression, as RAPTOR1 appears to be repressed by TOR activity. This work reveals novel insights into the molecular links that explain the developmental phenotype of TOR inhibition.

Details

Original languageEnglish
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Supervisors/Advisors
Award date1 Aug 2019