Abstract

Perennials such as woody plants, growing in the high northern part of the earth have to cope with seasonal changes alternating between mild summer and the harsh winter periods. To survive and adapt their reproductive phase to the most favorable environmental conditions trees cycle between periods of active growth during summer and a state of growth arrest during winter, referred to as the activity- dormancy cycle. Studies underlying this thesis are aimed to increase our understanding of how plants growing in the high northern latitudes cope with the seasonal changes at a molecular level. Analysis of the global transcription in poplar showed that progression through the different stages of the annual activity- dormancy cycle is accompanied by massive transcriptional changes. Our data shows that genes involved in cell cycle regulation, chromatin remodeling and plant hormone signaling and biosynthesis are regulated during short day induced dormancy, suggesting key roles for these genes in the regulation of dormancy. Furthermore, we show that PttFIE, a plant homolog of the ESC component of the chromatin remodeling polycomb repression complex in Drosophila melanogaster, is a key regulator of dormancy. We also show that variation of timing of growth cessation and other physiological processes between ecotypes during dormancy induction could results from genetic variation in components downstream of the short day signal perception rather than in the perception of the short day signal.

Keywords

populus; dormancy; meristems; seasonal variation; plant growth substances

Published in

Acta Universitatis Agriculturae Sueciae
2010, number: 2010:18
ISBN: 9789157674951
Publisher: Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences

Authors' information