Cold-induced secondary dormancy and its regulatory mechanisms in Beta vulgaris

James Hourston, Tina Steinbrecher, Jake Chandler, Marta Perez Suarez, Katrin Dietrich, V. Turečková, D. Tarkowska, Mirek Strnad, Fridjof Weltmeier, Juliane Meinhard, Uwe Fischer, Karin FiedlerWiechers, Michael Ignatz, Gerhard Leubner

Research output: Contribution to journalArticlepeer-review

Abstract

The dynamic behaviour of seeds in soil seed banks depends on their ability to act as sophisticated environmental sensors to adjust their sensitivity thresholds for germination by dormancy mechanisms. Here we show that prolonged incubation of sugar beet fruits at low temperature (chilling at 5 ºC, generally known to release seed dormancy of many species) can induce secondary nondeep physiological dormancy of an apparently nondormant crop species. The physiological and biophysical mechanisms underpinning this cold-induced secondary dormancy include the chilling-induced accumulation of abscisic acid (ABA) in the seeds, a reduction in the embryo growth potential and a block in weakening of the endosperm covering the embryonic root. A transcriptome analysis revealed distinct gene expression patterns in the different temperature regimes and upon secondary dormancy induction and maintenance. The chilling caused reduced expression of cell wall remodelling protein genes required for embryo cell elongation growth and endosperm weakening, as well as increased expression of seed maturation genes such as for late embryogenesis abundant proteins. A model integrating the hormonal signalling and master regulator expression with the temperature-control of seed dormancy and maturation programmes is proposed. The revealed mechanisms of the cold-induced secondary dormancy are important for a climate-smart agriculture and food security.
Original languageEnglish
Pages (from-to)1315-1332
Number of pages18
JournalPlant, Cell and Environment
Volume45
Issue number4
Early online date22 Jan 2022
DOIs
Publication statusPublished - Apr 2022

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