Understanding chilling responses in Arabidopsis seeds and their contribution to life history

Abstract

Winter chilling is of central importance in the phenology of temperate annual and perennial plants. Chilling accelerates flowering through the process of vernalization and breaks both bud and seed dormancy, permitting the onset of growth in the spring. The quantitative effects of chilling in floral promotion in winter annual Arabidopsis accessions are well-documented, but very little is known about the basic physiology underlying summer annual responses to winter chilling, which acts on seeds within the soil seed bank. Here, we analyse the response of wild accessions to extended chilling in seeds, and explore the interaction between seed-maturation temperature and chilling responses. We show that two weeks of chilling induces secondary dormancy, and that this time period is not dependent on seed-maturation temperature. In addition, we found that seeds for most accessions set under simulated summer conditions in the laboratory are unable to overwinter in the soil seed bank, as they germinate without light during extended chilling treatments. This shows that these seeds are committed to re-establishment in the same growing season. Understanding how winter chilling affects the timing of Arabidopsis phenology will enable us to explore the genetics behind adaptation to changing climates, and inform rational approaches to breeding crops with improved performance under new climate scenarios and develop a systems ecology of Arabidopsis.

Differential control of seed primary dormancy in Arabidopsis ecotypes by the transcription factor SPATULA

“…Low temperature also increases seed dormancy in wheat and this correlates with an increase in Ta-MFT gene expression (29). Once primary dormancy is released, secondary dormancy can be induced depending on environmental conditions (46). A recent study has demonstrated that secondary dormancy of Arabidopsis Cvi ecotype seeds correlated with low seasonal soil temperatures and high MFT expression (47).…”

Systems approaches in global change and biogeochemistry research

“…Bayesian techniques show some promise in uncertainty analysis and for model calibration, and new methods are available for quantifying and attributing uncertainty in model outputs. Model data fusion offers new approaches to better combine models with diverse and complex datasets [55], while optimal fingerprinting using spatially and temporally explicit data will allow us to use models to attribute observed global changes to different drivers [51], which is of the utmost importance if we are to manage our planet to mitigate adverse impacts and to maximize benefits. As we increasingly employ systems approaches, and conduct research in multi-disciplinary teams, the transfer of skills, techniques and ideas across disciplines offers exciting opportunities for predictive ecology.…”

Alexandrium catenella cyst dynamics in a coastal embayment : temperature dependence of dormancy, germination, and bloom Initiation

“…A common, simple model was applied that assigns one CU for each degree below T max , a temperature below which an organism perceives chilling (e.g. Luedeling et al 2009;Penfield and Springthorpe 2012). Daily chilling-units were thus calculated for the average daily temperature (T i ) that cysts experienced during cold storage using the following formula:…”

“…A common model assigns one CU for each degree below T max , a temperature below which an organism perceives chilling (Luedeling et al 2009;Penfield and Springthorpe 2012). For A.…”