The Effects of Seed Production Temperature on the Circadian Rhythms and Flowering Time of Arabidopsis thaliana

Lynch, Deirdre (2025) The Effects of Seed Production Temperature on the Circadian Rhythms and Flowering Time of Arabidopsis thaliana. Doctoral thesis, University of East Anglia.

[thumbnail of 2025LynchDPhD.pdf] PDF
Restricted to Repository staff only until 30 January 2028.

Request a copy

Abstract

The sessile nature of most plants means they must adapt to changing climates and unexpected weather events. Plants use information from the environment to entrain daily rhythms through which physiological and developmental processes are regulated. The relevance of day length relative to a plant’s geographical position is changing, due to climate change. Photoperiod may become an unreliable indicator of seasonal temperature in the future, having important consequences for biodiversity and agriculture. By producing seeds of Arabidopsis at different temperatures, I studied the effect of seed-maturation temperature on circadian phenotypes, flowering time, and development of the resulting progeny.

I show that higher temperatures during seed development leads to a later circadian phase in pCCA1::LUC and pTOC1::LUC reporter seeds as they germinate. This phase difference persists under light-dark cycles but synchronises as the seeds age under entraining conditions and is lost in a second generation of seeds matured under uniform conditions. I show that higher seed maturation temperatures result in earlier flowering, while seeds matured at lower temperatures show delayed flowering. In a reverse genetic screening of flowering time mutants, I identified PhyA, PhyB, ARP6, and FLC as potential regulatory genes affecting the seed-set temperature dependency of flowering time. Analysing the transcriptome of seedlings as they transition to flowering revealed differential gene expression patterns in photosynthetic processes dependent on the maturation temperature of the seeds. Opposing expression patterns of FLC and FT in plants grown from seeds of different maturation temperatures indicate key regulatory pathways through which seed-set temperature-dependent flowering may occur. Finally, I show that seed maturation temperature does not ultimately affect the growth or photosynthetic capacity of mature plants.

This research explores how aspects of seasonal behaviour in plants are shaped by temperature during seed development, providing insights as to how plants may respond to a changing climate.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Chris White
Date Deposited: 08 Jul 2025 14:24
Last Modified: 08 Jul 2025 14:24
URI: https://ueaeprints.uea.ac.uk/id/eprint/99867
DOI:

Actions (login required)

View Item View Item